Octylene copolymerization heat shrinkage packaging film resin and preparation method thereof
By controlling the reaction parameters in the polyethylene device and using Ziegler Nata catalyst, the octene copolymerized heat shrink packaging film resin is prepared, and the problem of insufficient internal tear and temperature resistance in the prior art is solved, and high-performance packaging film production is achieved.
Patent Information
- Application Number
- CN202311819998.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-27
- Publication Date
- 2025-07-01
AI Technical Summary
Octene copolyethylene products prepared by the existing solution method have insufficient internal tear properties and temperature resistance, resulting in increased production costs.
The solution process is adopted, and the reaction parameters are controlled in the polyethylene device to make octene-1 uniformly distributed on the polymer main chain, and the octene copolymerized heat shrink packaging film resin is prepared, and the reaction conditions are used to perform the polymerization reaction.
The toughness, tear resistance and temperature resistance of the octene copolymerized heat shrink packaging film resin is improved, and the product packaging requirements are met and production costs are reduced.
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Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of plastic processing applications, and relates to an octene copolymer heat shrinkable packaging film resin and a preparation method thereof. Specifically, it relates to a special resin for multi-layer co-extruded heat shrinkable packaging film and a preparation method thereof. Background Art
[0002] POF is the full name of multi-layer co-extruded polyolefin heat shrinkable film. It uses linear low-density polyethylene as the middle layer (LLDPE) and co-polypropylene (pp) as the inner and outer layers. It is plastically extruded through three extruders, and then processed through special processes such as die forming and film bubble inflation. It is mainly used for packaging products with regular and irregular shapes. Due to its non-toxic and environmentally friendly, high transparency, high shrinkage rate, good heat sealing performance, high surface gloss, good toughness, high tear resistance, uniform heat shrinkage, and suitability for fully automatic high-speed packaging, etc., after shrink packaging, the corners at the sealed part are soft; non-toxic, and no toxic gas is generated during heat sealing processing; thin and tough, with uniform thickness, soft texture, better moisture resistance, excellent cold resistance, not hard or brittle in winter, and not easily broken during transportation. After shrink packaging, the tightening force will not change, ensuring that the packaged items will not deform after long-term storage. It is widely used in automotive supplies, plastic products, stationery, books, electronics, circuit boards, MP3, VCD, handicrafts, wooden products such as photo frames, toys, pesticides, daily necessities, food, cosmetics, canned beverages, dairy products, medicine, cassette tapes, video tapes and other products.
[0003] It has basically replaced PVC heat shrinkable film packaging, and POF heat shrinkable film has become the mainstream product in heat shrinkable packaging materials. The heat shrinkable film is designed based on the principle of stretching and orienting high molecular chains of the extract, and is formed by the method of rapid cooling and setting. Its physical principle is: when the polymer is in the high elastic state, it is stretched and oriented, and then the high polymer is rapidly cooled below the glass transition temperature, and the molecular orientation is frozen. When it is heated during the packaging process of items, due to the stress relaxation caused by molecular movement, the molecules return to their original state and shrinkage occurs.
[0004] For the existing products prepared by the solution method for octene copolymerized polyethylene, the produced products have poor internal tear resistance and temperature resistance, and the products often cannot complete the subsequent packaging work, greatly increasing the overall production cost. Summary of the Invention
[0005] In order to overcome the deficiencies of the prior art, the present invention provides an octene copolymer heat shrinkable packaging film resin and a preparation method thereof, which are produced by a solution method process in a polyethylene device through controlling reaction parameters. The octene-1 is evenly distributed on the polymer main chain, and an octene copolymer heat shrinkable packaging film resin with excellent tear resistance and temperature resistance is produced.
[0006] The above object of the present invention is achieved by the following technical solutions:
[0007] An octene copolymer heat - shrinkable packaging film resin, in which the long chain of the octene monomer runs through the whole polymer, making the resin have good toughness. Its composition includes the following raw materials by mass percentage: 98.4% - 98.0% polyethylene and 1.6 - 2.0% octene content.
[0008] The resin has a density of 0.920 ± 0.03 g / cm3, a melt index of 1.00 ± 0.3 g / 10 min, an octene content of 6.4 - 8.4 wt%, and a melt flow ratio of the molecular weight distribution of 3.0 ± 0.1.
[0009] The preparation method of the above - mentioned octene copolymer heat - shrinkable packaging film resin uses ethylene as the raw material, adopts a highly efficient catalyst, and carries out the polymerization reaction by the solution process. After ethylene and octene in the reactor are pre - heated by a pre - heater, they enter the copolymerization reactor. In the copolymerization reactor, polymerization reaction is carried out with ethylene as the raw material and octene as the comonomer. By limiting the reaction conditions (polymerization pressure, temperature, octene dosage), extrusion granulation is carried out. By limiting the temperature of the extruder to 200 - 210 °C, the octene copolymer heat - shrinkable packaging film resin is obtained, which is a special resin for multi - layer co - extrusion packaging films.
[0010] The highly efficient catalyst is a Ziegler - Natta catalyst, and the addition amount is 20 ppm.
[0011] Furthermore, during the polymerization reaction, the average reaction temperature is 237 - 287 °C, and the system pressure is 10 - 16 MPA.
[0012] Furthermore, an antioxidant and hydrogen are added at the beginning of the reaction, and the addition amounts are 1000 ppm and 5 ppm in sequence.
[0013] Furthermore, the antioxidant is 1010 and 168, and it is diluted with cyclohexane. 1010 and 168 are from Shandong Sanfeng Chemical Co., Ltd.
[0014] Furthermore, during the polymerization reaction, the system pressure is preferably 10 MPA.
[0015] Furthermore, during the polymerization reaction, the average reaction temperature is preferably 237 °C.
[0016] The present invention also claims the application of the octene copolymer heat - shrinkable packaging film resin prepared by the above - mentioned preparation method in the preparation of multi - layer co - extrusion packaging films. It is applied in the industrial production of Fushun Oilfield. The results of industrial production show that it meets the quality requirements of downstream users, and the product quality reaches the best product performance indicators.
[0017] The beneficial effects of the present invention compared with the prior art are:
[0018] Compared with the prior art, the octene copolymerized heat-shrinkable packaging film resin of the present invention has higher toughness. It has the advantages of good strength and toughness, and meets the transparency requirements for commodity packaging. With higher tensile strength, puncture resistance, tear resistance and elongation rate, it is particularly suitable for making films. The impact resistance and tear resistance can also be greatly improved. For a given resin with the same melt index and density, the octene copolymerized heat-shrinkable packaging film resin of the present invention has improved impact and tear performance by up to 300%. The longer side chains of the octene copolymerized heat-shrinkable packaging film resin of the present invention play a role like "knot" molecules between the chains, improving the toughness of the compound. The preparation method of the octene copolymerized heat-shrinkable packaging film resin of the present invention can produce high-performance linear polyethylene POF packaging films by defining process parameters and using octene as the comonomer. Detailed implementation manners
[0019] The present invention will be described in detail below through specific examples, but the protection scope of the present invention is not limited. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can be obtained from commercial channels.
[0020] Example 1
[0021] A preparation method of octene copolymerized heat-shrinkable packaging film resin, using ethylene as the raw material (feeding speed is 8t / h) and octene as the comonomer (feeding speed is 0.88t / h), carrying out a polymerization reaction in a copolymerization reactor to obtain a polymerization product; during the polymerization reaction process, the average reaction temperature is 237°C, the system pressure is 10MPA, and the total conversion rate is 94%. And 40 minutes after adding octene, the resin density and melt index are analyzed and tested, and the reaction is further adjusted according to the values obtained from the analysis and detection (the operating indicators, finished product indicators and target values are shown in Table 1). An antioxidant (1010) and hydrogen are added at the beginning of the reaction, and the addition amounts are 1000ppm and 5ppm in sequence.
[0022] The above-mentioned octene copolymerized heat-shrinkable packaging film resin is used to prepare a multi-layer co-extruded packaging film material (FX120). This packaging film material is mainly composed of linear PE and random copolymerized PP. That is, the middle layer is a special octene-1 copolymerized LLDPE (octene copolymerized heat-shrinkable packaging film resin), and the heat-sealing layer is a random copolymer of ethylene and propylene PP. It is prepared by blow molding and extrusion, and adopts the process of downward air blowing, water cooling and reheating and blowing. The product has a large shrinkage and rebound rate, good heat-sealing performance, high light permeability and gloss, good packaging effect, and can achieve tight packaging for various geometric products.
[0023] Example 2
[0024] Using ethylene as the raw material (feed rate: 8 t / h) and octene as the comonomer (feed rate: 0.88 t / h), a polymerization reaction is carried out in a copolymerization reactor to obtain a polymerization product. During the polymerization reaction, the average reaction temperature is 247 °C, the system pressure is 12 MPA, and the total conversion rate is 94%. And 40 minutes after adding octene, the resin density and melt index are analyzed and tested, and the reaction is further adjusted according to the values obtained from the analysis and detection (the operating indexes, finished product indexes and target values are shown in Table 1). An antioxidant (1010) and hydrogen are added at the beginning of the reaction, and the addition amounts are 1000 ppm and 5 ppm in sequence.
[0025] The above-mentioned octene copolymer heat-shrinkable packaging film resin is used to prepare a multilayer coextruded packaging film material (FX120). This packaging film material is mainly composed of linear PE and random copolymerized PP. That is, the middle layer is a special LLDPE for octene-1 copolymerization (octene copolymer heat-shrinkable packaging film resin), and the heat-sealing layer is a random copolymer of ethylene and propylene PP. It is prepared by blow molding and extrusion, and the downward air blowing and water cooling and reheating and blowing process are adopted. The product has a large shrinkage and rebound rate, good heat-sealing performance, high light permeability and gloss, good packaging effect, and can achieve tight packaging for various geometric products.
[0026] Example 3
[0027] Using ethylene as the raw material (feed rate: 8 t / h) and octene as the comonomer (feed rate: 0.88 t / h), a polymerization reaction is carried out in a copolymerization reactor to obtain a polymerization product. During the polymerization reaction, the average reaction temperature is 257 °C, the system pressure is 10 MPA, and the total conversion rate is 94%. And 40 minutes after adding octene, the resin density and melt index are analyzed and tested, and the reaction is further adjusted according to the values obtained from the analysis and detection (the operating indexes, finished product indexes and target values are shown in Table 1). An antioxidant (168) and hydrogen are added at the beginning of the reaction, and the addition amounts are 1000 ppm and 5 ppm in sequence.
[0028] The above-mentioned octene copolymer heat-shrinkable packaging film resin is used to prepare a multilayer coextruded packaging film material (FX120). This packaging film material is mainly composed of linear PE and random copolymerized PP. That is, the middle layer is a special LLDPE for octene-1 copolymerization (octene copolymer heat-shrinkable packaging film resin), and the heat-sealing layer is a random copolymer of ethylene and propylene PP. It is prepared by blow molding and extrusion, and the downward air blowing and water cooling and reheating and blowing process are adopted. The product has a large shrinkage and rebound rate, good heat-sealing performance, high light permeability and gloss, good packaging effect, and can achieve tight packaging for various geometric products.
[0029] Example 4
[0030] Using ethylene as the raw material (feed rate: 8 t / h) and octene as the comonomer (feed rate: 0.88 t / h), a polymerization reaction is carried out in a copolymerization reactor to obtain a polymerization product. During the polymerization reaction, the average reaction temperature is 267 °C, the system pressure is 10 MPA, and the total conversion rate is 94%. After adding octene for 40 minutes, the resin density and melt index are analyzed and tested, and the reaction is further adjusted according to the values obtained from the analysis and detection (the operating indicators, finished product indicators, and target values are shown in Table 1). An antioxidant (1010) and hydrogen are added at the beginning of the reaction, and the addition amounts are 1000 ppm and 5 ppm in sequence.
[0031] The above-mentioned octene copolymer heat-shrinkable packaging film resin is used to prepare a multilayer coextruded packaging film material (FX120). This packaging film material mainly consists of linear PE and random copolymer PP. Specifically, the middle layer is made of octene-1 copolymer special LLDPE (octene copolymer heat-shrinkable packaging film resin), and the heat-sealing layer is ethylene-propylene random copolymer PP. It is prepared by blow molding and extrusion, and the downward air blowing and water cooling and re-heating and blowing process is adopted. The product has a large shrinkage and rebound rate, good heat-sealing performance, high light permeability and gloss, good packaging effect, and can achieve tight packaging for various geometric products.
[0032] Example 5
[0033] Using ethylene as the raw material (feed rate: 8 t / h) and octene as the comonomer (feed rate: 0.88 t / h), a polymerization reaction is carried out in a copolymerization reactor to obtain a polymerization product. During the polymerization reaction, the average reaction temperature is 277 °C, the system pressure is 10 MPA, and the total conversion rate is 94%. After adding octene for 40 minutes, the resin density and melt index are analyzed and tested, and the reaction is further adjusted according to the values obtained from the analysis and detection (the operating indicators, finished product indicators, and target values are shown in Table 1). An antioxidant (1010) and hydrogen are added at the beginning of the reaction, and the addition amounts are 1000 ppm and 5 ppm in sequence.
[0034] The above-mentioned octene copolymer heat-shrinkable packaging film resin is used to prepare a multilayer coextruded packaging film material (FX120). This packaging film material mainly consists of linear PE and random copolymer PP. Specifically, the middle layer is made of octene-1 copolymer special LLDPE (octene copolymer heat-shrinkable packaging film resin), and the heat-sealing layer is ethylene-propylene random copolymer PP. It is prepared by blow molding and extrusion, and the downward air blowing and water cooling and re-heating and blowing process is adopted. The product has a large shrinkage and rebound rate, good heat-sealing performance, high light permeability and gloss, good packaging effect, and can achieve tight packaging for various geometric products.
[0035] Table 1 Operating indicators
[0036]
[0037] Comparative Example 1
[0038] The existing product, Dow 2045G from the United States.
[0039] Performance tests were conducted on the resins obtained in Examples 1 - 5 and Comparative Example 1 (the existing product, Dow 2045G from the United States), and the test results are as follows:
[0040] (1) Molecular weight and GPC distribution.
[0041] The test was carried out using an ASTM D6474 gel permeation chromatograph. The test results of the molecular weight and distribution of Examples 1 - 5 and Comparative Example 1 are shown in Table 2.
[0042] Table 2 Molecular weight and distribution
[0043] Sample Weight-average molecular weight Mw Number-average molecular weight Mn Molecular weight distribution PD Comparative Example 1 (Dow 2045G, USA) 15.7 3.8 4.1 Example 1 13.7 3.4 4.1 Example 2 14.0 3.3 4.2 Example 3 13.6 3.3 4.1 Example 4 15.4 3.5 4.4 Example 5 12.8 3.7 3.5
[0044] (2) Basic performance test of POF materials.
[0045] The test method refers to GB / T 3682. The melt indices and melt flow ratios of Examples 1 to 5 and Comparative Example 1 are shown in Table 3.
[0046] Table 3 Melt indices and melt flow ratios
[0047]
[0048] (3) DSC analysis of POF materials.
[0049] The test method refers to GB / T19466.6 - 2009. The thermal performance test results of Examples 1 - 5 and Comparative Example 1 are shown in Table 4.
[0050] Table 4 Thermal performance test
[0051] POF film material grade Melting temperature Tm °C Crystallization temperature Tc °C Melting enthalpy ΔHm J / g Crystallization enthalpy ΔHc J / g Comparative Example 1 124.86 104.34 -106.18 99.37 Example 1 123.35 102.32 -104.23 98.85 Example 2 123.45 103.76 -103.23 98.43 Example 3 124.49 104.15 -106.31 99.28 Example 4 123.72 103.84 -103.31 98.76 Example 5 126.56 108.58 -110.22 100.57
[0052] (4) Mechanical properties of POF materials.
[0053] The test method refers to GB / T1042.2 - 2006. The mechanical property test results of Examples 1 - 5 and Comparative Example 1 are shown in Table 5.
[0054] Table 5 Mechanical property test
[0055]
[0056] From the above data, it can be seen that the above - mentioned examples of the present invention have achieved the following technical effects:
[0057] Comparing Examples 1 - 5 with Comparative Example 1, it can be seen that the multi-layer co-extruded packaging film material prepared from the octene copolymerization heat-shrinkable packaging film resin prepared by the preparation method provided by the present invention has high elasticity and tensile properties.
[0058] Comparing Example 1 and Example 2, it can be seen that limiting the average reaction temperature and pressure of the polymerization reaction within the preferred range of the present invention is beneficial to improving the comprehensive properties of the multi-layer co-extruded packaging film material.
[0059] Comparing Example 1, Example 4 and Example 5, it can be seen that limiting the feed ratio of ethylene to octene and the addition amount of hydrogen within the preferred range of the present invention is beneficial to improving the comprehensive properties of the multi-layer co-extruded packaging film material.
[0060] The above-described embodiments are only the preferred embodiments of the present invention, and not all the feasible embodiments of the present invention. For those of ordinary skill in the art, any obvious modifications made without departing from the principles and spirit of the present invention should be considered to be included within the scope of protection of the claims of the present invention.
Claims
1. A resin for an octene copolymer heat shrinkable packaging film, characterized in that, The octene monomer has a long chain running through the entire polymer, and its composition includes the following raw materials by mass percentage: 98.4%-98.0% polyethylene and 1.6-2.0% octene content.
2. The octene copolymer heat shrinkable packaging film resin according to claim 1, characterized in that The resin has a density of 0.920 ± 0.03 g / cm 3 , a melt index of 1.00 ± 0.3 g / 10 min, an octene content of 6.4 - 8.0 wt%, and a melt flow ratio of the molecular weight distribution of 3.0 ± 0.
1.
3. The preparation method of an octene copolymer heat-shrinkable packaging film resin according to claim 2, characterized in that, Using ethylene as the raw material, a high-efficiency catalyst, and a solution process for polymerization reaction. After being preheated by a preheater, ethylene and octene in the reactor enter the copolymerization reactor. In the copolymerization reactor, polymerization reaction is carried out with ethylene as the raw material and octene as the comonomer. By limiting the reaction conditions, extrusion granulation is carried out to obtain the octene copolymer heat-shrinkable packaging film resin.
4. The preparation method of an octene copolymerized heat-shrinkable packaging film resin as described in claim 3, characterized in that, The high-efficiency catalyst is a Ziegler-Natta catalyst.
5. The preparation method of an octene copolymer heat shrinkable packaging film resin according to claim 3, characterized in that, During the polymerization reaction, the average reaction temperature is 237-287°C, and the system pressure is 10-16 MPA.
6. The preparation method of an octene copolymer heat-shrinkable packaging film resin according to claim 3, characterized in that, An antioxidant and hydrogen are added at the beginning of the reaction, and the addition amounts are 1000 ppm and 5 ppm in sequence.
7. The preparation method of an octene copolymerized heat-shrinkable packaging film resin as described in claim 6, characterized in that, The antioxidant is 1010 and 168, and it is diluted with cyclohexane.
8. The application of the octene copolymer heat-shrinkable packaging film resin prepared by the preparation method according to any one of claims 3-7 in the preparation of a multilayer coextruded packaging film.