Paper product, papermaking pulp, papermaking filler and preparation method thereof
By adding fillers to the galactomannan solution and adding polymers to the papermaking process, the papermaking filler solution is formed, which solves the problem of high-content filler affecting fiber bonding, and achieves the effect of increasing the amount of filler, saving fiber usage and environmental protection.
Patent Information
- Application Number
- CN202411530682.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-30
- Publication Date
- 2025-03-18
AI Technical Summary
During the papermaking process, the addition of high-content filler will affect the bonding between fibers, resulting in a decrease in paper strength and serious system pollution, affecting production efficiency.
By adding fillers to the galactomannan solution and adding polymers to it, a papermaking filler solution is formed, and the filler is processed in concert to reduce its impact on fiber binding.
On the premise of ensuring paper-forming strength and dehydration performance, increase the amount of filler, save fiber, reduce production costs, and reduce wood cutout and carbon emissions, which is conducive to environmental protection.
Smart Images
Figure CN119640612A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of papermaking pulp preparation, and in particular to a paper product, papermaking pulp, papermaking filler and a preparation method thereof. Background Art
[0002] Fillers are very important raw materials in the production of cultural paper and industrial paper such as white card. They improve the quality of paper and reduce production costs because their cost is much lower than that of fiber. However, the amount of fillers added is affected by their characteristics. Since fillers are inorganic products and very fine, excessive use will affect the quality of paper and cause serious system pollution. High filler content in paper affects the bonding between fibers, causing a decrease in paper strength indicators such as tensile strength, internal bonding, stiffness, etc. At the same time, the addition of high fillers will lead to poor system retention / filtration, increased white water concentration, and reduced system cleanliness, which will affect the production efficiency of the paper machine.
[0003] In the papermaking process, a variety of filler modification or pretreatment technologies have been proposed, among which filler pre-flocculation technology is the main representative. The filler is mixed with a flocculant and then added to the slurry for papermaking. After pre-flocculation, the filler particles flocculate, which reduces the effect on the bonding force between fibers, but its loose structure has a weak bonding force with the fibers, which affects the further increase of filler dosage. At the same time, an excessively large filler flocculation system will affect the uniformity of the finished paper and reduce the strength performance. Summary of the invention
[0004] A first aspect of the present application provides a method for preparing a papermaking filler solution, the preparation method comprising:
[0005] adding a filler to the galactomannan solution to form a first solution;
[0006] A high molecular weight polymer is added to the first solution to form a papermaking filler solution.
[0007] In some embodiments, in the step of adding a filler to the galactomannan solution to form a first solution, the concentration of the galactomannan solution is 0.1-1.0%, and the amount of the filler used is 1-6 kg / ton for absolute dry matter.
[0008] In some embodiments, the galactomannan is derived from any one or a combination of fenugreek gum, guar gum, carob gum, and tara gum.
[0009] In some embodiments, in the step of adding a high molecular weight polymer to the first solution to form a papermaking filler solution, the added high molecular weight polymer is in the form of a solution with a concentration of 0.1-1.0%, and the amount for absolute dry filler is 0.1-8.0 kg / ton; the high molecular weight polymer is an organic compound with a medium molecular weight of 500,000-12 million.
[0010] In some embodiments, the high molecular polymer includes a cationic polymer or an anionic polymer, or an amphoteric polymer, wherein the cationic polymer includes a copolymer and a terpolymer of (methyl)acrylamide and a quaternary ammonium form thereof prepared from dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate or dimethyl sulfate, methyl chloride or benzyl chloride; the anionic polymer includes a copolymer of acrylamide and sodium acrylate and / or 2-acrylamido-2-methylpropanesulfonic acid.
[0011] In some embodiments, the filler particle size range Dv(50) in the papermaking filler solution is 20-150 μm.
[0012] In a second aspect, an embodiment of the present application provides a method for preparing a papermaking filler solution, the preparation method comprising:
[0013] mixing the galactomannan with the high molecular weight polymer to form an intermediate solution;
[0014] Filler is added to the intermediate solution to form a papermaking filler solution.
[0015] In a third aspect, an embodiment of the present application provides a papermaking filler, which is prepared by the preparation method described in the above embodiment.
[0016] In a fourth aspect, an embodiment of the present application provides a papermaking pulp, wherein the papermaking pulp includes pulp and the papermaking filler described in the above embodiment.
[0017] In a fifth aspect, an embodiment of the present application provides a paper product, which is prepared using the papermaking pulp described in the above embodiment.
[0018] The preparation method of the papermaking filler solution provided in the embodiment of the present application can reduce the influence of the filler on the bonding between cellulose fibers by using galactomannan and a high molecular polymer to synergistically treat the filler. Under the premise of ensuring the strength of the paper and retaining / dehydrating, the amount of filler is increased, thereby saving the amount of fiber and reducing the total production cost per ton of paper; increasing the use of fillers can reduce the use of fiber raw materials, which will reduce the felling of wood, reduce carbon emissions, and benefit environmental protection. The preparation method of the papermaking filler solution in the embodiment of the present application uses a natural product (guar gum) which is beneficial to environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0020] Figure 1 It is a schematic flow chart of an embodiment of a method for preparing a papermaking filler of the present application;
[0021] Figure 2 It is a schematic flow chart of another embodiment of the method for preparing papermaking filler of the present application;
[0022] Figure 3 is a schematic diagram of the GCC particle size analysis Dv(50);
[0023] Figure 4 is a schematic diagram of dehydration evaluation before and after GCC treatment - collecting the same filtrate time;
[0024] Figure 5 It is a schematic diagram of the test results of GCC pretreatment on the ash content of finished paper;
[0025] Figure 6 This is a schematic diagram comparing the bonding strength within paper with different filler treatment methods. DETAILED DESCRIPTION
[0026] The present application is further described in detail below in conjunction with the accompanying drawings and examples. It is particularly noted that the following examples are only used to illustrate the present application, but are not intended to limit the scope of the present application. Similarly, the following examples are only some embodiments of the present application rather than all embodiments, and all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.
[0027] The terms "first", "second", and "third" in the embodiments of the present application are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first", "second", and "third" can expressly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. In the embodiments of the present application, all directional indications (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication also changes accordingly. The terms "including" and "having" in the embodiments of the present application and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or components inherent to these processes, methods, products, or devices.
[0028] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.
[0029] In view of the problems mentioned in the background technology, the present application embodiment proposes a method for preparing a papermaking filler solution, please refer to Figure 1 , Figure 1 It is a flow chart of an embodiment of a method for preparing a papermaking filler of the present application, and the preparation method includes but is not limited to the following steps.
[0030] Step S100, adding filler to the galactomannan solution to form a first solution.
[0031] In this step, galactomannan is derived from any one or a combination of fenugreek gum, guar gum, locust bean gum and tara gum, and guar gum has galactomannan with different degrees of branching. The "galactomannan" referred to in this application takes guar gum as an example, including but not limited to guar gum. Guar gum, whose English name is "guar gum", is a highly purified natural polysaccharide extracted from guar beans, a leguminous plant widely planted in the Indian subcontinent. Due to its unique molecular structure characteristics and naturalness, it has quickly become a new type of environmentally friendly papermaking additive with superior performance. Guar gum is a macromolecular natural hydrophilic colloid and belongs to natural galactomannan. Guar gum includes but is not limited to modified cationic guar, anionic or amphoteric, and a mixture of two or more of the above.
[0032] First, guar gum (galactomannan) solid can be dissolved and diluted to a concentration of 0.1-1.0% aqueous solution, and the specific concentration can be 0.2-0.4%, such as 0.2%, 0.21%, 0.24%, 0.25%, 0.3%, 0.32%, 0.38%, 0.4% and the like. The amount of guar gum used is 1-6 kg / ton of absolute dry filler, and specifically can be 1 kg / ton, 1.2 kg / ton, 1.5 kg / ton, 2 kg / ton, 2.8 kg / ton, 3 kg / ton, 3.3 kg / ton, 4 kg / ton, 4.6 kg / ton, 5 kg / ton, 6 kg / ton and the like.
[0033] The filler may be porcelain clay, light calcium, talcum powder, heavy calcium carbonate, titanium dioxide, calcium carbonate, talcum powder, kaolin, ground calcium carbonate, etc. In the embodiments of the present application, heavy calcium carbonate is used as an example for description.
[0034] Please continue reading Figure 1 The method for preparing a papermaking filler solution in this embodiment further includes step S200 of adding a high molecular polymer to the first solution to form a papermaking filler solution (ie, a filler flocculent).
[0035] In step S200, the added high molecular polymer is in the form of a solution with a concentration of 0.1-1.0%, specifically 0.4-0.6%, such as 0.4%, 0.41%, 0.44%, 0.45%, 0.5%, 0.52%, 0.58%, 0.6% and the like, and the amount of high molecular polymer to absolute dry filler is 0.1-8.0 kg / ton; specifically 0.1 kg / ton, 0.4 kg / ton, 0.5 kg / ton, 0.8 kg / ton, 1 kg / ton, 1.2 kg / ton, 1.5 kg / ton, 2 kg / ton, 2.8 kg / ton, 3 kg / ton, 3.3 kg / ton, 4 kg / ton, 4.6 kg / ton, 5 kg / ton, 6 kg / ton, 6.3 kg / ton, 7 kg / ton, 7.5 kg / ton, 8 kg / ton and the like. High molecular weight polymer is an organic compound with medium molecular weight of 500,000-12 million. The molecular weight can be 500,000, 800,000, 1 million, 1.2 million, 2 million, 2.5 million, 3.5 million, 5 million, 8 million, 9.5 million, 10 million, 12 million or the like.
[0036] The high molecular polymer can be prepared in solid form as an aqueous solution, a water-in-oil emulsion or a dispersion in water. Optionally, the high molecular polymer may include a cationic polymer or an anionic polymer, or an amphoteric polymer, wherein the cationic polymer includes: copolymers and terpolymers of (meth)acrylamide and dimethylaminoethyl methacrylate (DMAEM), dimethylaminoethyl acrylate (DMAEA), diethylaminoethyl acrylate (DEAEA), diethylaminoethyl methacrylate (DEAEM) or dimethyl sulfate, methyl chloride or benzyl chloride in their quaternary ammonium form; anionic polymers include copolymers of acrylamide and sodium acrylate and / or 2-acrylamido-2-methylpropanesulfonic acid (AMPS).
[0037] Optionally, the polymer in the present embodiment can be a cationic polymer or a mixture of a cationic polymer and an anionic, nonionic, zwitterionic or amphoteric polymer. Selecting guar gum and a cationic polymer combination is an embodiment, and can be other combinations of guar gum and a polymer, including combinations of anionic, nonionic, amphoteric and zwitterionic polymers with guar gum, respectively. Exemplary combinations of guar gum and a polymer include: guar gum and a cationic polymer, guar gum and a nonionic polymer, and guar gum and amphoteric and zwitterionic polymer combinations.
[0038] The polymer is usually prepared by: one or more cationic, anionic or nonionic monomers; one or more cationic monomers and one or more nonionic monomers; one or more anionic monomers and one or more nonionic monomers; one or more cationic monomers and one or more anionic monomers and optionally one or more nonionic monomers to form amphoteric polymers; or one or more zwitterionic monomers and optionally one or more nonionic monomers to form zwitterionic polymers. One or more zwitterionic monomers and optionally one or more nonionic monomers can also be copolymerized with one or more anionic or cationic monomers to give zwitterionic polymers cationic or anionic charges. The cationic charge content in the polymer can be obtained by dividing the molar number of cationic monomers in the polymer by the total molar number of monomers and then multiplying by 100%. In the embodiment of the present invention, the cationic charge content in the polymer is recommended to be 5-50 mole percent. Similarly, although anionic polymer polymers can be formed using anionic monomers, certain nonionic vinyl addition polymers can also be modified to form anionic charged polymers. This type of polymer includes polymers such as those prepared by hydrolysis of polyacrylamide.
[0039] Optionally, the filler floccules (solution) obtained by the preparation method in the examples of the present application have a filler particle size range Dv(50) of 20 to 150 μm.
[0040] See also Figure 2 , Figure 2 It is a flow chart of another embodiment of the method for preparing papermaking filler of the present application, and the preparation method includes but is not limited to the following steps.
[0041] Step S801, mixing galactomannan with a high molecular weight polymer to form an intermediate solution.
[0042] Among them, galactomannan is derived from any one or a combination of fenugreek gum, guar gum, locust bean gum and tara gum, and guar gum has galactomannan with different degrees of branching. The "galactomannan" referred to in this application takes guar gum as an example, including but not limited to guar gum. Guar gum, whose English name is "guar gum", is a highly purified natural polysaccharide extracted from guar beans, a leguminous plant widely planted in the Indian subcontinent. Due to its unique molecular structure characteristics and naturalness, it has quickly become a new type of environmentally friendly papermaking additive with superior performance. Guar gum is a macromolecular natural hydrophilic colloid and belongs to natural galactomannan. Guar gum includes but is not limited to modified cationic guar, anionic or amphoteric, and a mixture of two or more of the above.
[0043] First, guar gum (galactomannan) solid can be dissolved and diluted to a concentration of 0.1-1.0% aqueous solution, and the specific concentration can be 0.2-0.4%, such as 0.2%, 0.21%, 0.24%, 0.25%, 0.3%, 0.32%, 0.38%, 0.4% and the like. The amount of guar gum used is 1-6 kg / ton of absolute dry filler, and specifically can be 1 kg / ton, 1.2 kg / ton, 1.5 kg / ton, 2 kg / ton, 2.8 kg / ton, 3 kg / ton, 3.3 kg / ton, 4 kg / ton, 4.6 kg / ton, 5 kg / ton, 6 kg / ton and the like.
[0044] The added high molecular polymer is in the form of solution with a concentration of 0.1-1.0%, specifically 0.4-0.6%, such as 0.4%, 0.41%, 0.44%, 0.45%, 0.5%, 0.52%, 0.58%, 0.6% and the like. The amount of high molecular polymer to absolute dry filler is 0.1-8.0 kg / ton; specifically 0.1 kg / ton, 0.4 kg / ton, 0.5 kg / ton, 0.8 kg / ton, 1 kg / ton, 1.2 kg / ton, 1.5 kg / ton, 2 kg / ton, 2.8 kg / ton, 3 kg / ton, 3.3 kg / ton, 4 kg / ton, 4.6 kg / ton, 5 kg / ton, 6 kg / ton, 6.3 kg / ton, 7 kg / ton, 7.5 kg / ton, 8 kg / ton and the like. High molecular weight polymer is an organic compound with medium molecular weight of 500,000-12 million. The molecular weight can be 500,000, 800,000, 1 million, 1.2 million, 2 million, 2.5 million, 3.5 million, 5 million, 8 million, 9.5 million, 10 million, 12 million or the like.
[0045] The high molecular polymer can be prepared in solid form as an aqueous solution, a water-in-oil emulsion or a dispersion in water. Optionally, the high molecular polymer may include a cationic polymer or an anionic polymer, or an amphoteric polymer, wherein the cationic polymer includes: copolymers and terpolymers of (meth)acrylamide and dimethylaminoethyl methacrylate (DMAEM), dimethylaminoethyl acrylate (DMAEA), diethylaminoethyl acrylate (DEAEA), diethylaminoethyl methacrylate (DEAEM) or dimethyl sulfate, methyl chloride or benzyl chloride in their quaternary ammonium form; anionic polymers include copolymers of acrylamide and sodium acrylate and / or 2-acrylamido-2-methylpropanesulfonic acid (AMPS).
[0046] Optionally, the polymer in the present embodiment can be a cationic polymer or a mixture of a cationic polymer and an anionic, nonionic, zwitterionic or amphoteric polymer. Selecting guar gum and a cationic polymer combination is an embodiment, and can be other combinations of guar gum and a polymer, including combinations of anionic, nonionic, amphoteric and zwitterionic polymers with guar gum, respectively. Exemplary combinations of guar gum and a polymer include: guar gum and a cationic polymer, guar gum and a nonionic polymer, and guar gum and amphoteric and zwitterionic polymer combinations.
[0047] The polymer is usually prepared by: one or more cationic, anionic or nonionic monomers; one or more cationic monomers and one or more nonionic monomers; one or more anionic monomers and one or more nonionic monomers; one or more cationic monomers and one or more anionic monomers and optionally one or more nonionic monomers to form amphoteric polymers; or one or more zwitterionic monomers and optionally one or more nonionic monomers to form zwitterionic polymers. One or more zwitterionic monomers and optionally one or more nonionic monomers can also be copolymerized with one or more anionic or cationic monomers to give zwitterionic polymers cationic or anionic charges. The cationic charge content in the polymer can be obtained by dividing the molar number of cationic monomers in the polymer by the total molar number of monomers and then multiplying by 100%. In the embodiment of the present invention, the cationic charge content in the polymer is recommended to be 5-50 mole percent. Similarly, although anionic polymer polymers can be formed using anionic monomers, certain nonionic vinyl addition polymers can also be modified to form anionic charged polymers. This type of polymer includes polymers such as those prepared by hydrolysis of polyacrylamide.
[0048] Please continue reading Figure 2 The preparation method in the embodiment of the present application further includes step S802, adding filler to the intermediate solution to form a papermaking filler solution.
[0049] The filler may be porcelain clay, light calcium, talcum powder, heavy calcium carbonate, titanium dioxide, calcium carbonate, talcum powder, kaolin, ground calcium carbonate, etc. In the embodiments of the present application, heavy calcium carbonate is used as an example for description.
[0050] The papermaking filler solution obtained by the preparation method in the embodiment of the present application is a filler flocculent, and the filler flocculent (solution) is added to the papermaking system as a filler for papermaking.
[0051] The fiber raw materials, fillers and related additives used by a large cultural papermaking company were used as experimental raw materials and fixed in the experimental evaluation according to its process. The amount of guar gum and the proportion of high molecular polymer were adjusted. The samples were evaluated by horizontal comparison experiments with reference to standard test methods and relevant instrument operation manuals. The blank was untreated filler, and other conditions were the same as the evaluation samples. The test results are as follows:
[0052] (1) As the amount of guar gum increases, the particle size of GCC (heavy calcium carbonate) increases after treatment; the use of guar gum and high molecular polymer together can significantly improve the increase in filler particle size, such as Figure 3 As shown, Figure 3 Schematic diagram of GCC particle size analysis Dv(50).
[0053] (2) The method of using guar gum alone to treat GCC has a negative impact on dehydration. The treatment method of this patent can solve this negative impact and improve dehydration under certain circumstances, such as Figure 4 As shown, Figure 4 It is a schematic diagram of dehydration evaluation before and after GCC treatment - collecting the same filtrate time. It can be seen from the figure that guar gum + polymer can significantly improve the dehydration performance.
[0054] (3) Except for adjusting the GCC pre-wrapping scheme, the ash content of the finished paper increased significantly when the filler addition amount and other conditions remained the same, such as Figure 5 As shown, Figure 5 This is a schematic diagram of the test results of the ash content of the finished paper after GCC pretreatment. It can be seen from the figure that the ash content is significantly increased.
[0055] (4) The cohesive strength of GCC treated by the patented method is significantly improved when it is used for papermaking. Figure 6 As shown, Figure 6 3 is a schematic diagram comparing the bonding strength of paper in different filler treatment methods. It can be seen from the figure that the use of guar gum + polymer in the embodiment of the present application can significantly improve the bonding strength of paper.
[0056] The technical standards used in the above experiments include:
[0057] (1) GB / T 450-2000 Paper and paperboard sample collection and measurement of the longitudinal and transverse, front and back sides of the sample
[0058] (2) GB / T 451.2—2002 Determination of Basis Weight of Paper and Paperboard
[0059] (3) GB / T 10739-2002 Standard atmospheric conditions for handling and testing of paper, paperboard and pulp samples
[0060] (4) GB / T 12914-2008 "Determination of tensile strength of paper and paperboard"
[0061] (5) GB / T 1541-2014 "Determination of ash content of paper and paperboard"
[0062] (6) GB / T 26203-2010 "Determination of internal bonding strength of paper and paperboard" (Scott type)
[0063] (7) Particle size detection - laser particle size analyzer, Coulter LS230
[0064] (8) Dehydration Assessment Canadian Freeness Tester
[0065] The preparation method of the papermaking filler solution provided in the embodiment of the present application can reduce the influence of the filler on the bonding between cellulose fibers by using galactomannan and high molecular polymer to synergistically treat the filler. Under the premise of ensuring the strength of the paper and retention / dehydration, the amount of filler is increased, thereby saving the amount of fiber and reducing the total production cost per ton of paper; increasing the use of filler can reduce the use of fiber raw materials, which will reduce the felling of wood, reduce carbon emissions, and benefit environmental protection. The preparation method of the papermaking filler solution in the embodiment of the present application uses natural products, which is beneficial to environmental protection.
[0066] In addition, the embodiment of the present application further provides a paper product, which can be obtained by using the pulp in the above embodiment. Other preparation process characteristics and parameters of the paper product are within the scope of understanding of those skilled in the art and will not be described in detail here.
[0067] The above descriptions are only some embodiments of the present application, and do not limit the protection scope of the present application. Any equivalent device or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.
Claims
1. A method for preparing a papermaking filler solution, characterized in that: The preparation method comprises: adding a filler to the galactomannan solution to form a first solution; A high molecular weight polymer is added to the first solution to form a papermaking filler solution.
2. The preparation method according to claim 1, characterized in that: In the step of adding filler to the galactomannan solution to form the first solution, the concentration of the galactomannan solution is 0.1-1.0%, and the amount of the filler used is 1-6 kg / ton for absolute dryness.
3. The preparation method according to claim 2, characterized in that: The galactomannan is derived from any one or a combination of fenugreek gum, guar gum, locust bean gum, and tara gum.
4. The preparation method according to claim 1, characterized in that: In the step of adding a high molecular polymer to the first solution to form a papermaking filler solution, the added high molecular polymer is in the form of a solution with a concentration of 0.1-1.0% and an amount of 0.1-8.0 kg / ton for absolute dry filler; the high molecular polymer is an organic compound with a medium molecular weight of 500,000-12 million.
5. The preparation method according to claim 4, characterized in that: The high molecular polymer includes a cationic polymer or an anionic polymer, or an amphoteric polymer, wherein the cationic polymer includes a copolymer and a terpolymer in a quaternary ammonium form of (methyl)acrylamide and dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate or dimethyl sulfate, methyl chloride or benzyl chloride; the anionic polymer includes a copolymer of acrylamide and sodium acrylate and / or 2-acrylamido-2-methylpropanesulfonic acid.
6. The preparation method according to claim 1, characterized in that: The filler particle size range Dv(50) in the papermaking filler solution is 20 to 150 μm.
7. A method for preparing a papermaking filler solution, characterized in that: The preparation method comprises: mixing the galactomannan with the high molecular weight polymer to form an intermediate solution; Filler is added to the intermediate solution to form a papermaking filler solution.
8. A papermaking filler, characterized in that: The papermaking filler is prepared by the preparation method described in any one of claims 1 to 7.
9. A papermaking pulp, characterized in that: The papermaking slurry comprises pulp and the papermaking filler according to claim 8.
10. A paper product, characterized in that: The paper product is prepared using the papermaking pulp described in claim 9.