Flexible calcium carbonate with improved calcium carbonate holding rate, tissue paper including 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, a 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 manufacturing industry. Among them, in the paper manufacturing industry, calcium carbonate can be used as a filler and is known to have a small and uniform particle size, little equipment wear, fine and uniform paper products, a small particle size, 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 a polyethylene film 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, because calcium carbonate has a small particle size, thin tissue paper-like thin paper has the drawback that calcium carbonate falls off under the mesh during sheet formation and is difficult to retain. Therefore, research to increase the retention rate so that calcium carbonate can be well retained in the tissue paper without falling off has been continuously carried out.

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 provide FCC with improved retention rate containing microfibrillated cellulose, a tissue paper containing the same, and a method for producing the same.

Means for Solving the Problem

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

[0005] In addition, the tissue paper according to the present invention can include 1 to 10 parts by weight of the FCC according to various embodiments of the present invention.

[0006] A method for manufacturing a tissue paper according to an embodiment of the present invention can include a step of manufacturing microfibrillated cellulose (MFC), a step of synthesizing calcium carbonate in the microfibrillated cellulose to manufacture FCC, and a step of adding the FCC into the tissue paper.

Advantages of the Invention

[0007] The tissue paper containing the FCC according to the present invention can improve the retention rate. In addition, the whiteness can be increased.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0009] Unless otherwise defined, all terms used herein, including technical or scientific terms, shall have the same meaning as commonly understood by those of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries shall be interpreted to have a meaning consistent with the meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formal sense unless clearly defined in this application.

[0010] The FCC (Flexible Calcium Carbonate) of the present invention can contain microfibrillated cellulose (MFC) and calcium carbonate (CaCO₃). At this time, the calcium carbonate can be contained in a form attached to the microfibrillated cellulose. The microfibrillated cellulose can be in a fibrillated form and contain numerous branches. More detailed content will be described in the following explanation regarding the method for manufacturing tissue paper of the present invention.

[0011] The microfibrillated cellulose and calcium carbonate can have a weight ratio of 1:15 to 1:25, and preferably can have a weight ratio of 1:20. The FCC having the above weight ratio can have a length of 20 μm to 40 μm.

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

[0013] A method for manufacturing tissue paper according to an embodiment of the present invention can include a step of manufacturing microfibrillated cellulose (MFC), a step of synthesizing calcium carbonate in the microfibrillated cellulose to manufacture FCC, and a step of adding the FCC into the tissue paper.

[0014] The step of manufacturing the microfibrillated cellulose can be carried out by a colloid mill. Specifically, it can be carried out by beating hardwood pulp, dispersing it in purified water, and then grinding it with a colloid mill. Here, hardwood pulp is fibrous pulp obtained from trees belonging to dicotyledons, in other words, deciduous trees or broad-leaved trees with broad leaves, such as Oak, Cherry, Ebony, Mahogany, Teak, Lauwan, Red sanderwood, etc. It is obtained from broad-leaved trees, has a thin cell wall, and a short cellulose length. It is softer and weaker in strength than the softwood pulp described later. On the other hand, softwood pulp mainly means fibrous pulp obtained from coniferous trees such as Pine and Fir, and the pulp morphology is characterized by a thick cell wall and a long pulp cellulose length. It is stronger in strength and lower in softness than the hardwood pulp described above. Since the above classifications and terms are common in the technical field related to the present invention, the present invention is not particularly limited to examples of each type.

[0015] As described above, the hardwood pulp can be mechanically ground by a colloid mill to form fibrillated branches. More specifically, in the present invention, the microfibrillated cellulose can be composed of main branches and small branches. At this time, the main branches and small branches can be classified by the width and length of the branches. The main branches have a width of 5 μm to 12 μm and a length of 500 μm to 850 μm, and the small branches can have a width of 60 nm to 400 nm and a length of 8 μm to 18 μm. The main branches can have an aspect ratio of 75% to 100%, and the aspect ratio of the small branches can be 25% to 100%.

[0016] Also, the main branches and small branches can be made to exist in a ratio of 1:100 to 1:200.

[0017] In the step of manufacturing 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 manufacturing FCC can be carried out in a container into which CO2 is introduced, and it can serve to loosen so that the unattached calcium carbonate can fall off. The length of the FCC manufactured 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 manufacturing conventional tissue paper with the FCC of the present invention, and by containing the above-mentioned parts by weight, it is possible to manufacture 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 explaining the present invention more specifically, and the scope of the present invention is not limited by the following examples and experimental examples.

[0020] Example 1 Step of manufacturing microfibrillated 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 colloid mill disk was maintained at 30 μm to 250 μm, and the rotational speed of the disk was controlled at 1200 to 1900 rpm according to the discharge state of the sample. Microfibrillated cellulose was manufactured by processing in a total of 5 passes in response 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] Step of manufacturing FCC (Flexible Calcium Carbonate) The manufactured microfibrillated cellulose was adjusted to a concentration of 1 to 2% and charged into a reaction vessel of 1 L or more together with slaked lime at a concentration of 10% or more and water. Then, FCC was produced 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] Step of adding FCC (Flexible Calcium Carbonate) into 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 produced FCC were mixed and dispersed. Using a circular hand sheet former with an area of 200 cm 2 a hand sheet with a basis weight of 60 g containing the previously manufactured material was produced. The produced hand sheet was placed between blotting papers and dehydrated using a press, and then dried using a drum dryer to finally produce tissue paper.

[0024] Experimental Example 1 The structure, viscosity, and pH of the microfibrillated cellulose in the stage of manufacturing the microfibrillated cellulose of Example 1 were analyzed. FIG. 1 is an SEM image of the microfibrillated cellulose of Example 1, and FIGS. 2a, 2b, and 2c are SEM images showing both the width and length of the main branches and the small branches. Referring to FIGS. 1 and 2, it can be seen that the main branches have a width of 5 μm to 12 μm and a length of 500 μm to 850 μm, and the small branches have a width of 60 nm to 400 nm and a length of 8 μm to 18 μm. Furthermore, as a result of measuring the viscosity and pH of the microfibrillated cellulose, the viscosity was measured to be 7000 to 10000 cPs and the pH was 7.

[0025] Experimental Example 2 The structure, viscosity, and pH of the FCC in the production stage of Example 1 were analyzed. Figure 3 is the SEM image of the FCC of Example 1. Referring to Figure 3, the FCC has a length of 20 μm to 40 μm. Furthermore, as a result of measuring the viscosity and pH of the FCC, the viscosity was measured 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] Structure observation Figure 4 is the SEM image of the tissue paper according to Example 1. Referring to Figure 4, it can be seen that even in the state where the tissue paper was finally produced, calcium carbonate did not fall off and was well retained.

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

[0029] [Formula 1] Ash (%) = (W1 - W2) / S×100 (W1: mass of the crucible and ash after ashing (g), W2: mass of the dried crucible (g), S: amount of ash (g))

[0030] The above process was also carried out on the tissue paper base stock of Comparative Example 1. The amounts (g) of ash of the tissue paper base stocks of Example 1 and Comparative Example 1 obtained in this way were substituted into the following formula (2) to measure the retention rate (%).

[0031] [Formula (2)] Retention rate (%) = Amount of ash (g) / FCC addition amount (g) in the tissue paper base stock × 100

[0032] As a result, the retention rate of the tissue paper according to Example 1 increased by about 35 to 55% compared with the tissue paper according to Comparative Example 1.

[0033] Measurement of whiteness The whiteness of the tissue paper according to Example 1 and the tissue paper of Comparative Example 1 described above was measured. At this time, it was measured using a whiteness measuring instrument. As a result, the whiteness of the tissue paper according to Example 1 increased by 1.4 to 2.0%p compared with the tissue paper according to Comparative Example 1.

[0034] As described above, the desirable embodiments of the present invention have been mainly considered. Those having ordinary knowledge in the technical field to which the present invention pertains should be able to understand that the present invention can be embodied in a modified form without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered from an illustrative perspective rather than a limiting perspective. The scope of the present invention is shown not in the above description but in the claims, and any differences within the scope equivalent thereto should be construed as being included in the present invention.

Claims

1. Micro fibrillated cellulose (Micro Fibillated Cellulose, MFC); and Calcium carbonate attached to the micro fibrillated cellulose; FCC (Flexible Calcium Carbonate) characterized by comprising the same.

2. The FCC (Flexible Calcium Carbonate) according to Claim 1, characterized in that the micro fibrillated cellulose and calcium carbonate have a weight ratio of 1:15 to 1:

25.

3. The FCC (Flexible Calcium Carbonate) according to Claim 2, characterized in that the FCC has a length of 20 μm to 40 μm.

4. A tissue paper characterized by containing 1 to 10 parts by weight of FCC (Flexible Calcium Carbonate) according to any one of Claims 1 to 3.

5. A step of manufacturing micro fibrillated cellulose (Micro Fibillated Cellulose, MFC); A step of synthesizing calcium carbonate in the micro fibrillated cellulose to produce FCC (Flexible Calcium Carbonate); and A step of adding the FCC (Flexible Calcium Carbonate) into the tissue paper; A method for manufacturing a tissue paper comprising the steps.

6. The method for manufacturing a tissue paper according to Claim 5, characterized in that the step of manufacturing the micro fibrillated cellulose is performed by a colloid mill.

7. The step of manufacturing the micro fibrillated cellulose is The micro fibrillated cellulose is composed of main branches and small branches, The method for manufacturing a tissue paper according to Claim 5, characterized in that the main branches and small branches are present in a ratio of 1:100 to 1:

200.

8. The main branches have a width of 5 μm to 12 μm and a length of 500 μm to 850 μm, The method for manufacturing a tissue paper according to Claim 7, characterized in that the small branches have a width of 60 nm to 400 nm and a length of 8 μm to 18 μm.

9. In the step of manufacturing the FCC (Flexible Calcium Carbonate) The method for manufacturing a tissue paper according to Claim 5, characterized in that the micro fibrillated cellulose and calcium carbonate have a weight ratio of 1:15 to 1:

25.

10. The step of manufacturing the FCC (Flexible Calcium Carbonate) is carried out in a container into which CO ２ is introduced, and the method for manufacturing tissue paper according to claim 5, characterized in that it is carried out in a container into which CO is introduced.

11. The step of manufacturing the FCC (Flexible Calcium Carbonate) is performed such that the FCC has a length of 20 μm to 40 μm, the method for manufacturing tissue paper according to claim 5.

12. In the step of adding the FCC (Flexible Calcium Carbonate) into the tissue paper, the FCC (Flexible Calcium Carbonate) is contained in an amount of 1 to 10 parts by weight, the method for manufacturing tissue paper according to claim 5.

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