Crystal pearlescent paper with waterproof function and preparation method thereof

Abstract

The invention discloses crystal pearlescent paper with a waterproof function and a preparation method of the crystal pearlescent paper, and particularly relates to the technical field of special paper manufacturing. The pearlescent paper comprises water-based ink and body paper, the water-based ink is prepared from 30%-50% of water-based acrylic resin, 7%-20% of water-based amino resin, 4%-6% of a cross-linking agent, 5%-8% of a nanoscale organic silicon modifier, 10%-15% of pearlescent pigment, 1.5%-2.5% of a dispersing agent, 0.5%-1.2% of a rheological additive, 0.3%-0.8% of a wetting agent and the balance deionized water. The pearlescent paper is simple in raw material selection, safe, environmentally friendly, simple in preparation process, mild in preparation condition, high in preparation efficiency, good in ink adhesiveness during printing and rapid in absorption and drying, and the obtained pearlescent paper is good and durable in pearlescent effect, good in wear resistance, free of scratch, ink skin and other phenomena and high in water resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of special paper manufacturing, and particularly relates to a crystal pearlescent paper with waterproof function and a preparation method thereof. Background Art

[0002] Pearlescent paper is a synthetic paper with unique luster and texture, and is widely used in fields such as packaging and decoration. Traditional pearlescent paper usually uses polypropylene as the main material. For example, in Chinese Patent CN110656535A, a water-based environmental protection pearlescent paper and its production method, which solves the problems of poor refractive effect and poor environmental protection of existing pearlescent paper. It includes the following steps: (1) Soaking pearlescent powder in a treatment liquid composed of ethanol and water; (2) Mixing acrylic emulsions with high glass transition temperature and low glass transition temperature and then diluting with water to obtain a binder; (3) Adding the soaked pearlescent powder into the binder, and adding water to adjust to obtain a water-based environmental protection pearlescent coating; (4) Rotating the water-based environmental protection pearlescent coating onto the base paper through a coating roller; (5) Measuring with a measuring rod; (6) Air knife coating; (7) Drying. The pearlescent paper of the present invention has no phenomenon of exposing the base paper layer, has good refractive effect, is safe and environmentally friendly, and adjacent papers do not stick. The method of the present invention can be widely used for coating coatings on the surfaces of rough papers and embossed papers to prepare pearlescent paper. Although the pearlescent paper obtained by this patent has good water resistance and surface smoothness, there are problems such as high density, affected surface smoothness, and easy sedimentation of pigments. In addition, after long-term use, the calcium carbonate on the surface of the pearlescent paper may fall off, resulting in a rough surface of the pearlescent paper and affecting the quality.

[0003] In Chinese Patent CN113944066A, a pearlescent paper with good wear resistance and its preparation process, the pearlescent paper with good wear resistance is composed of four parts: base paper, pearlescent pigment, adhesive and thickener; after mixing the pearlescent pigment, adhesive and thickener, adding water and mixing evenly to obtain pearlescent ink; using a coating device to transfer the pearlescent ink onto both sides of the base paper, and then drying and curing the transferred paper to obtain the required pearlescent paper with good wear resistance. However, this patent fails to solve the problem of poor waterproofness of pearlescent paper.

[0004] Chinese Patent CN108677601A, a pearlescent paper and its manufacturing process. The pearlescent paper includes: a paper sheet and a pearlescent coating layer printed on the surface of the paper sheet. The pearlescent coating layer comprises the following raw materials in parts by weight: 150 - 200 parts of water; 0.5 - 1 part of a dispersant; 3 - 8 parts of silicon dioxide; 20 - 30 parts of 1000 pearlescent powder; 5 - 10 parts of 205 pearlescent powder; 10 - 15 parts of 100 pearlescent powder; 200 - 250 parts of 8011 pearlescent binder; 100 - 150 parts of 8019 pearlescent binder. Since silicon dioxide with good ink absorption performance is added to the pearlescent coating layer and 8019 pearlescent binder with good ink absorption performance is used, the ink absorption performance of the pearlescent paper and the problem of slow drying during printing are improved. However, the problem of poor waterproof performance of the pearlescent paper has not been solved yet. Summary of the Invention

[0005] For this reason, the present invention provides a crystal pearlescent paper with waterproof function and its preparation method to solve the problems in the prior art.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A crystal pearlescent paper with waterproof function according to the first aspect of the present invention, the pearlescent paper comprises water-based ink and base paper; wherein, the water-based ink includes: 30 - 50% of water-based acrylic resin, 7 - 20% of water-based amino resin, 4 - 6% of a cross-linking agent, 5 - 8% of nano-scale organosilicon modifier, 10 - 15% of pearlescent pigment, 1.5 - 2.5% of a dispersant, 0.5 - 1.2% of a rheology aid, 0.3 - 0.8% of a wetting agent, and the balance is deionized water.

[0008] Further, the ratio of the water-based acrylic resin to the water-based amino resin is 1.7 - 4:1. As an example, the preferred ratio is 3:1. The water-based acrylic resin and the water-based amino resin, as the main film-forming substances, have good film-forming properties. After drying, they can form a tough and elastic film on the surface of the paper, which can not only improve the waterproof property of the paper, but also enhance the physical properties such as abrasion resistance, scratch resistance and tear resistance of the paper, and improve the durability and service life of the pearlescent paper.

[0009] Further, the cross-linking agent is hexamethoxymethylmelamine resin. The addition of the cross-linking agent can cause the water-based acrylic resin and the water-based amino resin to undergo a cross-linking reaction under certain conditions to form a three-dimensional network structure. This not only improves the hardness, strength and stability of the resin film, but also improves the chemical resistance and heat resistance of the ink, so that the pearlescent paper can maintain good performance under different environmental conditions.

[0010] Furthermore, the pearlescent pigment is mica-based. The addition of the pearlescent pigment endows the pearlescent paper with a unique pearlescent luster and rich color effects. By controlling the content of the pearlescent pigment and adopting a suitable dispersion method during the preparation process, the pearlescent pigment can be evenly dispersed in the ink, so that the paper exhibits a bright and uniform pearlescent luster, enhancing the visual appeal and decorative properties of the printed matter.

[0011] Furthermore, the dispersant is polycarboxylate. The use of the dispersant helps to evenly disperse solid particles such as pearlescent pigments in the ink system, preventing pigment agglomeration and sedimentation, and ensuring the stability and consistency of the ink. At the same time, the dispersant can also improve the wettability between the ink and the paper surface, enabling the ink to adhere better to the paper and improving the printing quality.

[0012] Furthermore, the rheology modifier is fumed silica. The addition of the rheology modifier can adjust the rheology of the ink, giving it appropriate viscosity and thixotropic properties. During the printing process, the ink can have a lower viscosity under high shear forces, facilitating smooth transfer through the screen; after printing, the ink can quickly return to a higher viscosity, preventing the ink from flowing and bleeding, and ensuring the clarity and accuracy of the printed pattern. By adding deionized water to adjust the final viscosity and thixotropic index, it can be ensured that the ink has good fluidity during 150-mesh screen printing, meeting the requirements of different printing processes.

[0013] Furthermore, the wetting agent is alkynediol. The role of the wetting agent is to reduce the surface tension of the ink, improve the wettability and adhesion of the ink to the paper surface, enable the ink to spread better on the paper, form a uniform ink film, and avoid phenomena such as ink droplets and flying ink, thereby improving the printing quality and effect.

[0014] The nano-scale organosilicon modifier can improve the waterproof performance of the pearlescent paper. Organosilicon materials have a low surface energy and good hydrophobicity, and can form a uniform and dense waterproof protective film on the paper surface, effectively blocking the intrusion of moisture, so that the pearlescent paper can maintain stable performance even in a humid environment or when in contact with water, preventing problems such as deformation and color fading caused by water absorption.

[0015] Furthermore, the preparation method of the water-based ink is as follows:

[0016] 1) Pre-dispersion stage

[0017] Mix the water-based acrylic resin and deionized water in proportion, stir evenly, then add the water-based amino resin and the cross-linking agent, and mix evenly to obtain the base liquid; add the dispersant and the wetting agent to the base liquid, and continue stirring to form a premixed liquid;

[0018] As an example, the preferred stirring conditions are stirring at 800 - 1200 r / min for 8 - 15 minutes; the stirring conditions for continuous stirring are stirring at 800 - 1200 r / min for 3 - 8 minutes.

[0019] 2) Pretreatment of nano - organosilicon modifier

[0020] Premix the nano - organosilicon modifier with a part of the base liquid and disperse it by ultrasonic waves to obtain a nano - organosilicon mixed liquid;

[0021] As an example, the preferred amount of the part of the base liquid is 8 - 12%; ultrasonic dispersion: frequency 35 - 45 kHz, time 10 - 20 min.

[0022] 3) Addition of pigments and functional additives

[0023] Add the pearlescent pigment in batches to the remaining premixed liquid and disperse it with a high - speed disperser to prevent pigment sedimentation; add the rheology additive and the nano - organosilicon mixed liquid in sequence, and control the system temperature ≤ 35°C to prevent premature cross - linking of the resin;

[0024] As an example, the preferred high - speed dispersion: 1800 - 2200 r / min, 25 - 35 min.

[0025] 4) Regulation of rheology and viscosity

[0026] Adjust the viscosity, pH value and thixotropic index to ensure smooth printing;

[0027] As an example, the viscosity is 150 - 250 mPa·s (25°C), the thixotropic index is controlled at 3.5 - 4.0; the pH is 8.5 - 9.5.

[0028] 5) Filtration and storage

[0029] Filter to remove undispersed particles, fill into a sealed container and store in the dark to obtain the water - based ink.

[0030] As an example, filtration is carried out using a 200 - mesh filter screen.

[0031] According to a method for preparing a crystal pearlescent paper with a waterproof function provided by the second aspect of the present invention, the method includes using the base paper, adjusting the doctor blade pressure and printing speed, performing printing, pre - drying after printing, and then performing ultraviolet curing.

[0032] As an example, it is preferred to adjust the doctor blade pressure to 0.2 - 0.3 MPa, the printing speed is 5 - 8 m / min; pre - dry at 75 - 85°C for 1 - 2 min, and then perform ultraviolet curing (energy 800 mJ / cm 2 )

[0033] The preparation method further includes: improving the surface glossiness by a soft calender (pressure 10 - 15 kN, temperature 55 - 65 °C).

[0034] Application of a crystal pearlescent paper with waterproof function provided by the third aspect of the present invention in packaging paper, outdoor advertising or special printing paper.

[0035] Among them, packaging paper is usually used for high - end packaging, such as luxury gift boxes and wine labels, with both waterproof and pearlescent texture; outdoor advertising mainly has strong weather resistance and is suitable for posters and display boards in humid environments; special printing paper includes anti - counterfeiting marks and art albums that require high - precision screen printing.

[0036] The present invention has the following advantages:

[0037] In the water - based ink of the crystal pearlescent paper with waterproof function of the present invention, water - based acrylic resin and water - based amino resin are added as the main film - forming substances of the water - based ink, and cross - linking reaction occurs under the action of a cross - linker. The cross - linking reaction forms a three - dimensional network structure between resin molecules, enhancing the strength and stability of the resin film. The nano - level organosilicon modifier is tightly combined with the formed resin film, further enhancing the firmness and durability of the waterproof film. This synergistic effect not only improves the waterproof performance of the paper but also enables the waterproof effect to remain stable under long - term use and different environmental conditions.

[0038] The raw materials of the present invention are simply selected, safe, environmentally friendly, the preparation process is simple, the preparation conditions are mild, the preparation efficiency is high, the ink adhesion is good during printing, the absorption and drying are fast, the obtained pearlescent paper has a good and lasting pearlescent effect, not only has good abrasion resistance and will not produce phenomena such as scratches and ink skins, but also has high water - resistance performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only exemplary, and for those of ordinary skill in the art, without creative efforts, other implementation drawings can be obtained according to the provided drawings.

[0040] The structures, ratios, sizes, etc. illustrated in this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they do not have technical essence. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention.

[0041] Figure 1TEM image of a water-based ink provided in Example 1 of the present invention;

[0042] Figure 2 The pearlescent paper diagram provided in Example 1 of the present invention;

[0043] Figure 3 This is a TEM image of a water-based ink provided in Comparative Example 2 of the present invention. DETAILED DESCRIPTION

[0044] The following describes the implementation of the present invention using specific embodiments. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. Obviously, the embodiments described are only a portion of the present invention, not all of it. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are intended to fall within the scope of protection of the present invention.

[0045] Water-based acrylic resin: Pearlescent binder 830 containing water-based acrylic resin, Yingde Xinlian Chemical Co., Ltd.

[0046] Water-based amino resin: water-based fast-curing amino resin CYMEL 325, Adrianson;

[0047] Cross-linking agent: hexamethoxymethyl melamine resin, CAS No. 3089-11-0;

[0048] Nano-scale organosilicon modifier: Shanghai Tiger Polymer Technology Co., Ltd., organosilicon modifier Tech-2176;

[0049] Pearlescent pigment: 600 mesh mica-based pigments of different colors;

[0050] Dispersant: Guangdong Wengjiang Chemical Reagent Co., Ltd., polycarboxylate dispersant PB89005;

[0051] Rheological additive: Evonik Degussa, AEROSIL R812S;

[0052] Wetting agent: Shanghai Canghong Industrial Co., Ltd., acetylene glycol surfactant BETTERSOLI 607.

[0053] Example 1

[0054] This embodiment provides a crystal pearlescent paper with waterproof function: the pearlescent paper includes water-based ink and base paper;

[0055] Water-based ink formula and preparation: Formula composition (mass percentage):

[0056] Waterborne acrylic resin: 40%; Waterborne amino resin: 13.3% (acrylic resin: amino resin = 3:1); Hexamethoxymethylmelamine resin (crosslinking agent): 5%; Nano-organosilicon modifier: 6%; Mica-based pearlescent pigment: 12%; Polycarboxylate dispersant: 2%; Fumed silica (rheology aid): 0.8%; Alkynediol wetting agent: 0.5%; Deionized water: the balance (about 20.4%);

[0057] Mica-based pearlescent pigment: Shenzhen Hangcai Pigment Co., Ltd., YC-401 Glossy Black Pearlescent Pigment;

[0058] Preparation method:

[0059] 1. Premixing: Mix the waterborne acrylic resin and deionized water in proportion, stir evenly, then add the waterborne amino resin and crosslinking agent, and mix evenly as the base liquid, stir at 1000 r / min for 12 minutes; add the dispersant and wetting agent, and stir at 1000 r / min for 5 minutes.

[0060] 2. Nano-organosilicon pretreatment: Take 10% of the base liquid and the nano-organosilicon modifier, and ultrasonically disperse at 40 kHz for 15 minutes.

[0061] 3. Pigment dispersion: Add the pearlescent pigment in 3 batches to the remaining premixed liquid, disperse at high speed of 2000 r / min for 30 minutes; add the rheology aid and nano-organosilicon mixture in sequence, and control the temperature ≤ 35 °C.

[0062] 4. Regulation: Adjust the viscosity to 200 mPa·s (25 °C), pH to 9.0, and thixotropic index to 3.8.

[0063] 5. Filtration: Filter through a 200-mesh sieve and store in the dark to obtain the waterborne ink. The TEM image is as Figure 1 shown. It can be seen that the microscopic structure on the surface of the ink presents a relatively uniform distribution state, indicating that the nano-structure distribution on the hydrophobic surface of the ink is relatively consistent.

[0064] Pearlescent paper: 1. Use a 150-mesh screen, adjust the blade pressure to 0.25 MPa, and the printing speed to 6 m / min.

[0065] 2. Immediately pre-dry at 80 °C for 1 min after printing, and then cure by ultraviolet light (energy 800 mJ / cm 2 ) to enhance abrasion resistance.

[0066] 3. Calendering treatment: Improve the surface gloss through a soft roll calender (pressure 10 kN, temperature 60 °C). The appearance of the obtained black pearlescent paper is as Figure 2 shown.

[0067] Example 2

[0068] This embodiment provides a crystal pearlescent paper with waterproof function: The pearlescent paper includes water-based ink and base paper;

[0069] Formulation and preparation of water-based ink: Composition of the formulation (mass percentage):

[0070] Water-based acrylic resin: 30%; Water-based amino resin: 7.5% (acrylic resin: amino resin = 4:1); Hexamethoxymethyl melamine resin (crosslinking agent): 4%; Nano-organosilicon modifier: 5%; Mica-based pearlescent pigment: 10%; Polycarboxylate dispersant: 1.5%; Fumed silica (rheology aid): 0.5%; Alkynediol wetting agent: 0.3%; Deionized water: the balance (about 41.2%);

[0071] Mica-based pearlescent pigment: Shenzhen Hangcai Pigment Co., Ltd., YC-401 Glossy Black Pearlescent Powder;

[0072] Preparation method:

[0073] 1. Pre-dispersion: Mix water-based acrylic resin and deionized water in proportion, stir evenly, then add water-based amino resin and crosslinking agent, mix evenly to obtain the base liquid, stir at 800 r / min for 15 minutes; Add dispersant and wetting agent, stir at 800 r / min for 8 minutes.

[0074] 2. Nano-organosilicon pretreatment: Take 8% of the base liquid and nano-organosilicon modifier, ultrasonically disperse at 35 kHz for 20 minutes.

[0075] 3. Pigment dispersion: Add the pearlescent pigment in 5 batches to the remaining premixed liquid, disperse at high speed of 1800 r / min for 35 minutes; Add rheology aid and nano-organosilicon mixture in sequence, control the temperature ≤ 35 °C.

[0076] 4. Regulation: Adjust the viscosity to 150 mPa·s (25 °C), pH to 8.5, and thixotropic index to 3.8.

[0077] 5. Filtration: Filter through a 200-mesh sieve and store in the dark to obtain water-based ink.

[0078] Pearlescent paper: 1. Use a 150-mesh screen plate, adjust the blade pressure to 0.2 MPa, and the printing speed to 8 m / min.

[0079] 2. Immediately pre-dry at 85 °C for 2 min after printing, and then cure by ultraviolet light (energy 800 mJ / cm 2 ) to enhance abrasion resistance.

[0080] 3. Calendering treatment: Improve the surface gloss through a soft roll calender (pressure 10 kN, temperature 65 °C).

[0081] Example 3

[0082] This embodiment provides a crystal pearlescent paper with waterproof function: the pearlescent paper includes water-based ink and base paper;

[0083] Formulation and preparation of water-based ink: Composition of the formulation (mass percentage):

[0084] Water-based acrylic resin: 34%; water-based amino resin: 20% (acrylic resin: amino resin = 1.7:1); hexamethoxymethyl melamine resin (crosslinking agent): 6%; nano-organosilicon modifier: 8%; mica-based pearlescent pigment: 10%; polycarboxylate dispersant: 2%; fumed silica (rheology aid): 0.8%; alkynediol wetting agent: 0.8%; deionized water: the balance (about 18.4%);

[0085] Mica-based pearlescent pigment: Hangzhou Fubo Technology Co., Ltd., P110W (Soft Satin);

[0086] Preparation method:

[0087] 1. Pre-dispersion: Mix water-based acrylic resin and deionized water in proportion, stir evenly, then add water-based amino resin and crosslinking agent, and mix evenly as the base liquid, stir at 1200 r / min for 10 minutes; add dispersant and wetting agent, stir at 1000 r / min for 5 minutes.

[0088] 2. Nano-organosilicon pretreatment: Take 10% of the base liquid and nano-organosilicon modifier, disperse by ultrasonic at 40 kHz for 15 minutes.

[0089] 3. Pigment dispersion: Add pearlescent pigment in 3 batches to the remaining premixed liquid, disperse at high speed of 2200 r / min for 30 minutes; add rheology aid and nano-organosilicon mixture in turn, control the temperature ≤ 35 °C.

[0090] 4. Regulation: Adjust the viscosity to 250 mPa·s (25 °C), pH to 9.5, and thixotropic index to 3.8.

[0091] 5. Filtration: Filter through a 200-mesh sieve and store in the dark to obtain water-based ink. It can be seen that the microscopic structure on the surface of the ink shows a relatively uniform distribution state, indicating that the nano-structure distribution on the hydrophobic surface of the ink is relatively consistent.

[0092] Pearlescent paper: 1. Use a 150-mesh screen plate, adjust the scraper pressure to 0.3 MPa, and the printing speed to 5 m / min.

[0093] 2. Immediately pre-dry at 80 °C for 1.5 min after printing, and then cure by ultraviolet light (energy 800 mJ / cm 2 ) to enhance wear resistance.

[0094] 3. Calendering: The surface gloss is improved by a soft roll calender (pressure 12 kN, temperature 60 °C).

[0095] Example 4

[0096] This example provides a crystal pearlescent paper with waterproof function: The pearlescent paper includes water-based ink and base paper;

[0097] Formulation and preparation of water-based ink: Composition of the formulation (mass percentage):

[0098] Water-based acrylic resin: 50%; Water-based amino resin: 12.5% (acrylic resin: amino resin = 4:1); Hexamethoxymethylmelamine resin (crosslinking agent): 5%; Nano-organosilicon modifier: 5%; Mica-based pearlescent pigment: 10%; Polycarboxylate dispersant: 2%; Fumed silica (rheology aid): 0.8%; Alkynediol wetting agent: 0.8%; Deionized water: balance (about 13.4%);

[0099] Mica-based pearlescent pigment: Hangzhou Fubo Technology Co., Ltd., P110W (Soft Satin);

[0100] Preparation method:

[0101] 1. Pre-dispersion: Mix the water-based acrylic resin and deionized water in proportion, stir evenly, then add the water-based amino resin and crosslinking agent, mix evenly as the base liquid, stir at 1200 r / min for 15 minutes; Add the dispersant and wetting agent, stir at 1200 r / min for 8 minutes.

[0102] 2. Nano-organosilicon pretreatment: Take 10% of the base liquid and nano-organosilicon modifier, ultrasonically disperse at 40 kHz for 15 minutes.

[0103] 3. Pigment dispersion: Add the pearlescent pigment to the remaining premixed liquid in 5 batches, disperse at high speed of 2200 r / min for 30 minutes; Add the rheology aid and nano-organosilicon mixture in sequence, control the temperature ≤ 35 °C.

[0104] 4. Regulation: Adjust the viscosity to 250 mPa·s (25 °C), pH to 9.5, and thixotropic index to 3.8.

[0105] 5. Filtration: Filter through a 200-mesh sieve and store in the dark to obtain the water-based ink. The microscopic structure on the surface of the visible ink shows a relatively uniform distribution state, indicating that the nano-structure distribution on the hydrophobic surface of the ink is relatively consistent.

[0106] Pearlescent paper: 1. Use a 150-mesh screen plate, adjust the doctor blade pressure to 0.3 MPa, and the printing speed to 5 m / min.

[0107] 2. Immediately after printing, pre-dry at 80℃ for 2 minutes, and then UV cure (energy 800mJ / cm 2 ) Enhance wear resistance.

[0108] 3. Calendering treatment: Improve the surface gloss through a soft roller calender (pressure 12kN, temperature 60℃).

[0109] Comparative Example 1

[0110] This comparative example provides a crystal pearlescent paper:

[0111] In this comparative example, no crosslinking agent was added to the water-based ink, and other aspects were completely the same as in Example 1 to obtain pearlescent paper.

[0112] Comparative Example 2

[0113] This comparative example provides a crystal pearlescent paper:

[0114] The water-based ink formula composition of this comparative example water-based ink (mass percentage):

[0115] Water-based acrylic resin: 20%; water-based amino resin: 6% (acrylic resin: amino resin = 3.3:1); hexamethoxymethyl melamine resin (crosslinking agent): 5%; nano-organic silicon modifier: 6%; mica-based pearlescent pigment: 15%; polycarboxylate dispersant: 2%; fumed silica (rheological additive): 0.8%; acetylene glycol wetting agent: 0.8%; deionized water: balance (about 44.4%); a water-based ink was prepared using the method of Example 1, and the TEM image is shown in FIG. Figure 3 As shown, there are obvious cracks on the surface of the water-based ink nanostructure.

[0116] The other steps were exactly the same as in Example 1 to obtain pearlescent paper.

[0117] Comparative Example 3

[0118] This comparative example provides a crystal pearlescent paper:

[0119] In this comparative example, no nano-organic silicon modifier was added to the water-based ink, and the other properties were the same as those in Example 1 to obtain pearlescent paper.

[0120] Comparative Example 4

[0121] This comparative example provides a crystal pearlescent paper:

[0122] In this comparative example, the waterborne acrylic resin in the waterborne ink is 30%, the waterborne amino resin is 20% (acrylic resin: amino resin = 1.5:1), hexamethoxymethyl melamine resin (crosslinking agent): 6%; nano-organosilicon modifier: 8%; mica-based pearlescent pigment: 10%; polycarboxylate dispersant: 2%; fumed silica (rheology aid): 0.8%; alkynediol wetting agent: 0.8%; deionized water: the balance (about 22.4%); The waterborne ink was prepared by the method of Example 1, and the others were exactly the same as those of Example 1 to obtain pearlescent paper.

[0123] Comparative Example 5

[0124] This comparative example provides a crystal pearlescent paper:

[0125] Replace the nano-organosilicon modifier with paraffin emulsion, and the others are exactly the same as those of Example 1.

[0126] Experimental Example

[0127] Test the performance of the pearlescent papers obtained in Examples 1-4 and Comparative Examples 1-5, and the test results are shown in Table 1.

[0128] Abrasion resistance: aber test, CS-10 wheel, 500 g load, mass loss %;

[0129] Table 1

[0130] Water contact angle Mass loss % Water absorption rate in 24h % Glossiness / 60°GU Example 1 125° 0.7 Not water-absorbed 92 Example 2 115° 1.1 Not water-absorbed 88 Example 3 120° 0.9 Not water-absorbed 90 Example 4 120° 0.9 Not water-absorbed 90 Comparative example 1 90° 1.9 1.5 75 Comparative example 2 85° 2.0 2.2 70 Comparative example 3 95° 1.6 1.2 75 Comparative example 4 105° 1.5 0.8 80 Comparative example 5 80° 2.2 Not water-absorbed 70

[0131] As can be seen from Table 1, the waterborne ink formulations of Examples 1-4 perform excellently in terms of water contact angle, abrasion resistance, water absorption and glossiness, indicating that their formulations are reasonable and can effectively improve the comprehensive performance of pearlescent paper. However, due to the lack of some key components or improper component ratios in the comparative examples, their performance has declined, especially in terms of hydrophobicity, abrasion resistance and water absorption. This shows that in the formulation of waterborne ink, the reasonable combination and ratio control of each component are crucial for improving the performance of pearlescent paper.

[0132] Although the present invention has been described in detail above with general descriptions and specific examples, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection of the present invention.

Claims

1. A crystal pearlescent paper with waterproof function, characterized in that, The pearlescent paper comprises water-based ink and base paper; wherein, the water-based ink comprises: 30-50% of water-based acrylic resin, 7-20% of water-based amino resin, 4-6% of cross-linking agent, 5-8% of nano-level silicone modifier, 10-15% of pearlescent pigment, 1.5-2.5% of dispersant, 0.5-1.2% of rheology aid, 0.3-0.8% of wetting agent, and the balance being deionized water.

2. The water-proof crystal pearlescent paper according to claim 1, characterized in that, The ratio of the water-based acrylic resin to the water-based amino resin is 1.7-4:

1.

3. A crystal pearlescent paper with waterproof function according to claim 1, characterized in that, The cross-linking agent is hexamethoxymethyl melamine resin.

4. A crystal pearlescent paper with waterproof function according to claim 1, characterized in that, The pearlescent pigment is mica-based.

5. A crystal pearlescent paper with waterproof function according to claim 1, characterized in that, The dispersant is polycarboxylate.

6. A crystal pearlescent paper with a waterproof function according to claim 1, characterized in that, The rheology aid is fumed silica.

7. A crystal pearlescent paper with waterproof function according to claim 1, characterized in that, The wetting agent is alkynediol.

8. A crystal pearlescent paper with a waterproof function according to claim 1, characterized in that, The preparation method of the water-based ink is as follows: 1) Pre-dispersion stage Mix the water-based acrylic resin and deionized water in proportion, stir evenly, then add the water-based amino resin and cross-linking agent, and mix evenly to obtain a base liquid; add the dispersant and wetting agent to the base liquid, and continue to stir to form a premixed liquid. 2) Pretreatment of nano-level silicone modifier Premix the nano-level silicone modifier with part of the base liquid, and perform ultrasonic dispersion to obtain a nano-level silicone mixed liquid. 3) Addition of pigment and functional aids Add the pearlescent pigment to the remaining premixed liquid in batches, disperse it with a high-speed disperser to avoid pigment sedimentation; sequentially add the rheology aid and nano-level silicone mixed liquid, and control the system temperature ≤ 35°C to prevent premature cross-linking of the resin. 4) Regulation of rheology and viscosity Adjust the viscosity, pH value and thixotropic index to ensure smooth printing. 5) Filtration and storage Filter to remove undispersed particles, fill into a sealed container, and store in the dark to obtain the water-based ink.

9. A preparation method of a crystal pearlescent paper with waterproof function, characterized in that, The method includes using base paper, adjusting the doctor blade pressure and printing speed, performing printing, pre-drying after printing, and then performing UV curing.

10. Application of a waterproof crystal pearlescent paper in packaging paper, outdoor advertising or special printing paper.

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