A preparation process of surface-activated polymerized filler

Abstract

The present invention relates to the field of papermaking, and specifically relates to a preparation process of a surface-activated polymerized filler, which comprises the following steps: (1) Weigh palygorskite powder and mix it with deionized water, and continuously dropwise add a mixed solution of aluminum chloride and zirconium chloride to form a first mixed solution; (2) First weigh a small amount of sodium hexametaphosphate and dissolve it in deionized water, and then gradually and slowly add pectin and stir to form a uniform solution, that is, a second mixed solution; (3) Dropwise add the second mixed solution into the first mixed solution, adjust the pH of the reaction solution, continue stirring, and then through precipitation, centrifugation, washing, suction filtration and drying, pectin aluminum zirconium @ palygorskite powder is obtained. The filler prepared by the present invention not only solves the problem of the disintegration of palygorskite, but also can increase the binding force with fibers to a certain extent, thereby enhancing the performance of the paper.

Description

Technical Field

[0001] The present invention relates to the field of papermaking, and particularly to a preparation process of surface-activated polymerized filler. Background Art

[0002] Papermaking fillers refer to some solid particles that are basically insoluble in water and are added to pulp. The initial purpose is to reduce the cost of paper. Now the purpose of adding them is to improve the opacity, brightness, smoothness, printing adaptability (such as improving absorbency and ink absorbency), softness, uniformity and dimensional stability of paper. It can also make the paper feel good, reduce its hygroscopicity and reduce the fiber usage.

[0003] Due to different purposes of filling, the proportion of fillers in paper varies greatly. The use of one filler or several fillers depends on the special properties required for the paper. In the current papermaking industry, the most commonly used fillers are calcium carbonate, kaolin and talc powder. In addition, a small amount of amorphous silica, silicate and aluminum trihydroxide are also used as fillers. The physical properties of fillers have a great impact on the opacity and physical properties of paper. The pulp added with fillers is easy to dehydrate, easy to dry, can reduce energy consumption and lower the papermaking cost. However, due to the large differences in properties between fillers and fibers, the interaction force is weak and the interfacial bonding force is poor, resulting in a certain degree of decline in the stiffness and strength of the paper. In addition, there will also be phenomena such as powder dropping and fluffing. Summary of the Invention

[0004] Aiming at the problems existing in the prior art, the purpose of the present invention is to provide a preparation process of surface-activated polymerized filler.

[0005] The purpose of the present invention is achieved by the following technical solutions:

[0006] A preparation process of surface-activated polymerized filler includes the following steps:

[0007] (1) Weigh a certain amount of palygorskite powder and mix it with deionized water to form a uniform mixture under ultrasonic conditions. Then, under the condition of low-speed stirring, continuously drop a mixed solution of aluminum chloride and zirconium chloride. After the dropping is completed, accelerate stirring for 15 - 30 min to form a first mixed solution;

[0008] (2) First, weigh a small amount of sodium hexametaphosphate and dissolve it in deionized water, and then gradually and slowly add pectin and stir to form a uniform solution, that is, a second mixed solution;

[0009] (3) Add the second mixture dropwise into the first mixture, continuously stir during this process, and at the same time control the pH of the reaction solution to be 6 - 6.5. After the addition of the second mixture is completed, stir for 10 - 20 min, adjust the pH of the reaction solution to 7 - 7.5, continue stirring for 30 - 60 min, and then through precipitation, centrifugation, washing, suction filtration and drying, pectin aluminum zirconium @ palygorskite powder is obtained.

[0010] Preferably, in step (1), the particle size of the palygorskite powder is 20 - 50 μm.

[0011] Preferably, in step (1), the mass ratio of the palygorskite powder, deionized water and the mixed solution is 1:3 - 5:10 - 20.

[0012] Preferably, in step (1), the composition of the mixed solution of aluminum chloride and zirconium chloride is: the mass ratio of aluminum chloride, zirconium chloride and deionized water is 1.33 - 1.95:2.33 - 3.45:100.

[0013] Preferably, in step (1), the speed of low - speed stirring is 100 - 200 r / min, the speed of accelerated stirring is 300 - 400 r / min, and the dropping speed is 1 - 1.5 seconds per drop.

[0014] Preferably, in step (2), the mass ratio of sodium hexametaphosphate, pectin and deionized water is 0.3 - 0.6:0.5 - 5:100.

[0015] Preferably, in step (2), the degree of esterification of pectin is 10% - 25%, and the viscosity - average molecular weight is 15000 - 25000.

[0016] Preferably, in step (3), the mass ratio of the second mixture to the first mixture is 1 - 3:1.

[0017] Preferably, in step (3), after adjusting the pH of the reaction solution to 7 - 7.5, control the temperature of the reaction solution to be 25 - 60 °C.

[0018] Preferably, in step (3), after the reaction solution is cooled to room temperature for precipitation, pour the reaction solution into anhydrous ethanol under continuous stirring for precipitation, and the addition amount of ethanol is 1 - 2 times the mass of the reaction solution.

[0019] Preferably, in step (3), the centrifugation speed is 5000 - 8000 r / min, and the centrifugation time is 3 - 5 min.

[0020] Preferably, in step (3), the washing is to rinse the precipitate collected by centrifugation with purified water at least three times.

[0021] Preferably, in step (3), the suction filtration is to filter the washed product through a vacuum suction filter to remove the liquid.

[0022] Preferably, in step (3), the drying is carried out in an oven at 100-120°C.

[0023] The beneficial effects of the present invention are as follows:

[0024] 1. In the preparation of paper, in addition to fibers, some fillers are generally added to enhance the properties of the paper. In the present invention, palygorskite with a large specific surface area and strong adsorption performance is selected as the filler substrate, and surface activation treatment is carried out on this basis. That is, a solution containing aluminum salt and zirconium salt is first mixed with palygorskite to make Al 3+ and Zr 2+ fully and evenly adsorbed on the surface of palygorskite, and then a solution dissolved with pectin is gradually dropped into it, and continuously stirred during this process, so that pectin can be more fully dispersed, and thus more fully combined with the metal ions on the surface of palygorskite, so that the complexed precipitate is also more evenly modified on the surface of palygorskite. The filler prepared by the present invention not only solves the problem of the disintegration of palygorskite, but also can increase the binding force with fibers to a certain extent, thereby enhancing the performance of the paper.

[0025] 2. Palygorskite is a hydrous magnesium-aluminum silicate clay mineral with a chain-layered structure. It has good dispersibility in water, showing good colloidal properties and adsorption capacity, and its properties are very suitable for the requirements of papermaking fillers. However, palygorskite has too strong rheology and will quickly disintegrate when soaked in water, which greatly affects its application in papermaking fillers. In addition, the binding force between palygorskite and pulp fibers is also insufficient, which also affects the strength of the paper to a certain extent.

[0026] 3. The performance of the paper is affected by many factors, and the most important one is the binding force between fibers. The binding force between fibers generally includes: chemical bonds, hydrogen bonds, van der Waals forces and fiber surface interweaving forces. The surface of pulp fibers generally carries negative charges, and the metal positive charges in the synthesized aluminum zirconium pectin of the present invention can adsorb the negative charges in the ligand, thereby enhancing the formation of hydrogen bonds between the aluminum zirconium pectin and the pulp fibers. Therefore, the prepared aluminum zirconium pectin@palygorskite powder can increase the binding force with fibers, thereby enhancing the performance of the paper.

[0027] 4. In recent years, more and more complexes have been researched, developed and widely applied. However, they are less applied in the field of papermaking fillers. Through exploration, the present invention finds that pectin easily forms complexes with metal ions, and it itself belongs to a natural polysaccharide polymer. If pectin is used as an auxiliary material for fillers, there will be great potential. During the research on pectin, the present invention selects the composite complexation of two metal ions, aluminum and zirconium, to coat and modify palygorskite powder, and prepares a pectin aluminum zirconium @ palygorskite powder composite material for use as a filler. It is found that the disintegration property of palygorskite is improved, and its strength can be enhanced to a certain extent.

[0028] 5. Sodium hexametaphosphate shows weak acidity in aqueous solution. The present invention uses an aqueous solution containing a small amount of sodium hexametaphosphate to gradually dissolve pectin. During the process of gradually dropping the pectin solution, the pH of the reaction solution is controlled to be slightly acidic to enable pectin to have a better reaction environment. In addition, after the dropping is completed, the pH of the reaction solution is adjusted to be slightly alkaline to neutral, and even heated to promote the formation of the complex. However, the temperature should not be raised too high and the pH should not be too large here, otherwise the formed complex will not be uniform enough, which will affect the subsequent performance.

[0029] 6. The present invention selects two metal ions, aluminum and zirconium, to complex with pectin simultaneously. The positive charges of the metal ions can adsorb the negative charges in the ligand and gradually form a dense network gel complex. On the one hand, both metal ions appear white, which can enhance the brightness and opacity of the paper. On the other hand, aluminum ions have a certain degradation effect on cellulose. Excessive aluminum ions are not conducive to the storage of the paper. The complexation of pectin and the substitution of some aluminum by zirconium well solve this problem. In addition, the strength of zirconium and the flexibility of aluminum cooperate with each other to enhance the strength and stiffness of the paper. Specific embodiments

[0030] To more clearly illustrate the present invention and have a clearer understanding of the technical features, purposes and beneficial effects of the present invention, the technical solutions of the present invention are described in detail below, but it should not be understood as a limitation on the scope of implementation of the present invention.

[0031] The present invention is further described below in conjunction with the following embodiments.

[0032] Example 1

[0033] A preparation process for a surface-activated polymerized filler includes the following steps:

[0034] (1) Weigh a certain amount of palygorskite powder and mix it with deionized water. The particle size of the palygorskite powder is 30 ± 5 μm. Under ultrasonic conditions, a uniform mixed solution is formed. Then, under the condition of low-speed stirring at 150 r / min, continuously dropwise add a mixed solution of aluminum chloride and zirconium chloride, control the dropping speed to be 1.5 seconds per drop. The mass ratio of aluminum chloride, zirconium chloride and deionized water in the mixed solution is 1.64:2.91:100. After the dropping is completed, accelerate to 350 r / min and stir for 20 min to form the first mixed solution; among them, the mass ratio of palygorskite powder, deionized water and the mixed solution is 1:4:15.

[0035] (2) First, weigh a small amount of sodium hexametaphosphate and dissolve it in deionized water, and then gradually and slowly add pectin. The degree of esterification of pectin is 15%, and the viscosity-average molecular weight is 20,000. Stir to form a uniform solution, that is, the second mixed solution; among them, the mass ratio of sodium hexametaphosphate, pectin and deionized water is 0.4:2.5:100.

[0036] (3) Dropwise add the second mixed solution into the first mixed solution. The mass ratio of the second mixed solution to the first mixed solution is 2:1. During this period, continuously stir, and at the same time control the pH of the reaction solution to be 6 - 6.5. After the second mixed solution is completely dropped, stir for 15 min, adjust the pH of the reaction solution to 7 - 7.5, control the temperature of the reaction solution to be 45 °C, continue to stir for 50 min, and then after the reaction solution is cooled to room temperature, pour the reaction solution into 1.5 times the mass of anhydrous ethanol under continuous stirring for precipitation. Then centrifuge at 6000 r / min for 4 min. Wash the centrifuged precipitate with purified water at least three times, and filter the washed product through a vacuum filter to remove the liquid. Finally, dry it in an oven at 110 °C to obtain pectin aluminum zirconium @ palygorskite powder.

[0037] Example 2

[0038] A preparation process of a surface-activated polymerized filler, comprising the following steps:

[0039] (1) Weigh a certain amount of palygorskite powder and mix it with deionized water. The particle size of the palygorskite powder is 20 - 30 μm. Under ultrasonic conditions, a uniform mixed solution is formed. Then, under the condition of low-speed stirring at 120 r / min, continuously dropwise add a mixed solution of aluminum chloride and zirconium chloride. The dropping speed is 1 second per drop. The mass ratio of aluminum chloride, zirconium chloride and deionized water in the mixed solution is 1.47:2.68:100. After the dropping is completed, accelerate to 300 r / min and stir for 20 min to form the first mixed solution; among them, the mass ratio of palygorskite powder, deionized water and the mixed solution is 1:3:10.

[0040] (2) Weigh a small amount of sodium hexametaphosphate and dissolve it in deionized water first, and then gradually and slowly add pectin. The degree of esterification of pectin is 20%, and the viscosity-average molecular weight is 22,000. Stir to form a uniform solution, which is the second mixed solution. Among them, the mass ratio of sodium hexametaphosphate, pectin and deionized water is 0.4:3:100.

[0041] (3) Dropwise add the second mixed solution into the first mixed solution. The mass ratio of the second mixed solution to the first mixed solution is 1.5:1. During this process, continuously stir, and at the same time control the pH of the reaction solution to be 6 - 6.5. After the second mixed solution is completely added, stir for 15 min, adjust the pH of the reaction solution to 7 - 7.5, control the temperature of the reaction solution to be 35 °C, continue to stir for 40 min, and then after the reaction solution is cooled to room temperature, pour the reaction solution into anhydrous ethanol with a mass 1 time that is continuously stirred for precipitation. Then centrifuge at 7000 r / min for 3 min, wash the centrifuged precipitate with purified water at least three times, filter the washed product through a vacuum filter to remove the liquid, and finally dry it in an oven at 100 °C to obtain pectin aluminum zirconium@palygorskite powder.

[0042] Example 3

[0043] A preparation process for a surface-activated polymerized filler, comprising the following steps:

[0044] (1) Weigh a certain amount of palygorskite powder and mix it with deionized water. The particle size of the palygorskite powder is 40 - 50 μm. Under ultrasonic conditions, form a uniform mixed solution, and then under the condition of low-speed stirring at 160 r / min, continuously dropwise add a mixed solution of aluminum chloride and zirconium chloride. The dropping speed is 1.5 seconds per drop. The mass ratio of aluminum chloride, zirconium chloride and deionized water in the mixed solution is 1.74:2.86:100. After the dropping is completed, accelerate to 350 r / min and stir for 15 min to form the first mixed solution. Among them, the mass ratio of palygorskite powder, deionized water and the mixed solution is 1:5:20.

[0045] (2) Weigh a small amount of sodium hexametaphosphate and dissolve it in deionized water first, and then gradually and slowly add pectin. The degree of esterification of pectin is 15%, and the viscosity-average molecular weight is 18,000. Stir to form a uniform solution, which is the second mixed solution. Among them, the mass ratio of sodium hexametaphosphate, pectin and deionized water is 0.5:3.5:100.

[0046] (3) Add the second mixed solution dropwise into the first mixed solution. The mass ratio of the second mixed solution to the first mixed solution is 2.5:1. Stir continuously during this process, and at the same time control the pH of the reaction solution to be 6 - 6.5. After the second mixed solution is completely added dropwise, stir for 20 min, adjust the pH of the reaction solution to 7 - 7.5, control the temperature of the reaction solution to be 55 °C, continue to stir for 35 min, and then after the reaction solution is cooled to room temperature, pour the reaction solution into anhydrous ethanol with 1.8 times the mass under continuous stirring for precipitation. Then centrifuge at 6500 r / min for 5 min. Wash the precipitated matter collected by centrifugation with purified water at least three times. Filter the washed product through a vacuum filter to remove the liquid. Finally, dry it in an oven at 120 °C to obtain pectin aluminum zirconium@palygorskite powder.

[0047] Example 4

[0048] A preparation process for a surface-activated polymerized filler, comprising the following steps:

[0049] (1) Weigh a certain amount of palygorskite powder and mix it with deionized water. The particle size of the palygorskite powder is 20 - 30 μm. Under ultrasonic conditions, form a uniform mixed solution, and then under the condition of low-speed stirring at 100 r / min, continuously dropwise add a mixed solution of aluminum chloride and zirconium chloride. The dropping speed is 1 drop / second. The mass ratio of aluminum chloride, zirconium chloride and deionized water in the mixed solution is 1.33:2.33:100. After the dropping is completed, accelerate to 300 r / min and stir for 15 min to form the first mixed solution; among them, the mass ratio of palygorskite powder, deionized water and the mixed solution is 1:3:10.

[0050] (2) First, weigh a small amount of sodium hexametaphosphate and dissolve it in deionized water, and then gradually and slowly add pectin. The degree of esterification of pectin is 10%, and the viscosity-average molecular weight is 15000. Stir to form a uniform solution, that is, the second mixed solution; among them, the mass ratio of sodium hexametaphosphate, pectin and deionized water is 0.3:0.5:100.

[0051] (3) Add the second mixed solution dropwise into the first mixed solution. The mass ratio of the second mixed solution to the first mixed solution is 1:1. Stir continuously during this process, and at the same time control the pH of the reaction solution to be 6 - 6.5. After the second mixed solution is completely added dropwise, stir for 10 min, adjust the pH of the reaction solution to 7 - 7.5, control the temperature of the reaction solution to be 25 °C, continue to stir for 30 min, and then after the reaction solution is cooled to room temperature, pour the reaction solution into anhydrous ethanol with 1 times the mass under continuous stirring for precipitation. Then centrifuge at 5000 r / min for 3 min. Wash the precipitated matter collected by centrifugation with purified water at least three times. Filter the washed product through a vacuum filter to remove the liquid. Finally, dry it in an oven at 100 °C to obtain pectin aluminum zirconium@palygorskite powder.

[0052] Example 5

[0053] A preparation process of surface-activated polymerized filler, comprising the following steps:

[0054] (1) Weigh a certain amount of palygorskite powder and mix it with deionized water. The particle size of the palygorskite powder is 40 - 50 μm. Under ultrasonic conditions, a uniform mixed solution is formed. Then, under the condition of low-speed stirring at 200 r / min, a mixed solution of aluminum chloride and zirconium chloride is continuously added dropwise. The dropping speed is 1.5 seconds per drop. The mass ratio of aluminum chloride, zirconium chloride and deionized water in the mixed solution is 1.95:3.45:100. After the dropping is completed, the stirring speed is increased to 400 r / min and stirred for 30 min to form a first mixed solution; wherein, the mass ratio of palygorskite powder, deionized water and the mixed solution is 1:5:20.

[0055] (2) First, weigh a small amount of sodium hexametaphosphate and dissolve it in deionized water, and then gradually and slowly add pectin. The degree of esterification of pectin is 25%, and the viscosity-average molecular weight is 25000. Stir to form a uniform solution, that is, a second mixed solution; wherein, the mass ratio of sodium hexametaphosphate, pectin and deionized water is 0.6:5:100.

[0056] (3) Dropwise add the second mixed solution into the first mixed solution. The mass ratio of the second mixed solution to the first mixed solution is 3:1. During this process, continuously stir, and at the same time control the pH of the reaction solution to be 6 - 6.5. After the second mixed solution is completely added dropwise, stir for 20 min, adjust the pH of the reaction solution to 7 - 7.5, control the temperature of the reaction solution to be 60 °C, continue to stir for 60 min. Then, after the reaction solution is cooled to room temperature, pour the reaction solution into anhydrous ethanol with a mass 1 - 2 times that of the reaction solution and stir continuously for precipitation. Then, centrifuge at 8000 r / min for 5 min. Wash the centrifuged precipitate with purified water at least three times. Filter the washed product through a vacuum filter to remove the liquid. Finally, dry it in an oven at 120 °C to obtain pectin aluminum zirconium @ palygorskite powder.

[0057] Comparative Example 1

[0058] A preparation process of surface-activated polymerized filler, which is different from Example 1 in that:

[0059] Use palygorskite powder without surface-activated polymerization as the filler. The particle size of the palygorskite powder is 30 ± 5 μm. That is, aluminum ions and zirconium ions are not added in step (1), and pectin is not added for crosslinking later.

[0060] Comparative Example 2

[0061] A preparation process of surface-activated polymerized filler, which is different from Example 1 in that:

[0062] The surface activation polymerization method of palygorskite powder is different from that of Example 1. After the surface of palygorskite powder adsorbs aluminum ions and zirconium ions, a filler is formed, and pectin is not added for cross-linking.

[0063] The specific operation steps are as follows:

[0064] (1) Weigh a certain amount of palygorskite powder and mix it with deionized water. The particle size of the palygorskite powder is 30 ± 5 μm. Under ultrasonic conditions, a uniform mixture is formed. Then, under the condition of low-speed stirring at 150 r / min, a mixed solution of aluminum chloride and zirconium chloride is continuously added dropwise, and the dropping speed is controlled at 1.5 seconds per drop. The mass ratio of aluminum chloride, zirconium chloride, and deionized water in the mixed solution is 1.64:2.91:100. After the dropping is completed, the stirring speed is increased to 350 r / min and stirred for 20 min to form a mixed solution; among them, the mass ratio of palygorskite powder, deionized water, and the mixed solution is 1:4:15.

[0065] (2) Centrifuge the mixed solution at 6000 r / min for 4 min. The precipitate collected by centrifugation is washed with purified water at least three times. The washed product is filtered by a vacuum filter to remove the liquid, and finally dried in an oven at 110 °C to obtain the filler.

[0066] Comparative Example 3

[0067] A preparation process of a surface-activated polymerized filler, which is different from Example 1 in that:

[0068] The surface activation polymerization method of palygorskite powder is different from that of Example 1. Only aluminum ions are adsorbed on the surface of palygorskite powder, zirconium ions are not added, and zirconium ions are replaced with an equal mass of aluminum ions, and then pectin is added for cross-linking to form a filler.

[0069] The specific operation steps are as follows:

[0070] (1) Weigh a certain amount of palygorskite powder and mix it with deionized water. The particle size of the palygorskite powder is 30 ± 5 μm. Under ultrasonic conditions, a uniform mixture is formed. Then, under the condition of low-speed stirring at 150 r / min, an aluminum chloride solution is continuously added dropwise, and the dropping speed is controlled at 1.5 seconds per drop. The mass ratio of aluminum chloride and deionized water in the aluminum chloride solution is 4.55:100. After the dropping is completed, the stirring speed is increased to 350 r / min and stirred for 20 min to form a first mixed solution; among them, the mass ratio of palygorskite powder, deionized water, and the aluminum chloride solution is 1:4:15.

[0071] (2) Weigh a small amount of sodium hexametaphosphate and dissolve it in deionized water, then gradually and slowly add pectin. The degree of esterification of pectin is 15%, and the viscosity-average molecular weight is 20,000. Stir to form a uniform solution, which is the second mixed solution. Among them, the mass ratio of sodium hexametaphosphate, pectin, and deionized water is 0.4:2.5:100.

[0072] (3) Dropwise add the second mixed solution into the first mixed solution. The mass ratio of the second mixed solution to the first mixed solution is 2:1. During this process, continuously stir, and at the same time control the pH of the reaction solution to be 6 - 6.5. After the second mixed solution is completely added dropwise, stir for 15 min, adjust the pH of the reaction solution to 7 - 7.5, control the temperature of the reaction solution to be 45 °C, continue to stir for 50 min, and then after the reaction solution is cooled to room temperature, pour the reaction solution into anhydrous ethanol with 1.5 times the mass and stir continuously for precipitation. Then centrifuge at 6000 r / min for 4 min. Wash the centrifuged precipitate with purified water at least three times. Filter the washed product through a vacuum filter to remove the liquid. Finally, dry it in an oven at 110 °C to obtain pectin aluminum@palygorskite powder.

[0073] Comparative Example 4

[0074] A preparation process of a surface-activated polymerized filler, which is different from Example 1 in that:

[0075] The surface activation polymerization method of palygorskite powder is different from that in Example 1. Only adsorb zirconium ions on the surface of palygorskite powder, do not add aluminum ions, and replace aluminum ions with zirconium ions of equal mass, and then add pectin for crosslinking to form a filler.

[0076] The specific operation steps are as follows:

[0077] (1) Weigh a certain amount of palygorskite powder and mix it with deionized water. The particle size of palygorskite powder is 30 ± 5 μm. Under ultrasonic conditions, form a uniform mixed solution, and then under the condition of low-speed stirring at 150 r / min, continuously dropwise add zirconium chloride solution, control the dropping speed to be 1.5 seconds per drop. The mass ratio of zirconium chloride to deionized water in the zirconium chloride solution is 4.55:100. After the dropping is completed, accelerate the stirring speed to 350 r / min and stir for 20 min to form the first mixed solution. Among them, the mass ratio of palygorskite powder, deionized water, and zirconium chloride solution is 1:4:15.

[0078] (2) Weigh a small amount of sodium hexametaphosphate and dissolve it in deionized water, then gradually and slowly add pectin. The degree of esterification of pectin is 15%, and the viscosity-average molecular weight is 20,000. Stir to form a uniform solution, which is the second mixed solution. Among them, the mass ratio of sodium hexametaphosphate, pectin, and deionized water is 0.4:2.5:100.

[0079] (3) The second mixture was added dropwise into the first mixture, and the mass ratio of the second mixture to the first mixture was 2:1. During this process, continuous stirring was carried out, and at the same time, the pH of the reaction solution was controlled to be 6 - 6.5. After the addition of the second mixture was completed, stirring was continued for 15 min, then the pH of the reaction solution was adjusted to 7 - 7.5, the temperature of the reaction solution was controlled to be 45 °C, and stirring was continued for 50 min. Then, after the reaction solution was cooled to room temperature, it was poured into anhydrous ethanol with a mass 1.5 times that of the continuously stirred ethanol for precipitation. After that, centrifugation was carried out at 6000 r / min for 4 min, and the precipitate collected by centrifugation was rinsed with purified water at least three times. The washed product was filtered by a vacuum filter to remove the liquid, and finally dried in an oven at 110 °C to obtain pectin zirconium@palygorskite powder.

[0080] Experimental example

[0081] In order to reflect the effects of Example 1 of the present invention, four control experiments, namely Comparative Examples 1 - 4, were set up. The fillers obtained from Example 1 and Comparative Examples 1 - 4 were detected and compared, and the obtained fillers were respectively used in the papermaking process.

[0082] The papermaking process was as follows: Eucalyptus pulp fiber slurry with a beating degree of 52°SR was used as the pulp. First, it was mixed with water, and the mass ratio of the pulp to water was 1.2:10. Then, a filler (accounting for 20% of the dry pulp) and a pulp strengthening agent cationic polyacrylamide (with a molecular weight of 6 million and accounting for 0.5% of the dry pulp) were added in sequence. After mixing evenly, through the forming of a paper machine, dehydration and drying treatments were carried out to form paper.

[0083] The obtained papers were respectively tested, and the detection standards were GB / T 453, GB / T 24328.4, and GB / T 463; for the wet tensile strength, the immersion time was 1 h and the temperature was 25 °C.

[0084] The results are shown in Table 1:

[0085] Table 1 Detection results of paper parameters

[0086] Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 <![CDATA[Paper grammage (g / m 2 )]]> 98.2 93.5 94.7 97.9 98.5 Ash content of paper (%) 20.5 13.3 14.2 19.8 21.2 Crosswise stiffness (mN·m) 93.6 77.8 81.9 93.4 90.1 Longitudinal stiffness (mN·m) 118.0 90.1 95.3 118.5 113.4 Dry tensile strength (kN / m) 4.9 3.5 3.5 4.3 4.6 Wet tensile strength (kN / m) 1.8 0.8 0.9 1.2 1.5

[0087] The filler prepared in Example 1 of the present invention was used in papermaking. Not only did no hair shedding and powder shedding occur, but it also had better stiffness and strength, and the wet strength retention rate was also higher, all far higher than the market standards. Although Comparative Examples 3 and 4 also had relatively excellent performances in many aspects, compared with Example 1, the paper manufactured using the filler of Example 1 of the present invention had more balanced properties, indicating that Example 1 of the present invention had stronger comprehensive performance.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A preparation process of a surface-activated polymerized filler, characterized in that, It includes the following steps: (1) Weigh a certain amount of palygorskite powder and mix it with deionized water to form a homogeneous mixture under ultrasonic conditions. Then, under the condition of low-speed stirring, continuously dropwise add a mixed solution of aluminum chloride and zirconium chloride. After the addition is completed, accelerate the stirring for 15 - 30 min to form a first mixed solution; (2) First, weigh a small amount of sodium hexametaphosphate and dissolve it in deionized water, and then gradually and slowly add pectin and stir to form a homogeneous solution, that is, a second mixed solution; (3) Dropwise add the second mixed solution into the first mixed solution, continuously stir during this period, and at the same time control the pH of the reaction solution to be 6 - 6.

5. After the second mixed solution is completely added, stir for 10 - 20 min, adjust the pH of the reaction solution to 7 - 7.5, continue to stir for 30 - 60 min, and then through precipitation, centrifugation, washing, suction filtration and drying, pectin aluminum zirconium / palygorskite powder is obtained; In step (1), the particle size of the palygorskite powder is 20 - 50 μm; the mass ratio of the palygorskite powder, deionized water and the mixed solution is 1:3 - 5:10 - 20; In step (1), the composition of the mixed solution of aluminum chloride and zirconium chloride is: the mass ratio of aluminum chloride, zirconium chloride and deionized water is 1.33 - 1.95:2.33 - 3.45:100; The esterification degree of pectin is 10% - 25%, and the viscosity-average molecular weight is 15000 - 25000.

2. The preparation process of a surface-activated polymerized filler according to claim 1, wherein, In step (1), the speed of low-speed stirring is 100 - 200 r / min, the speed of accelerated stirring is 300 - 400 r / min, and the dropping speed is 1 - 1.5 seconds / drop.

3. The preparation process of a surface-activated polymerized filler according to claim 1, characterized in that In step (2), the mass ratio of sodium hexametaphosphate, pectin and deionized water is 0.3 - 0.6:0.5 - 5:

100.

4. A preparation process of a surface-activated polymerized filler according to claim 1, characterized in that, In step (3), the mass ratio of the second mixed solution to the first mixed solution is 1 - 3:

1.

5. A preparation process of a surface-activated polymerized filler according to claim 1, characterized in that, In step (3), after adjusting the pH of the reaction solution to 7 - 7.5, control the temperature of the reaction solution to be 25 - 60 °C.

6. A preparation process of a surface-activated polymerized filler according to claim 1, characterized in that, In step (3), precipitation is carried out by pouring the reaction solution into continuously stirred absolute ethanol after the reaction solution is cooled to room temperature, and the addition amount of ethanol is 1 - 2 times the mass of the reaction solution.

7. A preparation process of a surface-activated polymerized filler according to claim 1, characterized in that, In step (3), the centrifugation speed is 5000 - 8000 r / min, and the centrifugation time is 3 - 5 min; washing is to rinse the precipitate collected by centrifugation with purified water at least three times; suction filtration is to filter the washed product through a vacuum suction filter to remove the liquid; drying is to dry in an oven at 100 - 120 °C.