A thick and loose aluminized label paper and its preparation method

Abstract

The present invention relates to the technical field of label paper, and discloses a bulky aluminized label paper and a preparation method thereof, comprising a base paper layer, an ion coating, an inner coating, an aluminized film layer, and an outer coating arranged sequentially from bottom to top; the base paper layer is an acidic base paper that has not been supercalendered; the ion coating contains a modified acrylic polyurethane resin and a layered double hydroxide; the inner coating and the outer coating are both coatings formed by applying and drying an anionic water-based acrylic emulsion; and the outer coating has an outer surface smoothness of ≥2000S. The base paper layer that has not been supercalendered retains its original fiber looseness, so that the back of the bulky aluminized label paper has good water absorption, which can prevent the bulky aluminized label paper from shifting and bubbling when used in high-speed labeling machines; the ion coating can prevent moisture adsorbed by the base paper from being transferred upward to the inner coating, and can also prevent the bulky aluminized label paper from bubbling, wrinkling, and warping during use.

Description

Technical Field

[0001] The present invention relates to the technical field of label paper, in particular to a bulky aluminized label paper and a preparation method thereof. Background Art

[0002] Aluminum-coated paper label paper has the advantages of being smooth, bright and durable. It is suitable for processing operations of various printing machines, embossing machines and high-speed die-cutting machines. Therefore, it is widely used as beer bottle or beverage bottle label paper.

[0003] The aluminized paper label paper in the prior art is made of aluminized film layer covering waterproof coated paper, the back and surface of the aluminized film layer are coated with a primer and a topcoat respectively, wherein the outer surface of the topcoat is the ink printing surface, the primer is located between the back of the aluminized film layer and the inner surface of the waterproof coated paper, and the back of the waterproof coated paper is also coated with a backcoat.

[0004] Because the waterproof coated paper is super-calendered, the paper fiber structure of the waterproof coated paper is tight and the gaps between the paper fibers are small, so the water absorption of the aluminized paper label paper is poor, and it cannot quickly absorb and release the moisture in the casein protein glue or synthetic glue. When used in a high-speed labeling machine for labeling, the aluminized paper label paper will curl and deform due to moisture absorption, which makes the aluminized paper label paper prone to shifting and bubbling. Then, when the aluminized paper label paper is stored in a humid environment during use, it will also experience bubbling, wrinkling and warping. Summary of the Invention

[0005] In response to the above problems, the purpose of the present invention is to provide a bulky and thick aluminized label paper, which can effectively prevent the aluminized label paper from curling and deforming due to moisture absorption, thereby avoiding the aluminized label paper from shifting, bubbling, wrinkling and warping.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A bulky aluminized label paper, comprising a base paper layer, an ion coating layer, an inner coating layer, an aluminized film layer and an outer coating layer arranged in sequence from bottom to top;

[0008] The base paper layer is acidic base paper that has not been supercalendered;

[0009] The ionic coating contains modified acrylic polyurethane resin and layered double hydroxide;

[0010] The inner coating and the outer coating are both coatings formed by coating and drying anionic water-based acrylic emulsion;

[0011] The smoothness of the outer surface of the outer coating layer is ≥2000S.

[0012] Specifically, calculated by weight, the raw materials of the ion coating are composed of 59 parts of modified acrylic polyurethane resin, 34.8 parts of layered double hydroxide, 0.2 parts of film-forming aid, 5 parts of citric acid and 1 part of ammonia water.

[0013] Furthermore, the layered double hydroxide is a mixture of hydrotalcite, montmorillonite, kaolin, muscovite and illite.

[0014] Preferably, the brightness of the aluminum-plated film layer is 5-7 gloss units.

[0015] Preferably, the solid content of the aqueous acrylic emulsion is 25-30%.

[0016] Furthermore, the present invention provides a method for preparing a bulky aluminized label paper, which is used for the bulky aluminized label paper described above, comprising the following steps:

[0017] S1) Weighing modified acrylic polyurethane resin, layered double hydroxide, film-forming aid, citric acid and ammonia water according to parts by weight, mixing and stirring uniformly to prepare an ionic coating;

[0018] S2) using a coating machine to apply the ionic coating to the surface of a base paper that has not been supercalendered, and drying the base paper to obtain a first substrate containing the ionic coating;

[0019] S3) preparing a water-based acrylic emulsion and coating the surface of the first substrate with the water-based acrylic emulsion using a coating machine, and drying the water-based acrylic emulsion to form an inner coating on the surface of the ion coating, thereby preparing a second substrate comprising the ion coating and the inner coating;

[0020] S4) using a vacuum aluminum coating machine to sublime the aluminum wire by heating and forming an aluminum coating layer on the surface of the inner coating to prepare a third substrate comprising an ion coating, an inner coating and an aluminum coating layer;

[0021] S5) using a coating machine to apply the water-based acrylic emulsion on the surface of the third substrate, and the dried water-based acrylic emulsion forms an outer coating on the surface of the aluminized film layer, thereby producing the bulky aluminized label paper comprising an ion coating, an inner coating, an aluminized film layer, and an outer coating.

[0022] Specifically, in step S1), the pH value of the ionic coating is 8-8.5.

[0023] Preferably, in step S2), the coating temperature is 4-40°C, the drying temperature is 80-200°C, and the drying time is 1-4 minutes; the solid content of the ionic coating is 30%, and the coating amount is 11.7-13.3 g / m2.

[0024] Preferably, in step S3), the coating temperature is 4-40° C., the drying temperature is 80-200° C., and the drying time is 1-4 min; and the coating amount of the water-based acrylic emulsion is 5.0-6.7 g / m2.

[0025] Preferably, in step S5), the coating temperature is 4-40° C., the drying temperature is 80-200° C., and the drying time is 1-4 min; and the coating amount of the water-based acrylic emulsion is 2.7-3.3 g / m2.

[0026] The beneficial effects of the above technical solution of the present invention are as follows: the base paper layer of the bulky aluminized label paper is an acidic base paper that has not been super-calendered, which maintains the original fiber looseness, and the internal structure of the ion coating is tight, which can effectively reduce the penetration of the water-based acrylic emulsion into the ion coating during the application of the inner coating. Both the ion coating and the inner coating help to improve the gloss of the aluminized film layer. The ion coating can also prevent the moisture adsorbed by the base paper from being transferred upward to the inner coating, thereby avoiding bubbling, wrinkling and warping of the bulky aluminized label paper during use. In addition, the outer coating can protect the aluminized film layer and prevent the aluminized film layer from being oxidized or scratched. The outer surface smoothness of the outer coating is ≥2000S, and it can also meet the printing requirements of various inks and has good bonding strength with the ink. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic structural diagram of an embodiment of the bulky aluminized label paper of the present invention;

[0028] Figure 2 Schematic diagram of charge distribution of the ion coating of the bulky aluminized label paper of the present invention;

[0029] Figure 3 This is an electron microscope image of the base paper before ion coating;

[0030] Figure 4 This is an electron microscope image of the base paper after coating with ion coating;

[0031] Figure 5 The corresponding relationship between the distance between the lowest point and the highest point of the water warpage angle test specimen and the humidity sensitivity level;

[0032] Figure 6 This is a photo of the comparative example 1 during the alkali immersion resistance test;

[0033] Among them: base paper layer 1; ion coating layer 2; inner coating layer 3; aluminum coating layer 4; outer coating layer 5. DETAILED DESCRIPTION

[0034] The following is combined with Figure 1-4 The technical solution of the present invention is further illustrated through specific implementation methods.

[0035] The accompanying drawings are for illustrative purposes only and are not to be construed as limitations on this patent. To better illustrate this embodiment, some components of the accompanying drawings may be omitted, enlarged, or reduced in size, and do not represent the actual dimensions of the product. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted from the accompanying drawings.

[0036] A bulky aluminized label paper, comprising a base paper layer 1, an ion coating layer 2, an inner coating layer 3, an aluminized film layer 4 and an outer coating layer 5 arranged in sequence from bottom to top;

[0037] The base paper layer 1 is an acidic base paper that has not been supercalendered;

[0038] The ion coating 2 contains modified acrylic polyurethane resin and layered double hydroxide;

[0039] The inner coating 3 and the outer coating 5 are both coatings formed by coating and drying anionic water-based acrylic emulsion;

[0040] The smoothness of the outer surface of the outer coating 5 is ≥2000S.

[0041] Figure 1 It is a schematic structural diagram of the bulky aluminized label paper of the present invention.

[0042] The bulky aluminized label paper of the present invention has a base paper layer 1 that has not been subjected to supercalendering processing, thereby maintaining the original bulk of the base paper, so that the back side of the bulky aluminized label paper (i.e., the adhesive side of the label) has good water absorption, and can quickly absorb and release moisture in casein protein glue or synthetic glue, thereby preventing the bulky aluminized label paper from shifting and bubbling when used in a high-speed labeling machine; the layered double hydroxide contains positive and negative ion charges, and a coating containing a modified acrylic polyurethane resin and the layered double hydroxide is used and applied to the surface of the acidic base paper, and then dried to form a dense film layer, in which the negative ion charges in the film layer face downward (i.e., toward the inner surface of the base paper), and the positive ion charges face upward. Therefore, this film layer is called the ion coating 2. The internal structure of the ion coating 2 is tight, which can effectively reduce the amount of water-based acrylic emulsion penetrating into the ion coating 2 when applying the inner coating 3, and can also prevent the moisture adsorbed by the base paper from being transferred upward to the inner coating 3, thereby avoiding the bubbling, wrinkling and warping of the thick aluminum-plated label paper during the labeling process, and improving the interface bonding strength between the inner coating 3 formed by the anionic water-based acrylic emulsion and the ion coating 2; in addition, the outer coating 5 can protect the aluminum-plated film layer 4 and prevent the aluminum-plated film layer 4 from being oxidized or scratched. The outer surface smoothness of the outer coating 5 is ≥2000S, and it can also meet the printing requirements of various inks and has good bonding fastness with the ink.

[0043] Preferably, the base paper layer 1 is made of an acidic kraft paper base, tissue paper base, or dialysis paper base with a whiteness of ≥80%. The acidic base paper layer 1 imparts a positive ion charge to the base paper layer 1, which can combine with the negative ions concentrated on the lower surface of the ion coating 2 to form a stable bond.

[0044] The charge distribution diagram of the ion coating 2 is shown in Figure 2 shown.

[0045] Specifically, calculated by weight, the raw materials of the ion coating 2 are composed of 59 parts of modified acrylic polyurethane resin, 34.8 parts of layered double hydroxide, 0.2 parts of film-forming aid, 5 parts of citric acid and 1 part of ammonia water.

[0046] The citric acid and ammonia water in the raw materials of the ionic coating 2 are pH regulators; the film-forming aid is commercially available dodecyl alcohol ester, which helps to increase the film-forming speed of the ionic coating 2 coated on the surface of the base paper.

[0047] Furthermore, the layered double hydroxide is a mixture of hydrotalcite, montmorillonite, kaolin, muscovite and illite.

[0048] Preferably, calculated by weight, the layered double hydroxide comprises 2 parts of hydrotalcite, 4 parts of montmorillonite, 1.5 parts of kaolin, 1.5 parts of muscovite and 1 part of illite.

[0049] Preferably, the brightness of the aluminum-plated film layer 4 is 5-7 gloss units.

[0050] The aluminized film layer 4 with a brightness of 5-7 gloss units has a mirror effect, which can improve the clarity of the images and texts on the printed surface of the bulky aluminized label paper.

[0051] Specifically, the solid content of the aqueous acrylic emulsion is 25-30%.

[0052] The water-based acrylic emulsion with a solid content of 25-30% helps the coating to level during coating, forms a smooth inner coating on the surface of the ion coating 2, and forms a bright aluminum coating layer after vacuum aluminum plating.

[0053] Furthermore, the present invention provides a method for preparing a bulky aluminized label paper, which is used for the bulky aluminized label paper described above, comprising the following steps:

[0054] S1) Weighing modified acrylic polyurethane resin, layered double hydroxide, film-forming aid, citric acid and ammonia water according to parts by weight, mixing and stirring uniformly to prepare an ionic coating;

[0055] S2) using a coating machine to apply the ionic coating to the surface of the base paper that has not been supercalendered, and drying it to obtain a first substrate containing the ionic coating 2;

[0056] S3) preparing water-based acrylic emulsion;

[0057] S3) using a coating machine to apply the aqueous acrylic emulsion to the surface of the first substrate, and drying the aqueous acrylic emulsion to form an inner coating 3 on the surface of the ion coating 2, thereby preparing a second substrate comprising the ion coating 2 and the inner coating 3;

[0058] S4) using a vacuum aluminum coating machine to sublime the aluminum wire by heating, and forming an aluminum coating layer 4 on the surface of the inner coating layer 3, thereby preparing a third substrate comprising the ion coating layer 2, the inner coating layer 3 and the aluminum coating layer 4;

[0059] S5) Using a coating machine, the water-based acrylic emulsion is coated on the surface of the third substrate. After drying, the water-based acrylic emulsion forms an outer coating 5 on the surface of the aluminized film layer 4, thereby producing the bulky aluminized label paper comprising the ion coating 2, the inner coating 3, the aluminized film layer 4 and the outer coating 5.

[0060] The preparation method of the bulky aluminized label paper proposed in the present invention adopts base paper that has not been super-calendered, and after coating the surface of the base paper with an ion coating 2 and an inner coating 3, it is aluminum-plated, and then an outer coating 5 is coated on the outer surface of the aluminum-plated film layer. In this way, the unevenness of the aluminum-plated film layer caused by the low smoothness of the base paper surface can be avoided, thereby ensuring the glossiness of the aluminum-plated film layer. The ion coating 2 can also isolate and block the moisture in the inner coating 3 from penetrating into the base paper, thereby reducing the penetration of the applied water-based acrylic emulsion into the ion coating 2. The outer coating 5 can also improve the protection of the aluminum-plated film layer and improve the clarity of the images and texts printed on the outer surface of the outer coating 5.

[0061] The water warping angle of the prepared bulky aluminized label paper is less than 28 degrees, the water warping time is greater than 30 seconds, and the humidity sensitivity is level 4-6. Compared with the aluminized label paper using waterproof coated paper in the prior art, the aluminized label paper has better anti-warping performance.

[0062] Specifically, in step S1), the pH of the ionic coating is 8-8.5. During synthesis, citric acid is used to adjust the arrangement of positive and negative ions. Acidic ionic coatings can lose stability during long-term storage and use, becoming thicker or stratifying and solidifying. Weak alkalinity, on the other hand, promotes long-term stability. Therefore, after synthesis, the pH of the ionic coating needs to be adjusted to 8-8.5 by adding ammonia. Furthermore, ammonia evaporates completely during high-temperature baking, leaving no residue. This ensures that the ionic coating 2 possesses stable alkaline resistance, making it less susceptible to dissolution by alkaline substances in the glue during labeling.

[0063] Preferably, in step S2), the coating temperature is 4-40°C, the drying temperature is 80-200°C, and the drying time is 1-4 minutes; the solid content of the ionic coating is 30%, and the coating amount is 11.7-13.3 g / m2.

[0064] The applied ion coating is dried to form an ion coating 2. The coating operation can be carried out at a room temperature of 4-40°C.

[0065] Preferably, in step S3), the coating temperature is 4-40° C., the drying temperature is 80-200° C., and the drying time is 1-4 min; and the coating amount of the water-based acrylic emulsion is 5.0-6.7 g / m2.

[0066] The applied aqueous acrylic emulsion is dried to form an inner coating layer 3.

[0067] Preferably, in step S5), the coating temperature is 4-40° C., the drying temperature is 80-200° C., and the drying time is 1-4 min; and the coating amount of the water-based acrylic emulsion is 2.7-3.3 g / m2.

[0068] The water-based acrylic emulsion is dried to form an outer coating 5.

[0069] Examples 1-3 and Comparative Examples 1-4

[0070] 1. Based on the raw materials and process parameters of Examples 1-3 listed in Table 1, and the raw materials and process parameters of Comparative Examples 1-4 listed in Table 2, aluminized label papers of Examples 1-3 and Comparative Examples 1-4 were prepared according to the following steps:

[0071] S1) weighing the required raw materials according to the weight ratio, mixing and stirring them evenly to prepare the ionic coating;

[0072] S2) using a coating machine to coat the ionic coating on the surface of the base paper, and drying it to obtain a first substrate containing the ionic coating 2;

[0073] S3) preparing water-based acrylic emulsion;

[0074] S3) using a coating machine to apply the aqueous acrylic emulsion to the surface of the first substrate, and drying the aqueous acrylic emulsion to form an inner coating 3 on the surface of the ion coating 2, thereby preparing a second substrate comprising the ion coating 2 and the inner coating 3;

[0075] S4) using a vacuum aluminum coating machine to sublime the aluminum wire by heating, and forming an aluminum coating layer 4 on the surface of the inner coating layer 3, thereby preparing a third substrate comprising the ion coating layer 2, the inner coating layer 3 and the aluminum coating layer 4;

[0076] S5) using a coating machine to apply the aqueous acrylic emulsion to the surface of the third substrate, and drying the aqueous acrylic emulsion to form an outer coating 5 on the surface of the aluminized film layer 4, thereby producing the aluminized label paper comprising the ion coating 2, the inner coating 3, the aluminized film layer 4, and the outer coating 5;

[0077] Calculated by weight, the raw materials of the ion coating 2 are composed of 59 parts of modified acrylic polyurethane resin, 34.8 parts of layered double hydroxide, 0.2 parts of film-forming aid, 5 parts of citric acid and 1 part of ammonia water; the film-forming aid is commercially available dodecyl alcohol ester;

[0078] Calculated by weight, the layered double hydroxide comprises 2 parts of hydrotalcite, 4 parts of montmorillonite, 1.5 parts of kaolin, 1.5 parts of muscovite and 1 part of illite.

[0079] 2. The corresponding test items of Examples 1-3 and Comparative Examples 1-4 were tested according to the following steps, and the test results were recorded in Tables 1 and 2 respectively:

[0080] 2.1 Refer to GB / T7974-2002 to test the whiteness of the base paper and the smoothness of the base paper or the base paper surface coating.

[0081] 2.2 Refer to GB451.2-2002 to test the weight of the base paper or aluminized label paper.

[0082] 2.3 Refer to GB / T451.3-2002 to test the tightness and thickness of the base paper or aluminized label paper.

[0083] 2.4 Refer to GB / T1540-2002 to test the water absorption of base paper or aluminized label paper.

[0084] 2.5 Refer to the following method to test the alkali resistance of base paper or aluminized label paper:

[0085] 2.5.1 Take 200 mL of 2.5% NaOH solution and place it in a 500 mL Erlenmeyer flask. Heat it in a constant temperature water bath to 80 ± 2°C.

[0086] 2.5.2 Cut two 100mm×100mm specimens from the sample to be tested, place the specimens in the NaOH solution, and vigorously shake the flask 30 times while starting a stopwatch. Every 20 minutes, vigorously shake the flask 30 times and visually observe the specimens for damage.

[0087] 2.5.3 Judgment standard: If the sample remains intact after 60 minutes, it is considered qualified.

[0088] 2.6 Refer to the following method to test the water warping time and water warping angle of aluminized label paper:

[0089] 2.6.1 Cut specimens from the top, bottom, left, right, and center of the sample to be tested. Place the back of each specimen flat on the water surface with the back facing downwards. Use a stopwatch to start timing. When the specimen begins to curl (i.e., the curling speed suddenly accelerates), record it as the initial curling time S0. When the curled edge of the specimen contacts the paper surface of the specimen, stop timing and record the time it takes to curl as the water warping time S. If the curled edge of the specimen does not contact the paper surface of the specimen, it is judged to be in a semi-curled state, and the water warping time S is determined to be greater than 30s.

[0090] 2.6.2 Complete the water warpage time S test of five specimens according to the above steps, and calculate the average value of the five water warpage times S as the water warpage time S of the corresponding sample to be tested; if the average water warpage time S is greater than 30s, it is judged to be qualified;

[0091] 2.6.3 The water warping angle is defined as the angle between the curled edge of the specimen and the horizontal plane when the specimen is rolled and stopped in step 2.6.2. When the curled edge contacts the paper surface of the specimen, the water warping angle of the specimen is calculated as 180°. If the water warping angle is less than 30°, the specimen is considered qualified.

[0092] 2.7 Refer to the following method to test the moisture sensitivity of base paper or aluminized label paper:

[0093] 2.7.1 Take ten specimens from the sample to be tested, using the same sampling method as in step 2.6.1;

[0094] 2.7.2 Place five of the specimens (i.e., condition 1) in a constant temperature and humidity chamber at 35°C and 45% relative humidity, and place the remaining five specimens (i.e., condition 2) in a constant temperature and humidity chamber at 15°C and 80% relative humidity. After one hour, remove the specimens and test the degree of bending or curling.

[0095] 2.7.3 Use a ruler to measure the distance between the lowest point and the highest point of the curved or curled surface of the specimen. The larger the distance between the lowest point and the highest point, the stronger the moisture sensitivity of the corresponding specimen. The corresponding relationship between the distance between the lowest point and the highest point and the moisture sensitivity level is shown in the attached figure. Figure 5 As shown;

[0096] 2.7.4 Qualification criteria: Moisture sensitivity level is 4-6.

[0097] It should be noted that when beer bottles or beverage bottles are recycled and reused, they must first be soaked in a NaOH solution with a temperature of 80°C and a concentration of 2.5wt% in the alkali solution tank of the bottle washing machine for 20 minutes, and then rinsed to remove the old labels on the beer bottles or beverage bottles. The fallen old labels must stay in the alkali solution for about 30 minutes before being discharged with the cleaning solution. If the old labels are dissolved, damaged or rotted during the above process, they will be deposited at the bottom of the alkali solution tank and block the alkali solution circulation pipe of the bottle washing machine, causing the bottle washing machine to fail to operate normally. Therefore, the base paper and label paper must meet the above-mentioned inspection standards for alkali immersion resistance testing.

[0098] Table 1 Raw materials, process parameters and test results of Examples 1-3

[0099]

[0100] Table 2 Raw materials, process parameters and test results of Comparative Examples 1-4

[0101]

[0102] Based on the above content and the test results recorded in Tables 1 and 2, the analysis is as follows:

[0103] 1. The base papers used in Examples 1-3 were all unsupercalendered. The water warping angle, water warping time, and humidity sensitivity test results for Examples 1-3 all passed the test, indicating that the ionic coating 2 effectively prevented moisture adsorbed by the base paper from being transferred upward to the inner coating 3. This prevented bubbling, wrinkling, and warping of thick, bulky aluminized label paper during use.

[0104] 2. The difference between Comparative Example 1 and Example 3 is that the base paper used in Comparative Example 1 is offset paper, which has not been supercalendered or coated and has a relatively loose texture. The offset paper used in Comparative Example 1 completely dissolves into fragments after being immersed in a 2 wt % NaOH solution at 80°C for 56 minutes. Therefore, the offset paper is not suitable as the base paper for aluminum-coated label paper for recycled beer bottles or beverage bottles. Figure 6 This is a photo of the comparative example 1 during the alkali immersion resistance test.

[0105] 4.3 The difference between Comparative Example 2 and Example 3 is that the base paper used in Comparative Example 2 is commercially available 65g waterproof coated paper that has been supercalendered and coated, the aluminized label paper in Comparative Example 2 does not contain the coated ion coating 2, the water warping angle, water warping time and humidity sensitivity of Comparative Example 2 are all unqualified, and bubbling, wrinkling and warping will occur during labeling.

[0106] 4.4 The difference between Comparative Example 3 and Example 3 is that the aluminized label paper of Comparative Example 3 does not contain the ion coating 2; the surface smoothness of the aluminized film layer of Comparative Example 3 is only 1130S, and the glossiness of the aluminized film layer of Comparative Example 3 is only 2-3 gloss units, which will affect the clarity of the printed graphics and text, and bubbling, wrinkling and warping will also occur during labeling.

[0107] 4.5 The difference between Comparative Example 4 and Example 3 is that the aluminized label paper of Comparative Example 4 does not include the inner coating 3, resulting in the surface smoothness of the aluminized film layer of Comparative Example 4 being only 940S, and the glossiness of the aluminized film layer of Comparative Example 4 being only 5-6 gloss units, which will affect the clarity of the printed images and texts.

[0108] 4.6 Analysis of the test results of the surface smoothness of the aluminum film layer and the glossiness of the aluminum-plated film layer of Examples 1-3, Comparative Example 1, Comparative Example 3 and Comparative Example 4 shows that both the ion coating 2 and the inner coating 3 have an impact on the glossiness of the aluminum-plated film layer of the bulky aluminum-plated label paper. Therefore, only the glossiness of the bulky aluminum-plated label paper containing the ion coating 2 and the inner coating 3 can meet the quality requirements.

[0109] In summary, if Figure 1-4 In the embodiment shown, the bulky aluminized label paper of the present invention, the base paper layer 1 is an acidic base paper that has not been super-calendered, and the original fiber looseness is maintained. The internal structure of the ion coating 2 is tight, which can effectively reduce the penetration of the aqueous acrylic emulsion into the ion coating 2 when the inner coating 3 is applied. Both the ion coating 2 and the inner coating 3 help to improve the glossiness of the aluminized film layer. The ion coating 2 can also prevent the moisture adsorbed by the base paper from being transferred upward to the inner coating 3, thereby avoiding bubbling, wrinkling and warping of the bulky aluminized label paper during use. In addition, the outer coating 5 can protect the aluminized film layer 4 and prevent the aluminized film layer 4 from being oxidized or scratched. The outer surface smoothness of the outer coating 5 is ≥2000S, and can also meet the printing requirements of various inks and has good bonding strength with the ink.

[0110] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are intended solely to illustrate the principles of the present invention and are not to be construed in any way as limiting the scope of protection of the present invention. Based on the explanations herein, those skilled in the art will readily conceive of other specific embodiments of the present invention without inventive effort, and such embodiments will fall within the scope of protection of the present invention.

Claims

1. A bulky aluminized label paper, characterized in that: It includes a base paper layer, an ion coating layer, an inner coating layer, an aluminum coating layer and an outer coating layer arranged in sequence from bottom to top; The base paper layer is acidic base paper that has not been supercalendered; The ionic coating contains modified acrylic polyurethane resin and layered double hydroxide; The inner coating and the outer coating are both coatings formed by coating and drying anionic water-based acrylic emulsion; The smoothness of the outer surface of the outer coating is ≥2000S; The layered double hydroxide compound is a mixture of hydrotalcite, montmorillonite, kaolin, muscovite and illite; The pH value of the ionic paint used for coating and forming the ionic coating layer is 8-8.

5.

2. The bulky aluminized label paper according to claim 1, characterized in that: Calculated by weight, the raw materials of the ion coating consist of 59 parts of modified acrylic polyurethane resin, 34.8 parts of layered double hydroxide, 0.2 parts of film-forming aid, 5 parts of citric acid and 1 part of ammonia water.

3. The bulky aluminized label paper according to claim 1, characterized in that: The brightness of the aluminum-plated film layer is 5-7 gloss units.

4. The bulky aluminized label paper according to claim 1, characterized in that: The solid content of the aqueous acrylic emulsion is 25-30%.

5. A method for preparing bulky aluminized label paper, characterized in that: The method for preparing the bulky aluminized label paper according to any one of claims 1 to 4 comprises the following steps: S1) Weighing modified acrylic polyurethane resin, layered double hydroxide, film-forming aid, citric acid and ammonia water according to parts by weight, mixing and stirring uniformly to prepare an ionic coating; S2) using a coating machine to apply the ionic coating to the surface of a base paper that has not been supercalendered, and drying the base paper to obtain a first substrate containing the ionic coating; S3) preparing a water-based acrylic emulsion and coating the surface of the first substrate with the water-based acrylic emulsion using a coating machine, and drying the water-based acrylic emulsion to form an inner coating on the surface of the ion coating, thereby preparing a second substrate comprising the ion coating and the inner coating; S4) using a vacuum aluminum coating machine to sublime the aluminum wire by heating and forming an aluminum coating layer on the surface of the inner coating to prepare a third substrate comprising an ion coating, an inner coating and an aluminum coating layer; S5) using a coating machine to apply the water-based acrylic emulsion on the surface of the third substrate, and the dried water-based acrylic emulsion forms an outer coating on the surface of the aluminized film layer, thereby producing the bulky aluminized label paper comprising an ion coating, an inner coating, an aluminized film layer, and an outer coating.

6. The method for preparing bulky aluminized label paper according to claim 5, characterized in that: In step S2), the coating temperature is 4-40°C, the drying temperature is 80-200°C, and the drying time is 1-4 minutes; the solid content of the ionic coating is 30%, and the coating amount is 11.7-13.3 g / m2.

7. The method for preparing bulky aluminized label paper according to claim 5, characterized in that: In step S3), the coating temperature is 4-40° C., the drying temperature is 80-200° C., and the drying time is 1-4 minutes; the coating amount of the water-based acrylic emulsion is 5.0-6.7 g / m2.

8. The method for preparing bulky aluminized label paper according to claim 5, characterized in that: In step S5), the coating temperature is 4-40° C., the drying temperature is 80-200° C., and the drying time is 1-4 minutes; the coating amount of the water-based acrylic emulsion is 2.7-3.3 g / m2.

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