High-speed printing tto biaxially stretched polyester-based film and preparation method thereof

Abstract

The application discloses a high-speed printing TTO bidirectional stretching polyester-based film which is composed of an upper surface layer, a core layer and a lower surface layer; the upper surface layer and the lower surface layer comprise the following raw materials in percentage by mass: 70-90 wt% of blended modified chips and 10-30 wt% of polyester chips; the core layer comprises the following raw materials in percentage by mass: 30-50 wt% of blended modified chips and 50-70 wt% of polyester chips; wherein the blended modified chips are prepared by mixing polyisocyanate, a dispersing agent, SiO2 aerogel and polyester chips and then performing melt extrusion; and the application further discloses a preparation method of the polyester-based film. The application can realize the mechanical properties of high breaking strength of the film and the consistency of the microstructure of the film surface, the film surface has high roughness, the surface performance is excellent, and the application can meet the demand of high-speed printing.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of polyester films, in particular to a high-speed printing TTO biaxially stretched polyester base film and a preparation method thereof. BACKGROUND

[0002] The thermal transfer ribbon is a product with very wide application and very large consumption. With the online packaging identification demand of soft packaging products in China, people have more and more demand for online printing with high speed and high quality, and the traditional printing method in the market is difficult to meet the all-round demand of users in terms of printing quality and printing speed.

[0003] The TTO ribbon is a consumable used by a TTO coding machine, and is very popular in the food industry in European and American countries. The TTO wins the favor of customers due to its unique advantages, has the characteristics of flexibility, clear printing quality and low consumable cost, and has been widely applied to printing text, patterns, production dates, batch numbers, bar codes and randomly changed information (such as variable bar codes and anti-fake traceability information) on film or flat carton automatic packaging production lines.

[0004] With the further pursuit of printing speed in the market, high requirements are put forward for the TTO biaxially stretched polyester base film. However, the surface performance of the ordinary biaxially stretched polyester base film is poor, the ink adhesion and transfer performance cannot meet the requirement of printing clarity, and the mechanical property of the film is not high, so the film cannot adapt to high-speed operation. SUMMARY

[0005] Based on the technical problems existing in the background art, the application provides a high-speed printing TTO biaxially stretched polyester base film and a preparation method thereof.

[0006] The high-speed printing TTO biaxially stretched polyester base film provided by the application is composed of an upper surface layer, a core layer and a lower surface layer. The upper surface layer and the lower surface layer comprise the following raw materials in percentage by mass: 70-90 wt% of blended modified chips and 10-30 wt% of polyester chips. The core layer comprises the following raw materials in percentage by mass: 30-50 wt% of blended modified chips and 50-70 wt% of polyester chips.

[0007] The blended modified chips are prepared by mixing polyisocyanate, dispersant and SiO2 aerogel with polyester chips and then melt-extruding, wherein the mass ratio of polyisocyanate, dispersant and SiO2 aerogel is (0.01-0.03):(0.01-0.03):5.

[0008] Preferably, the viscosity of the blended modified chips is 0.65-0.70 dI / g.

[0009] Preferably, the preparation method of the blended modified chips is as follows:

[0010] (1) mixing polyisocyanate, dispersant and SiO2 aerogel, stirring at 130-140℃ for 0.5-2h, and then standing for 20-40min to obtain a mixture;

[0011] (2) mixing the mixture with conventional bright PET chips at a mass ratio of (4.95-5.05):1000, drying, and then adding into a twin-screw extruder to obtain a blended modified chip through melt extrusion.

[0012] Preferably, the particle size of the SiO2 aerogel is 500-1500nm.

[0013] Preferably, the polyisocyanate is hexamethylene diisocyanate, triphenylmethane triisocyanate or a combination thereof; preferably, the polyisocyanate consists of hexamethylene diisocyanate, triphenylmethane triisocyanate at a mass ratio of 1:(0.5-2).

[0014] Preferably, the dispersant is polyvinylpyrrolidone, polydimethylsilicone oil or a combination thereof; preferably, the dispersant consists of polyvinylpyrrolidone, polydimethylsilicone oil at a mass ratio of 1:(4-6).

[0015] Preferably, the thickness of the polyester-based film is 3.95-4.05μm, the thickness of the upper surface layer is 0.5-0.6μm, and the thickness of the lower surface layer is 0.5-0.6μm.

[0016] A preparation method of the high-speed printing TTO biaxially stretched polyester-based film, comprising the following steps:

[0017] The raw material of the upper surface layer and the raw material of the lower surface layer are respectively added into two auxiliary extruders; the raw material of the core layer is mixed, pre-crystallized, dried and added into a main extruder; after melt extrusion, the obtained cast sheet is subjected to biaxial stretching, heat setting, relaxation, cooling, traction and winding to obtain the product.

[0018] Preferably, the temperature of the melt extrusion is 275-280℃; the biaxial stretching comprises longitudinal stretching and transverse stretching in sequence, wherein the temperature of the longitudinal stretching is 98-105℃, the stretching ratio is 3.9-4.3, the temperature of the transverse stretching is 101-107℃, and the stretching ratio is 3.9-4.1.

[0019] The beneficial effects of the present application are as follows:

[0020] The polyisocyanate, dispersant, SiO2 aerogel and polyester chip are mixed, and then the blended modified chip is prepared through melt extrusion. The SiO2 aerogel is dispersed in the polyester chip through the combined action of the polyisocyanate and the dispersant, and the dispersion effect is good, the dispersion is more uniform, and the compatibility with the resin is high, so that the SiO2 aerogel can play a better role. The mechanical properties of the film are improved by adding 30-50wt% of the blended modified chip to the core layer of the film, and the nanoscale SiO2 particles in the PET chip play a role of nucleating agent in the biaxial stretching process, promoting the crystallization of PET. The surface properties of the film are improved by adding 70-90wt% of the blended modified chip to the upper and lower surface layers, so that the upper and lower surfaces of the film are uniformly covered with a layer of anti-adhesion SiO2 particles. The polyester film prepared by the application has the advantages of excellent surface roughness, ink adhesion and transfer performance, and has high mechanical properties. The TTO color bar prepared by the application has high printing clarity and high printing speed, which can meet the demand of high-speed and high-efficiency printing. DETAILED DESCRIPTION

[0021] The technical solutions of the application will be described in detail below through specific examples.

[0022] In the following examples and comparative examples, the production factory of the conventional bright PET chip is Yizheng Chemical Fibre, and the model is FG620; the production factory of the PET anti-adhesion masterbatch is Yizheng Chemical Fibre, and the model is FG610.

[0023] Example 1

[0024] Preparation of the blended modified chip:

[0025] (1) A mixture of hexamethylene diisocyanate and triphenylmethane triisocyanate, a mixture of polyvinylpyrrolidone and polydimethylsilicone oil, and SiO2 aerogel with a particle size of 500-1500nm were added to a sealed container in a mass ratio of 0.01:0.01:5, and stirred and reacted at 135℃ for 1h, and then stood for 30min to obtain a mixture; wherein the mass ratio of hexamethylene diisocyanate and triphenylmethane triisocyanate is 1:1, and the mass ratio of polyvinylpyrrolidone and polydimethylsilicone oil is 1:5;

[0026] (2) The mixture and the conventional bright PET chip were mixed in a mass ratio of 1:1000, dried at 150℃ for 3h, and then added to a twin-screw extruder, and melt extruded at 285℃ to obtain a blended modified chip with a specific viscosity of 0.682dL / g.

[0027] A high-speed printing TTO biaxial stretching polyester base film is composed of an upper surface layer, a core layer and a lower surface layer; the upper surface layer and the lower surface layer comprise the following raw materials in percentage by mass: 70wt% of blended modified chips and 30wt% of conventional bright PET chips; the core layer comprises the following raw materials in percentage by mass: 30wt% of blended modified chips and 70wt% of conventional bright PET chips; wherein the thickness of the polyester base film is 4μm, the thickness of the upper surface layer is 0.5μm, and the thickness of the lower surface layer is 0.5μm.

[0028] The preparation method of the above high-speed printing TTO biaxial stretching polyester base film is as follows:

[0029] The raw materials of the upper surface layer and the raw materials of the lower surface layer are respectively added into two auxiliary extruders; the raw materials of the core layer are mixed, pre-crystallized, dried and then added into a main extruder; after melt extrusion, the obtained cast sheet is subjected to biaxial stretching, heat setting, relaxation, cooling, traction and winding, and then the high-speed printing TTO biaxial stretching polyester base film is obtained; wherein the temperature of melt extrusion is 275-280℃; the biaxial stretching comprises longitudinal stretching and transverse stretching in sequence, wherein the temperature of longitudinal stretching is 98-105℃, the stretching ratio is 3.9-4.3, the temperature of transverse stretching is 101-107℃, and the stretching ratio is 3.9-4.1.

[0030] Example 2

[0031] A high-speed printing TTO biaxial stretching polyester base film is composed of an upper surface layer, a core layer and a lower surface layer; the upper surface layer and the lower surface layer comprise the following raw materials in percentage by mass: 80wt% of blended modified chips and 20wt% of conventional bright PET chips; the core layer comprises the following raw materials in percentage by mass: 40wt% of blended modified chips and 60wt% of conventional bright PET chips; wherein the thickness of the polyester base film is 4μm, the thickness of the upper surface layer is 0.5μm, and the thickness of the lower surface layer is 0.5μm.

[0032] The preparation method of the above high-speed printing TTO biaxial stretching polyester base film is as follows:

[0033] The preparation method of the above high-speed printing TTO biaxial stretching polyester base film is as follows:

[0034] Example 3

[0035] A high-speed printing TTO biaxial stretching polyester base film is composed of an upper surface layer, a core layer and a lower surface layer; the upper surface layer and the lower surface layer comprise the following raw materials in percentage by mass: 90wt% of blended modified chips and 10wt% of conventional bright PET chips; the core layer comprises the following raw materials in percentage by mass: 50wt% of blended modified chips and 50wt% of conventional bright PET chips; wherein the thickness of the polyester base film is 4μm, the thickness of the upper surface layer is 0.5μm, and the thickness of the lower surface layer is 0.5μm.

[0036] The preparation method of the blended modified chip is the same as that in Example 1.

[0037] The preparation method of the high-speed printing TTO biaxially stretched polyester base film is the same as that in Example 1.

[0038] Comparative Example 1

[0039] Comparative Example 1 differs from Example 1 only in that a conventional anti-adhesion PET chip is used instead of the blended modified chip, wherein the anti-adhesion PET chip comprises the following raw materials in mass percentage: 20wt% of conventional bright PET chip, and 80wt% of PET anti-adhesion masterbatch. The anti-adhesion PET chip is prepared by a conventional esterification polymerization method using terephthalic acid (PTA), ethylene glycol and micron-sized SiO2 as raw materials.

[0040] The preparation method of the polyester base film in Comparative Example 1 is the same as that in Example 1.

[0041] Comparative Example 2

[0042] Comparative Example 2 differs from Example 1 only in that the blended modified chip is different.

[0043] The preparation method of the blended modified chip in Comparative Example 2 is as follows:

[0044] (1) A mixture of polyvinylpyrrolidone and polydimethylsiloxane, and SiO2 aerogel with a particle size of 500-1500 nm are added to a sealed container in a mass ratio of 0.02:5, stirred and reacted at 135°C for 1h, and then left to stand for 30 min to obtain a mixture; wherein the mass ratio of polyvinylpyrrolidone and polydimethylsiloxane is 1:5;

[0045] (2) The mixture is mixed with conventional bright PET chip in a mass ratio of 1:1000, dried at 150°C for 3h, and then added to a twin-screw extruder for melt extrusion at 285°C to obtain a blended modified chip with a specific viscosity of 0.682dL / g.

[0046] Comparative Example 3

[0047] Comparative Example 3 differs from Example 1 only in that the blended modified chip is different.

[0048] The preparation method of the blended modified chip in Comparative Example 3 is as follows:

[0049] (1) A mixture of hexamethylene diisocyanate and triphenylmethane triisocyanate, and SiO2 aerogel with a particle size of 500-1500 nm are added to a sealed container in a mass ratio of 0.02:5, stirred and reacted at 135°C for 1h, and then left to stand for 30 min to obtain a mixture; wherein the mass ratio of hexamethylene diisocyanate and triphenylmethane triisocyanate is 1:1;

[0050] (2) The mixture is mixed with conventional bright PET chips at a mass ratio of 1:1000, dried at 150°C for 3h, and then fed into a twin-screw extruder, melted and extruded at 285°C to obtain blended modified chips with an intrinsic viscosity of 0.682dL / g.

[0051] Test Examples

[0052] The films prepared in the above Examples 1-3 and Comparative Examples 1-3 are respectively tested for anti-longitudinal breaking strength and surface roughness, and are made into ribbons for verifying the printing use effect. The anti-breaking strength is tested according to GB / T1040.3-2006, the surface roughness is tested according to GB / T13542.2-2009, and the ribbon use effect is verified according to the number of broken ribbons per 500m / min and the clarity of printed patterns. The specific results are shown in Table 1.

[0053] Table 1: Film performance test results

[0054]

[0055]

[0056] As shown in Table 1, the mechanical properties, surface properties and ribbon use effect of the films of Examples 1-3 of the present application are obviously superior to those of Comparative Examples 1-3, and can meet the requirements of customers with higher requirements. It is verified that the printing speed is obviously improved after 1 hour, the ribbon is not torn and broken at a printing speed of 500m / min, the printed pattern is clear, and the high-efficiency printing requirement can be met.

[0057] The above description is only the preferred specific implementation of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can make equivalent replacement or change according to the technical solution and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A high-speed printing method for TTO biaxially oriented polyester film, characterized in that, It consists of an upper surface layer, a core layer, and a lower surface layer; the upper and lower surface layers comprise the following raw materials by weight percentage: 70-90 wt% blended modified chips and 10-30 wt% polyester chips; the core layer comprises the following raw materials by weight percentage: 30-50 wt% blended modified chips and 50-70 wt% polyester chips. The blended modified chips are prepared by melt extrusion of polyisocyanate, dispersant, SiO2 aerogel and polyester chips. The mass ratio of polyisocyanate, dispersant and SiO2 aerogel is (0.01-0.03):(0.01-0.03):5; the mass ratio of the sum of the mass of polyisocyanate, dispersant and SiO2 aerogel to the mass of polyester chips is (4.95-5.05):1000. The method for preparing the blended modified slices is as follows: (1) After mixing polyisocyanate, dispersant and SiO2 aerogel, stir at 130-140℃ for 0.5-2h, and then let stand for 20-40min to obtain the mixture; (2) The mixture is mixed with conventional glossy PET chips at a mass ratio of (4.95-5.05):1000, dried, and then added to a twin-screw extruder. After melt extrusion, the blended modified chips are obtained.

2. The high-speed printed TTO biaxially oriented polyester film according to claim 1, characterized in that, The viscosity of the blended modified chips is 0.65-0.70 dI / g.

3. The high-speed printed TTO biaxially oriented polyester film according to claim 1, characterized in that, The particle size of the SiO2 aerogel is 500-1500 nm.

4. The high-speed printed TTO biaxially oriented polyester film according to claim 1, characterized in that, The polyisocyanate is hexamethylene diisocyanate, triphenylmethane triisocyanate, or a combination thereof.

5. The high-speed printed TTO biaxially oriented polyester film according to claim 1, characterized in that, The polyisocyanate is composed of hexamethylene diisocyanate and triphenylmethane triisocyanate in a mass ratio of 1:(0.5-2).

6. The high-speed printed TTO biaxially oriented polyester film according to claim 1, characterized in that, The dispersant is polyvinylpyrrolidone, polydimethylsilicone oil, or a combination thereof.

7. The high-speed printed TTO biaxially oriented polyester film according to claim 1, characterized in that, The dispersant is composed of polyvinylpyrrolidone and polydimethylsilicone in a mass ratio of 1:(4-6).

8. The high-speed printed TTO biaxially oriented polyester film according to claim 1, characterized in that, The polyester base film has a thickness of 3.95-4.05 μm, with the upper surface layer having a thickness of 0.5-0.6 μm and the lower surface layer having a thickness of 0.5-0.6 μm.

9. A method for preparing a high-speed printed TTO biaxially oriented polyester film as described in any one of claims 1-8, characterized in that, Includes the following steps: The raw materials for the upper and lower surfaces are added to two auxiliary extruders respectively; the raw materials for the core layer are mixed, pre-crystallized, dried, and then added to the main extruder; after melt extrusion, the resulting cast sheet is subjected to biaxial stretching, heat setting, relaxation, cooling, traction, and winding to obtain the final product.

10. The method for preparing a high-speed printed TTO biaxially oriented polyester film according to claim 9, characterized in that, The temperature of the melt extrusion is 275-280℃; the biaxial stretching includes longitudinal stretching and transverse stretching in sequence, wherein the temperature of longitudinal stretching is 98-105℃ and the stretching ratio is 3.9-4.3, and the temperature of transverse stretching is 101-107℃ and the stretching ratio is 3.9-4.1.

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