A method for manufacturing a solvent-free silicone oil type antibacterial release paper

Abstract

The application discloses a kind of solvent-free silicone oil type antibacterial release paper production method, belong to papermaking technical field, comprising the following steps: S1, conifer, broadleaf wood is cut into wood chip and then is cooked, after the wood chip after cooking is immersed in sulfite solution, it is taken out and excess moisture is removed by extrusion, and the wood chip is obtained sulfite pulp by disc mill;S2, after adding filler powder, wet strength agent, fiber dispersing agent, water in sulfite pulp, papermaking raw pulp is obtained, after papermaking raw pulp is treated by beating, rough base paper is obtained by papermaking operation;S3, after the two sides of rough base paper are coated with isolation pulp solution and antibacterial pulp solution, drying and calendering treatment are carried out, to obtain glassine paper;S4, solvent-free silicone oil release agent is coated on the surface of antibacterial coating of glassine paper, and after drying, antibacterial release paper is obtained;The antibacterial release paper of the application has good antibacterial effect, and the antibacterial coating and the release layer are firmly attached to each other.

Description

Technical Field

[0001] The invention relates to the technical field of papermaking, and in particular to a method for preparing solvent-free silicone oil type antibacterial release paper. Background Art

[0002] Release paper is usually required in sanitary products such as sanitary napkins and panty liners. In order to prevent the release paper from becoming a breeding ground for bacteria, it is usually necessary to have good antibacterial properties. The antibacterial properties of the release paper can improve the safety of these sanitary products. In the production process of release paper, adding antibacterial agents to the pulp or coating the surface of the base paper with antibacterial agents to form an antibacterial coating can make the release paper have good antibacterial properties. However, adding antibacterial agents to the pulp will cause a large amount of antibacterial agents to remain in the papermaking white water, resulting in waste of resources and increased costs. Coating the surface of the base paper with antibacterial agents to form an antibacterial coating can avoid the waste of antibacterial agents. The antibacterial coating can be arranged on the side of the base paper away from the release agent layer or between the base paper and the release agent layer. The former will expose the antibacterial coating to the environment and easily cause chemical migration, and the latter may affect the adhesion of the release agent to the surface of the base paper. The above methods of making the release paper have antibacterial properties all have defects.

[0003] Based on the above situation, Chinese patent publication number CN110886127A discloses a method for preparing antibacterial and antistatic release paper, which uses fast-growing pine wood as pulp raw material, and obtains glassine base paper through papermaking and papermaking. The glassine base paper is then soaked in an acetic acid solution, dried, corona pre-treated, and a mixed release agent is coated on the glassine base paper. The antibacterial and antistatic release paper is obtained by drying. The mixed release agent includes the following ingredients: food-grade methyl silicone oil, palladium calcium carbonate, antioxidant, chitosan, ultraviolet absorber, antistatic agent and palm oil.

[0004] In the release paper disclosed in the above patent, chitosan is added to the mixed release agent to make the release paper have an antibacterial effect. However, the methyl silicone oil in the mixed release agent can effectively prevent the release layer from the penetration of external moisture and gas, which easily makes it difficult for the chitosan inside the release layer to come into contact with the outside world and difficult to exert the antibacterial effect of chitosan, thereby resulting in unsatisfactory antibacterial effect of the release paper. Therefore, this release paper still has room for improvement. Summary of the Invention

[0005] In view of the technical defects existing in the background technology, the present invention proposes a method for preparing a solvent-free silicone oil-based antibacterial release paper, which solves the above technical problems and meets practical needs. The specific technical solution is as follows:

[0006] A method for preparing solvent-free silicone oil-based antibacterial release paper comprises the following steps:

[0007] S1. Debarking and defoliating coniferous and hardwood wood, and then cutting the wood chips into wood chips, placing the wood chips in a cooking vessel and steaming them, immersing the cooked wood chips in a sulfite solution, removing the impregnated wood chips and removing excess water by squeezing them, and then grinding the squeezed wood chips to obtain sulfite pulp;

[0008] S2. Adding filler powder, a wet strength agent, a fiber dispersant, and water to sulfite pulp to obtain a papermaking stock, beating the papermaking stock, spreading it on a mesh screen surface through a headbox, and shaping it into a paper blank through a finishing roller. The paper blank is then pressed to remove excess water and set, and then dried to obtain a coarse base paper.

[0009] S3. Applying an isolation slurry and an antibacterial slurry to both sides of the coarse base paper, drying the slurry, and calendering the slurry to obtain glassine paper; wherein the isolation slurry forms an isolation film layer on one side of the coarse base paper after drying, and the antibacterial slurry forms an antibacterial coating on the other side of the coarse base paper after drying. The glassine paper comprises the isolation film layer, the coarse base paper, and the antibacterial coating;

[0010] S4. A solvent-free silicone oil release agent is coated on the surface of the antibacterial coating of the glassine paper and then dried to form a release layer. The glassine paper and the release layer together constitute the antibacterial release paper.

[0011] As a further technical solution of the present invention, the antibacterial slurry includes the following components in percentage by mass: 63% to 75% aqueous polyacrylic acid emulsion, 3% to 6% antibacterial agent, 20% to 30% bridging particles, and 0.5% to 1% dispersant; the solid content of the aqueous polyacrylic acid emulsion is 10% to 20%, and the bridging particles are polyethylene particles with a particle size of 10 to 50 μm.

[0012] As a further technical solution of the present invention, the solvent-free silicone oil release agent includes the following components by mass percentage: 98% to 99% solvent-free silicone oil and 1% to 2% bridging aid; the bridging aid is selected from one of a silane coupling agent, diisopropylbenzene peroxide, and vinyltrimethoxysilane.

[0013] As a further technical solution of the present invention, the antibacterial agent is selected from one or more of polyhexamethylene guanidine hydrochloride, ε-polylysine, quaternary ammonium salt compounds, inorganic silver ion antibacterial agents, and inorganic zinc ion antibacterial agents; in step S3, the dry coating amount of the antibacterial slurry is 1~2gsm.

[0014] As a further technical solution of the present invention, in step S4, the dry coating weight of the solvent-free silicone oil release agent is 0.5-2 gsm.

[0015] As a further technical solution of the present invention, in step S4, the antibacterial release paper is dried at a temperature of 120-180°C.

[0016] As a further technical scheme of the present application, in step S1, the mass ratio of the wood chips to the sulfite solution is 1:(4~6), and the dry weight of the sulfite in the sulfite solution is 20%~40% of the dry weight of the wood chips.

[0017] As a further technical scheme of the present application, the concentration of the papermaking stock is 4%~8%, and the beating degree is 45~60°SR, the papermaking stock contains 10%~30% of filler powder, 0.5%~1.5% of wet strength agent, and 0.05%~0.2% of fiber dispersing agent, all based on the dry weight of the wood chips.

[0018] As a further technical scheme of the present application, the filler powder is selected from one or more of calcium carbonate powder, calcium silicate powder, talc powder, and mica powder.

[0019] As a further technical scheme of the present application, the release slurry comprises the following components in percentage by mass: 4%~8% of cassava oxidized starch, 0.5%~2% of starch enhancer, 0.2%~0.5% of sodium carboxymethyl cellulose, and the balance of water; in step S3, the dry coating amount of the release slurry is 1~2gsm.

[0020] The present application has the following beneficial effects:

[0021] The present application uses sulfite pulp to make Graassin paper, which is smooth on the surface and dense inside after calendering treatment, and has isolation film layers and antibacterial coating layers on both sides, thereby improving the surface waterproofness and antibacterial effect of the Graassin paper, and making the stress more evenly dispersed during the calendering treatment to avoid curling of the Graassin paper. After coating a solvent-free silicone oil release agent on the surface of the antibacterial coating layer of the Graassin paper, an antibacterial release paper is obtained, which has antibacterial effect while avoiding chemical migration caused by exposure of the antibacterial coating layer to the environment, and the release layer and the bridging particles in the antibacterial coating layer are crosslinked under the action of the bridging aid during the drying process, thereby improving the adhesion strength between the antibacterial coating layer and the release layer. DETAILED DESCRIPTION

[0022] The embodiments of the present application will be described below in conjunction with relevant examples, and the embodiments of the present application are not limited to the following examples, and the present application relates to the necessary components in the related technical field, which should be regarded as the known technology in the technical field and can be known and mastered by the person skilled in the art.

[0023] A method for making a solvent-free silicone oil type antibacterial release paper, comprising the following steps:

[0024] S1. Debarking and defoliating coniferous and hardwood wood, and then cutting the wood chips into wood chips, placing the wood chips in a cooking vessel and steaming them, immersing the cooked wood chips in a sulfite solution, removing the impregnated wood chips and removing excess water by squeezing them, and then grinding the squeezed wood chips to obtain sulfite pulp;

[0025] S2. Adding filler powder, a wet strength agent, a fiber dispersant, and water to sulfite pulp to obtain a papermaking stock, beating the papermaking stock, spreading it on a mesh screen surface through a headbox, and shaping it with a finishing roller to obtain a paper blank. The paper blank is then pressed to remove excess water and set, and then dried to obtain a coarse base paper.

[0026] S3. Applying an isolation slurry and an antibacterial slurry to both sides of the coarse base paper, drying the slurry, and calendering the slurry to obtain glassine paper; wherein the isolation slurry forms an isolation film layer on one side of the coarse base paper after drying, and the antibacterial slurry forms an antibacterial coating on the other side of the coarse base paper after drying. The glassine paper comprises the isolation film layer, the coarse base paper, and the antibacterial coating;

[0027] S4. A solvent-free silicone oil release agent is coated on the surface of the antibacterial coating of the glassine paper and then dried to form a release layer. The glassine paper and the release layer together constitute the antibacterial release paper.

[0028] The present invention mainly processes softwood and hardwood as raw materials into sulfite pulp and then produces glassine paper and release paper. In step S1, the softwood and hardwood need to remove the bark and leaves before cutting. This is because the bark and leaves contain more impurities such as resin, which can easily affect the purity of the pulp. The fiber structure of the pulp can be optimized and the quality of the final paper obtained can be better. The softwood and hardwood are cut into wood chips with uniform thickness and then steamed. During the steaming process, the fiber structure inside the wood chips will be softened and the connection structure between the fibers will be destroyed, so that the fibers inside the wood chips are flexible and plastic. Steaming can also kill the fine particles in the wood chips. The wood chips are soaked in a sulfite solution, and the pH of the sulfite solution is controlled within the range of 6 to 9. The wood chips are heated and soaked to effectively remove impurities such as lignin from the wood chips. The wood chips are then taken out and cleaned, and excess water is removed by a screw extruder before being refined by a disc grinder. The disc grinder exerts a strong mechanical action on the wood chips through high-speed rotating grinding discs, so that the fibers are further refined and dispersed into single fibers or fiber bundles. An appropriate amount of water is added during the disc grinding process to refine the fibers and improve the disc grinding efficiency. The wood chips are then disc ground to obtain sulfite pulp.

[0029] In step S2, the sulfite pulp can be bleached to an appropriate whiteness using a bleaching agent as needed, and then filler powder, a wet strength agent, a fiber dispersant, and water are added to the sulfite pulp to obtain a papermaking stock pulp with a concentration of 4% to 8%. The papermaking stock pulp is beaten by a trough beater. The beater mechanically separates and brooms the pulp fibers, thereby increasing the surface area and bonding strength of the fibers. The beating degree of the beater is 45 to 60° SR. During the beating process, the appropriate beating degree of the papermaking stock pulp is adjusted according to the required fiber refinement degree and fiber dispersion degree. After the beating, the papermaking stock pulp is completed. The internal fibers and the appropriate degree of dispersion and refinement are achieved; the papermaking pulp that has completed the pulping process is evenly distributed on the surface of the mesh curtain through the headbox, thus forming the initial shape of the paper. The finishing roller will then flatten and shape its surface to obtain a paper prototype. The shaping treatment by the finishing roller can further improve the flatness and smoothness of the paper prototype, and eliminate possible problems such as fiber orientation stripes. The paper prototype is then pressed by a pressing felt to remove excess moisture and improve the internal tightness of the paper prototype, and can make the surface of the coarse base paper smoother and flatter after drying.

[0030] Furthermore, the papermaking pulp contains 10% to 30% filler powder, 0.5% to 1.5% wet strength agent, and 0.05% to 0.2% fiber dispersant calculated based on the dry weight of the wood chips; the filler powder added to the papermaking pulp can fill the spaces between the fibers of the coarse base paper, reduce the pores of the coarse base paper, and improve the surface smoothness of the coarse base paper; the filler powder can also reduce the amount of fiber used in the papermaking pulp, thereby reducing the amount of raw materials such as coniferous wood and hardwood used; the wet strength agent is preferably polyamide polyepichlorohydrin resin, which can significantly improve the dry and wet strength of the paper, and the beating degree The higher the papermaking pulp, the larger the fiber surface area in the papermaking pulp, the greater the adsorption capacity for the wet strength agent, and the final dry and wet strength of the paper are correspondingly improved. In addition, the wet strength agent has a strong adsorption effect on negatively charged fillers, sizing agents and fine fibers, and has obvious retention and filtration effects in the papermaking process; the fiber dispersant is preferably polyethylene oxide, which can shorten the beating time and improve the softness and strength of the paper after papermaking. The fiber dispersant can also form a network and interact with the suspended solids present in the papermaking pulp to improve the retention rate of fillers and fibers.

[0031] In step S3, the isolation film layer is formed on one side of the rough base paper after the isolation slurry is coated on the side, which is similar to the sizing operation in the common papermaking process. The isolation film layer can significantly improve the water resistance, oil resistance, durability, surface smoothness and other properties of the paper, thereby improving the grade and quality of the paper. The antibacterial slurry is coated on the other side of the rough base paper, which can partially penetrate into the rough base paper and form an antibacterial coating layer on the surface. The antibacterial coating layer can kill bacteria by using the antibacterial agent with broad-spectrum bactericidal function, so as to avoid the internal part of the paper becoming a breeding ground for bacteria, and to make the final antibacterial release paper meet the antibacterial requirements of sanitary napkins and other sanitary products. After the isolation film layer and the antibacterial coating layer are formed on the two sides of the rough base paper respectively, the glassine paper is obtained by smoothing the surface and making the internal part dense and uniform for multiple times. The glassine paper has the isolation film layer and the antibacterial coating layer on the two sides respectively, so that the stress can be dispersed more uniformly during the calendering process, and the glassine paper can avoid the phenomenon of curling after the calendering process.

[0032] In step S4, the release layer is formed on the surface of the antibacterial coating layer of the glassine paper, which can avoid the chemical migration caused by the exposure of the antibacterial coating layer to the environment. The antibacterial coating layer can better protect the internal fibers in the antibacterial release paper, thereby improving the antibacterial effect of the antibacterial release paper.

[0033] As one of the preferred embodiments of the present application, the antibacterial slurry comprises the following components by mass percentage: water-based polyacrylic acid emulsion 63%~75%, antibacterial agent 3%~6%, bridging particles 20%~30%, dispersant 0.5%~1%. The water-based polyacrylic acid emulsion is used as the main film-forming component of the antibacterial slurry, and the solid content of the water-based polyacrylic acid emulsion is 10%~20%. The water in the water-based polyacrylic acid emulsion is used as the carrier or solvent of the antibacterial slurry, so as to dissolve or wrap the antibacterial agent, bridging particles and dispersant respectively, thereby forming a uniformly dispersed mixed system. The antibacterial agent has antibacterial effect after the antibacterial slurry is solidified into the antibacterial coating layer. The bridging particles are polyethylene particles with a particle size of 10~50 μm, which can be better filled into the position of the rough base paper surface downwardly depressed. The dispersant is preferably alkyl benzene sulfonate, which can ionize anions in water and form a negative charge layer on the surface of the bridging particles, thereby preventing the bridging particles from agglomerating.

[0034] As one of the preferred embodiments of the present application, the dry coating amount of the solvent-free silicone oil release agent is 0.5-2 gsm, and the solvent-free silicone oil release agent comprises the following components by mass percentage: 98-99% of solvent-free silicone oil, 1-2% of bridging aid; the solvent-free silicone oil contains silicone polymer, vinyl silicone oil, crosslinking agent, catalyst and the like, the silicone polymer and the vinyl silicone oil jointly constitute the basic framework of the solvent-free silicone oil, the silicone polymer and the vinyl silicone oil can undergo addition reaction with the active hydrogen atoms in the crosslinking agent, thereby curing the solvent-free silicone oil release agent into a release layer, the catalyst can significantly reduce the activation energy of the reaction and accelerate the crosslinking reaction, thereby shortening the curing time and improving the production efficiency.

[0035] Further, the bridging aid is selected from one of silane coupling agent, dicumyl peroxide, and vinyl trimethoxysilane; in the drying and molding process of the antibacterial coating layer of the glassine paper, the water in the antibacterial slurry volatilizes to form a polyacrylic film, the thickness of the film is lower than the particle size of the bridging microparticles, and the bridging microparticles are raised on the surface of the antibacterial coating layer; in the calendering process of the glassine paper, the bridging microparticles are embedded into the base paper at the bottom and are pressed flat at the top due to the pressure; after the solvent-free silicone oil release agent is coated, the antibacterial release paper is dried at a temperature of 120-180°C, which can heat the bridging microparticles into molten polyethylene; at this time, the bridging aid in the solvent-free silicone oil release agent can promote the crosslinking reaction between the polyethylene and the silicone polymer and the vinyl silicone oil to achieve bridging with each other, thereby firmly fixing the antibacterial coating layer and the release layer through the bridging microparticles and improving the adhesion of the release layer on the surface of the antibacterial release paper.

[0036] As one of the preferred embodiments of the present application, the dry coating amount of the antibacterial slurry is 1-2 gsm, and the antibacterial agent is selected from one or more of polyhexamethylene guanidine hydrochloride, ε-polylysine, quaternary ammonium salt compound, inorganic silver ion antibacterial agent, and inorganic zinc ion antibacterial agent; the polyhexamethylene guanidine hydrochloride inhibits the growth of bacteria by interfering with the synthesis of cell walls and destroys the structure of bacterial cell membranes to cause the death of bacteria; the ε-polylysine has obvious inhibitory and killing effects on various microorganisms such as yeast, gram-positive bacteria and gram-negative bacteria; the quaternary ammonium salt compound can react with ions in bacteria to achieve the antibacterial effect; the inorganic silver ion antibacterial agent combines with the cell membrane, cell wall and intracellular proteins, enzymes and other biological macromolecules of bacteria, fungi and other microorganisms through anions, interferes with their normal physiological functions, and thus plays a role in killing bacteria; the inorganic zinc ion antibacterial agent absorbs on the surface of bacteria through zinc ions, destroys the electrolyte balance of bacteria and causes the death of bacteria, and at the same time, the zinc ions also enter the inside of bacteria, react with cell enzymes and combine, thereby inhibiting the activity of cell enzymes and the reproduction and regeneration of bacteria.

[0037] As one of the preferred embodiments of the present invention, in step S1, the mass ratio of wood chips to sulfite solution is 1:(4-6), and the dry weight of sulfite in the sulfite solution is 20%-40% of the dry weight of the wood chips. The sulfite solution is preferably a sodium sulfite solution. The sulfite solution is an important raw material for making sulfite pulp. The sulfite ions in the sulfite solution react with the lignin in the wood chips to cause sulfonation and hydrolysis to form water-soluble lignin sulfonate. This chemical reaction effectively dissolves and removes lignin, which is beneficial to improving the quality and strength of paper. In addition, the removal of lignin and the purification of cellulose during the cooking process reduce colored substances in the pulp, which is beneficial to improving the subsequent bleaching effect of the pulp.

[0038] As one of the preferred embodiments of the present invention, the filler powder is selected from one or more of calcium carbonate powder, calcium silicate powder, talc powder, and mica powder; the above-mentioned powdered materials are all common papermaking fillers, among which calcium carbonate powder can provide a bright base color for paper and improve the fluffiness, durability, wear resistance and softness of the paper; calcium silicate powder can make the color of paper more stable and improve the strength and fluffiness of paper; talc powder is beneficial to making the surface of paper smoother and improving the wear resistance, chemical stability and softness of paper; mica powder is beneficial to improving the weather resistance, water resistance and chemical stability of paper; therefore, by adding filler powder to papermaking pulp, it is beneficial to improve the various properties of the final antibacterial release paper.

[0039] As one of the preferred embodiments of the present invention, the isolation slurry includes the following components by mass percentage: 4% to 8% oxidized cassava starch, 0.5% to 2% starch enhancer, 0.2% to 0.5% sodium carboxymethyl cellulose, and the balance is water. In step S3, the dry coating amount of the isolation slurry is 1 to 2 gsm. The oxidized cassava starch has good adhesion and film-forming properties, so that the isolation slurry can evenly form an isolation film layer on the surface of the coarse base paper, improving the tear resistance of the paper and making the paper smoother and flatter. The starch enhancer can enhance the adhesion, film-forming properties, and other properties of the oxidized cassava starch, thereby achieving better coating and film-forming effects at a lower dosage. The sodium carboxymethyl cellulose can improve the water resistance of the paper and make the paper surface smooth and delicate. The sodium carboxymethyl cellulose can enhance the interfiber bonding of the paper, thereby improving the mechanical strength of the paper, such as tear resistance and folding resistance.

[0040] The isolation slurry is prepared as follows: water is poured into a suitable container, and then the oxidized cassava starch and the starch enhancer are dispersed in the water, and heated to a liquid while stirring to gelatinize the oxidized cassava starch. After the liquid is fully gelatinized, sodium carboxymethyl cellulose is added and stirred evenly to obtain the isolation slurry.

[0041] In summary, the present invention uses sulfite pulp to produce glassine paper. After calendering, the glassine paper has a smooth surface and a dense interior. An isolation film layer and an antibacterial coating are provided on both sides of the glassine paper, respectively, to improve the surface waterproofness and antibacterial effect of the glassine paper, and to make the stress dispersion more uniform during the calendering process to avoid curling of the glassine paper. After a solvent-free silicone oil release agent is coated on the surface of the antibacterial coating of the glassine paper, the antibacterial release paper is obtained, so that the antibacterial release paper has an antibacterial effect while avoiding chemical migration caused by exposure of the antibacterial coating to the environment. In addition, during the drying process, the release layer undergoes a cross-linking reaction with the bridging particles in the antibacterial coating under the action of a bridging agent, thereby improving the strength of adhesion between the antibacterial coating and the release layer.

[0042] The present invention is further described below by way of examples and comparative examples.

[0043] Example 1

[0044] S1. Debarking and defoliating coniferous and hardwood wood, and then cutting the wood chips into wood chips, placing the wood chips in a cooking vessel and steaming them, immersing the cooked wood chips in a 6% sulfite solution, with a mass ratio of wood chips to sulfite solution of 1:5, removing the impregnated wood chips and removing excess water by squeezing, and then grinding the squeezed wood chips to obtain sulfite pulp;

[0045] S2. Adding 20% ​​calcium carbonate powder, calculated based on the dry weight of wood chips, 1% polyamide polyepichlorohydrin resin, and 0.1% polyethylene oxide to sulfite pulp to obtain a papermaking stock pulp. After beating the papermaking stock pulp, the papermaking stock pulp is spread flat on a mesh curtain surface through a headbox and shaped by a finishing roller to obtain a paper blank. The papermaking stock pulp has a concentration of 6% and a beating degree of 60° SR. The paper blank is then pressed to remove excess moisture and set, and then dried to obtain a coarse base paper.

[0046] S3. Applying an isolation slurry and an antibacterial slurry to both sides of a coarse base paper, drying the slurry, and calendering the slurry to obtain glassine paper; wherein, after drying, the isolation slurry forms an isolation film layer on one side of the coarse base paper, and after drying, the antibacterial slurry forms an antibacterial coating on the other side of the coarse base paper. The glassine paper comprises the isolation film layer, the coarse base paper, and the antibacterial coating. The isolation slurry has a dry coating weight of 1-2 gsm and comprises the following components by mass: 6% oxidized cassava starch, 1% starch enhancer, 0.3% sodium carboxymethyl cellulose, and the balance water. The antibacterial slurry has a dry coating weight of 1.5 gsm and comprises the following components by mass: 69.3% aqueous polyacrylic acid emulsion having a solid content of 15%, 5% quaternary ammonium salt compound, 25% polyethylene particles having a particle size of 10-50 μm, and 0.7% dispersant.

[0047] S4. After coating the antibacterial coating surface of glassine paper with a solvent-free silicone oil release agent, the resulting coating is heated to 160° C. in an oven and dried to form a release layer. The glassine paper and the release layer together constitute the antibacterial release paper. The dry coating weight of the solvent-free silicone oil release agent is 1.8 gsm. The solvent-free silicone oil release agent includes the following components by mass percentage: 98% to 99% solvent-free silicone oil and 1% to 2% silane coupling agent.

[0048] Comparative Example 1

[0049] The release paper was obtained based on Example 3 in the specification of a Chinese patent for a method for preparing antibacterial and antistatic release paper (Announcement No.: CN110886127A).

[0050] Comparative Example 2

[0051] The difference between this comparative example and the above-mentioned Example 1 is that in step S4, the solvent-free silicone oil release agent contains only solvent-free silicone oil, and the operations and component ratios of the remaining steps are the same.

[0052] The antibacterial properties of the release papers of Example 1 and Comparative Example 1 were tested based on the standard document GB / T31402-2015 "Test Method for Antibacterial Performance of Plastic Surfaces," and the antibacterial rates of the release papers were calculated. Antibacterial rate = (bacterial count of the blank sample - bacterial count of the antibacterial sample) / bacterial count of the blank sample × 100%. The antibacterial rate data are shown in Table 1 below.

[0053]

[0054] Table 1

[0055] Analysis of the data in Table 1 shows that during the antibacterial performance test of the release paper of Example 1, the culture solution can penetrate well into the interior of the paper and come into contact with the antibacterial agent in the antibacterial coating. The antibacterial agent dissolves in the culture solution to achieve a good antibacterial effect. However, in the release paper of Comparative Example 1, the culture solution cannot penetrate into the interior of the release layer to dissolve the chitosan, and can only perform antibacterial activities through the chitosan on the surface of the release layer, thereby affecting the antibacterial effect of the chitosan. Therefore, the antibacterial rate of the release paper is low.

[0056] The normal temperature peeling force, aging peeling force, residual adhesion, and silicon transfer rate of the centrifugal papers of all the above examples and comparisons were tested. The test results are shown in Table 2 below.

[0057]

[0058] Table 2

[0059] As can be seen from the data in Table 2, in the release paper of Example 1, because the release layer and the antibacterial coating are firmly fixed by cross-linking reaction, the silicone oil is not easy to adhere to the tape and be taken away during the peeling test, so the room temperature peeling force, aging peeling force, silicone transfer rate of the release paper are all low, and the residual tack is high, achieving good release effect.

[0060] The above only describes the preferred embodiments of the present application, and it should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered within the protection scope of the present application.

Claims

1. A method for preparing solvent-free silicone oil-based antibacterial release paper, characterized in that: The following steps are involved: S1. Debarking and defoliating coniferous and hardwood wood, and then cutting the wood chips into wood chips. The wood chips are placed in a cooking vessel and steamed. The cooked wood chips are immersed in a sulfite solution and heated to cook the wood chips. The cooked wood chips are removed and squeezed to remove excess water. The squeezed wood chips are then subjected to disc grinding to obtain sulfite pulp. S2. Adding filler powder, a wet strength agent, a fiber dispersant, and water to sulfite pulp to obtain a papermaking stock pulp. The papermaking stock pulp is beaten by a trough beater. The beater mechanically separates and brooms the pulp fibers, thereby increasing the surface area and bonding strength of the fibers. The beating degree of the beater is 45-60°SR. The beaten papermaking stock pulp is evenly distributed on the surface of the mesh curtain through a headbox, thereby forming the initial shape of the paper. The surface is then flattened and shaped by a finishing roller to obtain a paper prototype. The paper prototype is then squeezed to remove excess water and set, and then dried to obtain a coarse base paper. S3. Applying an isolation slurry and an antibacterial slurry to both sides of the coarse base paper, drying the slurry, and calendering the slurry to obtain glassine paper; wherein the isolation slurry forms an isolation film layer on one side of the coarse base paper after drying, and the antibacterial slurry forms an antibacterial coating on the other side of the coarse base paper after drying. The glassine paper comprises the isolation film layer, the coarse base paper, and the antibacterial coating; The antibacterial slurry comprises the following components by mass percentage: 63% to 75% aqueous polyacrylic acid emulsion, 3% to 6% antibacterial agent, 20% to 30% bridging particles, and 0.5% to 1% dispersant; the solid content of the aqueous polyacrylic acid emulsion is 10% to 20%, and the bridging particles are polyethylene particles with a particle size of 10 to 50 μm; The antibacterial agent is selected from one or more of polyhexamethylene guanidine hydrochloride, ε-polylysine, quaternary ammonium salt compounds, inorganic silver ion antibacterial agents, and inorganic zinc ion antibacterial agents; the dry coating weight of the antibacterial slurry is 1-2 gsm; S4. Applying a solvent-free silicone oil release agent on the surface of the antibacterial coating of the glassine paper and drying the resulting release layer to form the antibacterial release paper. The solvent-free silicone oil release agent comprises the following components by mass percentage: 98% to 99% solvent-free silicone oil and 1% to 2% bridging aid; the bridging aid is selected from one of dicumyl peroxide and vinyltrimethoxysilane; The dry coating weight of the solvent-free silicone oil release agent is 0.5-2 gsm; The drying temperature of the antibacterial release paper is 120-180°C.

2. The method for preparing the solvent-free silicone oil type antibacterial release paper according to claim 1, wherein: In step S1, the mass ratio of the wood chips to the sulfite solution is 1:(4-6), and the dry weight of sulfite in the sulfite solution is 20%-40% of the dry weight of the wood chips.

3. The method for preparing the solvent-free silicone oil type antibacterial release paper according to claim 1, characterized in that: The concentration of the papermaking pulp is 4% to 8%, and the papermaking pulp contains 10% to 30% of filler powder, 0.5% to 1.5% of wet strength agent, and 0.05% to 0.2% of fiber dispersant, calculated based on the dry weight of wood chips.

4. The method for preparing the solvent-free silicone oil type antibacterial release paper according to claim 1, characterized in that: The filler powder is selected from one or more of calcium carbonate powder, calcium silicate powder, talc powder and mica powder.

5. The method for making solvent-free silicone oil-based antibacterial release paper according to claim 1, characterized in that: The isolation slurry comprises the following components by mass percentage: 4% to 8% oxidized cassava starch, 0.5% to 2% starch enhancer, 0.2% to 0.5% sodium carboxymethyl cellulose, and the balance is water. In step S3, the coating dry weight of the isolation slurry is 1 to 2 gsm.

Images