Spectral polyethylene particle for agriculture and preparation method thereof

Abstract

The invention relates to the technical field of preparation of polyethylene particles, in particular to spectral polyethylene particles for agriculture and a preparation method of the spectral polyethylene particles. The preparation raw materials comprise the following materials: 80-90 parts of an ethylene monomer, 2-5 parts of a catalyst, 1-4 parts of an antioxidant, 1-4 parts of an organic tin stabilizer, 0.3-1 part of a deodorant, 4-10 parts of an ultraviolet light absorber, 4-10 parts of a light stabilizer, 6-40 parts of modified calcium carbonate particles and 0.1-4 parts of stearic acid. The deodorant is added into the ingredients of the polyethylene particles, the deodorant can effectively neutralize, decompose or adsorb peculiar smell molecules in the polyethylene particles, so that the odor generated in the preparation process is remarkably reduced, the ultraviolet light absorber and the modified calcium carbonate particles are adopted to replace carbon black, and the preparation process is simplified. The ultraviolet light absorber and the modified calcium carbonate particles improve the ultraviolet resistance and the mechanical property of the polyethylene particles, so that the polyethylene particles are not black, and color change during subsequent processing of the polyethylene particles is facilitated.

Description

Technical Field

[0001] The invention relates to the field of polyethylene particle preparation, in particular to spectral polyethylene particles used in agriculture and a preparation method thereof. Background Art

[0002] Polyethylene particles are a kind of high molecular compound made from ethylene as a monomer. They are a widely used plastic product with a very wide range of uses. When used in agriculture, they can be used to make ground films and greenhouse films, water storage and irrigation facilities, etc. The Raman spectrum of polyethylene is mainly manifested as CH stretching vibration and CC stretching vibration. The peak position and peak shape can reflect the crystal form, molecular weight and other properties of polyethylene.

[0003] Existing polyethylene particle preparation materials, for example, a formula of high temperature resistant polyethylene plastic particles proposed in patent application number "CN201711229274.8", includes the following components by weight: 70-80 parts of polyethylene, 5-10 parts of silane, 1.5-2 parts of stabilizer, 1.5-3 parts of plasticizer, 0.5-2 parts of carbon black, 2-3.5 parts of diatomaceous earth, 1-3 parts of cross-linking agent, 1-3 parts of impact modifier. The plastic particles obtained by the present invention have excellent high temperature resistance, insulation, physical and mechanical properties, elasticity, aging resistance, corrosion resistance, flame retardancy, weather resistance, etc., are cheap, have a high yield, excellent performance, and are environmentally friendly.

[0004] However, the existing polyethylene particle formula has defects. When polyethylene particles are prepared, multiple materials react and an odor is produced. This odor affects the nasal cavity of the preparer. In addition, carbon black exists in the formula of the prior art, which causes the produced polyethylene particles to appear black, making it inconvenient to change the color of the polyethylene particles during subsequent processing. Therefore, a spectral polyethylene particle for use in agriculture and a preparation method thereof are proposed. Summary of the invention

[0005] The object of the present invention is to provide a spectral polyethylene particle for use in agriculture and a preparation method thereof, so as to solve the problems raised in the above background technology.

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

[0007] A spectral polyethylene particle for agriculture, the preparation raw materials comprising the following materials: 80-90 parts of ethylene monomer, 2-5 parts of catalyst, 1-4 parts of antioxidant, 1-4 parts of organic tin stabilizer, 0.3-1 parts of deodorant, 4-10 parts of ultraviolet absorber, 4-10 parts of light stabilizer, 6-40 parts of modified calcium carbonate particles, and 0.1-4 parts of stearate.

[0008] Preferably, the catalyst is at least one of a chromium oxide catalyst, a titanium catalyst, and an aluminum alkane catalyst.

[0009] Preferably, the antioxidant is at least one of a phenolic antioxidant, a thiol antioxidant, an amine antioxidant, and a hydroxylamine antioxidant.

[0010] Preferably, the deodorant is at least one of a polyethylene deodorant, a polypropylene deodorant, and a recycled plastic deodorant.

[0011] Preferably, the ultraviolet absorber is at least one of 2-hydroxy-4-n-octyloxybenzophenone and 2-hydroxy-4-methoxybenzophenone.

[0012] Preferably, the light stabilizer is at least one of a cyanoteric light stabilizer and a hindered amine light stabilizer.

[0013] A method for preparing spectral polyethylene particles for use in agriculture comprises the following steps:

[0014] S1. Mixed processing

[0015] Adding ethylene monomer, catalyst, antioxidant, organic tin stabilizer, deodorant, ultraviolet absorber, light stabilizer, modified calcium carbonate particles, and stearate into a mixing device according to a certain proportion, and mixing various materials by using the mixing device to ensure uniform mixing to form a mixture;

[0016] S2. Polymerization

[0017] The mixed material is added into a polymerization reactor, and the parameters such as the pressure, temperature and time of the polymerization reaction are controlled. The polymerization reactor polymerizes the mixed material to synthesize the small molecule ethylene into a long-chain polymer;

[0018] S3. Cooling

[0019] After the polymerization reactor is finished, the various materials form polymers, and the polymers produced in the polymerization reactor are transferred to a cooler by releasing the pressure, and the cooler cools the polymers;

[0020] S4. Separation

[0021] The polymer after cooling is a mixture, and there are unreacted materials and by-products. Through separation operations such as distillation, condensation, and drying, polyethylene is separated from other substances, and the unreacted materials and by-products are recovered for utilization;

[0022] S4.1. Distillation

[0023] The mixture is added into a distillation tower, and a heating device is used to heat the distillation tower, and the polyethylene is evaporated by taking advantage of the different boiling points of different substances to form polyethylene vapor;

[0024] S4.2, Condensation

[0025] The polyethylene vapor is introduced into the condenser tube, and the outside of the condenser tube is controlled to be in a low temperature state, so that the polyethylene vapor condenses and crystallizes;

[0026] S4.3 Drying

[0027] There is water on the surface of the condensed polyethylene crystals, which is added to the drying equipment and the temperature is controlled to dry the polyethylene, and polyethylene with higher purity is formed after drying;

[0028] S5, Granulation

[0029] The separated polyethylene is granulated using a granulator to form spectral polyethylene particles.

[0030] Preferably, during the polymerization reaction, the polymerization reactor is heated to a high temperature to promote the polymerization reaction process, control the pressure of the polymerization reactor, and maintain steady-state reaction conditions.

[0031] Beneficial effects of the present invention:

[0032] 1. The present invention adds a deodorant to the ingredients of polyethylene particles. The deodorant adopts at least one of polyethylene deodorant, polypropylene deodorant, and recycled plastic deodorant. The deodorant can effectively neutralize, decompose or adsorb odor molecules in polyethylene particles, thereby significantly reducing the odor generated during the preparation process.

[0033] 2. The present invention adopts ultraviolet absorbers and modified calcium carbonate particles to replace carbon black. The ultraviolet absorber is at least one of 2-hydroxy-4-n-octyloxybenzophenone and 2-hydroxy-4-methoxybenzophenone. The ultraviolet absorber and modified calcium carbonate particles improve the ultraviolet resistance and mechanical properties of polyethylene particles, and will not make the polyethylene particles appear black, which is convenient for subsequent color change of the polyethylene particles during processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0035] Figure 1 It is a schematic diagram of the preparation process of polyethylene particles;

[0036] Figure 2 It is a schematic diagram of the polymer separation process; DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in 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.

[0038] A spectral polyethylene particle for agriculture, the preparation raw materials comprising the following materials: 80-90 parts of ethylene monomer, 2-5 parts of catalyst, 1-4 parts of antioxidant, 1-4 parts of organic tin stabilizer, 0.3-1 parts of deodorant, 4-10 parts of ultraviolet absorber, 4-10 parts of light stabilizer, 6-40 parts of modified calcium carbonate particles, and 0.1-4 parts of stearate.

[0039] Ethylene monomer is used as the basic material of the formula, and ethylene separated from petrochemical industry is generally used as raw material. Before processing, ethylene particles undergo steps such as removing impure substances, removing water and removing sulfur to ensure the purity and stability of the reaction. Catalysts increase the polymerization efficiency of spectral polyethylene particles. Antioxidants, deodorizers, ultraviolet absorbers, and light stabilizers improve the antioxidant and ultraviolet resistance of polyethylene particles. Organic tin stabilizers can improve the thermal stability of PVC materials, optimize the reaction process of chlorides and synthetic oils, and promote the polymerization reaction of PVC, thereby improving the efficiency of polymerization chemical reactions and giving the products extremely high transparency. Modified calcium carbonate particles play a heterogeneous nucleation role in the system, which improves the crystallinity of the material, increases the crystallization rate, shortens the crystallization time, refines the grains, improves the rigidity of the material, and improves the impact strength. Stiresters increase the crystallinity and tensile modulus of polyethylene, thereby making polyethylene harder and more wear-resistant.

[0040] Various materials are added and mixed in proportion. A deodorant is added to the ingredients of the polyethylene particles. The deodorant can effectively neutralize, decompose or adsorb odor molecules in the polyethylene particles, thereby significantly reducing the odor generated during the preparation process. Ultraviolet absorbers and modified calcium carbonate particles are used to replace carbon black. The ultraviolet absorbers and modified calcium carbonate particles improve the ultraviolet resistance and mechanical properties of the polyethylene particles, and will not make the polyethylene particles appear black, which is convenient for subsequent color change during the processing of the polyethylene particles.

[0041] The catalyst is at least one of a chromium oxide catalyst, a titanium catalyst, and an aluminum alkane catalyst.

[0042] The catalyst plays a major role in accelerating the polymerization reaction in the polyethylene production process, allowing ethylene monomer to be rapidly converted into high molecular weight polyethylene at lower temperature and pressure. The choice of catalyst has a significant impact on the molecular weight, crystallinity, and branching properties of polyethylene.

[0043] The antioxidant is at least one of a phenol antioxidant, a thiol antioxidant, an amine antioxidant, and a hydroxylamine antioxidant.

[0044] During the molding process of polyethylene, antioxidants can effectively inhibit the oxidation reaction of polyethylene, improve its thermal stability, prevent oxidation and deterioration at high temperatures, and at the same time delay the aging of polyethylene during long-term use and extend its service life.

[0045] The deodorant is at least one of a polyethylene deodorant, a polypropylene deodorant, and a recycled plastic deodorant.

[0046] Deodorants can effectively neutralize, decompose or adsorb odor molecules in polyethylene particles, thereby significantly reducing the odor generated during the preparation process. Polyethylene deodorants, polypropylene deodorants, and recycled plastic deodorants can all be used in the polyethylene processing process.

[0047] The ultraviolet absorber is at least one of 2-hydroxy-4-n-octyloxybenzophenone and 2-hydroxy-4-methoxybenzophenone.

[0048] UV absorbers absorb ultraviolet rays to prevent spectral polyethylene materials from aging. UV absorbers can absorb ultraviolet rays with a wavelength of 260-350nm, thereby protecting spectral polyethylene materials from damage by ultraviolet rays and preventing agricultural facilities such as ground films used outdoors from being affected by ultraviolet rays and causing rapid aging. Benzotriazole UV absorbers are also commonly used UV absorbers in the production of polyethylene particles.

[0049] The light stabilizer is at least one of a cyanoteric light stabilizer and a hindered amine light stabilizer.

[0050] The main function of light stabilizers is to protect polyethylene materials from the effects of light aging, shielding them from light and preventing light from directly penetrating into the interior of the polymer, thereby inhibiting light degradation.

[0051] like Figure 1-Figure 2 As shown, a method for preparing spectral polyethylene particles for agriculture comprises the following steps:

[0052] S1. Mixed processing

[0053] Adding ethylene monomer, catalyst, antioxidant, organic tin stabilizer, deodorant, ultraviolet absorber, light stabilizer, modified calcium carbonate particles, and stearate into a mixing device according to a certain proportion, and mixing various materials by using the mixing device to ensure uniform mixing to form a mixture;

[0054] S2. Polymerization

[0055] The mixed material is added into a polymerization reactor, and the parameters such as the pressure, temperature and time of the polymerization reaction are controlled. The polymerization reactor polymerizes the mixed material to synthesize the small molecule ethylene into a long-chain polymer;

[0056] S3. Cooling

[0057] After the polymerization reactor is finished, the various materials form polymers, and the polymers produced in the polymerization reactor are transferred to a cooler by releasing the pressure, and the cooler cools the polymers;

[0058] S4. Separation

[0059] The polymer after cooling is a mixture, and there are unreacted materials and by-products. Through separation operations such as distillation, condensation, and drying, polyethylene is separated from other substances, and the unreacted materials and by-products are recovered for utilization;

[0060] S4.1. Distillation

[0061] The mixture is added into a distillation tower, and a heating device is used to heat the distillation tower, and the polyethylene is evaporated by taking advantage of the different boiling points of different substances to form polyethylene vapor;

[0062] S4.2, Condensation

[0063] The polyethylene vapor is introduced into the condenser tube, and the outside of the condenser tube is controlled to be in a low temperature state, so that the polyethylene vapor condenses and crystallizes;

[0064] S4.3 Drying

[0065] There is water on the surface of the condensed polyethylene crystals, which is added to the drying equipment and the temperature is controlled to dry the polyethylene, and polyethylene with higher purity is formed after drying;

[0066] S5, Granulation

[0067] The separated polyethylene is granulated using a granulator to form spectral polyethylene particles.

[0068] During the polymerization reaction, the polymerization reactor is heated to a high temperature to promote the polymerization reaction process, control the pressure of the polymerization reactor, and maintain steady-state reaction conditions.

[0069] The high temperature state promotes the polymerization reaction process, and the pressure of the polymerization reactor is controlled to maintain steady-state reaction conditions.

[0070] Embodiment 1

[0071] A method for preparing spectral polyethylene particles for use in agriculture comprises the following steps:

[0072] S1. Mixed processing

[0073] 80 parts of ethylene monomer, 2 parts of catalyst, 1 part of antioxidant, 1 part of organotin stabilizer, 0.3 parts of deodorant, 4 parts of ultraviolet absorber, 4 parts of light stabilizer, 6 parts of modified calcium carbonate particles, and 0.1 parts of stearate are added into a mixing device, and various materials are mixed by the mixing device to ensure uniform mixing to form a mixture;

[0074] S2. Polymerization

[0075] The mixed material is added into a polymerization reactor, and the parameters such as the pressure, temperature and time of the polymerization reaction are controlled. The polymerization reactor polymerizes the mixed material to synthesize the small molecule ethylene into a long-chain polymer;

[0076] S3. Cooling

[0077] After the polymerization reactor is finished, the various materials form polymers, and the polymers produced in the polymerization reactor are transferred to a cooler by releasing the pressure, and the cooler cools the polymers;

[0078] S4. Separation

[0079] The polymer after cooling is a mixture, and there are unreacted materials and by-products. Through separation operations such as distillation, condensation, and drying, polyethylene is separated from other substances, and the unreacted materials and by-products are recovered for utilization;

[0080] S4.1. Distillation

[0081] The mixture is added into a distillation tower, and a heating device is used to heat the distillation tower, and the polyethylene is evaporated by taking advantage of the different boiling points of different substances to form polyethylene vapor;

[0082] S4.2, Condensation

[0083] The polyethylene vapor is introduced into the condenser tube, and the outside of the condenser tube is controlled to be in a low temperature state, so that the polyethylene vapor condenses and crystallizes;

[0084] S4.3 Drying

[0085] There is water on the surface of the condensed polyethylene crystals, which is added to the drying equipment and the temperature is controlled to dry the polyethylene, and polyethylene with higher purity is formed after drying;

[0086] S5, Granulation

[0087] The separated polyethylene is granulated using a granulator to form spectral polyethylene particles.

[0088] Embodiment 2

[0089] A method for preparing spectral polyethylene particles for use in agriculture comprises the following steps:

[0090] S1. Mixed processing

[0091] 85 parts of ethylene monomer, 2.5 parts of catalyst, 2 parts of antioxidant, 1 part of organotin stabilizer, 0.6 parts of deodorant, 7 parts of ultraviolet absorber, 7 parts of light stabilizer, 23 parts of modified calcium carbonate particles, and 2 parts of stearate are added into a mixing device, and various materials are mixed by the mixing device to ensure uniform mixing to form a mixture;

[0092] S2. Polymerization

[0093] The mixed material is added into a polymerization reactor, and the parameters such as the pressure, temperature and time of the polymerization reaction are controlled. The polymerization reactor polymerizes the mixed material to synthesize the small molecule ethylene into a long-chain polymer;

[0094] S3. Cooling

[0095] After the polymerization reactor is finished, the various materials form polymers, and the polymers produced in the polymerization reactor are transferred to a cooler by releasing the pressure, and the cooler cools the polymers;

[0096] S4. Separation

[0097] The polymer after cooling is a mixture, and there are unreacted materials and by-products. Through separation operations such as distillation, condensation, and drying, polyethylene is separated from other substances, and the unreacted materials and by-products are recovered for utilization;

[0098] S4.1. Distillation

[0099] The mixture is added into a distillation tower, and a heating device is used to heat the distillation tower, and the polyethylene is evaporated by taking advantage of the different boiling points of different substances to form polyethylene vapor;

[0100] S4.2, Condensation

[0101] The polyethylene vapor is introduced into the condenser tube, and the outside of the condenser tube is controlled to be in a low temperature state, so that the polyethylene vapor condenses and crystallizes;

[0102] S4.3 Drying

[0103] There is water on the surface of the condensed polyethylene crystals, which is added to the drying equipment and the temperature is controlled to dry the polyethylene, and polyethylene with higher purity is formed after drying;

[0104] S5, Granulation

[0105] The separated polyethylene is granulated using a granulator to form spectral polyethylene particles.

[0106] Embodiment 3

[0107] A method for preparing spectral polyethylene particles for use in agriculture comprises the following steps:

[0108] S1. Mixed processing

[0109] 90 parts of ethylene monomer, 5 parts of catalyst, 4 parts of antioxidant, 4 parts of organotin stabilizer, 1 part of deodorant, 10 parts of ultraviolet absorber, 10 parts of light stabilizer, 40 parts of modified calcium carbonate particles, and 4 parts of stearate are added into a mixing device, and various materials are mixed by the mixing device to ensure uniform mixing to form a mixture;

[0110] S2. Polymerization

[0111] The mixed material is added into a polymerization reactor, and the parameters such as the pressure, temperature and time of the polymerization reaction are controlled. The polymerization reactor polymerizes the mixed material to synthesize the small molecule ethylene into a long-chain polymer;

[0112] S3. Cooling

[0113] After the polymerization reactor is finished, the various materials form polymers, and the polymers produced in the polymerization reactor are transferred to a cooler by releasing the pressure, and the cooler cools the polymers;

[0114] S4. Separation

[0115] The polymer after cooling is a mixture, and there are unreacted materials and by-products. Through separation operations such as distillation, condensation, and drying, polyethylene is separated from other substances, and the unreacted materials and by-products are recovered for utilization;

[0116] S4.1. Distillation

[0117] The mixture is added into a distillation tower, and a heating device is used to heat the distillation tower, and the polyethylene is evaporated by taking advantage of the different boiling points of different substances to form polyethylene vapor;

[0118] S4.2, Condensation

[0119] The polyethylene vapor is introduced into the condenser tube, and the outside of the condenser tube is controlled to be in a low temperature state, so that the polyethylene vapor condenses and crystallizes;

[0120] S4.3 Drying

[0121] There is water on the surface of the condensed polyethylene crystals, which is added to the drying equipment and the temperature is controlled to dry the polyethylene, and polyethylene with higher purity is formed after drying;

[0122] S5, Granulation

[0123] The separated polyethylene is granulated using a granulator to form spectral polyethylene particles.

[0124] 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 spectral polyethylene particle for use in agriculture, characterized in that: The preparation raw materials include the following materials: 80-90 parts of ethylene monomer, 2-5 parts of catalyst, 1-4 parts of antioxidant, 1-4 parts of organic tin stabilizer, 0.3-1 parts of deodorant, 4-10 parts of ultraviolet absorber, 4-10 parts of light stabilizer, 6-40 parts of modified calcium carbonate particles and 0.1-4 parts of stearate.

2. The spectral polyethylene particles for use in agriculture according to claim 1, characterized in that: The catalyst is at least one of a chromium oxide catalyst, a titanium catalyst, and an aluminum alkane catalyst.

3. The spectral polyethylene particles for use in agriculture according to claim 1, characterized in that: The antioxidant is at least one of a phenol antioxidant, a thiol antioxidant, an amine antioxidant, and a hydroxylamine antioxidant.

4. The spectral polyethylene particles for use in agriculture according to claim 1, characterized in that: The deodorant is at least one of a polyethylene deodorant, a polypropylene deodorant, and a recycled plastic deodorant.

5. The spectral polyethylene particles for use in agriculture according to claim 1, characterized in that: The ultraviolet absorber is at least one of 2-hydroxy-4-n-octyloxybenzophenone and 2-hydroxy-4-methoxybenzophenone.

6. The spectral polyethylene particles for use in agriculture according to claim 1, characterized in that: The light stabilizer is at least one of a cyanoteric light stabilizer and a hindered amine light stabilizer.

7. The method for preparing spectral polyethylene particles for agriculture according to claim 1, characterized in that: The following steps are involved: S1. Mixed processing Adding ethylene monomer, catalyst, antioxidant, organic tin stabilizer, deodorant, ultraviolet absorber, light stabilizer, modified calcium carbonate particles, and stearate into a mixing device according to a certain proportion, and mixing various materials by using the mixing device to ensure uniform mixing to form a mixture; S2. Polymerization The mixed material is added into a polymerization reactor, and the parameters such as the pressure, temperature and time of the polymerization reaction are controlled. The polymerization reactor polymerizes the mixed material to synthesize the small molecule ethylene into a long-chain polymer; S3. Cooling After the polymerization reactor is finished, the various materials form polymers, and the polymers produced in the polymerization reactor are transferred to a cooler by releasing the pressure, and the cooler cools the polymers; S4. Separation The polymer after cooling is a mixture, and there are unreacted materials and by-products. Through separation operations such as distillation, condensation, and drying, polyethylene is separated from other substances, and the unreacted materials and by-products are recovered for utilization; S4.

1. Distillation The mixture is added into a distillation tower, and a heating device is used to heat the distillation tower, and the polyethylene is evaporated by taking advantage of the different boiling points of different substances to form polyethylene vapor; S4.2, Condensation The polyethylene vapor is introduced into the condenser tube, and the outside of the condenser tube is controlled to be in a low temperature state, so that the polyethylene vapor condenses and crystallizes; S4.3 Drying There is water on the surface of the condensed polyethylene crystals, which is added to the drying equipment and the temperature is controlled to dry the polyethylene, and polyethylene with higher purity is formed after drying; S5, Granulation The separated polyethylene is granulated using a granulator to form spectral polyethylene particles.

8. The method for preparing spectral polyethylene particles for agriculture according to claim 7, characterized in that: During the polymerization reaction, the polymerization reactor is heated to a high temperature to promote the polymerization reaction process, control the pressure of the polymerization reactor, and maintain steady-state reaction conditions.

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