Flexible Calcium Carbonate with improved calcium carbonate retention rate, tissue paper containing the same, and manufacturing method thereof.

Abstract

To provide FCC comprising micro fibrillated cellulose (MFC) and calcium carbonate attached to the micro fibrillated cellulose, tissue paper containing the same, and a manufacturing method therefor.SOLUTION: There is provided FCC (Flexible Calcium Carbonate) comprising micro fibrillated cellulose (MFC) and calcium carbonate attached to the micro-fibrillated cellulose. Also there are provided tissue paper containing an amount of 1 to 10 weight parts of FCC, and a method for manufacturing tissue paper including preparing MFC, synthesizing calcium carbonate attached to the MFC to produce FCC, and adding the FCC into the tissue paper.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to Flexible Calcium Carbonate (FCC) containing microfibrillated cellulose (MFC) and calcium carbonate attached to the microfibrillated cellulose, tissue paper containing the same, and a method for producing the same.

Background Art

[0002] Calcium carbonate (CaCO3) is used to improve physical properties in various industrial fields such as plastics, rubber, adhesives, coatings, and the paper industry. Among them, in the paper industry, calcium carbonate can be used as a filler. It is known to have small and uniform particle sizes, little equipment wear, fine and uniform paper products, small particle sizes, a high oil absorption value, and a specific surface area that helps with the rigidity of pigments. In addition, calcium carbonate is widely used to produce polyethylene films with excellent air permeability and water resistance in products such as tissue paper, feminine products, sanitary napkins, and diapers. Because of its small particle size, the product is delicate, does not irritate the skin, and does not cause sensory discomfort to the human body. However, due to its small particle size, calcium carbonate has the drawback that it is difficult to retain in thin tissue paper during sheet formation because it falls off under the mesh. Therefore, research is continuing to increase the retention rate so that calcium carbonate can be well retained in tissue paper without falling off.

Summary of the Invention

Problems to be Solved by the Invention

[0003] The present invention was created in consideration of various problems in the prior art as described above and aims to solve them, and provides FCC with improved retention rate containing microfibrillated cellulose, tissue paper containing the same, and a method for producing the same. [Means for solving the problem]

[0004] To achieve the above objectives, the FCC according to one embodiment of the present invention may include microfibrillated cellulose (MFC) and calcium carbonate attached to the microfibrillated cellulose.

[0005] Furthermore, the tissue paper according to the present invention may contain 1 to 10 parts by weight of FCC according to various embodiments of the present invention.

[0006] A tissue paper manufacturing method according to one embodiment of the present invention may include the steps of: producing microfibered cellulose (MFC); synthesizing calcium carbonate with the microfibered cellulose to produce FCC; and adding the FCC to tissue paper. [Effects of the Invention]

[0007] The tissue paper containing FCC according to the present invention can improve retention rates. Furthermore, it can increase the whiteness. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is an SEM image of the microfibrous cellulose from Example 1. [Figure 2] Figures 2a, b, and c are SEM images showing the width and length of the main branches and twigs, respectively. [Figure 3] Figure 3 is an SEM image of the FCC in Example 1. [Figure 4] Figure 4 is an SEM image of the tissue paper according to Example 1. [Modes for carrying out the invention]

[0009] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as those generally understood by a person of ordinary skill in the art to which this invention pertains. Terms as defined in commonly used dictionaries should be interpreted in the sense that they have in the context of the relevant art, and not in an ideal or overly formal sense unless expressly defined herein.

[0010] The FCC (Flexible Calcium Carbonate) of the present invention may contain microfibrillated cellulose (MFC) and calcium carbonate (CaCO3). In this case, the calcium carbonate may be included in a form attached to the microfibrillated cellulose. The microfibrillated cellulose may be in a fibrillated form and may contain numerous branches, and more detailed information will be described below in the description of the tissue paper manufacturing method of the present invention.

[0011] The microfiberized cellulose and calcium carbonate may have a weight ratio of 1:15 to 1:25, preferably 1:20. FCC having such a weight ratio may have a length of 20 μm to 40 μm.

[0012] The tissue paper according to the present invention may contain 1 to 10 parts by weight of the FCC according to the various embodiments described above.

[0013] A tissue paper manufacturing method according to one embodiment of the present invention may include the steps of: producing microfibered cellulose (MFC); synthesizing calcium carbonate with the microfibered cellulose to produce FCC; and adding the FCC to tissue paper.

[0014] The step of producing the aforementioned microfibrous cellulose can be carried out using a colloid mill. Specifically, hardwood pulp can be beaten, dispersed in purified water, and then pulverized in a colloid mill. Here, hardwood pulp refers to fibrous pulp obtained from dicotyledonous trees, in other words, deciduous trees or broad-leaved trees, such as oak, cherry, ebony, mahogany, teak, lauan, and red sanderwood, and is characterized by thin cell walls and short pulp fibers. It is softer and weaker in strength than softwood pulp, which will be described later. On the other hand, softwood pulp refers to fibrous pulp mainly obtained from coniferous trees such as pine and fir, and its pulp morphology is characterized by thick cell walls and long pulp fibers. It is stronger and less soft than the hardwood pulp described earlier. Since the above classification and terminology are common in the technical field of the present invention, the present invention is not particularly limited to each type of example.

[0015] As described above, fibrillated branches can be formed by mechanically crushing hardwood pulp using a colloid mill. More specifically, in the present invention, the microfibrous cellulose can be composed of main branches and twigs. In this case, the main branches and twigs can be classified by their width and length. The main branches may have a width of 5 μm to 12 μm and a length of 500 μm to 850 μm, while the twigs may have a width of 60 nm to 400 nm and a length of 8 μm to 18 μm. The main branches may have a length-to-width ratio of 75% to 100%, and the twigs may have a length-to-width ratio of 25% to 100%.

[0016] Furthermore, the main branches and twigs can be arranged in a ratio of 1:100 to 1:200.

[0017] In the step of producing FCC by synthesizing calcium carbonate with the microfibrillated cellulose, the microfibrillated cellulose and calcium carbonate can have a weight ratio of 1:15 to 1:25. Desirably, it can have a weight ratio of 1:20. Also, the step of producing FCC can be carried out in a container into which CO2 is introduced, and can serve to loosen so that the unattached calcium carbonate can fall off. The length of the FCC produced in this way can be 20 μm to 40 μm. Further, the calcium carbonate contained in the FCC has a spindle shape and can adhere to the microfibrillated cellulose.

[0018] In the step of adding the FCC into the tissue paper, the FCC can be contained in an amount of 1 to 10 parts by weight. It is possible to replace the hardwood pulp added when producing conventional tissue paper with the FCC of the present invention, and by containing the above-mentioned parts by weight, it is possible to produce a tissue paper having an improved retention rate.

[0019] Hereinafter, the present invention will be described in more detail through examples. However, the following examples and experimental examples are only for more specifically explaining the present invention, and the scope of the present invention is not limited by the following examples and experimental examples.

[0020] Example 1 The stage for producing microfiberized cellulose. Hardwood pulp beaten to a fiber width of 18.2 μm and a length of 0.81 mm was dispersed in purified water at 2 wt% and then pulverized with a colloid mill. The clearance of the disk of the colloid mill was maintained at 30 μm to 250 μm, and the rotational speed of the disk was controlled at 1200 to 1900 rpm depending on the discharge state of the sample. Microfibrillated cellulose was produced by treating it in a total of 5 passes according to the swelling due to the frictional heat of the disk and the increase in the viscosity of the sample. The clearance, temperature, and viscosity of the disk when performing a total of 5 passes are as shown in Table 1 below.

[0021]

Table 1

[0022] The stage of manufacturing FCC (Flexible Calcium Carbonate) The manufactured microfibrillated cellulose was put into a reaction vessel of 1 L or more at a concentration of 1 to 2% together with slaked lime at a concentration of 10% or more and water. Then, FCC was manufactured at a stirring speed of 1000 to 2000 rpm under temperature conditions of 40°C to 70°C and a CO2 concentration of 20 to 30%.

[0023] The stage of adding FCC (Flexible Calcium Carbonate) to the tissue paper. Hardwood pulp and softwood pulp were mixed at a weight ratio of 2:8, beaten, and then prepared as a stock solution with a concentration of 3%. Next, 95 parts by weight of the mixed and beaten stock solution and 5 parts by weight of the previously manufactured FCC were mixed and dispersed. Using a circular hand sheet-making machine with an area of 200 cm Experimental Example 2 , ,

[0025] , a hand sheet with a basis weight of 60 g containing the previously manufactured material was manufactured. The manufactured hand sheet was placed between blotting papers and dehydrated using a press, and then the hand sheet was dried using a drum dryer to finally manufacture tissue paper.

[0024] <00​​​​​​​The structure, viscosity, and pH of the FCC in Example 1 were analyzed during the manufacturing process. Figure 3 is an SEM image of the FCC in Example 1. Referring to Figure 3, the FCC has a length of 20 μm to 40 μm. Furthermore, the viscosity and pH of the FCC were measured, and the viscosity was found to be 100 cPs to 500 cPs, and the pH was measured to be 6 to 9.

[0026] Experimental Example 3 The structure of the tissue paper produced according to Example 1 was observed, and the calcium carbonate retention rate and whiteness of the tissue paper were measured.

[0027] Structural observation Figure 4 is an SEM image of the tissue paper produced in Example 1. Referring to Figure 4, it can be seen that the calcium carbonate is retained well without falling off even in the final state of tissue paper production.

[0028] Measurement of retention rate The calcium carbonate retention rate was measured for tissue paper produced according to Example 1 and tissue paper without FCC (hereinafter referred to as Comparative Example 1). In order to measure the retention rate, it is necessary to know the amount of ash in the tissue paper roll, so first an experiment was conducted to measure the amount of ash. First, the tissue paper roll and crucible from Example 1 were dried in an oven at 105°C. Then, after weighing the crucible, 2 to 5 g of the tissue paper roll was placed inside the crucible and ashed in an electric ashing furnace at 525°C for 4 to 5 hours. After ashing, the crucible was removed with crucible tongs and dried in an oven at 105°C. The dried crucible was then weighed to measure the amount of ash in the tissue paper roll. At this time, the ash content (%) was calculated according to the following formula 1.

[0029] [Formula 1] Ash content (%)=(W1-W2) / SX100 (W1: Mass of crucible and ash after ashing (g), W2: Mass of dry crucible (g), S: Amount of ash (g))

[0030] The same process described above was also applied to the tissue paper raw material of Comparative Example 1. The amount of ash content (g) of the tissue paper raw material for Example 1 and Comparative Example 1, obtained in this manner, was substituted into the following formula 2 to measure the retention rate (%).

[0031] [Formula 2] Retention rate (%) = Amount of ash (g) / Amount of FCC added in tissue paper roll (g) x 100

[0032] As a result, the tissue paper produced in Example 1 showed an increased retention rate of approximately 35 to 55% compared to the tissue paper produced in Comparative Example 1.

[0033] Measurement of whiteness The whiteness of the tissue paper produced in Example 1 and the tissue paper produced in Comparative Example 1, as described above, was measured. A whiteness meter was used for the measurement. As a result, the whiteness of the tissue paper produced in Example 1 was increased by 1.4 to 2.0%p compared to the tissue paper produced in Comparative Example 1.

[0034] The above discussion has focused on preferred embodiments of the present invention. Those with ordinary skill in the art to which the present invention pertains should understand that the present invention can be embodied in modified forms that do not depart from its essential characteristics. Therefore, the disclosed embodiments should be considered in an explanatory rather than restrictive manner. The scope of the present invention is defined in the claims, not in the above description, and any differences within an equivalent scope should be interpreted as being included within the scope of the present invention.

Claims

1. Microfiberized cellulose (MFC); and FCC (Flexible Calcium Carbonate) containing calcium carbonate attached to the aforementioned microfiberized cellulose, Hardwood pulp and, Contains softwood pulp, Tissue paper characterized by containing 1 to 10 parts by weight of the aforementioned FCC.

2. The tissue paper according to claim 1, characterized in that the microfiberized cellulose and calcium carbonate have a weight ratio of 1:15 to 1:

25.

3. The tissue paper according to claim 1, characterized in that the FCC has a length of 20 μm to 40 μm.

4. A step of beating and grinding hardwood pulp to produce microfibrous cellulose (MFC); A step of producing FCC (Flexible Calcium Carbonate) by synthesizing calcium carbonate with the aforementioned microfiberized cellulose; The stage of preparing the paper stock by mixing hardwood pulp and softwood pulp and beating them; A step of mixing and dispersing the FCC in the paper stock; A step of producing tissue paper containing 1 to 10 parts by weight of FCC by papermaking and drying the paper stock in which the FCC is dispersed; A method for manufacturing tissue paper that includes [a specific ingredient / method].

5. The tissue paper manufacturing method according to claim 4, characterized in that the step of producing the microfiberized cellulose is carried out by a colloid mill.

6. The step of producing the aforementioned microfiberized cellulose is: The aforementioned microfibrous cellulose is composed of main branches and twigs. The tissue paper manufacturing method according to claim 4, characterized in that the main branches and twigs are present in a ratio of 1:100 to 1:

200.

7. The main branch has a width of 5 μm to 12 μm and a length of 500 μm to 850 μm. The tissue paper manufacturing method according to claim 6, characterized in that the twigs have a width of 60 nm to 400 nm and a length of 8 μm to 18 μm.

8. In the stage of manufacturing the aforementioned FCC The method for producing tissue paper according to claim 4, characterized in that the microfiberized cellulose and calcium carbonate are in a weight ratio of 1:15 to 1:

25.

9. The step of manufacturing the aforementioned FCC is CO ２ The method for manufacturing tissue paper according to claim 4, characterized in that it is carried out in a container into which the substance is introduced.

10. The tissue paper manufacturing method according to claim 4, characterized in that the step of manufacturing the FCC is carried out so that the FCC has a length of 20 μm to 40 μm.

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