Fluorescence shielding glue solution as well as preparation method and application thereof

Abstract

The invention discloses a fluorescent shielding glue solution as well as a preparation method and application thereof, relates to the technical field of papermaking, and aims to solve the technical problem that existing synthetic fiber paper cannot meet application requirements. The fluorescent shielding glue solution comprises the following components: a glue solution and a mixture of diethylene glycol diethyl ether and benzotriazole. The fluorescent shielding glue solution is different from other granular chemical coatings and is hydrophilic, so that the air permeability, the surface strength and the watermark anti-counterfeiting effect under light transmission of synthetic fiber paper are not affected after surface sizing treatment is performed on the synthetic fiber paper, and the anti-counterfeiting effect of the synthetic fiber paper is improved while the requirement of the special paper for no fluorescent reaction is met. The papermaking performance and the anti-counterfeiting performance of the paper are not influenced, so that the application requirements are better met.

Description

Technical Field

[0001] The present application relates to the field of papermaking technology, and in particular to a fluorescent shielding glue solution and a preparation method and application thereof. Background Art

[0002] Synthetic fiber paper is a paper made of synthetic fiber raw materials (such as aramid, polyimide or nylon) by wet or dry process. Because it has excellent properties that plant fiber paper cannot match in terms of mechanical strength, water resistance, color change and anti-counterfeiting, paper texture, etc., synthetic fiber paper is a typical representative of high-performance specialty paper products. However, ordinary synthetic fiber paper has a strong fluorescence reaction, so when it is used in some special fields, it cannot meet the application requirements.

[0003] Therefore, the prior art often uses granular chemical coatings such as titanium dioxide or calcium carbonate to shield its fluorescent reaction, but at the same time it will affect other properties of synthetic fiber paper, thereby limiting its application. Summary of the invention

[0004] The present application provides a fluorescent shielding glue solution and a preparation method and application thereof, aiming to solve the technical problem that existing synthetic fiber paper cannot meet application requirements.

[0005] In order to solve the above technical problems, the embodiments of the present application provide: a fluorescent shielding glue solution, comprising the following components: glue solution, diethylene glycol diethyl ether and a benzotriazole mixture.

[0006] As some optional implementations of the present application, the mass ratio of the diethylene glycol diethyl ether to the glue is 5%-15%, and the mass ratio of the benzotriazole mixture to the glue is 5%-15%.

[0007] As some optional embodiments of the present application, each portion of the adhesive solution includes the following components in parts by weight: 5-12 parts of polyvinyl alcohol, 1-3 parts of urea, 0.3-0.8 parts of wet strength agent stock solution, 0.03-0.3 parts of melamine and 87-95 parts of water.

[0008] As some optional embodiments of the present application, each portion of the adhesive solution includes the following components in parts by weight: 5-10 parts of polyvinyl alcohol, 1-2 parts of urea, 0.5-0.6 parts of wet strength agent stock solution, 0.05-0.2 parts of melamine and 88.5-93.45 parts of water.

[0009] As some optional embodiments of the present application, the wet strength agent stock solution is polyamide epichlorohydrin resin;

[0010] The mass fraction of diethylene glycol diethyl ether is 95%-99%;

[0011] The mass fraction of the benzotriazole mixture is 10%-20%.

[0012] As some optional implementations of the present application, the viscosity of the fluorescent shielding glue is 15cp-35cp.

[0013] On the other hand, the embodiment of the present application provides a method for preparing the fluorescent shielding glue as described above, comprising the following steps:

[0014] Add melamine, wet strength agent solution, polyvinyl alcohol and urea into water in proportion, heat to 90°C-95°C, and stir to a preset concentration to obtain a glue solution;

[0015] Under normal temperature conditions, the mixture of diethylene glycol diethyl ether and benzotriazole is mixed uniformly to obtain a clear solution;

[0016] After the glue solution is cooled to room temperature, it is mixed with the clarified liquid and mixed evenly to obtain a fluorescent shielding glue solution.

[0017] On the other hand, an embodiment of the present application provides an application of the fluorescence shielding glue as described above, which is used to shield the fluorescence of synthetic fiber paper.

[0018] As some optional implementations of the present application, when the fluorescence shielding glue is used to shield the fluorescence of synthetic fiber paper, a surface sizing treatment is performed by means of an impregnated roller or a laminating film.

[0019] As some optional embodiments of the present application, when the fluorescent shielding glue is used to shield the fluorescence of synthetic fiber paper, the proportion of each component in the fluorescent shielding glue is obtained based on the initial fluorescence brightness value of the synthetic fiber paper.

[0020] Compared with the prior art, the fluorescent shielding glue provided by the present application includes the following components: glue, diethylene glycol diethyl ether and benzotriazole mixture. It can be seen that the fluorescent shielding glue described in the present application is different from other granular chemical coatings. The fluorescent shielding glue described in the present application is hydrophilic, so after the surface sizing treatment of synthetic fiber paper is performed, it will not affect the air permeability, surface strength and watermark anti-counterfeiting effect of the paper under light transmission. While meeting the requirements of special paper without fluorescent reaction, it does not affect the papermaking performance and anti-counterfeiting performance of the paper, so as to better meet the application requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the prior art description. In all drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0022] Figure 1 The present invention is a schematic diagram of the process flow of the preparation method of the fluorescent shielding glue involved in this application.

[0023] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0025] Fluorescence reaction refers to the process in which a substance is excited by ultraviolet invisible light and then converts the excited energy into visible light. The principle of fluorescence generation is: when light shines on certain atoms, the energy of light causes some electrons around the nucleus to jump from the original orbit to a higher energy orbit, that is, from the ground state to the first excited singlet state or the second excited singlet state, etc. The first excited singlet state or the second excited singlet state is unstable, so it will return to the ground state. When the transition electron returns to the ground state, the energy will be released in the form of light, so fluorescence is generated.

[0026] Synthetic fiber paper is paper made by wet or dry process using synthetic fiber raw materials (such as aramid, polyimide, nylon, etc.). Synthetic fiber paper is a typical representative of high-performance specialty paper products because it has excellent properties that cannot be matched by plant fiber paper in terms of mechanical strength, water resistance, color change and anti-counterfeiting, and paper texture. However, many types of synthetic fibers are fluorescent substances. This is because the necessary condition for the generation of fluorescence is that the molecules of the substance must have a structure that can absorb excitation light. Most of the chemical groups in the molecular chains of synthetic fibers have a conjugated system of carbonyl, carbon-nitrogen double bonds, and benzene rings, that is, they have a structure that can absorb excitation light, which makes the synthetic fiber security paper made from it have a strong fluorescence reaction. This is inconsistent with the non-fluorescence reaction characteristics required for high-grade security paper, which restricts the application of synthetic fibers in the field of high-grade security paper.

[0027] In the prior art, in order to solve the problem of strong fluorescence reaction of the above-mentioned synthetic fiber paper, one of the following methods is usually adopted: chemical treatment, that is, using specific chemicals, such as bleach or oxidant, to perform redox reaction on the fiber to remove the fluorescence reaction; this method may cause a certain degree of damage to the fiber and may affect the strength and durability of the fiber. Another example: ultraviolet irradiation, that is, using ultraviolet rays to irradiate the fiber to destroy the fluorescent substance; but this method usually requires specific equipment and technology, and the processing time is relatively long. Another example is heat treatment, that is, heat treatment of the fiber at high temperature to destroy the fluorescent substance; but this method may require high-temperature equipment and technology, and the processing cost is relatively high.

[0028] However, the above removal methods may cause excessive damage to the fibers in the paper, resulting in reduced paper quality and durability.

[0029] Therefore, some scholars have proposed that in order to reduce the damage to the fiber when implementing the above three methods, the following measures can be taken: for example, when taking chemical treatment, select appropriate chemical agents, and control the treatment time and concentration to reduce the damage to the fiber; protective agents or antioxidants can be used to protect the fiber so that it is not excessively damaged during the chemical treatment process. For example, when using ultraviolet irradiation, control the time and intensity of ultraviolet irradiation to avoid excessive irradiation and fiber damage; at the same time, other measures can be taken, such as using ultraviolet absorbers or antioxidants to protect the fiber. For example, when using heat treatment, control the heating time and temperature to avoid excessive heating and fiber damage; at the same time, appropriate heat treatment methods, such as steam heat treatment or infrared heat treatment, can be selected to reduce damage to the fiber. In addition, other measures can be taken during the treatment process, such as slow cooling or the use of protective agents to reduce damage to the fiber.

[0030] However, although the above measures can reduce the degree of damage to the fibers, at the same time, they will affect the removal effect of the fluorescence reaction.

[0031] Therefore, the present application proposes a process using surface sizing, and develops a surface sizing liquid with a fluorescence shielding function, which provides the paper with a layer of fluorescence shielding outer coat to eliminate the fluorescence of the paper without affecting other properties of the paper.

[0032] Specifically, in response to the above technical problems, the embodiment of the present application provides a fluorescent shielding glue, the viscosity of the fluorescent shielding glue is 15cp-35cp, and it has good film-forming properties and permeability inside the paper. While playing a role in fluorescent shielding of the paper, it can also give the paper excellent mechanical strength and water resistance. It should be noted that when the fluorescent shielding glue is used to remove the fluorescence of the paper, the viscosity of the fluorescent shielding glue is limited mainly to ensure that it has good fluidity so that it can penetrate into the paper evenly and play an effective role. If the viscosity of the fluorescent shielding glue is too high, it will lead to poor fluidity and cannot fully penetrate into the paper, thereby affecting the fluorescent shielding effect. The glue with lower viscosity can better penetrate into the paper and contact the fiber more fully, thereby achieving a better fluorescent shielding effect. In addition, viscosity is also one of the factors that affect the drying speed of the glue on the surface of the paper. Excessive viscosity will lead to slow drying speed, thereby affecting the processing and use of the paper. Therefore, when selecting the fluorescent shielding glue, it is necessary to select a suitable viscosity according to factors such as the type, thickness and processing requirements of the paper to ensure that it can fully exert the fluorescent shielding effect and ensure the quality and performance of the paper.

[0033] Specifically, the fluorescent shielding glue of the present application comprises the following components: glue, diethylene glycol diethyl ether and benzotriazole mixture. Specifically, the mass ratio of diethylene glycol diethyl ether to the glue is 5%-15%, and the mass ratio of the benzotriazole mixture to the glue is 5%-15%.

[0034] It should be noted that each portion of the glue solution includes the following components by weight: 5-12 portions of polyvinyl alcohol (PVA1799), 1-3 portions of urea, 0.3-0.8 portions of wet strength agent stock solution, 0.03-0.3 portions of melamine, and 87-95 portions of water. More specifically, each portion of the glue solution includes the following components by weight: 5-10 portions of polyvinyl alcohol, 1-2 portions of urea, 0.5-0.6 portions of wet strength agent stock solution, 0.05-0.2 portions of melamine, and 88.5-93.45 portions of water.

[0035] It should be noted that the wet strength agent stock solution is polyamide epichlorohydrin resin, the mass fraction of diethylene glycol diethyl ether is 95%-99%, and the mass fraction of the benzotriazole mixture is 10%-20%.

[0036] Among them, the polyvinyl alcohol helps to improve the transparency and color vividness of the paper. At the same time, polyvinyl alcohol has an adhesive effect and can firmly stick the paper together. When making paper printed materials such as books and magazines, using polyvinyl alcohol as a fluorescent shielding glue can enhance the adhesion between the papers, thereby improving the durability of the printed materials. In addition, polyvinyl alcohol can also protect the paper from damage by ultraviolet rays, oxidation and other factors, and extend the service life of the paper; at the same time, it can also improve the water resistance and stain resistance of the paper, making it easier to clean and maintain. However, it should be noted that when using polyvinyl alcohol as a raw material for paper fluorescent shielding glue, it is necessary to select an appropriate concentration and formula according to the specific application scenario to avoid changes in the viscosity of the glue affecting the uniformity of sizing and the fluorescent shielding effect. At the same time, it is also necessary to control parameters such as processing time and temperature to ensure that the glue can fully penetrate into the paper and achieve the desired effect.

[0037] Among them, the diethylene glycol diethyl ether can be used as a plasticizer to help the glue to better penetrate into the paper and enhance the softness and plasticity of the paper; this helps to improve the processing and use performance of the paper, making it easier to bend and fold. And in the embodiment of the present application, the diethylene glycol diethyl ether can also be used as a solvent to help the benzotriazole mixture to better dissolve and disperse in the glue; this helps to improve the stability and uniformity of the glue, so that it can better play its role. In addition, diethylene glycol diethyl ether itself also has the function of an adhesive, which can enhance the bonding force between papers. This helps to improve the durability of printed matter, making it easier to store and use.

[0038] Among them, the benzotriazole mixture can absorb fluorescent substances in paper, thereby reducing the fluorescent reaction of paper under ultraviolet light. This effect helps to improve the transparency and color vividness of paper. The benzotriazole mixture can also act as an antioxidant to protect paper from oxidation and free radical damage. This helps to extend the service life of paper and improve the durability of paper. In addition, the benzotriazole mixture has a certain antibacterial effect and can inhibit the growth and reproduction of bacteria and mold on the surface of paper. This helps to keep the paper clean and hygienic and prevent the paper from getting moldy and deteriorating. However, it should be noted that when the benzotriazole mixture is applied to the paper fluorescence shielding glue, its dosage and ratio need to be controlled to ensure that the glue can fully play its role and avoid excessive damage to the paper.

[0039] It should be noted that the wet strength agent stock solution is a water-soluble cationic thermosetting resin, and its chemical name is polyamide polyamine propylene oxide resin. This resin can significantly improve the dry and wet strength of paper, and can improve the retention rate of fine fibers and fillers. It does not contain formaldehyde and has excellent environmental protection. It is widely used in paper that requires wet strength, such as household paper, cup base paper, fruit bag paper, offset printing paper, packaging paper, newsprint, decorative paper, etc.

[0040] The purpose of adding wet strength agent to the fluorescent shielding glue is to improve the wet strength of the paper. The wet strength agent can combine with the fiber so that the paper can still maintain its structure and strength integrity when it is exposed to water or other solvents. When the paper is exposed to moisture, pressure or friction, if it does not have sufficient wet strength, it will easily break or be damaged, resulting in its inability to be used normally. After adding the wet strength agent, the wet strength of the paper can be significantly improved, so that it can maintain good integrity and usability in various environments. In addition, the wet strength agent can also improve the folding resistance of the paper, making it more resistant to folding and bending and not easy to break. This is very useful for occasions where paper needs to be folded or used frequently.

[0041] It should be noted that the purpose of adding melamine to the fluorescent shielding glue in the embodiment of the present application is to improve the strength and stability of the paper. Melamine is a resin with high adhesion and film-forming properties, which can increase the strength and water resistance of the paper and improve the stability and durability of the paper. In addition, melamine can also interact with the fluorescent shielding agent to enhance the fluorescent shielding effect and improve the anti-counterfeiting performance of the paper.

[0042] It should be noted that the purpose of adding urea to the fluorescent shielding glue in the embodiment of the present application is to increase the stability of the glue. Urea can promote the mixing and dispersion of the glue, making the composition of the glue more uniform and less likely to be stratified, thereby maintaining the stability of the glue. In addition, urea can also improve the water absorption and softness of paper, which helps to improve the printing and writing suitability of paper.

[0043] It can be seen that the fluorescent shielding glue described in the present application is different from other granular chemical coatings. The fluorescent shielding glue described in the present application is hydrophilic. Therefore, after the surface sizing treatment of synthetic fiber paper is performed, it will not affect the air permeability, surface strength and watermark anti-counterfeiting effect of the paper under light transmission. While meeting the requirements of special paper without fluorescent reaction, it does not affect the papermaking performance and anti-counterfeiting performance, so as to better meet application needs.

[0044] Specifically, hydrophilic fluorescent shielding glue can form hydrogen bonds with water molecules and has good water solubility. For fiber paper, the use of hydrophilic fluorescent shielding glue can enhance the water absorption of paper, making it softer, more breathable and easier to wet. This glue helps to increase the surface energy of paper, making it easier to be wetted by water, thereby improving the printing and writing suitability of paper.

[0045] This is determined by the mechanism of action of the hydrophilic fluorescent shielding glue. In actual operation, the hydrophilic fluorescent shielding glue mainly achieves the fluorescent shielding effect through chemical reaction or physical adsorption with the paper fiber; this mode of action may not have a significant negative impact on the air permeability, surface strength and watermark anti-counterfeiting effect of the paper under light transmission. However, it should be noted that when using hydrophilic fluorescent shielding glue, the best shielding effect can be achieved by controlling the dosage and ratio while avoiding excessive damage to the paper. The appropriate dosage and ratio may help maintain the original performance of the paper without adversely affecting its air permeability, surface strength and watermark anti-counterfeiting effect under light transmission.

[0046] Therefore, the proportions of the components described in the present application can be reasonably adjusted according to the intensity of the fluorescent brightness of the synthetic fiber security paper. For example, within the range of 5.0%-10.0%, the mass fraction of PVA1799 relative to the total solution is changed, thereby changing the viscosity of the shielding glue, reducing the penetration of the fluorescent shielding glue inside the paper, and increasing the retention of the fluorescent shielding glue on the surface of the paper, thereby enhancing the fluorescent shielding effect of the glue on the paper. For another example, within the range of 10%-20%, the mass fraction of the benzotriazole mixture relative to the total solution is changed to control the retention of the overall fluorescent shielding glue in the paper, thereby enhancing the fluorescent shielding performance of the fluorescent shielding glue on the paper. Or the above components can be reasonably adjusted at the same time to achieve the purpose of shielding the fluorescence of the paper.

[0047] On the other hand, in order to prepare the above-mentioned fluorescent shielding glue, the embodiment of the present application also provides the following Figure 1 The method for preparing the fluorescent shielding glue solution shown comprises the following steps:

[0048] Step S10, adding melamine, wet strength agent solution, polyvinyl alcohol and urea into water in proportion, heating to 90° C.-95° C., and stirring to a preset concentration to obtain a glue solution;

[0049] Step S20, at room temperature, mixing the mixture of diethylene glycol diethyl ether and benzotriazole uniformly to obtain a clear solution;

[0050] Step S30, after cooling the glue solution to room temperature, mixing it with the clarified liquid, mixing them evenly to obtain a fluorescent shielding glue solution.

[0051] That is, the preparation steps and feeding sequence of the fluorescent shielding glue described in the present application are as follows: based on the total solution mass calculated by the volume of the glue pot, first add 30%-40% of clean water to the glue pot, then add melamine, wet strength agent solution, PVA1799, and urea in sequence, heat to 90℃-95℃ and keep warm, stir for 1 to 2 hours to make a clear glue solution of the concentration required by the process. Then, after the temperature is lowered to room temperature, the clarified liquid of the pre-prepared mixture of diethylene glycol diethyl ether and benzotriazole at room temperature after stirring for 20 minutes is evenly added to the above clarified glue solution, and then stirred for another 10 to 20 minutes to complete the preparation of the fluorescent shielding glue solution.

[0052] After the fluorescent shielding glue solution is prepared through the above steps, the present application adopts the existing surface sizing equipment to carry out sizing treatment on the synthetic fiber, and in actual application, the viscosity of the fluorescent shielding glue solution and the mass fraction of the fluorescent shielding glue solution in the glue solution can be adjusted according to the fluorescent brightness of different security papers. By adjusting the viscosity, the penetration of the fluorescent shielding glue solution into the paper can be reduced, and the retention amount of the fluorescent shielding glue solution on the surface of the paper can be increased, thereby increasing the fluorescent shielding effect on the surface of the paper. By adjusting the mass fraction of the fluorescent shielding glue solution in the glue solution, the retention amount of the overall fluorescent shielding glue solution in the paper can be controlled, thereby adjusting the fluorescent shielding performance of the fluorescent shielding glue solution.

[0053] It can be seen that the fluorescent shielding glue described in the embodiment of the present application has good dispersibility, and does not adopt traditional surface coating with titanium dioxide as the main raw material or other fluorescent shielding methods outside the security paper industry such as other granular raw materials. Due to the excellent water resistance and printing adaptability of security paper, as well as the ink and printing process conditions suitable for security printing, special requirements are placed on the surface properties of paper. If granular chemical coatings (such as titanium dioxide, calcium carbonate, etc.) are used for coating, or aqueous fluorescent shielding substances are directly added to the glue, it is easy to affect the air permeability, surface strength and watermark anti-counterfeiting effect of the paper under light after surface sizing, thereby affecting the printing adaptability and anti-counterfeiting performance. While meeting the non-fluorescent reaction characteristics of high-grade security paper, the present application does not have a negative impact on other physical and chemical indicators, printing adaptability, and anti-counterfeiting performance of the paper.

[0054] The technical solution described in this application is described in detail below in conjunction with specific embodiments:

[0055] Example 1

[0056] Step S10, adding melamine, wet strength agent stock solution, polyvinyl alcohol and urea to water in proportion, heating to 90°C, stirring to a preset concentration, and obtaining a glue solution; 10 parts of polyvinyl alcohol, 2 parts of urea, 0.6 parts of wet strength agent stock solution, 0.05 parts of melamine and 87.35 parts of water;

[0057] Step S20, at room temperature, uniformly mixing diethylene glycol diethyl ether and a benzotriazole mixture to obtain a clear solution; the mass ratio of the diethylene glycol diethyl ether to the glue solution is 15%, and the mass ratio of the benzotriazole mixture to the glue solution is 15%;

[0058] Step S30, after cooling the glue solution to room temperature, mixing it with the clarified liquid, mixing them evenly to obtain a fluorescent shielding glue solution.

[0059] Example 2

[0060] Step S10, adding melamine, wet strength agent stock solution, polyvinyl alcohol and urea to water in proportion, heating to 95°C, stirring to a preset concentration, and obtaining a glue solution; 8 parts of polyvinyl alcohol, 2 parts of urea, 0.6 parts of wet strength agent stock solution, 0.2 parts of melamine and 89.2 parts of water;

[0061] Step S20, at room temperature, mixing diethylene glycol diethyl ether and a benzotriazole mixture uniformly to obtain a clear solution; the mass ratio of the diethylene glycol diethyl ether to the glue solution is 10%, and the mass ratio of the benzotriazole mixture to the glue solution is 10%;

[0062] Step S30, after cooling the glue solution to room temperature, mixing it with the clarified liquid, mixing them evenly to obtain a fluorescent shielding glue solution.

[0063] Example 3

[0064] Step S10, adding melamine, wet strength agent stock solution, polyvinyl alcohol and urea to water in proportion, heating to 92° C., stirring to a preset concentration, and obtaining a glue solution; 5 parts of polyvinyl alcohol, 1 part of urea, 0.5 parts of wet strength agent stock solution, 0.1 parts of melamine and 93.4 parts of water;

[0065] Step S20, at room temperature, uniformly mixing diethylene glycol diethyl ether and a benzotriazole mixture to obtain a clear solution; the mass ratio of the diethylene glycol diethyl ether to the glue solution is 5%, and the mass ratio of the benzotriazole mixture to the glue solution is 5%;

[0066] Step S30, after cooling the glue solution to room temperature, mixing it with the clarified liquid, mixing them evenly to obtain a fluorescent shielding glue solution.

[0067] Example 4

[0068] Using a spectroscopic fluorescence detector, the fluorescence intensity value of a certain synthetic fiber paper was detected to be 19.0 to 22.0.

[0069] Therefore, a fluorescent shielding liquid with a component ratio of 11.0%-12.0% is used, and the proportion of the glue PVA1799 component is 8.0%-9.0%.

[0070] By dipping glue, the glue coating amount is 3.5g / m 2 Up to 4.5g / m 2 , which can reduce the fluorescence value of paper to 8.3-9.8.

[0071] Example 5

[0072] Using a spectroscopic fluorescence detector, the fluorescence value of a certain synthetic fiber paper was detected to be 25.0 to 28.0.

[0073] Therefore, a fluorescent shielding liquid with a component ratio of 13.0%-14.0% is used, and the proportion of the glue PVA1799 component is 9.5%-10.5%.

[0074] By dipping glue, the glue coating amount is 4.5g / m 2 Up to 5.5g / m 2 , which can reduce the paper fluorescence value to 7.6-8.9.

[0075] Comparative Example 1

[0076] The preparation method of granular chemical coating 1 (titanium dioxide) is as follows: first add distilled water, start stirring, then add kaolin, porcelain clay, and titanium dioxide in sequence, after stirring evenly, add adhesive, and after fully stirring, it can be used.

[0077] Among them, the dosage of each component is 10-20 parts of kaolin, 10-20 parts of porcelain clay, 30-50 parts of titanium dioxide, 10-25 parts of adhesive, and 40-50 parts of distilled water.

[0078] When used for paper coating, the coating amount is 5g / m 2 Up to 13g / m 2 .

[0079] Comparative Example 2

[0080] The preparation method of granular chemical coating 2 (calcium carbonate) is as follows: first add distilled water, start stirring, then add kaolin, porcelain clay, and precipitated calcium carbonate (PCC) in sequence, after stirring evenly, add adhesive, and after fully stirring, it can be used.

[0081] The dosage of each component is: 10-20 parts of kaolin, 10-20 parts of porcelain clay, 30-50 parts of precipitated calcium titanate (PCC), 10-25 parts of adhesive, and 40-50 parts of distilled water.

[0082] When used for paper coating, the coating amount is 5g / m 2 Up to 13g / m 2 .

[0083] Application Example 1

[0084] The fluorescent shielding liquid prepared in Examples 1-3 is subjected to surface sizing treatment by means of a dipping roller or a laminating film.

[0085] When the surface sizing treatment is performed by the dipping roller method, the fluorescent shielding liquid is first pumped into the dipping tank. The tank body is designed as a device equipped with an overflow pipeline to ensure that during the continuous dipping operation, shielding liquid is continuously pumped into the tank and the liquid in the tank continuously overflows to ensure the stability of the fluorescent shielding liquid concentration.

[0086] The coating amount of fluorescent shielding liquid is 5g / m 2 Up to 6g / m 2 The impregnation speed is 20 to 60 meters per minute, the impregnation length is 1.0 to 1.8 meters, the impregnation time is 1 to 5.4 seconds, and the impregnated paper passes through two rubber-coated pressing rollers arranged vertically up and down. The rubber roller runs at a linear speed of 20 to 60 meters per minute to ensure that the paper obtains a stable and uniform coating amount.

[0087] Application Example 2

[0088] The fluorescent shielding liquid prepared in Example 1-3 was subjected to surface sizing treatment by means of laminating.

[0089] When using the laminating method for surface sizing treatment, first connect the fluorescent shielding liquid to the laminating equipment so that the laminating liquid is evenly sprayed on the paper surface. During laminating, the coating amount of the fluorescent shielding liquid is 4.5g / m 2 Up to 5.5g / m 2 The coated paper passes through two rubber-coated pressing rollers arranged vertically in the upper and lower directions. The running speed of the rubber rollers is 20 to 60 meters per minute, ensuring that the paper obtains a stable and uniform coating amount.

[0090] Application Example 3

[0091] The granular chemical coating prepared in Comparative Example 1-2 is applied to the surface of the synthetic fiber paper by coating.

[0092] Specific coating operation: The coating is applied to the paper base through a squeeze roller coating head, a material roller, and a scraper device, and then dried by far infrared rays, air cushion drying, drying cylinders, etc., to form coated paper. The squeeze roller coating head is composed of a double or triple roller combination. The coating amount is controlled by a gap feeding device. The coating roller transfers the coating to the paper web. The amount of coating on the paper web is determined by factors such as the affinity of the coating to the paper web, the coating to the coating roller, the viscosity of the coating, the absorbency of the paper web, the relative speed between the paper web and the coating roller, and the pressure between the rollers.

[0093] Precautions during coating: During the coating process, coating adaptability refers to the ability to coat well and form a uniform and smooth coating layer. To meet this requirement, the various components in the coating must be fully and evenly dispersed, and the coating concentration, viscosity and fluidity must be compatible with the form of the coating machine.

[0094] Experimental Example 1

[0095] The viscosity of the fluorescent shielding liquid prepared in Examples 1 to 3 was tested, and the test results are as follows:

[0096] The viscosity of the fluorescent shielding liquid prepared in Example 1 is 28.2 cP;

[0097] The viscosity of the fluorescent shielding liquid prepared in Example 2 is 22.4 cP;

[0098] The viscosity of the fluorescent shielding liquid prepared in Example 3 is 15.5 cP.

[0099] Experimental Example 2

[0100] The products of Examples 1-3 and the products of Comparative Examples 1-2 were respectively coated or glued on synthetic fiber paper having a fluorescence intensity value of 25.0 to 28.0, and the fluorescence of the coated or glued paper was tested. The test results are as follows:

[0101] The fluorescence value of the paper treated with the coating described in Comparative Example 1 is 17.5 to 20.6;

[0102] The fluorescence value of the paper treated with the coating described in Comparative Example 2 is 19.2 to 23.8;

[0103] The fluorescence value of the paper using the fluorescent shielding liquid described in Example 1 is 6.5 to 8.2;

[0104] The fluorescence value of the paper using the fluorescent shielding liquid described in Example 2 is 11.8 to 13.3;

[0105] The fluorescence value of the paper using the fluorescent shielding liquid described in Example 3 is 15.3 to 19.7.

[0106] It can be seen that the fluorescence value of the paper treated with the fluorescent shielding agent described in the example of the present application has been significantly reduced compared with that of comparative example 1-2.

[0107] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A fluorescent shielding glue, characterized in that: The invention comprises the following components: glue, diethylene glycol diethyl ether and benzotriazole mixture.

2. The fluorescent shielding glue according to claim 1, characterized in that: The mass ratio of the diethylene glycol diethyl ether to the glue solution is 5%-15%, and the mass ratio of the benzotriazole mixture to the glue solution is 5%-15%.

3. The fluorescent shielding glue according to claim 1, characterized in that: Each portion of the adhesive solution comprises the following components by weight: 5-12 portions of polyvinyl alcohol, 1-3 portions of urea, 0.3-0.8 portions of wet strength agent stock solution, 0.03-0.3 portions of melamine and 87-95 portions of water.

4. The fluorescent shielding glue according to claim 3, characterized in that: Each portion of the adhesive solution comprises the following components by weight: 5-10 portions of polyvinyl alcohol, 1-2 portions of urea, 0.5-0.6 portions of wet strength agent stock solution, 0.05-0.2 portions of melamine and 88.5-93.45 portions of water.

5. The fluorescent shielding glue according to claim 4, characterized in that: The wet strength agent stock solution is polyamide epichlorohydrin resin; The mass fraction of diethylene glycol diethyl ether is 95%-99%; The mass fraction of the benzotriazole mixture is 10%-20%.

6. The fluorescent shielding glue according to claim 1, characterized in that: The viscosity of the fluorescent shielding glue is 15cp-35cp.

7. A method for preparing the fluorescent shielding glue according to any one of claims 1 to 6, characterized in that: The following steps are involved: Add melamine, wet strength agent solution, polyvinyl alcohol and urea into water in proportion, heat to 90°C-95°C, and stir to a preset concentration to obtain a glue solution; Under normal temperature conditions, the mixture of diethylene glycol diethyl ether and benzotriazole is mixed uniformly to obtain a clear solution; After the glue solution is cooled to room temperature, it is mixed with the clarified liquid and mixed evenly to obtain a fluorescent shielding glue solution.

8. An application of the fluorescent shielding glue according to any one of claims 1 to 4, characterized in that: Used to shield the fluorescence of synthetic fiber paper.

9. The use of the fluorescent shielding glue according to claim 8, characterized in that: When the fluorescence shielding glue is used to shield the fluorescence of synthetic fiber paper, the surface sizing treatment is carried out by means of a dipping roller or a laminating film.

10. The use of the fluorescent shielding glue according to claim 8, characterized in that: When the fluorescence shielding glue is used to shield the fluorescence of synthetic fiber paper, the proportion of each component in the fluorescence shielding glue is obtained based on the initial fluorescence brightness value of the synthetic fiber paper.

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