Low-temperature high-shrinkage PETG shrinkage film and preparation system thereof

Abstract

The utility model discloses a low-temperature high-shrinkage PETG shrink film, which is a shrink film with a three-layer co-extrusion structure and comprises an A PETG surface layer, a B functional master batch core layer and a C PETG bottom layer, the thicknesses of the A layer and the C layer are 1-5 microns, the thickness of the B layer is 38-50 microns, and the total thickness of the A layer and the C layer is 40-60 microns. The utility model further discloses a preparation system of the low-temperature high-shrinkage PETG shrinkage film. The preparation system disclosed by the utility model can clearly and simply obtain the low-temperature high-shrinkage PETG shrinkage film with a three-layer co-extrusion structure, the shrinkage film prepared by the preparation system is suitable for being used as a label of an outer package of a product, the parameter range of the product can be flexibly adjusted as required, and the application range of the film disclosed by the utility model can be widened.

Description

Technical Field

[0001] The utility model relates to a low-temperature high-shrinkage PETG shrink film and a preparation system thereof. Background Art

[0002] Heat shrinkable films are often used as outer labels on the outer packaging of food and beverages. Existing heat shrinkable films have problems such as too high shrinking temperature and too large shrinking force. They have poor shrinking performance for containers such as special-shaped bottles and PP bottles, and are easily damaged and deformed, affecting appearance and use.

[0003] CN 115491000 B discloses a low-temperature high-toughness polyester shrink film for heat shrink labels and its preparation method and application. The raw material composition for preparing the low-temperature high-toughness polyester shrink film includes a polyester composition and an additive. The polyester composition, calculated by mass percentage as 100%, includes 60% to 70% of diol-modified polyethylene terephthalate, 20% to 30% of thermoplastic polyester resin, and 5% to 10% of dibasic acid-modified polyethylene terephthalate; the thermoplastic polyester resin includes polybutylene terephthalate and / or TPEE polyester elastomer; the mass of the additive is 500ppm to 1500ppm of the total mass of the polyester composition. The melting temperature of the low-temperature high-toughness polyester shrink film of the prior art is 180 to 190°C, the glass transition temperature is 55 to 60°C, and the heat shrinkage temperature is 60 to 85°C.

[0004] The polyethylene terephthalate in the shrink film of the prior art contains 60% to 70% of a diol-modified raw material and 5% to 10% of a dibasic acid-modified raw material, and 20% to 30% of a thermoplastic polyester resin is added. As a result, the shrink film prepared by mixing these raw materials has mixed components and the content of polyethylene terephthalate is too low, which is not conducive to recycling the shrink film as a raw material mainly composed of polyethylene terephthalate.

[0005] For example, CN 117162618 A previously applied by the applicant discloses a recycled heat shrink film and a preparation method thereof, wherein the recycled heat shrink film is composed of an extruded A-layer surface layer, a B-layer core layer and a C-layer bottom layer, wherein the A-layer and the C-layer are respectively arranged on both sides of the B-layer and are both made of ordinary film polyester, and the B-layer is made of recycled materials having 5wt% to 95wt% of the total mass of the core layer and ordinary film polyester; the recycled materials are prepared by mixing 60 to 80wt% of polyester recycled particles with 20 to 40wt% of functional master batch, wherein the polyester recycled particles are prepared from recycled PET bottles or heat shrink film labels, and the functional master batch is composed of a polyester carrier and diethyl phenylphosphonate, sodium dodecylbenzene sulfonate, tridecyl alcohol stearate, and magnesium carbonate. This prior art directly prepares heat shrink films by adding a functional master batch to the polyester recycled particles for melt modification treatment, and the recycled materials obtained can be used to prepare heat shrink films. Among them, the ingredients of recycled PET bottles or heat shrink film labels must at least meet certain purity requirements. If they contain 20% to 30% thermoplastic polyester resin, plus a large amount of diols and dibasic acid modified ingredients, the content of polyethylene terephthalate in the polyester recycled particles will be too low, which will seriously affect the recycling of shrink labels.

[0006] In addition, CN 113696572 B discloses a composite PETG heat shrinkable film and a preparation system thereof, 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 the total mass of PETG functional material slices, wherein the PETG functional material slices 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 the total mass of PS functional material slices.

[0007] The PETG slices used in the PETG functional material of the prior art can be partially or entirely from purchased or pre-prepared raw materials. Of course, as mentioned above, they can also be from PETG label recycled materials, etc. The components of these PETG as 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. Generally speaking, PETG is generally considered to be a copolymer product obtained by replacing part of ethylene glycol with 1,4-cyclohexanedimethanol (CHDM) in the synthesis process of polyethylene terephthalate (PET), wherein the different addition amounts of CHDM determine the crystallinity of the prepared PETG. The crystallinity of PET is very high, and only after the CHDM modification, the crystallinity is reduced to obtain relatively good shrinkage performance. Therefore, in the case where the shrinkage of the shrink film is determined by the non-crystalline region of the material, the shrinkage of the PETG obtained by copolymerization of different raw materials is also very different. Therefore, the above-mentioned prior art uses PETG slices composed of specific raw materials, and the shrinkage performance of the functional material prepared therefrom is relatively difficult to be significantly adjusted by the subsequent addition of other material components.

[0008] For example, the prior art adds nano boron nitride, aluminate, polydimethylsiloxane and potassium chloride to PETG slices, and its main adjustment goal is to reduce the die temperature during co-extrusion, but the shrinkage rate is relatively reduced. Although the reduction is not large, it can still be seen that the adjustment range of the functional masterbatch on the shrinkage performance is limited to a certain extent.

[0009] In addition, the prior art also lacks a system for preparing corresponding shrink films. Summary of the invention

[0010] The technical problem to be solved by the utility model is to provide a low-temperature high-shrinkage PETG shrink film and a preparation system thereof, so as to reduce or avoid the above-mentioned problems.

[0011] In order to solve the above technical problems, the utility model proposes a low-temperature and high-shrinkage PETG shrink film, which is a shrink film with a three-layer co-extrusion structure, including a PETG surface layer A, a functional masterbatch core layer B and a PETG bottom layer C, characterized in that the thickness of the A layer and the C layer is 1-5μm, the thickness of the B layer is 38-50μm, and the total thickness is 40-60μm.

[0012] Preferably, the thicknesses of the A layer, the B layer and the C layer are 2-3 μm, 41-44 μm and 2-3 μm respectively, and the total thickness is 45-50 μm.

[0013] Preferably, the width of the low-temperature high-shrinkage PETG shrink film is 1000-8700 mm.

[0014] Preferably, the width of the low-temperature high-shrinkage PETG shrink film is 1500-5000 mm.

[0015] The utility model also proposes a preparation system of a low-temperature high-shrinkage PETG shrink film, which is used for preparing a low-temperature high-shrinkage PETG shrink film composed of an extruded A-layer PETG surface layer, a B-layer functional masterbatch core layer and a C-layer PETG bottom layer, wherein the preparation system comprises a PETG polyester slice input pipeline for ordinary film, a first mixing bin and a second mixing bin, the output end of the PETG polyester slice input pipeline for ordinary film is respectively connected to the first mixing bin and the second mixing bin, and the input end of the second mixing bin is further connected to a functional masterbatch preparation device; the output end of the first mixing bin is respectively connected to a first twin-screw extruder and a third twin-screw extruder; the output end of the second mixing bin is connected to a second single-screw extruder; the first twin-screw extruder and the third twin-screw extruder are connected to each other. The output end of the rod extruder inputs the prepared A layer thick slice and C layer thick slice as the surface layer and the bottom layer into the film drawing mechanism, and the output end of the second single-screw extruder inputs the prepared B layer thick slice as the core layer into the film drawing mechanism; wherein the functional masterbatch preparation device includes at least one esterification tank and a condensation tank, the esterification tank has a first inlet for terephthalic acid, a second inlet for ethylene glycol and a third inlet for connecting the outlet of the esterification auxiliary material tank; the condensation tank has a fourth inlet for connecting the outlet of the esterification tank, a fifth inlet for connecting the outlet of the condensation auxiliary material tank and a sixth inlet for potassium tripolyphosphate; the outlet of the condensation 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.

[0016] Preferably, the esterification auxiliary material tank is provided with three inlets corresponding to the input of 1,4-cyclohexanedimethanol, triaryl phosphate and isocyanate respectively.

[0017] 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.

[0018] The preparation system of the utility model can clearly and concisely obtain a low-temperature high-shrinkage PETG shrink film with a three-layer co-extruded structure. The shrink film prepared thereby is suitable for use as a label for product outer packaging. The parameter range of the product can be flexibly adjusted as needed, thereby improving the application range of the film of the utility model. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The following drawings are only intended to illustrate and explain the present application, and do not limit the scope of the present application.

[0020] Figure 1 Shown is a schematic diagram of the cross-sectional structure of a low-temperature high-shrinkage PETG shrink film according to a specific embodiment of the present application.

[0021] Figure 2 Shown is a schematic structural diagram of a system for preparing a low-temperature, high-shrinkage PETG shrink film according to a specific embodiment of the present application.

[0022] Figure 3 Shown is a schematic structural diagram of a device for preparing a PETG functional masterbatch for a PETG shrink film according to another specific embodiment of the present application. DETAILED DESCRIPTION

[0023] 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.

[0024] like Figure 1 , which shows a cross-sectional structural schematic diagram of a low-temperature high-shrinkage PETG shrink film according to a specific embodiment of the present application. Figure 1 The low-temperature and high-shrinkage PETG shrink film of the present application is a shrink film with a three-layer co-extruded structure, including a PETG surface layer A, a functional masterbatch core layer B and a PETG bottom layer C. The A layer and the C layer are respectively arranged on both sides of the B layer and are both made of PETG for ordinary film. The B layer is made of 90wt% to 95wt% of the total mass of the core layer of PETG shrink film functional masterbatch and PETG for ordinary film.

[0025] Among them, the thickness of layer A and layer C is 1-5 μm, the thickness of layer B is 38-50 μm, and the total thickness of the low-temperature high-shrinkage PETG shrink film of the three-layer co-extruded structure is 40-60 μm. More preferably, the thickness of layer A, layer B, and layer C are 2-3 μm, 41-44 μm, and 2-3 μm, respectively, and the total thickness of the low-temperature high-shrinkage PETG shrink film is 45-50 μm. The width of the low-temperature high-shrinkage PETG shrink film is 1000-8700 mm, preferably 1500-5000 mm.

[0026] The PETG shrink film functional masterbatch in layer B 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] The low temperature high shrinkage PETG shrink film of the present application can be Figure 2 The preparation system shown is prepared.

[0029] like Figure 2 As shown, the preparation system of the low-temperature high-shrinkage PETG shrink film of the present application includes a PETG slice input pipeline 500 for ordinary film, a first mixing bin 501 and a second mixing bin 502, the output end of the PETG slice input pipeline 500 for ordinary film is respectively connected to the first mixing bin 501 and the second mixing bin 502, and the input end of the second mixing bin 502 is further connected to the PETG functional masterbatch preparation device 1000; the output end of the first mixing bin 501 is respectively connected to the first twin-screw extruder 503 and the third twin-screw extruder 504; the output end of the second mixing bin 502 is connected to the second single-screw extruder 505; the output ends of the first twin-screw extruder 503 and the third twin-screw extruder 504 input the prepared A layer thick slice and C layer thick slice as the surface layer and the bottom layer into the film drawing mechanism 400, and the output end of the second single-screw extruder 505 inputs the prepared B layer thick slice as the core layer into the film drawing mechanism 400.

[0030] When the preparation system of the present application is working, the PETG slices for ordinary film are respectively input into the first mixing bin 501 and the second mixing bin 502 through the PETG slice input pipeline 500 for ordinary film, and the prepared functional masterbatch slices are simultaneously input into the second mixing bin 502 through the PETG functional masterbatch preparation device 1000 according to the addition amount of 90wt% to 95wt% of the total mass of the core layer, the PETG slices for ordinary film in the first mixing bin 501 are respectively prepared into A layer thick slice and C layer thick slice through the first twin-screw extruder 503 and the third twin-screw extruder 504, and the second mixing bin 502 is prepared into B layer thick slice through the second single-screw extruder 505, and the A layer thick slice, the B layer thick slice and the C layer thick slice are respectively input into the film drawing mechanism 400, and the film drawing mechanism 400 can prepare the film by melt co-extrusion, die casting, transverse far-infrared stretching, cooling and shaping, winding, slitting and the like. Figure 1 The three-layer structure of PETG shrink film is shown.

[0031] Furthermore, the preparation system of the present application may also include: Figure 3 The PETG functional masterbatch preparation device 1000 shown in FIG. Figure 3As shown, the PETG functional masterbatch preparation device 1000 of the present application includes at least one esterification tank 100 and a polycondensation tank 200. Those skilled in the art should understand that the PETG functional masterbatch preparation device 1000 of the present application is not limited to 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 can 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.

[0032] 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 .

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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 .

[0037] Refer to the following Figure 3 The method for preparing the functional masterbatch of the present application is described in detail.

[0038] For example, 100-120 parts by weight of terephthalic acid and 80-100 parts by weight of ethylene glycol may be added into the esterification tank 100 through the first inlet 101 and the second inlet 102, respectively, and mixed uniformly at room temperature to perform a pre-reaction for 30-60 minutes.

[0039] 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 are added to the esterification auxiliary material tank 300 and mixed evenly, and then the three mixed esterification auxiliary materials are added to the esterification tank 100 through the third inlet 103. The reaction conditions of the esterification tank 100 are set to 230-250° C. and 0.2-0.3 MPa, and the esterification reaction is carried out. After the water output reaches the theoretical value, the system pressure is released to normal pressure.

[0040] Then, the esterification product is filtered through the outlet of the esterification tank 100 and transferred to the polycondensation tank 200 through the fourth inlet 204. At the same time, 0.01-0.02 parts by weight of potassium tripolyphosphate is added to the polycondensation tank 200 through the sixth inlet 206. The temperature is maintained at 230-250° C. and stirred at normal pressure for 10 minutes. Then, vacuum is drawn, the temperature in the polycondensation tank 200 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 pressure is restored to normal pressure.

[0041] 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 are added to the polycondensation auxiliary material tank 301 and mixed evenly, and then the mixed three polycondensation auxiliary materials are added to the polycondensation tank 200 through the fifth inlet 205.

[0042] The temperature in the polycondensation tank 200 is maintained at 230° C. and stirred for 30 minutes. Finally, the polymer melt is filtered and transported from the outlet of the polycondensation tank 200 to the extruder 600 for extrusion, and then pelletized by a pelletizer 700, and finally dried by a dryer 800 to obtain a PETG shrink film functional masterbatch.

[0043] The low-temperature high-shrinkage PETG shrink film of the present application can be prepared by the following steps.

[0044] For example, the prepared PETG shrink film functional masterbatch slices are added in an amount of 90wt% to 95wt% of the total mass of the core layer, and are uniformly mixed with PETG polyester slices for ordinary films to be used as the core layer raw materials; the PETG slices for ordinary films are used as the surface layer and bottom layer raw materials respectively, and a PETG shrink film with an ABC three-layer structure is made through melt co-extrusion, die casting, lateral far-infrared stretching, cooling and shaping, winding, and slitting.

[0045] The preparation system of the present application can clearly and concisely obtain a low-temperature, high-shrinkage PETG shrink film with a three-layer co-extruded structure. The shrink film prepared thereby is suitable for use as a label for product outer packaging. The parameter range of the product can be flexibly adjusted as needed, thereby increasing the application range of the film of the present application.

[0046] Example 1

[0047] 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.

[0048] 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.

[0049] In this embodiment, the intrinsic viscosity of the polycondensation reaction product can reach a maximum of 0.80 dl / g.

[0050] Finally, the polymer melt is extruded, pelletized and dried to obtain a PETG shrink film functional masterbatch.

[0051] The prepared PETG shrink film functional masterbatch is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled up, and slit to form a single-layer shrink film; 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 slices prepared in Example 1 were evenly mixed with the PETG polyester slices for ordinary film in an amount of 90wt% of the total mass of the core layer, and used as the core layer raw material; the PETG slices for ordinary film were used as the surface layer and bottom layer raw materials, respectively, and a PETG shrink film with an ABC three-layer structure was prepared by melt coextrusion, die casting, transverse far-infrared stretching, cooling and shaping, winding, and slitting.

[0054] The thickness of the A layer of the prepared PETG shrink film is 2 μm, the thickness of the B layer is 41 μm, the thickness of the C layer is 2 μm, the total thickness is 45 μm, and the width is 3000 mm.

[0055] The maximum shrinkage temperature of the prepared PETG shrink film is 83°C, the lateral heat shrinkage rate is 70% in 2 to 3 seconds, the light transmittance is 96%, and the shrinkage force is 6.0N / 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 up, and slit to form a single-layer shrink film; the maximum shrinkage temperature of the film is 80°C, the transverse heat shrinkage rate is 73% in 2 to 3 seconds, the light transmittance is 94%, and the shrinkage force is 5.8N / m 2 , thickness is 50μm.

[0062] Example 4

[0063] The PETG shrink film functional masterbatch slices prepared in Example 3 were evenly mixed with the PETG polyester slices for ordinary film in an addition amount of 93wt% of the total mass of the core layer, and used as the core layer raw material; the PETG slices for ordinary film were used as the surface layer and bottom layer raw materials, respectively, and a PETG shrink film with an ABC three-layer structure was made through melt coextrusion, die casting, lateral far-infrared stretching, cooling and shaping, winding, and slitting.

[0064] The thickness of the A layer of the prepared PETG shrink film is 3 μm, the thickness of the B layer is 44 μm, the thickness of the C layer is 3 μm, the total thickness is 50 μm, and the width is 5000 mm.

[0065] The maximum shrinkage temperature of the prepared PETG shrink film is 82°C, the lateral heat shrinkage rate in 2 to 3 seconds is 72%, the light transmittance is 95%, and the shrinkage force is 5.9N / m 2 .

[0066] Example 5

[0067] 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.

[0068] 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.

[0069] In this embodiment, the intrinsic viscosity of the polycondensation reaction product can reach a maximum of 0.82 dl / g.

[0070] Finally, the polymer melt is extruded, pelletized and dried to obtain a PETG shrink film functional masterbatch.

[0071] The prepared PETG shrink film functional masterbatch is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled up, and slit to form a single-layer shrink film; the maximum shrinkage temperature of the film is 80°C, the transverse heat shrinkage rate is 72% in 2 to 3 seconds, the light transmittance is 93%, and the shrinkage force is 6.2N / m 2 , thickness is 50μm.

[0072] Example 6

[0073] The PETG shrink film functional masterbatch slices prepared in Example 5 were evenly mixed with the PETG polyester slices for ordinary film in an addition amount of 95wt% of the total mass of the core layer, and used as the core layer raw material; the PETG slices for ordinary film were used as the surface layer and bottom layer raw materials, respectively, and a PETG shrink film with an ABC three-layer structure was made through melt coextrusion, die casting, transverse far-infrared stretching, cooling and shaping, winding, and slitting.

[0074] The thickness of the A layer of the prepared PETG shrink film is 5 μm, the thickness of the B layer is 50 μm, the thickness of the C layer is 5 μm, the total thickness is 60 μm, and the width is 3000 mm.

[0075] The maximum shrinkage temperature of the prepared PETG shrink film is 80°C, the lateral heat shrinkage rate in 2 to 3 seconds is 71%, the light transmittance is 94%, and the shrinkage force is 6.1N / m 2 .

[0076] Based on the limitation of the existing PETG shrink film being the PETG slices with fixed raw materials, this 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 PETG can be improved. The following is a comparison of the performance of the prepared shrink film using different preparation processes and raw material ratios.

[0077] Comparative Example 1

[0078] 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.

[0079] 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.

[0080] In this comparative example, the maximum intrinsic viscosity of the polycondensation reaction product can reach 0.69 dl / g.

[0081] The prepared PETG shrink film functional masterbatch is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled up, and slit to form a single-layer shrink film; the maximum shrinkage temperature of the film is 120°C, the transverse heat shrinkage rate is 67% in 2 to 3 seconds, the light transmittance is 85%, and the shrinkage force is 6.9N / m 2 , thickness is 50μm.

[0082] The prepared PETG shrink film functional masterbatch slices are added in an amount of 90wt% of the total mass of the core layer, uniformly mixed with PETG polyester slices for ordinary film, and used as the core layer raw materials; the PETG slices for ordinary film are used as the surface layer and bottom layer raw materials respectively, and the PETG shrink film with an ABC three-layer structure is made through melt co-extrusion, die casting, transverse far-infrared stretching, cooling and shaping, winding, and slitting.

[0083] The thickness of the A layer of the prepared PETG shrink film is 2 μm, the thickness of the B layer is 41 μm, the thickness of the C layer is 2 μm, the total thickness is 45 μm, and the width is 3000 mm.

[0084] The maximum shrinkage temperature of the prepared PETG shrink film is 125℃, the transverse heat shrinkage rate is 65% in 2-3 seconds, the light transmittance is 86%, and the shrinkage force is 7.1N / m 2 .

[0085] Comparative Example 2

[0086] 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.

[0087] 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.

[0088] In this comparative example, the maximum intrinsic viscosity of the polycondensation reaction product can reach 0.71 dl / g.

[0089] The prepared PETG shrink film functional masterbatch is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled up, and slit to form a single-layer shrink film; 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.

[0090] The prepared PETG shrink film functional masterbatch slices are added in an amount of 93wt% of the total mass of the core layer, uniformly mixed with PETG polyester slices for ordinary film, and used as the core layer raw materials; the PETG slices for ordinary film are used as the surface layer and bottom layer raw materials respectively, and the PETG shrink film with an ABC three-layer structure is prepared through melt co-extrusion, die casting, transverse far-infrared stretching, cooling and shaping, winding, and slitting.

[0091] The thickness of the A layer of the prepared PETG shrink film is 3 μm, the thickness of the B layer is 44 μm, the thickness of the C layer is 3 μm, the total thickness is 50 μm, and the width is 5000 mm.

[0092] The maximum shrinkage temperature of the prepared PETG shrink film is 117°C, the transverse heat shrinkage rate is 70% in 2 to 3 seconds, the light transmittance is 86%, and the shrinkage force is 6.5N / m 2 .

[0093] Comparative Example 3

[0094] 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.

[0095] 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.

[0096] In this comparative example, the maximum intrinsic viscosity of the polycondensation reaction product can reach 0.80 dl / g.

[0097] The prepared PETG shrink film functional masterbatch is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled up, and slit to form a single-layer shrink film; the maximum shrinkage temperature of the film is 120°C, the transverse heat shrinkage rate is 68% in 2 to 3 seconds, the light transmittance is 89%, and the shrinkage force is 6.8N / m 2 , thickness is 50μm.

[0098] The prepared PETG shrink film functional masterbatch slices are added in an amount of 95wt% of the total mass of the core layer, uniformly mixed with PETG polyester slices for ordinary film, and used as the core layer raw materials; the PETG slices for ordinary film are used as the surface layer and bottom layer raw materials respectively, and the PETG shrink film with an ABC three-layer structure is made through melt co-extrusion, die casting, transverse far-infrared stretching, cooling and shaping, winding, and slitting.

[0099] The thickness of the A layer of the prepared PETG shrink film is 5 μm, the thickness of the B layer is 50 μm, the thickness of the C layer is 5 μm, the total thickness is 60 μm, and the width is 3000 mm.

[0100] The maximum shrinkage temperature of the prepared PETG shrink film is 124°C, the lateral heat shrinkage rate is 66% in 2 to 3 seconds, the light transmittance is 88%, and the shrinkage force is 6.6N / m 2 .

[0101] Comparative Example 4

[0102] 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.

[0103] 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.

[0104] In this comparative example, the intrinsic viscosity of the polycondensation reaction product can reach a maximum of 0.75 dl / g.

[0105] The prepared PETG shrink film functional masterbatch is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled up, and slit to form a single-layer shrink film; the maximum shrinkage temperature of the film is 120°C, the transverse heat shrinkage rate is 75% in 2 to 3 seconds, the light transmittance is 92%, and the shrinkage force is 6.5N / m 2 , thickness is 50μm.

[0106] The prepared PETG shrink film functional masterbatch slices are added in an amount of 90wt% of the total mass of the core layer, uniformly mixed with PETG polyester slices for ordinary film, and used as the core layer raw materials; the PETG slices for ordinary film are used as the surface layer and bottom layer raw materials respectively, and the PETG shrink film with an ABC three-layer structure is made through melt co-extrusion, die casting, transverse far-infrared stretching, cooling and shaping, winding, and slitting.

[0107] The thickness of the A layer of the prepared PETG shrink film is 2 μm, the thickness of the B layer is 41 μm, the thickness of the C layer is 2 μm, the total thickness is 45 μm, and the width is 3000 mm.

[0108] The maximum shrinkage temperature of the PETG shrink film is 123℃, the transverse heat shrinkage rate is 73% in 2-3 seconds, the light transmittance is 93%, and the shrinkage force is 6.7N / m 2 .

[0109] Comparative Example 5

[0110] 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.

[0111] 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.

[0112] In this comparative example, the maximum intrinsic viscosity of the polycondensation reaction product can reach 0.73 dl / g.

[0113] The prepared PETG shrink film functional masterbatch is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled up, and slit to form a single-layer shrink film; the maximum shrinkage temperature of the film is 108°C, the transverse heat shrinkage rate is 76% in 2 to 3 seconds, the light transmittance is 90%, and the shrinkage force is 6.5N / m 2 , thickness is 50μm.

[0114] The prepared PETG shrink film functional masterbatch slices are added in an amount of 93wt% of the total mass of the core layer, uniformly mixed with PETG polyester slices for ordinary film, and used as the core layer raw materials; the PETG slices for ordinary film are used as the surface layer and bottom layer raw materials respectively, and the PETG shrink film with an ABC three-layer structure is prepared through melt co-extrusion, die casting, transverse far-infrared stretching, cooling and shaping, winding, and slitting.

[0115] The thickness of the A layer of the prepared PETG shrink film is 3 μm, the thickness of the B layer is 44 μm, the thickness of the C layer is 3 μm, the total thickness is 50 μm, and the width is 5000 mm.

[0116] The maximum shrinkage temperature of the prepared PETG shrink film is 110°C, the lateral heat shrinkage rate is 77% in 2 to 3 seconds, the light transmittance is 91%, and the shrinkage force is 6.6N / m 2 .

[0117] Comparative Example 6

[0118] 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.

[0119] 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.

[0120] In this comparative example, the maximum intrinsic viscosity of the polycondensation reaction product can reach 0.80 dl / g.

[0121] The prepared PETG shrink film functional masterbatch is melt-extruded, die-cast, transversely far-infrared stretched, cooled and shaped, rolled up, and slit to form a single-layer shrink film; 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.

[0122] The prepared PETG shrink film functional masterbatch slices are added in an amount of 95wt% of the total mass of the core layer, uniformly mixed with PETG polyester slices for ordinary film, and used as the core layer raw materials; the PETG slices for ordinary film are used as the surface layer and bottom layer raw materials respectively, and the PETG shrink film with an ABC three-layer structure is made through melt co-extrusion, die casting, transverse far-infrared stretching, cooling and shaping, winding, and slitting.

[0123] The thickness of the A layer of the prepared PETG shrink film is 5 μm, the thickness of the B layer is 50 μm, the thickness of the C layer is 5 μm, the total thickness is 60 μm, and the width is 3000 mm.

[0124] The maximum shrinkage temperature of the prepared PETG shrink film is 108°C, the lateral heat shrinkage rate in 2 to 3 seconds is 77%, the light transmittance is 86%, and the shrinkage force is 7.6N / m 2 .

[0125] By comparing the above embodiments and comparative examples, it can be seen that the single-layer shrinkage film prepared with 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. The three-layer PETG shrinkage film prepared with the functional masterbatch of the present application as the core layer has a transverse heat shrinkage rate of more than 70% at 80°C, and has a high shrinkage force. When used as a label for the outer packaging of the product, it has good shrinkage packaging performance for special-shaped bottles, ordinary PP bottles, etc., and is not easy to cause the packaging bottles to be damaged or deformed. Moreover, since the surface layer and the bottom layer of the film are both ordinary PETG, the component content is high, which is conducive to recycling. Ordinary PETG can also be used to neutralize the masterbatch cost and adjust the parameter range of the product, so as to increase the application range of the film of the present application.

[0126] 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.

[0127] 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 low-temperature high-shrinkage PETG shrink film, which is used to prepare a low-temperature high-shrinkage PETG shrink film consisting of an extruded A-layer PETG surface layer, a B-layer functional masterbatch core layer and a C-layer PETG bottom layer, characterized in that: The preparation system comprises a PETG polyester slice input pipeline for common film, a first mixing bin and a second mixing bin, the output end of the PETG polyester slice input pipeline for common film is respectively connected to the first mixing bin and the second mixing bin, and the input end of the second mixing bin is further connected to a functional masterbatch preparation device; the output end of the first mixing bin is respectively connected to a first twin-screw extruder and a third twin-screw extruder; the output end of the second mixing bin is connected to a second single-screw extruder; the output ends of the first twin-screw extruder and the third twin-screw extruder input the prepared A layer thick slice and C layer thick slice as the surface layer and the bottom layer into the film drawing mechanism, and the second single-screw extruder is connected to the second single-screw extruder. The output end of the machine inputs the prepared B layer thick sheet as the core layer into the film drawing mechanism; wherein the functional masterbatch preparation device includes at least one esterification tank and a condensation tank, the esterification tank has a first inlet for terephthalic acid, a second inlet for ethylene glycol and a third inlet for connecting the outlet of the esterification auxiliary material tank; the condensation tank has a fourth inlet for connecting the outlet of the esterification tank, a fifth inlet for connecting the outlet of the condensation auxiliary material tank and a sixth inlet for potassium tripolyphosphate; the outlet of the condensation 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.

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

3. The preparation system according to claim 1, characterized in that: 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.

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