PET (Polyethylene Terephthalate) coating packaging material with color changing effect and preparation process thereof

Abstract

The invention discloses a PET (Polyethylene Terephthalate) coating packaging material with a color changing effect and a preparation process thereof, and belongs to the technical field of packaging materials. The packaging material comprises a PET film layer, a color-changing stripping layer, a first vacuum plating layer, a color-changing material layer, a second vacuum plating layer and a base material which are sequentially stacked, the coating dry weight of the color-changing stripping layer is 0.1-0.2 g / m < 2 >, and the coating dry weight of the color-changing material layer is 0.8-1.2 g / m < 2 >. The preparation process mainly comprises the following steps of coating, vacuum evaporation, coating, vacuum evaporation and transfer compounding. According to the color changing principle, a resin melt extrusion process is converted into a coating and evaporation process to prepare the packaging material, the light refraction and interference principle is utilized, the color changing effect like magical colors of the packaging material is achieved, the resin thickness and the number of times of superposition are effectively reduced, and effective degradation of the material can be achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of packaging materials, and more particularly to a color-changing PET-coated packaging material and a preparation process thereof. BACKGROUND

[0002] The color-changing film is also known as rainbow film, multicolor film, fantasy film, color-changing film, and laser rainbow film. Based on different multilayer film materials and different refractive indices, the color-changing film uses the principle of light interference to change the refraction and interference between layers under light irradiation, and produces a fantasy effect. The color-changing film also presents different color-changing effects at different distances and angles. However, the existing color-changing film must be under sufficient light conditions to present the fantasy color, and the color-changing effect is not ideal.

[0003] In addition, the traditional color-changing film is made of a composite plastic film by melting and extruding two or more resins with different refractive indices and sequentially and intermittently stacking at least 70 layers or more. Since the process must go through a melting and extrusion process, partial mixing occurs between the melts of resins with different refractive indices, which reduces the difference in refractive index between the layers of the color-changing film. Therefore, a large number of resin layers need to be stacked to achieve good light effects, and the processing technology is complicated. For example, patent No. CN02159049.4 discloses a multilayer light interference rainbow film and a preparation method thereof. The rainbow film is composed of a resin core layer composed of 70 or more A layers and B layers, and the processing technology is complicated, requiring more raw materials. SUMMARY

[0004] The present application aims to overcome the shortcomings of the prior art and provide a color-changing PET-coated packaging material and a preparation process thereof. The present application uses the principle of light refraction and interference to achieve a color-changing effect like the fantasy of the sky, effectively reduces the thickness and number of stacked layers of the resin, and realizes effective degradation of the material when transferred to paper.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] A color-changing PET-coated packaging material, which comprises PET film layers, a color-changing release layer, a first vacuum coating layer, a color-changing material layer, a second vacuum coating layer, and a substrate stacked in sequence. The dry coating amount of the color-changing release layer is 0.1-0.2 g / m 2 ; and the dry coating amount of the color-changing material layer is 0.8-1.2 g / m 2 .

[0007] Further, the color-changing release layer is a coating layer formed by a color-changing material composed of cellulose resin, ethyl acetate, n-propyl acetate, and color powder.

[0008] Further, the mass ratio of the cellulose resin, ethyl acetate, n-propyl acetate, and toner is (0.2-0.5) kg:(2-5) kg:(1-3) kg:(50-100) g.

[0009] Further, the color-changing material layer is a coating layer formed by the color-changing material composed of the acrylic resin, ethyl acetate, n-propyl acetate, and toner.

[0010] Further, the mass ratio of the acrylic resin, ethyl acetate, n-propyl acetate, and toner is (0.8-1.7) kg:(2-5) kg:(1-2) kg:(50-100) g.

[0011] Further, the thickness of the first vacuum plating layer is 80-120 angstroms, and the thickness of the second vacuum plating layer is 300-350 angstroms.

[0012] Further, the first vacuum plating layer and the second vacuum plating layer are both aluminum plating layers or zinc sulfide plating layers.

[0013] A preparation process of a color-changing effect PET film-coated packaging material, comprising the following steps:

[0014] S1, coating: coating a color-changing material on a PET film layer to form a color-changing release layer;

[0015] S2, vacuum evaporation: vacuum evaporating an aluminum layer or a ZnS layer on the color-changing release layer to form a first vacuum plating layer;

[0016] S3, coating: coating a color-changing material on the first vacuum plating layer to form a color-changing material layer;

[0017] S4, vacuum evaporation: vacuum evaporating an aluminum layer or a ZnS layer on the color-changing material layer to form a second vacuum plating layer;

[0018] S5, transfer and compounding: transferring and compounding the material obtained in step S4 to a substrate to obtain a color-changing effect PET film-coated packaging material.

[0019] Further, in steps S1 and S3, the coating process parameters are set as follows: the coating temperatures are 80℃, 110℃, 140℃, 140℃, 120℃, and 80℃, respectively; the coating speed is 110 m / min; the film tension during coating is 9-10 kg; the film tension during receiving is 9-10 kg; and the pressure of the coating roller is 2.4-2.5 MPa.

[0020] Further, in steps S2 and S4, the vacuum degree of vacuum evaporation is <9.9×10 -2 Pa; the diameter of the aluminum wire used for vacuum evaporation of the aluminum layer is 1.8 mm, and the purity is ≥99.98%.

[0021] In summary, the present application has the following beneficial effects:

[0022] The present application prepares PET film-coated packaging material in a superimposed manner of color-changing coating and vacuum plating layer, through the design of the thickness of the color-changing coating and the thickness of the vacuum plating layer, the different layers have different refractive indices, according to the color of the nano pigment in the toner and the hue of the color-changing pearlescent, the combination between the color-changing coating and the plating layer is used to realize the packaging material with strong metallic texture and different color-changing effects; compared with the traditional process, the number of superimposed layers is reduced, not only the color-changing effect of the fantasy color is realized, but also the coating can be attached to different substrates and degraded, fully reflecting the diversity and innovation of the development of packaging materials, meeting the market demand of fully integrating low-carbon environmental protection and aesthetic design. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a schematic diagram of the distribution of each layer of the color-changing effect PET film-coated packaging material of the present application.

[0024] Figure 2 It is a partial appearance diagram of the material obtained after step S2 in Example 1.

[0025] Figure 3 It is a partial appearance diagram of the color-changing effect PET film-coated packaging material prepared in Example 1.

[0026] Figure 4 It is a partial appearance diagram of the packaging material obtained in Comparative Example 1.

[0027] Figure 5 It is a partial appearance diagram of the packaging material obtained in Comparative Example 2.

[0028] Figure 6 It is a partial appearance diagram of the packaging material obtained in Comparative Example 3.

[0029] Figure 7 It is a partial appearance diagram of the packaging material obtained in Comparative Example 4.

[0030] Figure 8 It is a partial appearance diagram of the packaging material obtained in Comparative Example 5.

[0031] Figure 9 It is a partial appearance diagram of the packaging material obtained in Comparative Example 6.

[0032] Figure 10 It is a partial appearance diagram of the packaging material obtained in Comparative Example 7.

[0033] Figure 11 It is a partial appearance diagram of the packaging material obtained in Comparative Example 8.

[0034] Figure 12 It is a partial appearance diagram of the packaging material obtained in Comparative Example 9.

[0035] In the figure: PET film layer 1, color-changing stripping layer 2, first vacuum plating layer 3, color-changing material layer 4, second vacuum plating layer 5, substrate 6. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0037] The color-changing effect PET plating film packaging material comprises PET film layer 1, color-changing stripping layer 2, first vacuum plating layer 3, color-changing material layer 4, second vacuum plating layer 5 and substrate 6 which are sequentially stacked, and the distribution of each layer is as shown in Figure 1 .

[0038] The dry coating amount of the color-changing stripping layer 2 is 0.1-0.2 g / m 2 The color-changing stripping layer 2 is a coating layer formed by a color-changing material composed of cellulose resin, ethyl acetate, n-propyl acetate and color powder, and the mass ratio of the cellulose resin, ethyl acetate, n-propyl acetate and color powder is (0.2-0.5) kg:(2-5) kg:(1-3) kg:(50-100) g.

[0039] The thickness of the first vacuum plating layer 3 is 80-120 angstroms, and the thickness of the second vacuum plating layer 5 is 300-350 angstroms. The first vacuum plating layer 3 and the second vacuum plating layer 5 are both aluminum plating layers or zinc sulfide plating layers.

[0040] The dry coating amount of the color-changing material layer 4 is 0.8-1.2 g / m 2 The color-changing material layer 4 is a coating layer formed by a color-changing material composed of acrylic resin, ethyl acetate, n-propyl acetate and color powder, and the mass ratio of the acrylic resin, ethyl acetate, n-propyl acetate and color powder is (0.8-1.7) kg:(2-5) kg:(1-2) kg:(50-100) g.

[0041] The substrate 6 is preferably a cardboard.

[0042] The preparation process of the color-changing effect PET plating film packaging material comprises the following steps:

[0043] S1, coating: coating a color-changing material on the PET film layer 1 to form a color-changing release layer 2; the coating process parameters are set as follows: the coating temperature is 80℃, 110℃, 140℃, 140℃, 120℃ and 80℃ in sequence, the thermal effect is controlled at 82-88℃, a 200-mesh screen roller is used, the coating speed is 110 m / min, the film tension is 9-10 kg, the take-up tension is 9-10 kg, and the coating pressure is 2.4-2.5 MPa.

[0044] S2, vacuum evaporation: vacuum evaporating an aluminum layer or a ZnS layer on the color-changing release layer 2 to form a first vacuum plated layer 3; the vacuum degree of vacuum evaporation is <9.9×10 -2 Pa; the diameter of the aluminum wire used in vacuum evaporation of the aluminum layer is 1.8 mm, and the purity is ≥99.98%.

[0045] S3, coating: coating a color-changing material on the first vacuum plated layer 3 to form a color-changing material layer 4; the coating process parameters are set as follows: the coating temperature is 80℃, 110℃, 140℃, 140℃, 120℃ and 80℃ in sequence, the thermal effect is controlled at 82-88℃, a 200-mesh screen roller is used, the coating speed is 110 m / min, the film tension is 9-10 kg, the take-up tension is 9-10 kg, and the coating pressure is 2.4-2.5 MPa.

[0046] S4, vacuum evaporation: vacuum evaporating an aluminum layer or a ZnS layer on the color-changing material layer 4 to form a second vacuum plated layer 5; the vacuum degree of vacuum evaporation is <9.9×10 -2 Pa; the diameter of the aluminum wire used in vacuum evaporation of the aluminum layer is 1.8 mm, and the purity is ≥99.98%.

[0047] S5, transfer and compounding: transferring and compounding the material obtained in step S4 to a substrate 6 to obtain a color-changing effect PET plated film packaging material.

[0048] Example 1

[0049] S1, coating a color-changing material [0.2 kg of cellulose resin (American Eastman CAB-381-0.5), 3.3 kg of ethyl acetate, 1.4 kg of n-propyl acetate, and 75 g of color powder (a mixture of direct blue 86, acid yellow 61, direct red 89, and acid blue 83 in a mass ratio of 1:1:1:1)] on the PET film layer 1 to form a color-changing release layer 2 with a coating dry weight of 0.15 g / m 2 ; wherein the coating process parameters are as follows: the coating temperature is 80℃, 110℃, 140℃, 140℃, 120℃ and 80℃ in sequence, the thermal effect is controlled at 85℃, a 200-mesh screen roller is used, the film tension and the take-up tension are both 9.5 kg, the coating pressure is 2.4 MPa, and the coating speed is 110 m / min.

[0050] S2, evaporate a layer of aluminum on the color-changing stripping layer 2 in a vacuum evaporation manner to form a first vacuum plated layer 3 with a plated layer thickness of 100 angstroms, a vacuum degree <9.9x10 -2 Pa, an aluminum wire diameter of 1.8 mm, and a purity ≥99.98%.

[0051] S3, perform color-changing material coating on the first vacuum plated layer 3 [mix 1 kg of methacrylic acid resin, 3.3 kg of ethyl acetate, 1.4 kg of n-propyl acetate, and 75 g of color powder (a mixture of direct blue 86, acid yellow 61, direct red 89, and acid blue 83 in a mass ratio of 1:1:1:1) to obtain the color-changing material] to form a color-changing material layer 4 with a coating dry weight of 1 g / m 2 The coating process parameters are the same as in step S1.

[0052] S4, evaporate a layer of aluminum on the color-changing stripping layer 2 in a vacuum evaporation manner to form a second vacuum plated layer 5 with a plated layer thickness of 350 angstroms; a vacuum degree <9.9x10 -2 Pa, an aluminum wire diameter of 1.8 mm, and a purity ≥99.98%.

[0053] S5, transfer the material obtained after step S4 to a white card paper by water-based glue transfer to obtain a color-changing effect PET plated film packaging material.

[0054] Comparative Example 1

[0055] This comparative example is to prepare a PET plated film packaging material by sequentially coating a color-changing stripping layer 2 and vacuum evaporating a second vacuum plated layer 5 on a PET film base layer and then transferring to a white card paper; that is, prepared according to steps S1, S4, and S5 of Example 1.

[0056] Comparative Example 2

[0057] This comparative example is to prepare a PET plated film packaging material by sequentially coating a color-changing material layer 4 and vacuum evaporating a second vacuum plated layer 5 on a PET film base layer and then transferring to a white card paper; that is, prepared according to steps S3, S4, and S5 of Example 1.

[0058] Comparative Example 3

[0059] This comparative example is to prepare a PET plated film packaging material by sequentially coating a color-changing stripping layer 2, a color-changing material layer 4, and vacuum evaporating a second vacuum plated layer 5 on a PET film base layer and then transferring to a white card paper; that is, prepared according to steps S1, S3, S4, and S5 of Example 1.

[0060] Comparative Example 4

[0061] A PET-coated packaging material was prepared according to Example 1, but the dry coating weight of the color-shifting release layer 2 in S1 was set to 0.05 g / m 2 The rest was the same.

[0062] Comparative Example 5

[0063] A PET-coated packaging material was prepared according to Example 1, but the dry coating weight of the color-shifting release layer 2 in S1 was set to 0.3 g / m 2 The rest was the same.

[0064] Comparative Example 6

[0065] A PET-coated packaging material was prepared according to Example 1, but the coating thickness of the first vacuum-coated layer 3 in S2 was set to 70 angstroms, and the rest was the same.

[0066] Comparative Example 7

[0067] A PET-coated packaging material was prepared according to Example 1, but the coating thickness of the first vacuum-coated layer 3 in S2 was set to 150 angstroms, and the rest was the same.

[0068] Comparative Example 8

[0069] A PET-coated packaging material was prepared according to Example 1, but the dry coating weight of the color-shifting material layer 4 in S3 was set to 0.7 g / m 2 The rest was the same.

[0070] Comparative Example 9

[0071] A PET-coated packaging material was prepared according to Example 1, but the dry coating weight of the color-shifting material layer 4 in S3 was set to 1.4 g / m 2 The rest was the same.

[0072] The appearance of the material obtained after step S3 in Example 1 is shown in Figure 2 , the color-shifting effect of the PET-coated packaging material prepared in Example 1 is shown in Figure 3 , and the PET-coated packaging materials prepared in Comparative Examples 1-9 are shown in Figures 4-12 , Figures 2-12All are taken under the same shooting conditions at 30℃ sunny indoor natural lighting. It is found that the final product PET film-coated packaging material prepared in Example 1 has the best discoloration effect under the condition of 30℃ sunny indoor natural lighting, and can present the iridescent discoloration effect from different distances (≤5m) and different angles (the discoloration effect of the material is basically the same when the observation distance is 5m and 1m), and can also present a better iridescent discoloration effect under indoor lighting of 40-50 lux on a cloudy day; while the three materials obtained after steps S1, S2 and S3 and the packaging materials prepared in Comparative Examples 1-3 cannot present the iridescent discoloration effect, although the packaging materials prepared in Comparative Examples 4-9 can also present a certain discoloration effect under the condition of sunny indoor natural lighting, but cannot present from different angles, and the discoloration effect becomes poor when the observation distance is more than 4m (under the condition of 30℃ sunny indoor natural lighting, the same observation angle and observation distance of 4m, taking 5 points as full score, the discoloration effect of the material of Example 1 is evaluated as 5 points, and the discoloration effect of the materials of Comparative Examples 4-9 is 3-4 points), and the discoloration effect is also worse than that of Example 1 under indoor lighting of 40-50 lux (under the condition of indoor lighting of 45 lux, the same observation angle and observation distance of 1.5m, taking 5 points as full score, the discoloration effect of the material of Example 1 is evaluated as 4 points, and the discoloration effect of the materials of Comparative Examples 4-9 is 2-3 points).

[0073] The PET film-coated packaging materials obtained in Example 1 and Comparative Examples 1-9 were respectively tested for performance (the tensile strength was determined according to the method of GB / T12914-2008; during the experiment, the PET film layer 1 of the PET film-coated packaging material was peeled off, and the soil filling test method in GB / T19275-2024 “Evaluation of the potential biodegradation and disintegration of materials under the action of specific microorganisms” was used, and the filling time was 90 days). The test results show that the tensile strength of the samples of Example 1 and Comparative Examples 1-9 is 48.7, 40.6, 39.8, 41.5, 43.2, 44.01, 42.35, 43.6, 43.12, 43.93 N·m / g, respectively, and the 90-day biodegradation rate is 76.2-85.9%, and the 90-day biodegradation rate of the sample of Example 1 is 84.1%.

[0074] The above is only the preferred embodiment of the present application, and the protection scope of the present application is not limited to the above examples. Any technical solutions falling within the concept of the present application shall fall within the protection scope of the present application. It should be noted that, for ordinary technical personnel in the technical field, some improvements and refinements without departing from the principles of the present application shall also be considered as the protection scope of the present application.

Claims

1. A color-changing PET coating packaging material, characterized in that: The packaging material comprises a PET film layer (1), a color-changing peeling layer (2), a first vacuum coating layer (3), a color-changing material layer (4), a second vacuum coating layer (5) and a substrate (6) stacked in sequence, wherein the dry coating weight of the color-changing peeling layer (2) is 0.1-0.2 g / m 2 The color-changing material layer (4) has a dry coating weight of 0.8-1.2 g / m 2 .

2. The color-changing PET coating packaging material according to claim 1, characterized in that: The color-changing peeling layer (2) is a coating formed by a color-changing material composed of cellulose resin, ethyl acetate, n-propyl acetate, and color powder.

3. The color-changing PET coating packaging material according to claim 2, characterized in that: The mass ratio of the cellulose resin to ethyl acetate, n-propyl acetate and toner is (0.2-0.5) kg: (2-5) kg: (1-3) kg: (50-100) g.

4. The color-changing PET coating packaging material according to claim 1, characterized in that: The color-changing material layer (4) is a coating formed by a color-changing material composed of acrylic resin, ethyl acetate, n-propyl acetate, and color powder.

5. The color-changing PET coating packaging material according to claim 4, characterized in that: The mass ratio of the acrylic resin to ethyl acetate, n-propyl acetate and toner is (0.8-1.7) kg: (2-5) kg: (1-2) kg: (50-100) g.

6. The color-changing PET coating packaging material according to claim 1, characterized in that: The thickness of the first vacuum coating (3) is 80-120 angstroms; the thickness of the second vacuum coating (5) is 300-350 angstroms.

7. The color-changing PET coating packaging material according to claim 1, characterized in that: The first vacuum coating (3) and the second vacuum coating (5) are both aluminum coating layers or zinc sulfide coating layers.

8. A process for preparing the color-changing PET coating packaging material according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, coating: coating a color-changing material on the PET film layer (1) to form a color-changing peeling layer (2); S2, vacuum evaporation: vacuum evaporating an aluminum layer or a ZnS layer on the color-changing peeling layer (2) to form a first vacuum coating layer (3); S3, coating: coating a color-changing material on the first vacuum coating layer (3) to form a color-changing material layer (4); S4, vacuum evaporation: vacuum evaporating an aluminum layer or a ZnS layer on the color-changing material layer (4) to form a second vacuum coating layer (5); S5, reprinting and laminating: laminating the material obtained in step S4 onto the substrate (6) to obtain a PET coated packaging material with a color-changing effect.

9. The process for preparing a color-changing PET coating packaging material according to claim 8, characterized in that: In step S1 and step S3, the coating process parameters are set as follows: the coating temperatures are 80°C, 110°C, 140°C, 140°C, 120°C, and 80°C, respectively; the coating speed is 110 m / min; the film unwinding tension is 9-10 kg; the film winding tension is 9-10 kg; and the coating roller pressure is 2.4-2.5 MPa.

10. The process for preparing a color-changing PET coating packaging material according to claim 8, characterized in that: In step S2 and step S4, the vacuum degree of vacuum evaporation is less than 9.9×10 -2 Pa; the diameter of the aluminum wire used in the vacuum evaporation of the aluminum layer is 1.8mm, and the purity is ≥99.98%.

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