Preparation method of weather-resistant anti-aging PE (polyethylene) heat shrinkage film

Abstract

The invention discloses a preparation method of a weather-resistant and anti-aging PE heat shrink film. The preparation method comprises the following steps: 1) preparing quantitative raw materials in parts by weight: low-density polyethylene, high-density polyethylene, polyvinyl alcohol, polyethylene wax, an inorganic additive, metallocene polyethylene and anti-ultraviolet and anti-aging master batch; (2) feeding various raw materials in the step (1) into a reaction device for preheating and stirring; 3) performing high-temperature mixing on various raw materials under the condition of 140-200 DEG C; and (4) transferring a product obtained in the step (3) into a film blowing unit, extruding and blowing plastic, and sequentially carrying out cooling shaping, traction stretching and slitting rolling to obtain the PE heat shrinkage film. According to the preparation method of the weather-resistant and anti-aging PE heat shrink film, the PE heat shrink film prepared by the method has the advantages of good flexibility, impact resistance, high tear resistance, difficulty in damage, moisture resistance, high transparency, good strength, high toughness and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat-shrinkable film, in particular to a preparation method of weather-resistant and anti-aging PE heat-shrinkable film. BACKGROUND

[0002] The heat-shrinkable film is commonly known as shrink film, which can tightly wrap articles and keep its shape for a long time after being heated. The heat-shrinkable film is designed based on the principle of high polymer molecular chain stretching orientation and formed by rapid cooling and setting.

[0003] The polyethylene heat-shrinkable film, as one of important polyethylene film products, has good flexibility, strong impact resistance and tear resistance, is not easy to break, is not afraid of moisture, has large shrinkage, and is widely used in foreign trade export, papermaking, hardware, plastics, chemical industry, building materials, food and medicine related industries.

[0004] In the early market, most of the polyethylene heat-shrinkable films are produced by using high-pressure polyethylene or high-density polyethylene and high-pressure polyethylene blending alone. Although the heat-shrinkable film has high shrinkage and mechanical properties, the film product is relatively thick, usually more than 100 μm, and the transparency is poor, which affects the appearance of the packaged goods. With the development of heat-shrinkable film processing technology, thinning and increasing transparency of heat-shrinkable film have become a new development trend. The medium-density metallocene polyethylene gradually becomes one of the main raw materials for processing heat-shrinkable film. By adding metallocene polyethylene resin, the mechanical properties of the heat-shrinkable film are further improved, the thickness of the film is reduced, and the transparency of the film is improved. However, the existing heat-shrinkable film has high heat-shrinkability in one direction, but the toughness is too low and is easy to be brittle in the other direction. Therefore, it is of great significance to further improve the toughness of the polyethylene heat-shrinkable film. SUMMARY

[0005] In view of the above defects or deficiencies in the prior art, it is desirable to provide a preparation method of weather-resistant and anti-aging PE heat-shrinkable film.

[0006] The present application provides a preparation method of weather-resistant and anti-aging PE heat-shrinkable film, which comprises the following steps:

[0007] 1) Prepare a certain amount of raw materials according to the weight ratio: low-density polyethylene, high-density polyethylene, polyvinyl alcohol, polyethylene wax, inorganic additives, metallocene polyethylene and anti-UV anti-aging masterbatch;

[0008] 2) Put the various raw materials in step 1) into the reaction device for preheating and stirring;

[0009] 3) High-temperature mixing of the various raw materials under the condition of 140-200℃;

[0010] 4) The product obtained in step 3) is transferred to a film blowing machine, and the plastic is extruded and blown, and sequentially cooled, stretched and cut and rolled to obtain the PE heat-shrinkable film.

[0011] Further, the weight ratio is 40-62 parts of low-density polyethylene, 17-25 parts of high-density polyethylene, 3-4 parts of polyvinyl alcohol, 1-4 parts of polyethylene wax, 2-12 parts of inorganic additives, 4-18 parts of metallocene polyethylene, and 10-20 parts of anti-UV and anti-aging master batch.

[0012] Further, the anti-UV and anti-aging master batch comprises 0.1-2 parts of hindered amine light stabilizer, 1-3 parts of ultraviolet absorber, 3-5 parts of composite antioxidant, 0.1-0.5 parts of silane coupling agent, and 0.3-0.8 parts of slip agent.

[0013] Further, the low-density polyethylene has a density of 0.910-0.918 g / cm 3 , and a melt index of <0.7 g / 10 min.

[0014] Further, the high-density polyethylene has a density of 0.958-0.960 g / cm 3 , and a melt index of <0.150 g / 10 min.

[0015] Further, the metallocene polyethylene has a density of 0.930-0.950 g / cm 3 , and a melt index of <0.280 g / 10 min.

[0016] Further, the inorganic additives are one or more of calcium carbonate, diatomite and kaolin.

[0017] Further, the inorganic additives are 2-5 parts of calcium carbonate, 1-5 parts of diatomite and 2-6 parts of kaolin.

[0018] Further, the preheating and stirring reaction temperature is set to 40-70 DEG C, and the reaction time is set to 4-15 min, and the stirring is continuously performed during the reaction.

[0019] Further, the high-temperature mixing time is set to 16-25 min.

[0020] Compared with the prior art, the application has the following beneficial effects:

[0021] The preparation method of the weather-resistant and anti-aging PE heat-shrinkable film has the advantages of good flexibility, strong anti-impact and anti-tearing ability, not easy to break, moisture resistance, high transparency, good strength, high toughness, excellent weather resistance, etc.

[0022] It is to be understood that the description in the summary is not intended to identify key or essential features of embodiments of the application, nor is it intended to limit the scope of the application. Other features of the application will be apparent from review of the following description. DETAILED DESCRIPTION

[0023] It is to be understood that the specific examples described herein are merely illustrative of the application and are not intended to limit its scope.

[0024] It is to be understood that the description in the summary is not intended to identify key or essential features of embodiments of the application, nor is it intended to limit the scope of the application. Other features of the application will be apparent from review of the following description.

[0025] The embodiment of the application provides a preparation method of a weather-resistant and anti-aging PE heat-shrinkable film, which comprises the following steps:

[0026] 1) preparing a certain amount of raw materials according to the proportion of weight parts: low-density polyethylene, high-density polyethylene, polyvinyl alcohol, polyethylene wax, inorganic additives, metallocene polyethylene and anti-ultraviolet and anti-aging master batch;

[0027] 2) feeding the various raw materials in step 1) into a reaction device to perform preheating and stirring;

[0028] 3) performing high-temperature mixing of the various raw materials under the condition of 140-200 DEG C;

[0029] 4) transferring the product obtained in step 3) to a film blowing machine set to perform extrusion blowing of the plastic, and sequentially performing cooling and setting, traction stretching and slitting and winding to obtain the PE heat-shrinkable film.

[0030] In a preferred embodiment, the proportion of weight parts is that the low-density polyethylene is 40-62 parts, the high-density polyethylene is 17-25 parts, the polyvinyl alcohol is 3-4 parts, the polyethylene wax is 1-4 parts, the inorganic additives are 2-12 parts, the metallocene polyethylene is 4-18 parts and the anti-ultraviolet and anti-aging master batch is 10-20 parts.

[0031] The anti-ultraviolet and anti-aging master batch is a kind of anti-ultraviolet plastic master batch prepared by grafting anti-ultraviolet functional additives into plastic polymers through nano dispersion and multi-stage polymerization. The master batch has good weather resistance and can effectively absorb ultraviolet rays in the 200nm-380nm band, thereby protecting plastic products from fading and aging caused by ultraviolet irradiation;

[0032] The main components of the anti-ultraviolet and anti-aging master batch include:

[0033] The ultraviolet absorber is composed of organic and inorganic nanomaterials and high molecular materials, which can absorb ultraviolet rays and convert their energy into harmless heat energy, preventing the damage of ultraviolet rays to plastic products;

[0034] Base resin: such as polyethylene (PE), polypropylene (PP) and the like, as the main material of the masterbatch, carrying other functional additives;

[0035] Antioxidant: to prevent the degradation of plastics caused by heat and oxygen during processing and use

[0036] Light stabilizer: such as hindered amine light stabilizer (HALS), synergistic effect with ultraviolet absorber, providing better anti-aging effect;

[0037] In a preferred embodiment, the anti-ultraviolet aging masterbatch includes 0.1-2 parts by weight of hindered amine light stabilizer, 1-3 parts of ultraviolet absorber, 3-5 parts of composite antioxidant, 0.1-0.5 parts of silane coupling agent, 0.3-0.8 parts of slip agent.

[0038] Among them, the hindered amine light stabilizer includes bis(2,2,6,6-tetramethyl-4-hydroxypiperidine) sebacate; the ultraviolet absorber includes 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole; the composite antioxidant includes two or three of amine antioxidant, ester antioxidant and phenolic antioxidant; the slip agent includes stearic acid amide.

[0039] In a preferred embodiment, the density of low-density polyethylene is 0.910-0.918 g / cm 3 , and the melt index is <0.7 g / 10 min.

[0040] In a preferred embodiment, the density of high-density polyethylene is 0.958-0.960 g / cm 3 , and the melt index is <0.150 g / 10 min.

[0041] In a preferred embodiment, the density of metallocene polyethylene is 0.930-0.950 g / cm 3 , and the melt index is <0.280 g / 10 min.

[0042] In a preferred embodiment, the inorganic additive is one or more of calcium carbonate, diatomite or kaolin.

[0043] In a preferred embodiment, the inorganic additive is 2-5 parts of calcium carbonate, 1-5 parts of diatomite and 2-6 parts of kaolin.

[0044] In a preferred embodiment, the preheating and stirring reaction temperature is set to 40-70℃, and the reaction time is set to 4-15 min, with continuous stirring during the process.

[0045] In a preferred embodiment, the high-temperature mixing time is set to 16-25 min.

[0046] Example 1

[0047] A weather-resistant and anti-aging PE heat-shrinkable film is composed of the following raw materials in parts by weight: low-density polyethylene 45 parts, high-density polyethylene 20 parts, polyvinyl alcohol 3 parts, polyethylene wax 2 parts, inorganic additive 5 parts, metallocene polyethylene 6 parts, and anti-UV and anti-aging master batch 15 parts.

[0048] A preparation method of a weather-resistant and anti-aging PE heat-shrinkable film includes the following steps:

[0049] 1) Prepare a certain amount of raw materials according to the proportion by weight;

[0050] 2) Put the various raw materials in step 1) into a reaction device for preheating and stirring, the preheating and stirring reaction temperature is set to 50℃, the reaction time is set to 10min, and stirring is continuously performed during the process;

[0051] 3) High-temperature mixing of the various raw materials is performed at 160℃, and the high-temperature mixing time is set to 20min;

[0052] 4) The product obtained in step 3) is transferred to a film blowing machine set, the plastic is extruded and blown, and then cooled, shaped, drawn and stretched, and cut and rolled, to obtain a PE heat-shrinkable film.

[0053] Example 2

[0054] A weather-resistant and anti-aging PE heat-shrinkable film is composed of the following raw materials in parts by weight: low-density polyethylene 45 parts, high-density polyethylene 20 parts, polyvinyl alcohol 3 parts, polyethylene wax 2 parts, inorganic additive 5 parts, metallocene polyethylene 6 parts, and anti-UV and anti-aging master batch 15 parts.

[0055] A preparation method of a weather-resistant and anti-aging PE heat-shrinkable film includes the following steps:

[0056] 1) Prepare a certain amount of raw materials according to the proportion by weight;

[0057] 2) Put the various raw materials in step 1) into a reaction device for preheating and stirring, the preheating and stirring reaction temperature is set to 60℃, the reaction time is set to 12min, and stirring is continuously performed during the process;

[0058] 3) High-temperature mixing of the various raw materials is performed at 180℃, and the high-temperature mixing time is set to 22min;

[0059] 4) The product obtained in step 3) is transferred to a film blowing machine set, the plastic is extruded and blown, and then cooled, shaped, drawn and stretched, and cut and rolled, to obtain a PE heat-shrinkable film.

[0060] Example 3

[0061] A weather-resistant and aging-resistant PE heat shrinkable film, composed of the following raw materials in parts by weight: 60 parts of low-density polyethylene, 25 parts of high-density polyethylene, 4 parts of polyvinyl alcohol, 4 parts of polyethylene wax, 12 parts of inorganic additives, 15 parts of metallocene polyethylene, and 20 parts of anti-UV and aging-resistant masterbatch;

[0062] A method for preparing a weather-resistant and aging-resistant PE heat shrinkable film comprises the following steps:

[0063] 1) Prepare a certain amount of raw materials according to the weight ratio;

[0064] 2) The various raw materials in step 1) were fed into a reaction apparatus for preheating and stirring. The reaction temperature for preheating and stirring was set to 65° C., and the reaction time was set to 15 min, with continuous stirring during the process;

[0065] 3) Mix various raw materials at a high temperature of 185°C for 20 minutes;

[0066] 4) The product obtained in step 3) is transferred to a film blowing unit, the plastic is extruded and blown, and then cooled and shaped, stretched, and slit and wound in sequence to obtain a PE heat shrinkable film.

[0067] The PE heat shrinkable film prepared according to the above method has the advantages of good flexibility, strong impact resistance and tear resistance, not easy to be damaged, moisture-resistant, high transparency, good strength, and strong toughness.

[0068] In this specification, the terms "connect," "install," and "fix" should be understood broadly. For example, "connect" can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a direct connection or an indirect connection through an intermediary. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0069] Throughout this specification, terms such as "one embodiment" or "some embodiments" mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0070] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A method for preparing a weather-resistant and aging-resistant PE heat shrinkable film, characterized in that: The steps include: 1) Prepare a certain amount of raw materials according to the weight ratio: low-density polyethylene, high-density polyethylene, polyvinyl alcohol, polyethylene wax, inorganic additives, metallocene polyethylene and anti-UV and anti-aging masterbatch; 2) feeding the various raw materials in step 1) into a reaction device for preheating and stirring; 3) Mix various raw materials at high temperature of 140-200°C; 4) The product obtained in step 3) is transferred to a film blowing unit, the plastic is extruded and blown, and then cooled and shaped, stretched, and slit and wound in sequence to obtain a PE heat shrinkable film.

2. The method for preparing the weather-resistant and aging-resistant PE heat shrinkable film according to claim 1, characterized in that: The weight proportions are: 40-62 parts of low-density polyethylene, 17-25 parts of high-density polyethylene, 3-4 parts of polyvinyl alcohol, 1-4 parts of polyethylene wax, 2-12 parts of inorganic additives, 4-18 parts of metallocene polyethylene, and 10-20 parts of anti-UV and aging-resistant masterbatch.

3. The method for preparing the weather-resistant and aging-resistant PE heat shrinkable film according to claim 1, characterized in that: The anti-ultraviolet and anti-aging masterbatch comprises, by weight, 0.1-2 parts of a hindered amine light stabilizer, 1-3 parts of an ultraviolet absorber, 3-5 parts of a composite antioxidant, 0.1-0.5 parts of a silane coupling agent, and 0.3-0.8 parts of a lubricant.

4. The method for preparing the weather-resistant and aging-resistant PE heat shrinkable film according to claim 1, characterized in that: The density of the low-density polyethylene is 0.910-0.918 g / cm 3 , melt index <0.7g / 10min.

5. The method for preparing the weather-resistant and aging-resistant PE heat shrinkable film according to claim 1, characterized in that: The density of the high-density polyethylene is 0.958-0.960 g / cm 3 , melt index <0.150g / 10min.

6. The method for preparing the weather-resistant and aging-resistant PE heat shrinkable film according to claim 1, characterized in that: The density of the metallocene polyethylene is 0.930-0.950 g / cm 3 , melt index <0.280g / 10min.

7. The method for preparing the weather-resistant and aging-resistant PE heat shrinkable film according to claim 1, characterized in that: The inorganic additive is one or more of calcium carbonate, diatomaceous earth or kaolin.

8. The method for preparing the weather-resistant and aging-resistant PE heat shrinkable film according to claim 1, characterized in that: The inorganic additives are 2-5 parts of calcium carbonate, 1-5 parts of diatomaceous earth and 2-6 parts of kaolin.

9. The method for preparing the weather-resistant and aging-resistant PE heat shrinkable film according to claim 1, characterized in that: The reaction temperature of the preheating and stirring is set to 40-70° C., the reaction time is set to 4-15 min, and stirring is performed continuously during the process.

10. The method for preparing the weather-resistant and aging-resistant PE heat shrinkable film according to claim 1, characterized in that: The high temperature mixing time is set to 16-25 minutes.