Coated pearlescent paper and manufacturing method thereof

Abstract

The invention relates to coated pearlescent paper and a manufacturing method thereof. The coated pearlescent paper comprises pearlescent paper and a coating. The pearlescent paper comprises a main layer and two auxiliary layers located on the two sides of the main layer, the main layer comprises first resin and a plurality of first mixed inorganic particles, and each auxiliary layer comprises second resin and a plurality of second mixed inorganic particles. A coating liquid forming the coating layer includes a third resin, a plurality of third mixed inorganic particles, and water. And the third resin is polyurethane resin grafted and modified by acrylate. Based on 100 wt% of the total weight of the coating liquid, the content of the third resin is between 18.5 wt% and 21.5 wt%, the content of the third mixed inorganic particles is between 4 wt% and 8 wt%, and the content of water is between 71.8 wt% and 76.8 wt%. According to the coated pearlescent paper and the manufacturing method thereof, the problem that the coating on the existing pearlescent paper is not easy to be attached by ink can be effectively improved.

Description

Technical Field

[0001] The invention relates to pearl paper and a manufacturing method thereof, in particular to coated pearl paper and a manufacturing method thereof. Background Art

[0002] In the prior art, in order to print ink on pearl paper, a coating is first applied on the pearl paper. However, due to the poor compatibility between the coating and the ink or the pearl paper, the ink is not easy to adhere to the coating. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a coated pearlescent paper and a manufacturing method thereof in view of the deficiencies of the prior art, which can effectively improve the problem that the coating on the existing pearlescent paper is not easily attached by ink.

[0004] In order to solve the above technical problems, one of the technical solutions adopted by the present invention is to provide a coated pearl paper, which includes: pearl paper; wherein the pearl paper includes a main layer and two sub-layers located on both sides of the main layer, the main layer includes a first resin and a plurality of first mixed inorganic particles, the first resin includes polypropylene, the first mixed inorganic particles include calcium carbonate, silicon dioxide and titanium dioxide, each of the sub-layers includes a second resin and a plurality of second mixed inorganic particles, the second resin includes polypropylene, and the second mixed inorganic particles include calcium carbonate, silicon dioxide and titanium dioxide; and a coating layer, by coating The invention relates to a method for preparing a pearlescent paper, wherein the coating liquid is coated on one of the sub-layers of the pearlescent paper; wherein the coating liquid comprises a third resin, a plurality of third mixed inorganic particles and water; wherein the third resin is a polyurethane resin grafted with acrylate, and the third mixed inorganic particles comprise calcium carbonate, silicon dioxide and titanium dioxide; wherein, based on the total weight of the coating liquid being 100wt%, the content of the third resin is between 18.5wt% and 21.5wt%, the content of the third mixed inorganic particles is between 4wt% and 8wt%, and the content of water is between 71.8wt% and 76.8wt%.

[0005] Preferably, the third resin is grafted modified using monomers consisting of the following components, and the sum of the following components is 100wt%: (a) 90-95wt% of alkyl-containing (meth)acrylate; (b) 4-9wt% of hydroxyl-containing (meth)acrylate; (c) 1-5wt% of carboxyl-containing vinyl monomer.

[0006] Preferably, in the third mixed inorganic particles, based on the total weight of the coating liquid being 100wt%, the content of calcium carbonate is between 0.5wt% and 7wt%, the content of silicon dioxide is between 0.5wt% and 6wt%, and the content of titanium dioxide is between 0.5wt% and 2wt%.

[0007] Preferably, the coating liquid further comprises an additive, and the additive is at least one of an auxiliary agent, a catalyst or a co-solvent; wherein, based on the total weight of the coating liquid being 100wt%, the content of the additive is between 0.5wt% and 1wt%.

[0008] Preferably, based on the total weight of the main layer being 100wt%, the content of the first resin is between 85wt% and 95wt%, and the content of the first mixed inorganic particles is between 5wt% and 15wt%; based on the total weight of each of the sub-layers being 100wt%, the content of the second resin is between 85wt% and 95wt%, and the content of the second mixed inorganic particles is between 5wt% and 15wt%; wherein, in the main layer, the content of calcium carbonate or the content of silicon dioxide is higher than the content of titanium dioxide, and in each of the sub-layers, the content of titanium dioxide is higher than the content of silicon dioxide.

[0009] Preferably, the coated pearlescent paper has a light transmittance between 20.5% and 20.8% and a haze between 98.1% and 98.8%.

[0010] In order to solve the above technical problems, another technical solution adopted by the present invention is to provide a method for manufacturing coated pearl paper, which includes: a pearl paper forming step, using an extruder to co-extrude polypropylene, calcium carbonate, silicon dioxide and titanium dioxide to form pearl paper; wherein the pearl paper includes a main layer and two sub-layers located on both sides of the main layer, the main layer includes a first resin and a plurality of first mixed inorganic particles, the first resin includes polypropylene, the first mixed inorganic particles include calcium carbonate, silicon dioxide and titanium dioxide, each of the sub-layers includes a second resin and a plurality of second mixed inorganic particles, the second resin includes polypropylene, and the second mixed inorganic particles include calcium carbonate, silicon dioxide and titanium dioxide. Titanium dioxide; and a coating step, coating the coating liquid on the pearl paper to form a coating on one of the sub-layers of the pearl paper and form a coated pearl paper; wherein the coating liquid comprises a third resin, a plurality of third mixed inorganic particles and water; wherein the third resin is an acrylate grafted modified polyurethane resin, and the third mixed inorganic particles comprise calcium carbonate, silicon dioxide and titanium dioxide; wherein, based on the total weight of the coating liquid being 100wt%, the content of the third resin is between 18.5wt% and 21.5wt%, the content of the third mixed inorganic particles is between 4wt% and 8wt%, and the content of water is between 71.8wt% and 76.8wt%.

[0011] A method for manufacturing coated pearlescent paper, wherein the third resin is graft-modified using monomers consisting of the following components, and the sum of the following components is 100wt%: (a) 90-95wt% of alkyl-containing (meth)acrylate; (b) 4-9wt% of hydroxyl-containing (meth)acrylate; (c) 1-5wt% of carboxyl-containing vinyl monomer.

[0012] Preferably, in the third mixed inorganic particles, based on the total weight of the coating liquid being 100wt%, the content of calcium carbonate is between 0.5wt% and 7wt%, the content of silicon dioxide is between 0.5wt% and 6wt%, and the content of titanium dioxide is between 0.5wt% and 2wt%.

[0013] Preferably, the coating liquid further comprises an additive, and the additive is at least one of an auxiliary agent, a catalyst or a co-solvent; wherein, based on the total weight of the coating liquid being 100wt%, the content of the additive is between 0.5wt% and 1wt%.

[0014] Preferably, based on the total weight of the main layer being 100wt%, the content of the first resin is between 85wt% and 95wt%, and the content of the first mixed inorganic particles is between 5wt% and 15wt%; based on the total weight of each of the sub-layers being 100wt%, the content of the second resin is between 85wt% and 95wt%, and the content of the second mixed inorganic particles is between 5wt% and 15wt%; wherein, in the main layer, the content of calcium carbonate or the content of silicon dioxide is higher than the content of titanium dioxide, and in each of the sub-layers, the content of titanium dioxide is higher than the content of silicon dioxide.

[0015] Preferably, the coated pearlescent paper has a light transmittance between 20.5% and 20.8% and a haze between 98.1% and 98.8%.

[0016] One of the beneficial effects of the present invention is that the coated pearlescent paper and the manufacturing method thereof provided by the present invention can effectively improve the problem that the coating on the existing pearlescent paper is not easily attached by ink through the technical solutions of "the coating liquid comprises the third resin, a plurality of the third mixed inorganic particles and water, the third resin is an acrylate grafted modified polyurethane resin, and the third mixed inorganic particles comprise calcium carbonate, silicon dioxide and titanium dioxide" and "based on the total weight of the coating liquid being 100wt%, the content of the third resin is between 18.5wt% and 21.5wt%, the content of the third mixed inorganic particles is between 4wt% and 8wt%, and the content of water is between 71.8wt% and 76.8wt%".

[0017] In order to further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are only for reference and description and are not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the coated pearlescent paper according to an embodiment of the present invention.

[0019] Figure 2 The flowchart of the method for manufacturing the coated pearlescent paper according to the embodiment of the present invention is shown. DETAILED DESCRIPTION

[0020] The following is an explanation of the implementation methods of the "coated pearlescent paper and its manufacturing method" disclosed in the present invention through specific embodiments. Those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of the present invention. In addition, the drawings of the present invention are only simple schematic illustrations and are not depicted according to actual sizes. It is stated in advance. The following embodiments will further explain the relevant technical contents of the present invention in detail, but the disclosed contents are not intended to limit the scope of protection of the present invention.

[0021] It should be understood that, although the terms "first", "second", "third", etc. may be used herein to describe various components or signals, these components or signals should not be limited by these terms. These terms are mainly used to distinguish one component from another component, or one signal from another signal. In addition, the term "or" used herein may include any one or more combinations of the associated listed items depending on the actual situation.

[0022] [Pearl coated paper]

[0023] See also Figure 1 As shown, Figure 1 Schematic diagram of a coated pearl paper according to an embodiment of the present invention. The embodiment of the present invention provides a coated pearl paper 100. The coated pearl paper comprises a pearl paper 1 and a coating 2. Ink can be easily printed on the coating 2 of the coated pearl paper 100 and is not easily peeled off from the coating 2.

[0024] The pearlescent paper 1 includes a main layer 11 and two sub-layers 12 located on both sides of the main layer 11, the main layer 11 includes a first resin and a plurality of first mixed inorganic particles, the first resin includes polypropylene, the first mixed inorganic particles include calcium carbonate, silicon dioxide and titanium dioxide, each of the sub-layers 12 includes a second resin and a plurality of second mixed inorganic particles, the second resin includes polypropylene, and the second mixed inorganic particles include calcium carbonate, silicon dioxide and titanium dioxide.

[0025] Based on the total weight of the main layer 11 being 100wt%, the content of the first resin is between 85wt% and 95wt%, and the content of the first mixed inorganic particles is between 5wt% and 15wt%. Based on the total weight of each of the sub-layers 12 being 100wt%, the content of the second resin is between 85wt% and 95wt%, and the content of the second mixed inorganic particles is between 5wt% and 15wt%.

[0026] The main layer 11 and each of the sub-layers 12 may be composed of polypropylene only. In addition, in the main layer 11, the number average molecular weight of polypropylene may be between 100,000 and 200,000, and in each of the sub-layers 12, the number average molecular weight of polypropylene may be between 100,000 and 200,000.

[0027] Preferably, in the main layer 11, the content of calcium carbonate or silicon dioxide may be higher than that of titanium dioxide, and in each of the sub-layers 12, the content of titanium dioxide may be higher than that of silicon dioxide. In the main layer 11, a higher content of calcium carbonate or silicon dioxide is matched with a lower content of titanium dioxide to reduce the cost of the coated pearl paper 100. The thickness of each of the sub-layers 12 is lower than that of the main layer 11, and a higher content of titanium dioxide is added to each of the sub-layers 12 to make the coated pearl paper 100 white.

[0028] Specifically, in the main layer 11, based on the total weight of the first mixed inorganic particles being 100wt%, the content of calcium carbonate is between 50wt% and 80wt%, the content of silicon dioxide is between 10wt% and 20wt%, and the content of titanium dioxide is between 1wt% and 10wt%. In each of the sub-layers 12, based on the total weight of the second mixed inorganic particles being 100wt%, the content of calcium carbonate is between 50wt% and 80wt%, the content of silicon dioxide is between 1wt% and 10wt%, and the content of titanium dioxide is between 10wt% and 20wt%. In addition, the thickness of the main layer 11 is between 20 microns and 40 microns, and the thickness of each of the sub-layers 12 is between 5 microns and 15 microns.

[0029] The coating layer 2 is formed by coating a coating liquid on one of the sub-layers 12 of the pearlescent paper 1. The thickness of the coating layer 2 may be between 2 micrometers and 3 micrometers.

[0030] The coating liquid comprises a third resin, a plurality of third mixed inorganic particles and water. The third resin is a polyurethane resin grafted with acrylate, and the third mixed inorganic particles comprise calcium carbonate, silicon dioxide and titanium dioxide. Based on the total weight of the coating liquid being 100wt%, the content of the third resin is between 18.5wt% and 21.5wt%, the content of the third mixed inorganic particles is between 4wt% and 8wt%, and the content of water is between 71.8wt% and 76.8wt%. The third resin has excellent compatibility with the pearl paper, and the third resin also has excellent compatibility with the ink printed on the coating, so that the coating 2 is not easy to peel off from the pearl paper 1 and the ink printed on the coating 2 is not easy to peel off from the coating 2. In addition, the third mixed inorganic particles can absorb the pigment in the ink, thereby improving the printing quality of the ink.

[0031] The third resin is obtained by grafting a polyurethane resin with a monomer composed of the following components, and the sum of the following components is 100 wt %: (a) 90-95 wt % of an alkyl-containing (meth)acrylate; (b) 4-9 wt % of a hydroxyl-containing (meth)acrylate; and (c) 1-5 wt % of a carboxyl-containing vinyl monomer. The alkyl-containing (meth)acrylate is selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, lauryl (meth)acrylate, octadecyl (meth)acrylate, cyclohexyl (meth)acrylate, methoxyethyl (meth)acrylate and ethoxymethyl (meth)acrylate, and one of them is used alone or in combination of more than one, the hydroxyl-containing (meth)acrylate is selected from the group consisting of 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxypropyl chloroacrylate, diethylene glycol mono(meth)acrylate and allyl alcohol, and the carboxyl-containing vinyl monomer is selected from at least one of the material group consisting of acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid and maleic anhydride. In addition, the number average molecular weight of the polyurethane resin may be between 5,000 and 30,000.

[0032] In the third mixed inorganic particles, based on the total weight of the coating liquid being 100wt%, the content of calcium carbonate is between 0.5wt% and 7wt%, the content of silicon dioxide is between 0.5wt% and 6wt%, and the content of titanium dioxide is between 0.5wt% and 2wt%.

[0033] The coating liquid may further include an additive, which is at least one of an auxiliary agent, a catalyst or a co-solvent. Based on the total weight of the coating liquid being 100wt%, the content of the additive is between 0.5wt% and 1wt%.

[0034] The auxiliary agent can adjust the surface tension of the coating liquid and improve the flatness of the coating layer 2 and the wettability with the pearlescent paper 1. The catalyst can control the bridging reaction rate of the coating liquid. The co-solvent can control the volatilization rate of the liquid component in the coating liquid.

[0035] The auxiliary agent may be a silicon-containing additive, a fluorine-containing additive, or a silicon- and fluorine-containing additive. The silicon-containing additive may be BYK307, BYK325, BYK331, BYK380N or BYK381 of BYK, the fluorine-containing additive may be FC-4430, FC-4432 of 3M, Zonyl FSN-100 of DuPont of the United States or DSX of Daikin of Japan, and the silicon- and fluorine-containing additive may be BYK346, BYK347 or BYK348 of BYK.

[0036] The catalyst may be a metal salt, an inorganic substance, a salt, an organic substance, an alkaline substance or an acidic substance. The co-solvent is at least one selected from the group consisting of methanol, ethanol, n-propanol, isopropanol, butanol, dimethyl sulfoxide, acetone and tetrahydrofuran solvents.

[0037] The coated pearlescent paper 100 has a light transmittance between 20.5% and 20.8% and a haze between 98.1% and 98.8%.

[0038] [Method for producing coated pearlescent paper]

[0039] See also Figure 2 As shown, Figure 2 Flow chart of the method for manufacturing coated pearl paper according to an embodiment of the present invention. The embodiment of the present invention also provides a method for manufacturing coated pearl paper, and the aforementioned coated pearl paper 100 can be but is not limited to being prepared by the method for manufacturing coated pearl paper. The method for manufacturing coated pearl paper includes a pearl paper forming step S110 and a coating step S120.

[0040] In the pearl paper forming step S110, polypropylene, calcium carbonate, silicon dioxide and titanium dioxide are co-extruded into pearl paper by an extruder. The pearl paper 1 comprises a main layer 11 and two sub-layers 12 located on both sides of the main layer 11, the main layer 11 comprises a first resin and a plurality of first mixed inorganic particles, the first resin comprises polypropylene, the first mixed inorganic particles comprise calcium carbonate, silicon dioxide and titanium dioxide, each of the sub-layers 12 comprises a second resin and a plurality of second mixed inorganic particles, the second resin comprises polypropylene, and the second mixed inorganic particles comprise calcium carbonate, silicon dioxide and titanium dioxide.

[0041] Based on the total weight of the main layer 11 being 100wt%, the content of the first resin is between 85wt% and 95wt%, and the content of the first mixed inorganic particles is between 5wt% and 15wt%. Based on the total weight of each of the sub-layers 12 being 100wt%, the content of the second resin is between 85wt% and 95wt%, and the content of the second mixed inorganic particles is between 5wt% and 15wt%. In the main layer 11, the content of calcium carbonate or the content of silicon dioxide is higher than the content of titanium dioxide, and in each of the sub-layers 12, the content of titanium dioxide is higher than the content of silicon dioxide.

[0042] In the coating step S120, a coating liquid is coated on the pearl paper 1 to form a coating layer 2 on one of the sub-layers 12 of the pearl paper and form a coated pearl paper 100. The coating liquid comprises a third resin, a plurality of third mixed inorganic particles and water. The third resin is a polyurethane resin grafted with acrylate, and the third mixed inorganic particles comprise calcium carbonate, silicon dioxide and titanium dioxide. Based on the total weight of the coating liquid being 100wt%, the content of the third resin is between 18.5wt% and 21.5wt%, the content of the third mixed inorganic particles is between 4wt% and 8wt%, and the content of water is between 71.8wt% and 76.8wt%.

[0043] In addition, before the coating step S120 and after the pearl paper forming step S110, the method for manufacturing the coated pearl paper may further include a biaxial stretching step. In the biaxial stretching step, the pearl paper having a three-layer structure is biaxially stretched. The biaxial stretching method may be, for example, a longitudinal uniaxial stretching method, a transverse uniaxial stretching method, a longitudinal sequential biaxial stretching method, or a longitudinal simultaneous biaxial stretching method, which is not limited by the present invention. Furthermore, the biaxial stretching method may be, for example, preheating the unstretched pearl paper at a stretching temperature of 50°C to 150°C, and stretching the unstretched pearl paper in the width direction (or transverse direction, TD) according to different stretching ratios, and further stretching the pearl paper in the length direction (or longitudinal direction, MD).

[0044] The third resin is graft-modified using monomers consisting of the following components, and the sum of the following components is 100wt%: (a) 90-95wt% of alkyl-containing (meth)acrylate; (b) 4-9wt% of hydroxyl-containing (meth)acrylate; (c) 1-5wt% of carboxyl-containing vinyl monomer.

[0045] In the third mixed inorganic particles, based on the total weight of the coating liquid being 100wt%, the content of calcium carbonate is between 0.5wt% and 7wt%, the content of silicon dioxide is between 0.5wt% and 6wt%, and the content of titanium dioxide is between 0.5wt% and 2wt%.

[0046] The coating liquid further comprises an additive, which is at least one of an auxiliary agent, a catalyst or a co-solvent. Based on the total weight of the coating liquid being 100wt%, the content of the additive is between 0.5wt% and 1wt%.

[0047] The coated pearlescent paper 100 has a light transmittance between 20.5% and 20.8% and a haze between 98.1% and 98.8%.

[0048] [Experimental data test]

[0049] Hereinafter, the present invention will be described in detail with reference to Examples 1 to 5 and Comparative Examples 1 to 3. However, the following examples are only provided to help understand the present invention, and the scope of the present invention is not limited to these examples.

[0050] In Examples 1 to 5 and Comparative Examples 1 to 3, different coating solutions are applied on the same pearlescent paper. The main layer of the pearlescent paper contains 70 wt % of polypropylene, 21 wt % of calcium carbonate, 6 wt % of silicon dioxide and 3 wt % of titanium dioxide, and each sub-layer of the pearlescent paper contains 70 wt % of polypropylene, 21 wt % of calcium carbonate, 3 wt % of silicon dioxide and 6 wt % of titanium dioxide.

[0051] Example 1: The coating liquid comprises 18.5 wt% of acrylate grafted modified polyurethane resin, 4 wt% of the third mixed inorganic particles, 76.8 wt% of water and 0.7 wt% of additives. The thickness of the coating is 2.2 microns. The third mixed inorganic particles comprise 3.4 wt% of calcium carbonate, 0.5 wt% of silicon dioxide and 0.1 wt% of titanium dioxide.

[0052] Example 2: The coating solution includes 18.5 wt% of acrylate grafted modified polyurethane resin, 6 wt% of the third mixed inorganic particles, 74.8 wt% of water and 0.7 wt% of additives. The thickness of the coating is 2.5 microns. The third mixed inorganic particles include 5.4 wt% of calcium carbonate, 0.5 wt% of silicon dioxide and 0.1 wt% of titanium dioxide.

[0053] Example 3: The coating solution comprises 18.5 wt% of acrylate grafted modified polyurethane resin, 8 wt% of the third mixed inorganic particles, 72.8 wt% of water and 0.7 wt% of additives. The coating thickness is 2.5 microns. The third mixed inorganic particles comprise 7.4 wt% of calcium carbonate, 0.5 wt% of silicon dioxide and 0.1 wt% of titanium dioxide.

[0054] Example 4: The coating solution includes 20 wt% of acrylate grafted modified polyurethane resin, 6 wt% of the third mixed inorganic particles, 73.3 wt% of water and 0.7 wt% of additives. The thickness of the coating is 2.8 microns. The third mixed inorganic particles include 5.4 wt% of calcium carbonate, 0.5 wt% of silicon dioxide and 0.1 wt% of titanium dioxide.

[0055] Example 5: The coating liquid comprises 21.5 wt% of acrylate grafted modified polyurethane resin, 6 wt% of the third mixed inorganic particles, 71.8 wt% of water and 0.7 wt% of additives. The thickness of the coating is 3 microns. The third mixed inorganic particles comprise 5.4 wt% of calcium carbonate, 0.5 wt% of silicon dioxide and 0.1 wt% of titanium dioxide.

[0056] Comparative Example 1: The coating liquid comprises 24.5wt% of acrylate graft-modified polyurethane resin, 0.05wt% of the third mixed inorganic particles, 74.8wt% of water and 0.7wt% of additives. The thickness of the coating is 3 microns. The third mixed inorganic particles comprise 0.030wt% of calcium carbonate, 0.015wt% of silicon dioxide and 0.005wt% of titanium dioxide.

[0057] Comparative Example 2: The coating solution comprises 14.8 wt% of acrylate grafted modified polyurethane resin, 4.8 wt% of the third mixed inorganic particles, 79.7 wt% of water and 0.7 wt% of additives. The thickness of the coating is 0.8 microns. The third mixed inorganic particles comprise 4.2 wt% of calcium carbonate, 0.5 wt% of silicon dioxide and 0.1 wt% of titanium dioxide.

[0058] Comparative Example 3: The coating liquid comprises 6.5 wt% of acrylate grafted modified polyurethane resin, 18 wt% of the third mixed inorganic particles, 74.8 wt% of water and 0.7 wt% of additives. The thickness of the coating is 3 microns. The third mixed inorganic particles comprise 15.0 wt% of calcium carbonate, 2.5 wt% of silicon dioxide and 0.5 wt% of titanium dioxide.

[0059] The composition ratios and thicknesses of the coatings of Examples 1 to 5 and Comparative Examples 1 to 3, as well as the light transmittance, haze, gloss, adhesion, printing quality and printing fastness of the coated pearlescent paper are shown in Table 1, and the relevant test methods are described below.

[0060] Light transmittance test: haze meter TC-H IIIDPK.

[0061] Haze test: Haze meter TC-H IIIDPK.

[0062] Gloss test: gloss meter ZGM1110.268.

[0063] Adhesion test: 3M tape / 100-grid test.

[0064] Printing quality test: observe the printing appearance and image resolution.

[0065] Printing fastness test: 3M tape / 100-grid test.

[0066] Surface roughness testing of coatings: 3D laser microscopy.

[0067] [Table 1: Ratio of ingredients and physicochemical properties of the examples and comparative examples]

[0068]

[0069]

[0070] [Test results discussion]

[0071] In Examples 1 to 5, by having a third resin content of 18.5wt% to 21.5wt%, a third mixed inorganic particle content of 4wt% to 8wt%, a water content of 71.8wt% to 76.8wt%, and a coating thickness of 2.2 microns to 3 microns, the coated pearlescent paper can have a light transmittance of 20.5% to 20.8%, a haze of 98.1% to 98.7%, a gloss of 5.1GU to 5.9GU, and excellent adhesion, printing quality, and printing fastness, and the coating has a surface roughness (Ra) of 0.55 microns to 0.728 microns.

[0072] In Comparative Example 1, the content of the third mixed inorganic particles was low, resulting in high glossiness of the coated pearl paper and poor UV ink absorption, resulting in NG printing quality. In Comparative Example 2, the coating thickness was thin, resulting in NG printing quality of the coated pearl paper, and NG printing fastness with UV ink. In Comparative Example 3, the content of the third mixed inorganic particles was high, resulting in peeling of the coating, and NG printing fastness of the coating with pearl paper and UV ink.

[0073] [Beneficial effects of the embodiments of the present invention]

[0074] One of the beneficial effects of the present invention is that the coated pearlescent paper and the manufacturing method thereof provided by the present invention can effectively improve the problem that the coating on the existing pearlescent paper is not easily attached by ink through the technical solutions of "the coating liquid comprises the third resin, a plurality of the third mixed inorganic particles and water, the third resin is an acrylate grafted modified polyurethane resin, and the third mixed inorganic particles comprise calcium carbonate, silicon dioxide and titanium dioxide" and "based on the total weight of the coating liquid being 100wt%, the content of the third resin is between 18.5wt% and 21.5wt%, the content of the third mixed inorganic particles is between 4wt% and 8wt%, and the content of water is between 71.8wt% and 76.8wt%".

[0075] The contents disclosed above are only preferred feasible embodiments of the present invention, and are not intended to limit the scope of the present invention. Therefore, all equivalent technical changes made using the contents of the present invention description and drawings are included in the scope of the present invention.

Claims

1. A coated pearlescent paper, characterized in that: The coated pearlescent paper comprises: Pearlescent paper; wherein the pearlescent paper comprises a main layer and two sub-layers located on both sides of the main layer, the main layer comprises a first resin and a plurality of first mixed inorganic particles, the first resin comprises polypropylene, the first mixed inorganic particles comprise calcium carbonate, silicon dioxide and titanium dioxide, each of the sub-layers comprises a second resin and a plurality of second mixed inorganic particles, the second resin comprises polypropylene, and the second mixed inorganic particles comprise calcium carbonate, silicon dioxide and titanium dioxide; and A coating layer formed by applying a coating liquid to one of the sub-layers of the pearlescent paper; The coating liquid comprises a third resin, a plurality of third mixed inorganic particles and water; wherein the third resin is a polyurethane resin grafted with acrylate, and the third mixed inorganic particles comprise calcium carbonate, silicon dioxide and titanium dioxide; Wherein, based on the total weight of the coating liquid being 100wt%, the content of the third resin is between 18.5wt% and 21.5wt%, the content of the third mixed inorganic particles is between 4wt% and 8wt%, and the content of water is between 71.8wt% and 76.8wt%.

2. The pearlescent coated paper according to claim 1, characterized in that: The third resin is graft-modified using monomers consisting of the following components, and the sum of the following components is 100wt%: (a) 90-95wt% of alkyl-containing (meth)acrylate; (b) 4-9wt% of hydroxyl-containing (meth)acrylate; (c) 1-5wt% of carboxyl-containing vinyl monomer.

3. The pearlescent coated paper according to claim 1, characterized in that: In the third mixed inorganic particles, based on the total weight of the coating liquid being 100wt%, the content of calcium carbonate is between 0.5wt% and 7wt%, the content of silicon dioxide is between 0.5wt% and 6wt%, and the content of titanium dioxide is between 0.5wt% and 2wt%.

4. The pearlescent coated paper according to claim 1, characterized in that: The coating liquid further comprises an additive, which is at least one of an auxiliary agent, a catalyst or a co-solvent; wherein, based on the total weight of the coating liquid being 100wt%, the content of the additive is between 0.5wt% and 1wt%.

5. The coated pearlescent paper according to claim 1, characterized in that: Based on the total weight of the main layer being 100wt%, the content of the first resin is between 85wt% and 95wt%, and the content of the first mixed inorganic particles is between 5wt% and 15wt%; based on the total weight of each of the sub-layers being 100wt%, the content of the second resin is between 85wt% and 95wt%, and the content of the second mixed inorganic particles is between 5wt% and 15wt%; wherein, in the main layer, the content of calcium carbonate or the content of silicon dioxide is higher than the content of titanium dioxide, and in each of the sub-layers, the content of titanium dioxide is higher than the content of silicon dioxide.

6. The coated pearlescent paper according to claim 1, characterized in that: The coated pearlescent paper has a light transmittance between 20.5% and 20.8% and a haze between 98.1% and 98.8%.

7. A method for producing coated pearlescent paper, characterized in that: The method for manufacturing the coated pearlescent paper comprises: a pearl paper forming step, wherein polypropylene, calcium carbonate, silicon dioxide and titanium dioxide are formed into pearl paper by co-extrusion through an extruder; wherein the pearl paper comprises a main layer and two sub-layers located on both sides of the main layer, the main layer comprises a first resin and a plurality of first mixed inorganic particles, the first resin comprises polypropylene, the first mixed inorganic particles comprise calcium carbonate, silicon dioxide and titanium dioxide, each of the sub-layers comprises a second resin and a plurality of second mixed inorganic particles, the second resin comprises polypropylene, and the second mixed inorganic particles comprise calcium carbonate, silicon dioxide and titanium dioxide; and A coating step, coating the pearlescent paper with a coating liquid to form a coating layer on one of the sub-layers of the pearlescent paper and form a coated pearlescent paper; wherein the coating liquid comprises a third resin, a plurality of third mixed inorganic particles and water; wherein the third resin is an acrylate grafted modified polyurethane resin, and the third mixed inorganic particles comprise calcium carbonate, silicon dioxide and titanium dioxide; wherein, based on the total weight of the coating liquid being 100wt%, the content of the third resin is between 18.5wt% and 21.5wt%, the content of the third mixed inorganic particles is between 4wt% and 8wt%, and the content of water is between 71.8wt% and 76.8wt%.

8. The method for producing coated pearlescent paper according to claim 7, characterized in that: The third resin is graft-modified using monomers consisting of the following components, and the sum of the following components is 100wt%: (a) 90-95wt% of alkyl-containing (meth)acrylate; (b) 4-9wt% of hydroxyl-containing (meth)acrylate; (c) 1-5wt% of carboxyl-containing vinyl monomer.

9. The method for producing coated pearlescent paper according to claim 7, characterized in that: In the third mixed inorganic particles, based on the total weight of the coating liquid being 100wt%, the content of calcium carbonate is between 0.5wt% and 7wt%, the content of silicon dioxide is between 0.5wt% and 6wt%, and the content of titanium dioxide is between 0.5wt% and 2wt%.

10. The method for producing coated pearlescent paper according to claim 7, characterized in that: The coating liquid further comprises an additive, which is at least one of an auxiliary agent, a catalyst or a co-solvent; wherein, based on the total weight of the coating liquid being 100wt%, the content of the additive is between 0.5wt% and 1wt%.

11. The method for producing coated pearlescent paper according to claim 7, characterized in that: Based on the total weight of the main layer being 100wt%, the content of the first resin is between 85wt% and 95wt%, and the content of the first mixed inorganic particles is between 5wt% and 15wt%; based on the total weight of each of the sub-layers being 100wt%, the content of the second resin is between 85wt% and 95wt%, and the content of the second mixed inorganic particles is between 5wt% and 15wt%; wherein, in the main layer, the content of calcium carbonate or the content of silicon dioxide is higher than the content of titanium dioxide, and in each of the sub-layers, the content of titanium dioxide is higher than the content of silicon dioxide.

12. The method for producing coated pearlescent paper according to claim 7, characterized in that: The coated pearlescent paper has a light transmittance between 20.5% and 20.8% and a haze between 98.1% and 98.8%.

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