Preparation system for polyester transparent low-shrinkage shrink film

Abstract

The utility model provides a preparation system for a polyester transparent low-shrinkage shrink film, which comprises a mixing bin, an inlet of the mixing bin is respectively connected with first preheating and drying equipment for PETG shrink film functional master batch, second preheating and drying equipment for PET slices for common films, third preheating and drying equipment for polyvinyl butyral and fourth preheating and drying equipment for butylated hydroxytoluene; an outlet of the mixing bin is connected with an inlet of the twin-screw extruder, an outlet of the twin-screw extruder is connected with an inlet of the casting unit, an outlet of the casting unit is connected with an inlet of the stretching mechanism, an outlet of the stretching mechanism is connected with an inlet of the cooling mechanism, and an outlet of the cooling mechanism is connected with the receiving roller. The preparation system is simple in structure and can be used for manufacturing the polyester transparent low-shrinkage shrink film at low cost. By means of the preparation system, the adding amount of all the components can be adjusted according to needs, and wider adaptability is achieved.

Description

Technical Field

[0001] The utility model relates to a preparation system for a polyester transparent low-shrinkage shrink film. Background Art

[0002] Shrink film is a commonly used packaging material, widely used in the packaging of various foods, beverages, daily chemical products, etc. Its main feature is that it can shrink under conditions such as heating or freezing, forming a tightly fitting packaging effect with the packaged items. Different types of shrink films have their unique application scenarios in different product packaging. When using shrink film, it is necessary to select according to the requirements of the nature of the packaged items, the packaging shape and the packaging effect to be achieved, so as to achieve the best use effect while ensuring freshness, beauty and convenience.

[0003] For example, when the items to be packaged have specific requirements for the shrinkage rate of the shrink film, or when the shrink film needs to be stored at room temperature, it is necessary to choose a shrink film with a low shrinkage rate. Shrink films with low shrinkage rates are usually suitable for the following situations:

[0004] Storage at room temperature: Since low shrinkage shrink film has the characteristic of low natural shrinkage at room temperature, it can be stored in an environment with room temperature below 25°C without worrying about difficulty in unfolding or label deformation.

[0005] Specific packaging needs: For certain specific packaging needs, such as the need to keep the package flat or avoid excessive shrinkage causing packaging deformation, low shrinkage shrink film is a more appropriate choice. For example, POF low-temperature shrink film has a low shrinkage temperature and low shrinkage rate, and is suitable for achieving an ideal shrinkage rate at a temperature of 80-100°C.

[0006] Environmental considerations: In some cases, choosing a shrink film with a low shrinkage rate is also for environmental considerations. For example, the recyclable, reusable, energy-saving and environmentally friendly PETG shrink film, even if recyclable raw materials are added during the production process, has the same performance as conventional PETG shrink film, and is widely used in various bottle types, especially sleeve labels for special-shaped bottles, which is environmentally friendly.

[0007] Printing and design freedom: For product packaging that requires high-quality printing and design freedom, low-shrinkage shrink film can provide better support. High transparency and excellent printing performance can enhance the brand recognition of the bottle label. Printing from the inside will not cause the label to discolor and break due to friction. It can also make a 360-degree overall label design that integrates multiple colors and high-quality printing.

[0008] In summary, low shrinkage shrink film has important application value in areas such as room temperature storage, specific packaging requirements, environmental considerations, and printing and design freedom.

[0009] The commonly used POF shrink film is a multi-layer co-extruded polyolefin thermal film. The common type uses LLDPE in the middle layer and polypropylene (PP) in the inner and outer layers. It is made by co-extrusion of three or more layers and then through a special double-bubble method of synchronous biaxial stretching. POF shrink film has the advantages of high gloss, good toughness, and high tear strength, but it also has defects such as high production cost, sensitivity to high temperature environment, uneven shrinkage, easy tearing and blistering. In addition, the film layers of different components also have the disadvantages of complex raw materials and difficulty in recycling.

[0010] The existing commonly used PETG shrink film has the advantages of high limit shrinkage, low natural shrinkage, flat shrinkage curve, high transparency and gloss, excellent printing color, and good environmental coordination. However, the high shrinkage makes it unsuitable as a low-shrinkage material for packaging specific products.

[0011] For example, CN 113696572 B discloses a composite PETG heat shrinkable film and its preparation system, wherein the composite PETG heat shrinkable film is composed of an extruded surface layer A, a core layer B and a bottom layer C. The surface layers A and C both include PETG and 5.5wt% to 9.5wt% of PETG functional material slices, which include 80-95 parts by weight of PETG slices, 2-5 parts by weight of nano boron nitride, 1-2 parts by weight of aluminate, 6-10 parts by weight of polydimethylsiloxane and 2-3 parts by weight of potassium chloride. The B layer includes PS and 14.5wt% to 21.5wt% of PS functional material slices.

[0012] The PETG slices used in the PETG functional material of the prior art can be partially or completely from purchased or pre-prepared raw materials, and of course, can also be from PETG label recycled materials, etc. The components of these PETG raw materials are single and relatively fixed, so the performance of the PETG functional material prepared therefrom will be limited by the PETG slices with fixed raw materials, such as the shrinkage rate is maintained within a specific range. For example, the prior art adds nano boron nitride, aluminate, polydimethylsiloxane and potassium chloride to the PETG slices, and its main adjustment target is to reduce the die head temperature during co-extrusion, but it can only slightly reduce the shrinkage rate, and it is difficult to prepare a low-shrinkage shrink film.

[0013] In addition, the prior art also lacks a system for preparing low-shrinkage shrink films. Summary of the invention

[0014] The technical problem to be solved by the present application is to provide a preparation system for polyester transparent low-shrinkage shrink film to reduce or avoid the above-mentioned problems.

[0015] In order to solve the above technical problems, the present application proposes a preparation system for polyester transparent low-shrinkage shrink film, including a mixing bin, the inlet of which is respectively connected to a first preheating and drying device for PETG shrink film functional masterbatch, a second preheating and drying device for PET slices for ordinary film, a third preheating and drying device for polyvinyl butyral, and a fourth preheating and drying device for butylated hydroxytoluene; the outlet of the mixing bin is connected to the inlet of a twin-screw extruder, the outlet of the twin-screw extruder is connected to the inlet of a casting unit, the outlet of the casting unit is connected to the inlet of a stretching mechanism, the outlet of the stretching mechanism is connected to the inlet of a cooling mechanism, and the outlet of the cooling mechanism is connected to a receiving roller.

[0016] Preferably, the receiving roller is further connected to a slitting mechanism.

[0017] Preferably, the inlet of the first preheating and drying equipment is further connected to a functional masterbatch preparation device for preparing a functional masterbatch of PETG shrink film; wherein the functional masterbatch preparation device comprises at least one esterification tank and a polycondensation tank, the esterification tank having a first inlet for terephthalic acid, a second inlet for ethylene glycol and a third inlet for connecting to the outlet of an esterification auxiliary material tank; the polycondensation tank having a fourth inlet for connecting to the outlet of the esterification tank, a fifth inlet for connecting to the outlet of a polycondensation auxiliary material tank and a sixth inlet for potassium tripolyphosphate; the outlet of the polycondensation tank is connected to at least one extruder, the outlet of the extruder is connected to a pelletizer, and the outlet of the pelletizer is connected to a dryer.

[0018] Preferably, the esterification auxiliary material tank is provided with three inlets corresponding to the input of 1,4-cyclohexanedimethanol, triaryl phosphate and isocyanate respectively.

[0019] Preferably, the polycondensation auxiliary material tank is provided with three inlets corresponding to the input of magnesium aluminum silicate, disodium ethylenediaminetetraacetate and other auxiliary agents respectively.

[0020] The preparation system of the present application has a simple structure and can be used to manufacture polyester transparent low-shrinkage shrink film at low cost. Through the preparation system of the present application, the addition amount of each component can be adjusted as needed, and it has a wider adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The following drawings are only intended to illustrate and explain the present application, and do not limit the scope of the present application.

[0022] Figure 1 Shown is a schematic structural diagram of a system for preparing a polyester transparent low-shrinkage shrink film according to a specific embodiment of the present application.

[0023] Figure 2Shown is a schematic structural diagram of a device for preparing a PETG functional masterbatch for a polyester transparent low-shrinkage shrink film according to another specific embodiment of the present application. DETAILED DESCRIPTION

[0024] In order to have a clearer understanding of the technical features, purposes and effects of the present application, the specific implementation of the present application is now described with reference to the accompanying drawings, wherein the same components are numbered the same.

[0025] The present application provides a polyester transparent low-shrinkage shrink film, which is made of PETG shrink film functional masterbatch slices, PET slices for ordinary films, polyvinyl butyral and butylated hydroxytoluene.

[0026] The PETG shrink film functional masterbatch is prepared from the following raw materials in parts by weight: 100-120 parts by weight of terephthalic acid, 30-50 parts by weight of 1,4-cyclohexanedimethanol, 80-100 parts by weight of ethylene glycol, 0.1-0.2 parts by weight of triaryl phosphate, 0.01-0.03 parts by weight of isocyanate, 0.01-0.02 parts by weight of potassium tripolyphosphate, 0.1-0.2 parts by weight of magnesium aluminum silicate, 0.2-0.4 parts by weight of disodium ethylenediaminetetraacetate, and 0.3-0.5 parts by weight of other additives.

[0027] Among them, other additives include but are not limited to anti-adhesive agents, antioxidants, stabilizers, leveling agents, flame retardants, etc., or a combination thereof.

[0028] In the shrinkage film of the present application, a functional masterbatch with relatively high shrinkage performance is used. When it is needed to be applied to certain scenarios with relatively low parameter requirements, the shrinkage parameters can be reduced by subsequently adding polyvinyl butyral and butylated hydroxytoluene. Therefore, with a functional masterbatch with wider applicability, the polyester transparent low-shrinkage shrinkage film of the present application can be obtained relatively easily.

[0029] The PETG shrink film functional masterbatch of the present application can be prepared by the following steps.

[0030] For example, 100-120 parts by weight of terephthalic acid and 80-100 parts by weight of ethylene glycol can be added to the esterification tank, mixed evenly at room temperature, and pre-reacted for 30-60 minutes. After that, 30-50 parts by weight of 1,4-cyclohexanedimethanol, 0.1-0.2 parts by weight of triaryl phosphate, and 0.01-0.03 parts by weight of isocyanate that are evenly mixed are added to the esterification tank. The reaction conditions of the esterification tank are set to 230-250°C and 0.2-0.3Mpa, and the esterification reaction is carried out. After the water output reaches the theoretical value, the system pressure is released to normal pressure.

[0031] Then, the esterification product is filtered and transferred from the outlet of the esterification tank to the polycondensation tank, and 0.01-0.02 parts by weight of potassium tripolyphosphate is added to the polycondensation tank, the temperature is maintained at 230-250°C, and the mixture is stirred at normal pressure for 10 minutes. Then, vacuum is drawn, the temperature in the polycondensation tank is raised to 285°C, the pressure is reduced to below 100 Pa, the reaction is carried out for more than 3 hours, the intrinsic viscosity reaches more than 0.80 dl / g, the temperature is reduced to 230°C, and the mixture is returned to normal pressure.

[0032] 0.1-0.2 parts by weight of aluminum magnesium silicate, 0.2-0.4 parts by weight of disodium ethylenediaminetetraacetate, and 0.3-0.5 parts by weight of other additives that have been uniformly mixed are added into the polycondensation tank.

[0033] The temperature in the polycondensation tank was maintained at 230° C. and stirred for 30 minutes. Finally, the polymer melt was filtered, extruded, pelletized, and dried from the outlet of the polycondensation tank to obtain a PETG shrink film functional masterbatch.

[0034] The polyester transparent low-shrinkage shrink film of the present application can be prepared by the following steps.

[0035] For example, the prepared PETG shrink film functional masterbatch is uniformly mixed with PET chips for ordinary films, polyvinyl butyral and butylated hydroxytoluene to form a mixture, and the mixture is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled, and slit to make the shrink film.

[0036] Refer to the following Figure 1 and Figure 2 , further describing the preparation system for the polyester transparent low-shrinkage shrink film of the present application, wherein, Figure 1 Shown is a schematic structural diagram of a system for preparing a polyester transparent low-shrink shrink film according to a specific embodiment of the present application; Figure 2 Shown is a schematic structural diagram of a device for preparing a PETG functional masterbatch for a polyester transparent low-shrinkage shrink film according to another specific embodiment of the present application.

[0037] As shown in the figure, the preparation system for polyester transparent low-shrink shrink film of the present application may include a mixing bin 500, the inlet of the mixing bin 500 is respectively connected to the first preheating and drying device 501 for PETG shrink film functional masterbatch, the second preheating and drying device 502 for PET slices for ordinary film, the third preheating and drying device 503 for polyvinyl butyral, and the fourth preheating and drying device 504 for butylated hydroxytoluene; the outlet of the mixing bin 500 is connected to the inlet of the twin-screw extruder 510, the outlet of the twin-screw extruder 510 is connected to the inlet of the casting unit 520, the outlet of the casting unit 520 is connected to the inlet of the stretching mechanism 540, the outlet of the stretching mechanism 540 is connected to the inlet of the cooling mechanism 550, and the outlet of the cooling mechanism 550 is connected to the receiving roller 560. After the material is collected by the receiving roller 560, the film can be further cut by a cutting mechanism 570 connected to the receiving roller 560.

[0038] Furthermore, the inlet of the first preheating and drying device 101 can also be connected to a functional masterbatch preparation device 1000 for preparing a functional masterbatch of a PETG shrink film.

[0039] like Figure 2 As shown, the functional masterbatch preparation device 1000 of the present application may include at least one esterification tank 100 and one polycondensation tank 200. Those skilled in the art should understand that the functional masterbatch preparation device 1000 of the present application is not limited to having only one esterification tank and one polycondensation tank. For example, for different production scales, two or more esterification tanks 100 and two or more polycondensation tanks 200 may be connected in series in sequence, wherein the front esterification tank 100 and polycondensation tank 200 are used for pre-reaction, and the last esterification tank 100 and polycondensation tank 200 are used for final reaction.

[0040] The esterification tank 100 has a first inlet 101 for terephthalic acid, a second inlet 102 for ethylene glycol, and a third inlet 103 for connecting to the outlet of the esterification auxiliary material tank 300 .

[0041] The esterification auxiliary material tank 300 is provided with three inlets for inputting 1,4-cyclohexanedimethanol, triaryl phosphate and isocyanate respectively. Initially, terephthalic acid and ethylene glycol can be added for pre-reaction, and then the three auxiliary materials mixed in the esterification auxiliary material tank 300 are added to the esterification tank 100.

[0042] The polycondensation tank 200 has a fourth inlet 204 for connecting to the outlet of the esterification tank 100 , a fifth inlet 205 for connecting to the outlet of the polycondensation auxiliary material tank 301 , and a sixth inlet 206 for potassium tripolyphosphate.

[0043] The polycondensation auxiliary material tank 301 is provided with three inlets for respectively inputting magnesium aluminum silicate, disodium ethylenediaminetetraacetate and other auxiliary agents. Initially, potassium tripolyphosphate can be added for pre-reaction, and then the three auxiliary materials mixed in the polycondensation auxiliary material tank 301 are added to the polycondensation tank 200.

[0044] Furthermore, the outlet of the polycondensation tank 200 is connected to at least one extruder 600 , the outlet of the extruder 600 is connected to a pelletizer 700 , and the outlet of the pelletizer 800 is connected to a dryer 800 .

[0045] Example 1

[0046] 100 parts by weight of terephthalic acid, 80 parts by weight of ethylene glycol, 30 parts by weight of 1,4-cyclohexanedimethanol, 0.1 parts by weight of triaryl phosphate, and 0.01 parts by weight of isocyanate were added into an esterification tank to carry out an esterification reaction.

[0047] The esterification product is transferred to a polycondensation tank, and 0.01 parts by weight of potassium tripolyphosphate, 0.1 parts by weight of magnesium aluminum silicate, 0.2 parts by weight of disodium ethylenediaminetetraacetate, and 0.3 parts by weight of nano calcium carbonate anti-adhesive are added to the polycondensation tank to carry out a polycondensation reaction.

[0048] In this embodiment, the intrinsic viscosity of the polycondensation reaction product can reach a maximum of 0.80 dl / g.

[0049] Finally, the polymer melt is extruded, pelletized and dried to obtain a PETG shrink film functional masterbatch.

[0050] The prepared PETG shrink film functional masterbatch is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled, and slit to make a shrink film.

[0051] The maximum shrinkage temperature of the film is 81°C, the transverse heat shrinkage rate is 71% in 2 to 3 seconds, the light transmittance is 95%, and the shrinkage force is 6.1N / m 2 , thickness is 50μm.

[0052] Example 2

[0053] The PETG shrink film functional masterbatch prepared in Example 1 is uniformly mixed with PET slices for ordinary film, polyvinyl butyral and butylated hydroxytoluene to form a mixture, and the mixture is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled, and slit to produce the shrink film.

[0054] Among them, the total weight of the PETG shrink film functional masterbatch slices, the PET slices for ordinary film, polyvinyl butyral and butylated hydroxytoluene is 100wt%, the added amount of the PETG shrink film functional masterbatch slices is 75wt%, the added amount of polyvinyl butyral is 5wt%, the added amount of butylated hydroxytoluene is 3wt%, and the rest are PET slices for ordinary film.

[0055] The maximum shrinkage temperature of the shrink film is 101°C, the transverse heat shrinkage rate is 33% in 2 to 3 seconds, the light transmittance is 96%, and the shrinkage force is 5.8N / m 2 .

[0056] Example 3

[0057] 110 parts by weight of terephthalic acid, 90 parts by weight of ethylene glycol, 40 parts by weight of 1,4-cyclohexanedimethanol, 0.15 parts by weight of triaryl phosphate, and 0.02 parts by weight of isocyanate were added into an esterification tank to carry out an esterification reaction.

[0058] The esterification product was transferred to a polycondensation tank, and 0.015 parts by weight of potassium tripolyphosphate, 0.15 parts by weight of magnesium aluminum silicate, 0.3 parts by weight of disodium ethylenediaminetetraacetate, and 0.4 parts by weight of polytetrahydrofuran leveling agent were added to the polycondensation tank to carry out a polycondensation reaction.

[0059] In this embodiment, the maximum intrinsic viscosity of the polycondensation reaction product can reach 0.81 dl / g.

[0060] Finally, the polymer melt is extruded, pelletized and dried to obtain a PETG shrink film functional masterbatch.

[0061] The prepared PETG shrink film functional masterbatch is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled, and slit to make a shrink film.

[0062] The maximum shrinkage temperature of the film is 80℃, the transverse heat shrinkage rate is 73% in 2-3 seconds, the light transmittance is 94%, and the shrinkage force is 5.8N / m 2 , thickness is 50μm.

[0063] Example 4

[0064] The PETG shrink film functional masterbatch prepared in Example 3 is uniformly mixed with PET slices for ordinary film, polyvinyl butyral and butylated hydroxytoluene to form a mixture, and the mixture is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled, and slit to produce the shrink film.

[0065] Among them, the total weight of the PETG shrink film functional masterbatch slices, the PET slices for ordinary film, polyvinyl butyral and butylated hydroxytoluene is 100wt%, the added amount of the PETG shrink film functional masterbatch slices is 80wt%, the added amount of polyvinyl butyral is 7wt%, the added amount of butylated hydroxytoluene is 4wt%, and the rest are PET slices for ordinary film.

[0066] The maximum shrinkage temperature of the shrink film is 98°C, the transverse heat shrinkage rate is 35% in 2 to 3 seconds, the light transmittance is 95%, and the shrinkage force is 5.6N / m 2 .

[0067] Example 5

[0068] 120 parts by weight of terephthalic acid, 100 parts by weight of ethylene glycol, 50 parts by weight of 1,4-cyclohexanedimethanol, 0.2 parts by weight of triaryl phosphate, and 0.03 parts by weight of isocyanate were added into an esterification tank to carry out an esterification reaction.

[0069] The esterification product is transferred to a polycondensation tank, and 0.02 parts by weight of potassium tripolyphosphate, 0.2 parts by weight of magnesium aluminum silicate, 0.4 parts by weight of disodium ethylenediaminetetraacetate, 0.3 parts by weight of nano titanium dioxide stabilizer, and 0.2 parts by weight of decabromodiphenyl ether flame retardant are added to the polycondensation tank to carry out a polycondensation reaction.

[0070] In this embodiment, the intrinsic viscosity of the polycondensation reaction product can reach a maximum of 0.82 dl / g.

[0071] Finally, the polymer melt is extruded, pelletized and dried to obtain a PETG shrink film functional masterbatch.

[0072] The prepared PETG shrink film functional masterbatch is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled, and slit to make a shrink film.

[0073] The maximum shrinkage temperature of the film is 80℃, the transverse heat shrinkage rate is 72% in 2-3 seconds, the light transmittance is 93%, and the shrinkage force is 6.2N / m 2 , thickness is 50μm.

[0074] Example 6

[0075] The PETG shrink film functional masterbatch prepared in Example 5 is uniformly mixed with PET chips for ordinary films, polyvinyl butyral and butylated hydroxytoluene to form a mixture, and the mixture is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled, and slit to produce the shrink film.

[0076] Among them, the total weight of the PETG shrink film functional masterbatch slices, the PET slices for ordinary film, polyvinyl butyral and butylated hydroxytoluene is 100wt%, the added amount of the PETG shrink film functional masterbatch slices is 85wt%, the added amount of polyvinyl butyral is 8wt%, the added amount of butylated hydroxytoluene is 5wt%, and the rest are PET slices for ordinary film.

[0077] The maximum shrinkage temperature of the shrink film is 97°C, the transverse heat shrinkage rate is 37% in 2 to 3 seconds, the light transmittance is 94%, and the shrinkage force is 5.5N / m 2 .

[0078] The functional masterbatch of the present application proposes a new preparation process and a combination of specific raw materials based on the raw materials. By adding different raw material ratios in the esterification and polycondensation stages, the shrinkage performance of the prepared shrink film can be improved. On the basis of the prepared functional masterbatch, by adding polyvinyl butyral and butylated hydroxytoluene, a low-shrinkage transparent shrink film can be obtained. The following comparative examples compare the performance of the prepared shrink films with different preparation processes and raw material ratios.

[0079] Comparative Example 1

[0080] 100 parts by weight of terephthalic acid, 80 parts by weight of ethylene glycol, and 30 parts by weight of 1,4-cyclohexanedimethanol were added into an esterification tank to carry out an esterification reaction.

[0081] The esterification product is transferred to a polycondensation tank, and 0.3 parts by weight of a nano calcium carbonate anti-adhesive agent is added to the polycondensation tank to carry out a polycondensation reaction. Finally, the polymer melt is extruded, pelletized, and dried to obtain a PETG shrink film functional masterbatch.

[0082] In this comparative example, the maximum intrinsic viscosity of the polycondensation reaction product can reach 0.69 dl / g.

[0083] The prepared PETG shrink film functional masterbatch is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled, and slit to make a shrink film.

[0084] The maximum shrinkage temperature of the film is 120℃, the transverse heat shrinkage rate is 67% in 2-3 seconds, the light transmittance is 85%, and the shrinkage force is 6.9N / m 2 , thickness is 50μm.

[0085] The prepared PETG shrink film functional masterbatch is uniformly mixed with PET slices for ordinary films, polyvinyl butyral and butylated hydroxytoluene to form a mixture, and the mixture is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled, and slit to make the shrink film.

[0086] Among them, the total weight of the PETG shrink film functional masterbatch slices, the PET slices for ordinary film, polyvinyl butyral and butylated hydroxytoluene is 100wt%, the added amount of the PETG shrink film functional masterbatch slices is 75wt%, the added amount of polyvinyl butyral is 5wt%, the added amount of butylated hydroxytoluene is 3wt%, and the rest are PET slices for ordinary film.

[0087] The maximum shrinkage temperature of the shrink film is 122°C, the transverse heat shrinkage rate is 54% in 2 to 3 seconds, the light transmittance is 96%, and the shrinkage force is 5.1N / m 2 .

[0088] Comparative Example 2

[0089] 110 parts by weight of terephthalic acid, 90 parts by weight of ethylene glycol, 40 parts by weight of 1,4-cyclohexanedimethanol, 0.15 parts by weight of triaryl phosphate, and 0.02 parts by weight of isocyanate were added into an esterification tank to carry out an esterification reaction.

[0090] The esterification product is transferred to a polycondensation tank, and 0.4 parts by weight of polytetrahydrofuran leveling agent is added to the polycondensation tank to carry out a polycondensation reaction. Finally, the polymer melt is extruded, pelletized, and dried to obtain a PETG shrink film functional masterbatch.

[0091] In this comparative example, the maximum intrinsic viscosity of the polycondensation reaction product can reach 0.71 dl / g.

[0092] The prepared PETG shrink film functional masterbatch is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled, and slit to make a shrink film.

[0093] The maximum shrinkage temperature of the film is 115°C, the transverse heat shrinkage rate is 73% in 2 to 3 seconds, the light transmittance is 88%, and the shrinkage force is 6.7N / m 2 , thickness is 50μm.

[0094] The prepared PETG shrink film functional masterbatch is uniformly mixed with PET slices for ordinary films, polyvinyl butyral and butylated hydroxytoluene to form a mixture, and the mixture is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled, and slit to make the shrink film.

[0095] Among them, the total weight of the PETG shrink film functional masterbatch slices, the PET slices for ordinary film, polyvinyl butyral and butylated hydroxytoluene is 100wt%, the added amount of the PETG shrink film functional masterbatch slices is 80wt%, the added amount of polyvinyl butyral is 7wt%, the added amount of butylated hydroxytoluene is 4wt%, and the rest are PET slices for ordinary film.

[0096] The maximum shrinkage temperature of the prepared PETG shrink film is 127°C, the transverse heat shrinkage rate in 2 to 3 seconds is 51%, the light transmittance is 95%, and the shrinkage force is 5.5N / m 2 .

[0097] Comparative Example 3

[0098] 120 parts by weight of terephthalic acid, 100 parts by weight of ethylene glycol, 50 parts by weight of 1,4-cyclohexanedimethanol, 0.2 parts by weight of triaryl phosphate, and 0.03 parts by weight of isocyanate were added into an esterification tank to carry out an esterification reaction.

[0099] The esterification product is transferred to a polycondensation tank, and 0.3 parts by weight of a nano titanium dioxide stabilizer is added to the polycondensation tank to carry out a polycondensation reaction. Finally, the polymer melt is extruded, pelletized, and dried to obtain a PETG shrink film functional masterbatch.

[0100] In this comparative example, the maximum intrinsic viscosity of the polycondensation reaction product can reach 0.80 dl / g.

[0101] The prepared PETG shrink film functional masterbatch is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled, and slit to make a shrink film.

[0102] The maximum shrinkage temperature of the film is 120℃, the transverse heat shrinkage rate is 68% in 2-3 seconds, the light transmittance is 89%, and the shrinkage force is 6.8N / m 2 , thickness is 50μm.

[0103] The prepared PETG shrink film functional masterbatch is uniformly mixed with PET slices for ordinary films, polyvinyl butyral and butylated hydroxytoluene to form a mixture, and the mixture is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled, and slit to make the shrink film.

[0104] Among them, the total weight of the PETG shrink film functional masterbatch slices, the PET slices for ordinary film, polyvinyl butyral and butylated hydroxytoluene is 100wt%, the added amount of the PETG shrink film functional masterbatch slices is 85wt%, the added amount of polyvinyl butyral is 8wt%, the added amount of butylated hydroxytoluene is 5wt%, and the rest are PET slices for ordinary film.

[0105] The maximum shrinkage temperature of the shrink film is 124°C, the transverse heat shrinkage rate is 55% in 2 to 3 seconds, the light transmittance is 96%, and the shrinkage force is 5.3N / m 2 .

[0106] Comparative Example 4

[0107] 100 parts by weight of terephthalic acid, 80 parts by weight of ethylene glycol, 30 parts by weight of 1,4-cyclohexanedimethanol and 0.1 parts by weight of triaryl phosphate were added into an esterification tank to carry out an esterification reaction.

[0108] The esterification product is transferred to a polycondensation tank, and 0.01 parts by weight of potassium tripolyphosphate, 0.1 parts by weight of magnesium aluminum silicate, and 0.3 parts by weight of nano calcium carbonate anti-adhesive agent are added to the polycondensation tank to carry out a polycondensation reaction. Finally, the polymer melt is extruded, pelletized, and dried to obtain a PETG shrink film functional masterbatch.

[0109] In this comparative example, the intrinsic viscosity of the polycondensation reaction product can reach a maximum of 0.75 dl / g.

[0110] The prepared PETG shrink film functional masterbatch is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled, and slit to make a shrink film.

[0111] The maximum shrinkage temperature of the film is 120℃, the transverse heat shrinkage rate is 75% in 2-3 seconds, the light transmittance is 92%, and the shrinkage force is 6.5N / m 2 , thickness is 50μm.

[0112] The prepared PETG shrink film functional masterbatch is uniformly mixed with PET slices for ordinary films, polyvinyl butyral and butylated hydroxytoluene to form a mixture, and the mixture is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled, and slit to make the shrink film.

[0113] Among them, the total weight of the PETG shrink film functional masterbatch slices, the PET slices for ordinary film, polyvinyl butyral and butylated hydroxytoluene is 100wt%, the added amount of the PETG shrink film functional masterbatch slices is 75wt%, the added amount of polyvinyl butyral is 5wt%, the added amount of butylated hydroxytoluene is 3wt%, and the rest are PET slices for ordinary film.

[0114] The maximum shrinkage temperature of the shrink film is 123℃, the transverse heat shrinkage rate is 56% in 2-3 seconds, the light transmittance is 94%, and the shrinkage force is 5.5N / m 2 .

[0115] Comparative Example 5

[0116] 110 parts by weight of terephthalic acid, 90 parts by weight of ethylene glycol, 40 parts by weight of 1,4-cyclohexanedimethanol and 0.02 parts by weight of isocyanate were added into an esterification tank to carry out an esterification reaction.

[0117] The esterification product is transferred to a polycondensation tank, and 0.015 parts by weight of potassium tripolyphosphate, 0.15 parts by weight of magnesium aluminum silicate, 0.3 parts by weight of disodium ethylenediaminetetraacetate, and 0.4 parts by weight of polytetrahydrofuran leveling agent are added to the polycondensation tank to carry out a polycondensation reaction. Finally, the polymer melt is extruded, pelletized, and dried to obtain a PETG shrink film functional masterbatch.

[0118] In this comparative example, the maximum intrinsic viscosity of the polycondensation reaction product can reach 0.73 dl / g.

[0119] The prepared PETG shrink film functional masterbatch is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled, and slit to make a shrink film.

[0120] The maximum shrinkage temperature of the film is 108℃, the transverse heat shrinkage rate is 76% in 2-3 seconds, the light transmittance is 90%, and the shrinkage force is 6.5N / m 2 , thickness is 50μm.

[0121] The prepared PETG shrink film functional masterbatch is uniformly mixed with PET slices for ordinary films, polyvinyl butyral and butylated hydroxytoluene to form a mixture, and the mixture is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled, and slit to make the shrink film.

[0122] Among them, the total weight of the PETG shrink film functional masterbatch slices, the PET slices for ordinary film, polyvinyl butyral and butylated hydroxytoluene is 100wt%, the added amount of the PETG shrink film functional masterbatch slices is 80wt%, the added amount of polyvinyl butyral is 7wt%, the added amount of butylated hydroxytoluene is 4wt%, and the rest are PET slices for ordinary film.

[0123] The maximum shrinkage temperature of the prepared PETG shrink film is 120°C, the lateral heat shrinkage rate in 2 to 3 seconds is 57%, the light transmittance is 92%, and the shrinkage force is 5.3N / m 2 .

[0124] Comparative Example 6

[0125] 120 parts by weight of terephthalic acid, 100 parts by weight of ethylene glycol, 50 parts by weight of 1,4-cyclohexanedimethanol, 0.2 parts by weight of triaryl phosphate, and 0.03 parts by weight of isocyanate were added into an esterification tank to carry out an esterification reaction.

[0126] The esterification product is transferred to a polycondensation tank, and 0.02 parts by weight of potassium tripolyphosphate, 0.4 parts by weight of disodium ethylenediaminetetraacetate, 0.3 parts by weight of nano titanium dioxide stabilizer, and 0.2 parts by weight of decabromodiphenyl ether flame retardant are added to the polycondensation tank to carry out a polycondensation reaction. Finally, the polymer melt is extruded, pelletized, and dried to obtain a PETG shrink film functional masterbatch.

[0127] In this comparative example, the maximum intrinsic viscosity of the polycondensation reaction product can reach 0.80 dl / g.

[0128] The prepared PETG shrink film functional masterbatch is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled, and slit to make a shrink film.

[0129] The maximum shrinkage temperature of the film is 109°C, the transverse heat shrinkage rate is 75% in 2 to 3 seconds, the light transmittance is 84%, and the shrinkage force is 7.9N / m 2 , thickness is 50μm.

[0130] The prepared PETG shrink film functional masterbatch is uniformly mixed with PET slices for ordinary films, polyvinyl butyral and butylated hydroxytoluene to form a mixture, and the mixture is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled, and slit to make the shrink film.

[0131] Among them, the total weight of the PETG shrink film functional masterbatch slices, the PET slices for ordinary film, polyvinyl butyral and butylated hydroxytoluene is 100wt%, the added amount of the PETG shrink film functional masterbatch slices is 85wt%, the added amount of polyvinyl butyral is 8wt%, the added amount of butylated hydroxytoluene is 5wt%, and the rest are PET slices for ordinary film.

[0132] The maximum shrinkage temperature of the shrink film is 118°C, the transverse heat shrinkage rate is 59% in 2 to 3 seconds, the light transmittance is 93%, and the shrinkage force is 5.6N / m 2 .

[0133] By comparing the above examples with the comparative examples, it can be seen that the single-layer shrinkage film prepared by the functional masterbatch obtained by the method of the present application has relatively excellent shrinkage performance, a low shrinkage temperature, and excellent transverse heat shrinkage rate. Based on the functional masterbatch of the present application, polyvinyl butyral and butylated hydroxytoluene are added to prepare a low-shrinkage shrinkage film, which is relatively simpler in process, more adaptable, and lower in cost.

[0134] Those skilled in the art should understand that although the present application is described in the form of multiple embodiments, not every embodiment contains only one independent technical solution. Such description in the specification is only for the sake of clarity, and those skilled in the art should understand the specification as a whole and regard the technical solutions involved in each embodiment as being able to be combined into different embodiments to understand the scope of protection of the present application.

[0135] The above description is only an illustrative embodiment of the present application and is not intended to limit the scope of the present application. Any equivalent changes, modifications and combinations made by any technician in the field without departing from the concept and principle of the present application shall fall within the scope of protection of the present application.

Claims

1. A system for preparing a polyester transparent low-shrinkage shrink film, characterized in that: The preparation system comprises a mixing bin, the inlet of which is respectively connected to a first preheating and drying device for PETG shrink film functional masterbatch, a second preheating and drying device for PET slices for ordinary film, a third preheating and drying device for polyvinyl butyral, and a fourth preheating and drying device for butylated hydroxytoluene; the outlet of the mixing bin is connected to the inlet of a twin-screw extruder, the outlet of the twin-screw extruder is connected to the inlet of a casting unit, the outlet of the casting unit is connected to the inlet of a stretching mechanism, the outlet of the stretching mechanism is connected to the inlet of a cooling mechanism, and the outlet of the cooling mechanism is connected to a receiving roller.

2. The preparation system according to claim 1, characterized in that: The receiving roller is further connected to a slitting mechanism.

3. The preparation system according to claim 1 or 2, characterized in that: The inlet of the first preheating and drying equipment is further connected to a functional masterbatch preparation device for preparing a functional masterbatch of a PETG shrink film; wherein the functional masterbatch preparation device comprises at least one esterification tank and a polycondensation tank, the esterification tank having a first inlet for terephthalic acid, a second inlet for ethylene glycol, and a third inlet for connecting the outlet of an esterification auxiliary material tank; the polycondensation tank having a fourth inlet for connecting the outlet of the esterification tank, a fifth inlet for connecting the outlet of a polycondensation auxiliary material tank, and a sixth inlet for potassium tripolyphosphate; the outlet of the polycondensation tank is connected to at least one extruder, the outlet of the extruder is connected to a pelletizer, and the outlet of the pelletizer is connected to a dryer.

4. The preparation system according to claim 3, characterized in that: The esterification auxiliary material tank is provided with three inlets for respectively inputting 1,4-cyclohexanedimethanol, triaryl phosphate and isocyanate.

5. The preparation system according to claim 3, characterized in that: The polycondensation auxiliary material tank is provided with three inlets corresponding to the input of magnesium aluminum silicate, disodium ethylenediaminetetraacetate and auxiliary agents respectively.

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