KR20120094393A

KR20120094393A - Method for manufacturing lignocellulosic fillers for papermaking and the lignocellulosic fillers prepared thereby

Info

Publication number: KR20120094393A
Application number: KR1020110013884A
Authority: KR
Inventors: 김철환
Original assignee: 경상대학교산학협력단
Priority date: 2011-02-16
Filing date: 2011-02-16
Publication date: 2012-08-24

Abstract

PURPOSE: A method for manufacturing a filler for lignocellulose paper is provided to improve turbidity of white water and to reuse the white water. CONSTITUTION: A method for manufacturing a filler for a lignocellulose paper comprises: a step of pulverizing wood materials at 20,000-30,000 rpm for 30-90 seconds to prepare wood powder; a step of bleaching the wood powder; a step of mixing the bleached wood powder and inorganic filler in a weight ratio of 60-80:20-40; and a step of adding polymer electrolyte as an binder. The bleaching step comprises: a step of adding 10 wt% of sodium hydroxide to 4wt% of wood powder and treating at pH 11.5-12.5 and 65-75 Deg. C. for 90-150 minutes; a step of adding 5% sodium hydrochlorite to 1wt% of wood powder and treating at pH 11-11.5 and 55-65 Deg. C. for 90-150 minutes; a step of adding 10% chlorine dioxide to 1 wt% of wood powder and treating at pH 3.5-4.0 and 75-85 Deg. C. for 150-210 minutes; and a step of adding 10% hydrogen peroxide to 3 wt% of wood powder and treating at 75-85 Deg. C. for 90-150 minutes.

Description

Method for manufacturing lignocellulosic paper-based fillers and lignocellulosic paper-based fillers prepared by this method {Method for manufacturing lignocellulosic fillers for papermaking and the lignocellulosic fillers prepared}

The present invention relates to a method for producing a lignocellulosic paper-based filler and a lignocellulosic paper-based filler prepared by the present invention. More specifically, the step of surface modification treatment with an inorganic filler after bleaching the pulverized wood is performed. It relates to a method for producing a lignocellulosic paper-based filler comprising and a lignocellulosic paper-based filler produced thereby.

In the manufacture of paper, inorganic fillers such as calcium carbonate, clay, and talc are added up to 20 to 30% in order to improve the opacity of the paper and increase the affinity with the printing ink. Since inorganic fillers are cheaper than pulp, which is the main raw material of paper, high filling technology is applied to reduce the manufacturing cost of paper. However, since the chemical bonding between the inorganic fillers and the cellulose fibers hardly occurs, the use of retention aids for maximum retention of the inorganic fillers in the fiber network is essential. Nevertheless, in the dehydration process on the paper machine's wire, large amounts of filler are released, which not only increases the pollution of white water, but also causes problems in recycling of white water. Even if the inorganic fillers are retained in the fiber network, there is a problem that these fillers interfere with the hydrogen bonding between the fibers, resulting in a decrease in the strength of the paper.

Therefore, unlike inorganic fillers, if organic fillers having high affinity with cellulose fibers can be developed, not only the retention can be improved, but also the turbidity of white water can be improved, and in addition, the reduction of physical properties of the paper can be suppressed. This can cause significant changes in the paper manufacturing process.

In general, many chemical methods are used to modify wood samples, and most of the chemically treated woods are controlled by the infiltration of chemicals into the amorphous regions of cellulose and hemicelluloses and lignin. It is possible to change the intrinsic properties of the wood. Among the methods for reforming wood, methods using heat treatment, amine or ammonia treatment, and microwaves are mainly used.

Among these methods, alkali treatment elutes a part of hemicellulose and lignin from the cell wall to form voids in the matrix, and gives plasticity to the fiber by changing the shape of the inclination or bending of the microfibrils oriented in the matrix. At this time, it can be expected that the cell wall of the wood will swell easily, and the pores of the cell wall will be expanded, and eventually physical bonding with various paper additives will be easier. At this time, excessive chemical treatment accelerates the fibrosis of the fine wood flour particles, it is difficult to expect the function as a filler. In order to use wood flour particles as a filler, it is desirable to have some lignin remaining in the fiber, so it is most ideal to chemically modify it under mild conditions.

However, the modified wood powder has improved binding strength with cellulose fibers, but may have a negative effect on the opacity of the paper. Even though a small amount of lignin is included in the lignocellulosic powder, the lignocellulosic powder may have a refractive index close to that of the papermaking fiber because it is mainly composed of cellulose. This can lead to lower light scattering coefficients compared to common inorganic fillers, which in turn can reduce opacity. This problem has been solved through modification of organic fillers.

It is thought that wood powder has better retention of cellulose fibers, which improves turbidity of white water, making it easier to recycle white water and conserving paper strength. Using these positive aspects, there is a need for research to develop lignocellulosic fillers that combine the advantages of inorganic fillers with minimal use of inorganic fillers that are currently widely used.

The present inventors have studied the problems of lignocellulosic organic fillers compared to inorganic fillers to reduce the paper's opacity, low optical properties, paper strength and surface properties, and the surface of bleached wood powder with inorganic fillers. A lignocellulosic paper-based filler was prepared by reforming, and paper or paperboard using the lignocellulosic paper-based filler was improved in physical properties, optical properties, and surface properties, compared to inorganic fillers, and dehydration and white water of paper. It was confirmed that the turbidity of the improved and completed the present invention.

The present invention is to provide a method for producing a lignocellulosic paper-based filler and a lignocellulosic paper-based filler prepared thereby.

Paper and paperboard prepared by adding the lignocellulosic paper-based filler according to the present invention have a bulk increase as compared with paper and paperboard prepared by adding the inorganic filler, and lowers the strength. This may complement the limitations of inorganic fillers in increasing filler content to reduce raw materials in paper and cardboard manufacturing. In addition, the lignocellulosic paper-making filler of the present invention is expected to have better retention than inorganic fillers to improve turbidity of white water and to facilitate recycling of white water.

1 is a diagram schematically illustrating a modification process of a lignocellulosic filler according to an embodiment of the present invention.
Fig. 2 is an electron micrograph of the surface of wood flour mixed with carbonate and mixed with the modified wood.
Figure 3 is a diagram illustrating a state in which the inorganic filler is lignocellulosic filler adsorbed to the pulp fibers.
Figure 4 is a SEM photograph (300 times) of the paper cross-section prepared according to an embodiment of the present invention.
5 is an electron micrograph of a lignocellulosic filler.
6 is a graph showing particle size distribution of lignocellulosic filler and hard calcium carbonate (PCC).
7 is an electron micrograph of PCC particles, lignocellulosic filler, and polymer modified filler.
Figure 8 (a) is a photograph taken with a high magnification of the surface structure of the PCC-added sheet, Figure 8 (b) is a photograph taken with a high magnification the surface structure of the lignocellulosic filler modified to a polymer.
9 is (a) preparing a lignocellulosic filler; And (b) schematic diagrams of organic filler particles modified with a polymer.
10 is a schematic view of (a) PCC particles suspended between fibers; And (b) a schematic view of lignocellulosic filler held between fibers.
Figure 11 is a graph showing the bulk (bulk) change for each type of paper with a filler prepared according to an embodiment of the present invention.
12 is a graph showing the breaking length of each type of paper added with a filler prepared according to an embodiment of the present invention.
Figure 13 is a graph showing the burst strength (burst strebgth) of each type of paper with a filler prepared according to an embodiment of the present invention.
14 is a graph showing the tensile strength (tear strength) of each type of paper with a filler prepared according to an embodiment of the present invention.
15 is a graph showing the stiffness (stiffness) for each type of paper added with a filler prepared according to an embodiment of the present invention.
FIG. 16 is a graph showing whiteness (brightness) for each type of paper to which a filler prepared according to an embodiment of the present invention is added.
FIG. 17 is a graph showing opacity for each type of paper added with a filler prepared according to an embodiment of the present invention. FIG.
FIG. 18 is a graph showing whiteness (brightness) of each type of paper to which a bleaching step-filled filler is prepared according to an embodiment of the present invention.
FIG. 19 is a graph showing whiteness and whiteness according to the amount of fluorescent brightener added in a paper prepared according to an embodiment of the present invention. FIG.
20 is a graph showing the smoothness of paper manufactured according to an embodiment of the present invention.
FIG. 21 is a graph showing surface roughness of paper manufactured according to an embodiment of the present invention. FIG.
22 is a graph showing air permeability of paper manufactured according to an embodiment of the present invention.
FIG. 23 is a graph showing the drainage rate of each type of paper added with a filler prepared according to an embodiment of the present invention. FIG.
24 is a graph measuring the turbidity (tubility) of the white water dehydrated through the DFS in paper manufacturing according to an embodiment of the present invention.
25 is a graph showing the bulk change of the cardboard according to the lignocellulosic extender particle size.
FIG. 26 is a graph showing the breaking length of each type of paperboard added with a filler prepared according to an embodiment of the present invention. FIG.
FIG. 27 is a graph illustrating changes in burst strength of cardboards to which fillers are prepared according to an embodiment of the present invention.
FIG. 28 is a graph showing a change in tear strength of each type of paperboard added with a filler prepared according to an embodiment of the present invention. FIG.
29 is a view showing a change in the opacity (opacity) of the cardboard with a filler prepared according to an embodiment of the present invention.
Figure 30 shows the bulk of the cardboard (bulk) according to the addition ratio of lignocellulosic extender.
FIG. 31 shows the breaking length of cardboard according to the addition ratio of lignocellulosic extender.
Figure 32 shows the change in the burst strength (burst strength) of the paperboard according to the addition ratio of the lignocellulosic extender.
33 shows the tensile strength of the paperboard according to the addition ratio of the lignocellulosic extender.
34 is a graph showing the bulk change of the multi-layered cardboard according to the addition ratio of wood flour filler.
FIG. 35 is a graph showing the breaking length of multi-layered cardboard according to the addition ratio of wood flour filler.
FIG. 36 is a graph showing changes in burst strength of multi-layered cardboard according to the addition ratio of wood flour filler.
FIG. 37 is a graph showing the tensile strength of the multi-layered cardboard according to the addition ratio of wood flour filler.
FIG. 38 is a graph showing the drainage rate of a paper to which a filler prepared according to an embodiment of the present invention is added, and is used when unbleached kraft pulp (UKP) is used as a stock.
FIG. 39 is a graph showing the drainage rate of a paper to which a filler prepared according to an embodiment of the present invention is added, in which OCC is used as a stock. FIG.
40 is a graph measuring turbidity of white water dehydrated through DFS.

The present invention

(1) pulverizing wood to prepare wood flour;

(2) bleaching the wood powder; And

(3) mixing the bleached wood powder and the inorganic filler in a weight ratio of 60 to 80: 20 to 40, and adding a polymer electrolyte as a binder to perform surface modification treatment; preparing lignocellulosic paper-based filler Provide a method.

The present invention also provides a lignocellulosic paper-based filler prepared by the above method.

Hereinafter, the present invention will be described in detail.

In the manufacturing method of the present invention, step (1) is a step of preparing wood powder, and then pulverized for 30 to 90 seconds at 20,000 ~ 30,000 rpm after chipping wood. The pulverized wood flour is separated into the wood powder remaining through 100 mesh, the wood powder remaining in 100 mesh, the wood powder remaining in 200 mesh, the wood powder remaining in 200 mesh, and the wood powder remaining in 400 mesh.

Step (2) is a step of bleaching the wood powder, in order to improve the low optical properties of the paper to increase the bleaching step from the conventional two-stage bleaching to four-stage bleaching, the wood powder remaining in the 400 mesh (a) Adding 4% by weight of 10% sodium hydroxide to the total weight of the wood powder and treating it at pH 11.5-12.5, 65-75 ° C. for 90-150 minutes; (b) adding 1% by weight of 5% sodium hypochlorite to the total weight of wood flour and treating it at pH 11-11.5, 55-65 ° C. for 90-150 minutes; (c) adding 1% by weight of 10% chlorine dioxide to the total weight of wood meal and treating it for 150-210 minutes at pH 3.5-4.0, 75-85 ° C .; And (d) 10% hydrogen peroxide (hydrogen peroxide) is added to the total weight of the wood powder 3wt%, bleaching treatment through a step of 90 to 150 minutes at 75 ~ 85 ℃.

Step (3) is a step of surface-modifying the bleached wood powder, and mixing the bleached wood powder and the inorganic filler in a weight ratio of 60 to 80:20 to 40, preferably in a weight ratio of 70:30, as a binder The surface is treated by adding a polymer electrolyte.

The inorganic fillers include, but are not limited to, light calcium carbonate (PCC) or heavy calcium carbonate (GCC).

The polymer electrolyte includes but is not limited to cationic PAM or cationic starch.

The surface modification treatment method may be performed by the following two methods.

First, when the polymer electrolyte is cationic PAM, cationic PAM is added to the mixture of bleached wood powder and inorganic filler, and then mixed for 1 to 3 minutes after adding 0.005 to 0.015 wt% of the total weight of the mixture. A lignocellulosic filler can be prepared which has been modified with PAM.

Secondly, when the polymer electrolyte is cationic starch, cationic starch is added to the mixture of bleached wood powder and inorganic filler with 0.20 to 0.30wt% of the total weight of the mixture and heat-treated in an oven for 20 to 28 hours. After mixing for 20 to 40 seconds, a lignocellulosic filler modified with cationic starch may be prepared.

The paper and paperboard prepared by adding the lignocellulosic paper-based filler prepared by the above method has a bulk increase and a decrease in tensile strength, tear strength and tear strength compared to paper and paperboard prepared by adding the inorganic filler. The physical properties are reduced, and the optical properties are improved by improving the opacity, whiteness and whiteness. Therefore, the lignocellulosic paper-based filler of the present invention can be usefully used for paper and cardboard production.

Hereinafter, the present invention will be described in more detail with reference to Examples.

However, the following examples are only for illustrating the present invention, and the contents of the present invention are not limited to the following examples.

Wood used as a material of the lignocellulosic filler in the present invention used oyster oak ( Quercus variabilis ) and pine ( Pinus densiflora ), which are less than 15 years old, collected from the academic forest of Deoksan (Jirisan), Gyeongsang National University, Sancheong-gun, Gyeongnam. Fillers for reforming organic fillers include powder type hard calcium carbonate (PCC, Precipitated Calcium Carbonate, D60, Polytech & net Co, Korea) and heavy calcium carbonate (GCC, Ground Calcium Carbonate, Hydrocarb-90K, Omya, Korea), and cationic starch (Cationic starch, 60L, Daesang Co., Ltd, Korea) having a degree of substitution (DS) of 0.06 ) Was used. In addition, the fluorescein was used as a K-D-FWA, which supplies fluorescein to Korean paper companies, and cationic PAM was used as a retention agent.

The public pulp was mixed with softwood BKP (Hw-BKP, Hard Woob-Bleached Kraft Pulp) and softwood BKP (Sw-BKP, Soft Woob-Bleached Kraft Pulp), a market pulp used by M Paper. Old Corrugated Container (OCC), Unbleached Kraft Pulp (UKP) and Hardwood UKP were used. At this time, the UKP manufactured Paulownia coreana and Pinus rigida chips of less than 15 years of age from the academic forest using Digester.

Example 1 Surface Modification of Wood Powder

1-1) Crushing Wood

In order to obtain a sample of the organic filler of the present invention, the test material was chipped and ground for 60 seconds using Wonder Blender (WB-01, Sanplatec corp., Japan) at a speed of 25,000 rpm. The wood powder was passed through 80 mesh and remained in 100 mesh, the wood powder was passed through 100 mesh and remained in 200 mesh, and the wood powder was passed through 200 mesh and remaining in 400 mesh.

1-2) bleached wood

In order to improve the whiteness of the classified wood flour, four stages of bleaching were carried out under the conditions shown in Table 1 below, but only the wood flour passing through the 200 mesh and remaining in the 400 mesh was bleached.

Table 1 Bleaching Conditions for the Preparation of Lignocellulosic Fillers

1-3) Using filler Woody Reforming treatment

The bleached wood powder (mother particle) and PCC (subparticle) were modified using Wonder Blender (WB-01, Sanplatec Corp., Japan) under the conditions shown in Table 2 below. The surface modification treatment step of the present invention is shown in FIG.

Scanning electron microscope (JSM-6380LV, Jeol, Japan) and electric field scanning electron microscope (JSM-6701F, Jeol, Japan) were used to observe the surface modification of wood flour.

[Table 2] Surface modification treatment conditions of lignocellulosic filler

Experimental Example 1 Surface Modification Effect Experiment Using Inorganic Filler

By modifying the surface of the wood particles with an inorganic filler, the whiteness of the lignocellulosic organic filler in which lignin is not removed can be increased. In other words, after mechanically mixing an inorganic filler such as calcium carbonate and an inorganic filler such as calcium carbonate, and filtering out only the lignocellulosic filler particles, the inorganic filler particles are interposed between the lumens, pits and cracks in the wall of the lignocellulosic filler. As well as sticking to the surface will be able to completely change the physical properties of the lignocellulosic filler.

In order to investigate the modification effect of the lignocellulosic filler of the present invention, wood powder passed through a 200 mesh wire was mixed with heavy calcium carbonate for papermaking (GCC), and the surface of the lignocellulosic filler which was mechanically mixed and modified was treated with electrons. The photograph observed with the microscope is shown in FIG. According to FIG. 2, it can be easily confirmed that the fine heavy calcium carbonate particles enter and fill the gap between the crack and the hole of the lignocellulosic particles and cover the surface of the lignocellulosic powder. Therefore, due to the coated inorganic filler, the whiteness of the lignocellulosic filler can be further improved.

3 shows a process in which the lignocellulosic filler is bonded to the pulp fiber in the state in which the inorganic filler is adsorbed on the surface of the lignocellulosic powder. Since the lignocellulosic powder is composed of carbohydrates including cellulose and hemicellulose together with lignin, the affinity with pulp fibers is much greater than that of inorganic fillers. Therefore, the addition of a small amount of retention enhancer is expected to significantly improve the retention of lignocellulosic powder to which inorganic fillers are bound. Through this, it was judged that the strength deterioration phenomenon due to the inorganic filler and the problem of retention failure could be solved.

Paper added with lignocellulosic filler increased the bulk as filler input increased, but the value increased nearly 20% from the initial value, whereas paper added with calcium carbonate showed negative value when added. . FIG. 4 is a cross-sectional view of a cross section of paper without added lignocellulosic filler and paper with filler, and according to FIG. 4 (b), lignocellulosic fillers having a larger particle size and smaller density than calcium carbonate are fibers. It can be seen that the density is prevented by being held in between.

In addition, the bulk effect of lignocellulosic fillers prepared from oak rather than pine is better because the average particle size of lignocellulosic fillers using oak is higher than that of pine. As the bulk of the paper becomes higher, the same thickness of paper can be obtained with less raw material, which helps to reduce raw materials and at the same time, it can use less expensive pulp for the same basis weight, thereby saving energy for paper drying. will be.

Figure 5 is a photograph of the surface after adding a physical impact by mixing the pulverized wood powder and filler without adding a cationic polymer. Wood powder used oyster oak as hardwood (Hw), pine as coniferous (Sw), and PCC or GCC as inorganic filler. As shown in FIG. 5, the inorganic filler penetrates through the cracks of the wood powder surface by physical impact, and thus the wood powder and the filler are combined, and some of the fillers are physically fixed to the wood surface.

Experimental Example 2 Particle Size Analysis of Fillers

In order to know the particle size of the pulverized body, it was passed through 80 mesh prepared according to Example 1, wood powder remaining in 100 mesh, wood powder remaining in 100 mesh, wood powder remaining in 200 mesh, and 200 mesh remaining in 400 mesh. The particle size of wood flour and wood flour modified with polyelectrolyte were analyzed. In this case, the particle size analyzer (LS-230, Beckman culture, USA) used in the measurement range of 0.04 ~ 2000 ㎛ and distilled water was used as a dispersion solvent of pulverized wood powder. Hard calcium carbonate (PCC) was also used to compare with the inorganic papermaking fillers.

Table 3 below shows the average particle size of the lignocellulosic organic filler and the inorganic filler PCC measured by the particle size analyzer. The average particle size of the lignocellulosic organic filler that passed through the 80 mesh wire and did not pass through 100 mesh was 434.7 μm, and the average particle size of the lignocellulosic organic filler that passed through the 100 mesh wire and did not pass through 200 mesh was about 320.1 μm. In addition, the average particle size of the lignocellulosic organic filler that passed through the 200 mesh wire and failed to pass the 400 mesh was 124.7 μm.

The average particle size of the organic filler modified with PAM, which is a polymer electrolyte, was 66.18 μm, and the average particle size of the organic filler modified with starch was 59.41 μm, with no significant difference in particle size. The reason that the particle size was smaller than that of the lignocellulosic filler that passed through the 200 mesh wire and failed to pass the 400 mesh was considered to be due to the high degree of grinding due to the modification treatment. The average particle size of the inorganic filler PCC is 5.073 μm, which shows the lowest particle size.

Table 3 Average Particle Size of Fillers

6 graphically illustrates the particle size distribution of a filler. In the case of PCC, which is an inorganic filler, it can be seen that the organic filler has a relatively uniform size and a narrow distribution in the average particle size range. On the other hand, since the lignocellulosic filler has a wide distribution in the average particle size range, it is considered to be good for the retention and bulk of the particles compared to the inorganic filler, but the surface properties such as smoothness, roughness and air permeability can be expected to be poor. . In addition, the particle size distribution curve of the lignocellulosic filler modified with the polymer is biased toward a smaller size than that of the general lignocellulosic filler, and thus, the fine inorganic filler and the large organic filler coexist.

Experimental Example 3 Surface Observation of Modified Lignocellulosic Filler

Scanning electron microscope (JSM-6380LV, Jeol, Japan) and field emission scanning electron microscope (JSM-6701F, Jeol, Japan) were used to confirm the surface modification state of the modified wood flour according to Example 1.

7 shows electron micrographs of PCC particles, lignocellulosic fillers, and polymer-modified lignocellulosic fillers using them, and surface photographs of paper prepared by adding them. It is easy to observe that the surface of the lignocellulosic filler before the modification is subjected to significant damage to the surface of the wood or the wood itself during the modification, and that the PCC particles are stuck between these damaged sites during the polymer modification process to function as a filler. It was confirmed that this is improved. The surface of paper prepared by adding lignocellulosic fillers was very difficult to distinguish between filler and pulp fibers, unlike the surface of paper added with PCC only.

FIG. 8 (a) shows a high magnification of the surface structure of the PCC-added sheet, and FIG. 8 (b) shows a high magnification of the surface structure of the lignocellulosic filler modified with a polymer. Unlike the surface of the sheet to which the inorganic filler is added to form hydrogen bonds between fibers, the surface of the sheet to which the lignocellulosic filler is added has fine fibrils of neighboring fibers bonded to the lignocellulosic filler particles. You can easily observe it. This means that the addition of organic filler can reduce the decrease in the strength of the paper.

Figure 9 (a) is a process for producing a lignocellulosic filler by applying a physical force (shear force) to the wood chip, Figure 9 (b) shows a schematic diagram of the particles of these fillers modified with a polymer. As shown in the electron micrograph of FIG. 7, the powder is penetrated into the crevices of the organic filler in which the filler is cracked by applying a physical force to the cracked and damaged part of the powder, and the bonding of the powder and filler occurs at the same time by the polymer binder. The inorganic filler was fixed to the surface of the organic filler. Unlike the general inorganic filler of FIG. 10 (a), the polymer-modified organic filler shown in FIG. 10 (b) not only forms inter-fiber bonds by fine fibrils even when held between the fibers, but also forms PCC on the surface of the organic filler. Because the particles remain partially fixed, the ability to scatter light is also expected to increase.

Example 2 Preparation of Unbleached Kraft Pulp (UKP)

2-1) Chip Manufacturing

Paulownia and Rigida pines were cut to 50 cm in length, dried to dryness and then chipped to a size of about 3 × 2 × 0.2 cm.

2-2) Kraft pulping

By using digest, kraft pulping is performed under pulping conditions of active alkali concentration of 35%, sulfidation degree of 25%, cooking temperature of 170 ° C, cooking time of 180 minutes, and chip / liquor of 1: 4. Was carried out.

Example 3. Paper Preparation I

In order to analyze the availability of the modified wood flour as a filler, Hw-BKP and Sw-BKP were mixed with Yeosu-do 450 ml CSF using a laboratory valley beater and mixed. Next, a paper of 80 g / m 2 basis weight was prepared using a laboratory square water paper machine under the conditions of Table 4, and then subjected to a humidity treatment for 24 hours in a constant temperature and humidity room.

TABLE 4 Addition ratio of pulp and filler in paper I

Example 4 Paper Preparation II

To determine the degree of bleaching of wood powder, Hw-BKP and Sw-BKP were mixed with Yeosu 450 ml CSF using a laboratory valley beater. Next, the paper was manufactured in a basis weight of 80 g / m 2 using a laboratory square water paper under the conditions shown in Table 5, and then subjected to humidity treatment for 24 hours in a constant temperature and humidity room.

TABLE 5 Addition ratio of pulp and filler in Paper II

Example 5 Paper Preparation III

In order to improve the optical properties of the paper to which the organic filler was added, D-FWA, an internal fluorescent brightener, was used. In order to examine the effect of organic filler on paper, Hw-BKP and Sw-BKP were mixed with Yeosu-do 450 ml CSF using a Valley Valley beater, and then mixed. After the paper was prepared using a basis weight of 80 g / m 2, humidity treatment was performed for 24 hours in a constant temperature and humidity room.

[Table 6] Addition ratio of pulp, filler and optical brightener in paper III

Example 6 Paperboard Preparation

In order to determine the effect of particle size of the organic filler on the physical properties of the paperboard Hw-UKP and Sw-UKP was mixed with Yeosu 500 ㎖ CSF using a laboratory valley beater and mixed, and experimented under the conditions shown in Table 7 below. Cardboard was manufactured in a basis weight of 260 g / ㎡ using a practical square water machine was subjected to a humidity treatment for 24 hours in a constant temperature and humidity room.

Table 7 Addition of Pulp and Filler in Cardboard I

Example 7 Papermaking II

Hw-UKP and Sw-UKP were fed to Yeosu 380 ml CSF and OCC Yeosu 480 ml CSF by using a laboratory valley beater. Next, a cardboard was manufactured in a basis weight of 250 g / m 2 using a laboratory square water paper machine under the conditions shown in Table 8, followed by a humidity treatment for 24 hours in a constant temperature and humidity room.

[Table 8] Addition Rate of Pulp and Filler in Cardboard II

Example 8 Cardboard Manufacturing III

In order to investigate the effect of the addition rate of the organic filler on the characteristics of the multi-layered cardboard, Sw-UKP was beaten to 450 ml CSF in Yeosu, 480 ml CSF in Yeosu and 480 ml CSF using Valley beater for laboratory. As a condition, a top and back layer was 60 g / m 2, and a filler layer was 180 g / m 2, using a laboratory square water paper machine. Each layer prepared was laminated to produce a cardboard and then humidified for 24 hours in a constant temperature and humidity room.

TABLE 9 Addition ratio of pulp and filler in cardboard III

Example 9 Calendar Processing

In order to improve the smoothness of the paper surface was calendered using Soft & Super Calender (SMT, CO, LTD), the calendering conditions were the temperature 21 ℃, nip pressure 0.127 × 100 kN, speed 10.0 m / min. At this time, in order to compare and judge in the same bulk, the paper with PCC and the paper without filler were subjected to two nips and the paper with lignocellulosic filler was performed four times.

Experimental Example 4 Physical Properties of Paper Added Modified Wood Powder as Filler

Tensile strength, tear strength and tear strength, smoothness, roughness and air permeability were measured according to the TAPPI Standard method to measure the basis weight of the humidified paper.

FIG. 11 shows the bulk change of the paper according to the addition of the inorganic filler and the organic filler. In general, since the density of the inorganic filler is greater than that of the pulp fibers, the bulk of the paper decreases when the amount of the inorganic filler is added at the same basis weight. As can be seen in FIG. 11, the organic filler without modification was the best bulk, and the modified organic filler also showed better bulk than paper without PCC and filler. The reason is that the particles of the organic filler are larger than the particles of the PCC, which is an inorganic filler, and thus the retention is increased because they do not pass through the pores formed in the fiber network, and the bulk is increased because the organic filler is larger and smaller in density than the inorganic filler. It is feed. In addition, calendering was performed to improve the surface properties.The nip number of the organic filler added paper showed better bulk even though the nip number of the organic filler was more than twice the nip number applied to the PCC and the paper without the filler 4 times. The retention performance was also proven to be very good.

FIG. 12 shows the breaking length of the paper, and it can be seen that as the filler is added, the bonding strength with the fiber is lowered, resulting in a decrease in strength. However, the organic filler having better binding strength with the fiber at the same addition level showed a higher value than the inorganic filler. Organic fillers, such as lignocellulosic fillers, are less likely to interfere with hydrogen bonding between fibers because the particle size is larger than PCC. In addition, in the case of organic fillers modified with polymers, the cationic polymers bound to the organic fillers seem to have improved tensile strength because they positively affect the hydrogen bonding between fibers.

13 and 14 show the burst strength and tear strength of the paper, respectively, and the paper with the organic filler reduced the burst and tear strength reductions compared to the paper with only PCC. In addition, the organically modified organic fillers contributed more to the strength of paper than the unmodified organic fillers. In particular, organic fillers modified with cationic starch showed the highest strength values. This is believed to be because starch increased the binding force between the fibers even more by partially fixing the PCC to the organic filler surface.

FIG. 15 shows the stiffness of the paper. The bending stiffness of the paper with the organic filler was higher than that with the PCC. In addition, high flexural rigidity was maintained even after calendering. It is generally known that proper flexural stiffness is essential for good operability on paper or paperboard, on paper machines, printers, and processing equipment. Even if the organic filler modified with the cationic polymer, the PCC partially covered the surface of the organic filler, the flexural stiffness was significantly reduced compared to the unmodified organic filler.

Experimental Example 5. Optical Properties of Paper Added Modified Wood Powder as Filler

After measuring the basis weight of the humidity-treated paper, whiteness, whiteness, and opacity were measured according to the TAPPI Standard method to analyze physical properties.

When light shines on paper, some are reflected, some are absorbed, and others are transmitted. The optical properties are determined by the amount of light assigned to each of these categories and the amount of light refracted and diffused among the reflected or transmitted light. Brightness, whiteness and opacity were measured to determine the optical properties.

As shown in FIG. 16, when the PCC, the inorganic filler, was added, the whiteness was improved, but the whiteness of the paper added with the organic filler was decreased. Whiteness is generally designed to evaluate the degree of bleaching of pulp, which is considered to be due to the low level of bleaching of wood flour compared to market pulp. In addition, the whiteness was slightly increased due to the reforming treatment, but this may be due to the increased amount of PCC.

Figure 17 shows the opacity of the paper with the addition of the filler, the opacity of the paper added with inorganic, organic filler was improved. In the case of lignocellulosic fillers, the surface modified fillers showed a better light scattering effect than the unmodified fillers, resulting in higher opacity.

Figure 18 shows the whiteness of the paper added to the bleaching step filler to determine the degree of bleaching wood powder. According to FIG. 18, the whiteness is lowered at the first and second stages of bleaching because the lignin remaining in the wood powder is darkened and the color is darkened. Higher whiteness was obtained at 4 stages of bleaching than before bleaching. However, the whiteness was still low, and in order to compensate for this, fluorescent whitening agent was added to improve the whiteness of the organic filler.

Table 10 and Figure 19 shows the optical properties of the paper according to the addition amount of the optical brightener, it can be seen that the whiteness and whiteness increased as more fluorescent brightener was added. Whiteness, originally designed to evaluate the degree of bleaching of pulp, is obtained by selectively measuring the reflectance of light at 457 nm, the wavelength most sensitive to the color change that occurs when bleaching pulp. Used to assess how much has been removed. In addition, whiteness is a standard plate, and magnesium oxide with a total reflectance of 97% to 98% is used to represent a degree of whiteness of a human, and is used as an important factor in product value. White sensitivity, on the other hand, is an optical property determined by the total reflectance of white light and the uniformity of reflectance at all wavelengths, and means uniformity of reflectance in the visible region.

According to Table 10, it can be seen that the whiteness is increased from 72.05 to 79.09, which can be used for white paper or art paper that requires high optical properties since the optical properties lowered by the organic filler can be sufficiently compensated with fluorescent brighteners. It seems to be.

[Table 10] Whiteness and whiteness of paper according to the added flavor of fluorescent brightener

Experimental Example 6. Surface Characteristics of Paper Added Modified Wood Powder as a Filler

Surface properties of the paper, smoothness, roughness, and air permeability were measured based on TAPPI Standard Method T 447 and ISO 5627, TAPPI Standard Method T 555 and ISO 8791, and TAPPI Standard Method T 538 and ISO 5636, respectively.

20 and 21 are graphs showing smoothness and surface roughness of paper. When only the inorganic filler PCC was added, the surface properties were improved by filling the voids between the fibers of the fine particles of the PCC, but the paper added with the organic filler composed of relatively coarse particles reduced the surface smoothness and roughness. However, the addition of cationic polymers and PCC-modified organic fillers to paper showed much better smoothness and roughness than unmodified organic fillers. In the case of calender treatment to improve smoothness, all of the fillers showed similar smoothness and roughness. Through this, the surface characteristics of the paper due to the lignocellulosic filler were inorganic through calendering to improve the surface smoothness. It was confirmed that the filler can be improved to the level of surface properties of the paper.

22 is a graph showing air permeability with filler addition. The addition of fillers to the paper impedes cohesion between the fibers and voids between them, resulting in low air resistance. Especially, organic fillers are more bulky and less crystalline than PCC. do. However, it can be seen that this can also be supplemented through calendar processing. The air permeability after calendering showed similar values in both PCC-treated paper and paper treated with lignocellulosic fillers.

Experimental Example 7. Dehydration and Turbidity of Paper Added Modified Wood Powder as a Filler

7-1) Dehydration Measurement

In order to evaluate dehydration, cationic PAM 0.02% was added to less than 1% of the mixed material of filler, followed by stirring for 30 seconds at 800 rpm using DFS (Dynamic Filtration System, BTG, Switzerland), and then 0.17. The amount of white water discharged for 60 seconds through the wire of mm was measured.

According to FIG. 23, it can be seen that the PCC, which is an inorganic filler, was not dehydrated better than that of the organic filler, and did not show a significant difference from the case where the organic filler was added as compared with the dehydrating property of the paper without the filler. It is expected that the organic filler can be expected to reduce the drying cost because it is superior in the dehydration performance compared to the paper containing the inorganic filler PCC.

7-2) Turbidity Measurement

To measure the retention, turbidity was measured using a portable turbidimeter (P Compact, Aqualytic, Germany) for the white water discharged through the wire from the DFS to measure the dehydration and to compare the relative retention of fillers.

24 is a graph measuring the turbidity of white water dehydrated through DFS. In general, turbidity values are used as indicators to measure the retention of fines in the paper including inorganic fillers, and when the fines in the paper are poorly retained, the color of the white water becomes turbid. When the turbidity is measured from the white water, the turbidity is measured. Comes out very high. As can be seen in Figure 23, the turbidity of the white water added with an inorganic filler such as PCC was very high compared to the turbidity of the white water containing lignocellulosic filler. That is, it seems that fine particles such as PCC are not well held in the fiber network, so that a large amount of fines are leaked together with the white water. However, in the case of lignocellulosic fillers, the polymer-modified organic fillers, except for the unmodified organic fillers, were leaked with the white water as the PCC particles bound to the organic filler were desorbed to increase the turbidity of the white water. Nevertheless, it showed much lower turbidity than the feedstock containing only PCC, which was considered to be very effective in recycling white water.

Experimental Example 8. Physical and Optical Properties of Cardboard According to Particle Size of Extender

8-1) Physical Characteristics

Figure 25 shows the bulk changes of the cardboard according to the lignocellulosic extender particle size. The best bulk was obtained by adding the wood powder which passed through 80 mesh and remaining in 100 mesh as an extender, and the wood powder which passed through 100 mesh and remaining in 200 mesh and 200 mesh and remaining in 400 mesh. Phage added with was also bulkier than paperboard without the extender.

In other words, the smaller the particle size of the lignocellulosic extender, the smaller the bulk of the paperboard. This is because the smaller the particle size, the smaller the effect of the fine particles on the bonding distance between the fibers, even if filling the pores of the fiber network or located between neighboring fibers to create a more compact structure.

FIG. 26 is a view illustrating thermal shortening of cardboard, in which cardboard passed through 80 mesh, remaining in 100 mesh, and passed through 100 mesh, and added wood powder remaining in 200 mesh as an extender, passed through 200 mesh and remained in 400 mesh. The strength value was higher than the paperboard added with wood flour as an extender. As the extender is added, the bond strength with the fiber is lowered, which leads to a decrease in strength. However, the cardboard and the extender added with the wood powder remaining through the 100 mesh and the wood powder remaining through the 100 mesh and the remaining wood powder as the extender are not added. The difference in thermal dressing value from the paperboard was not large.

In general, the smaller the particle size of the added extender is retained between the fibers, which significantly interferes with the interfiber bonding, which in turn results in a decrease in paper strength. However, since the reduction was very small due to the chemical properties of the lignocellulosic extender, the effect as a extender was judged to be excellent. In particular, the bulk of the mechanical pulp with excellent bulk is used in the inner layer of the cardboard, if the economic value of the organic type extender as a bulk improver is likely to contribute significantly to the reduction in manufacturing cost.

FIG. 27 is a graph showing the change in burst strength of cardboard by the particle size of lignocellulosic extender. Smaller particles of the extender negatively affected the strength of the paper as in the case of ordinary inorganic fillers.Unexpectedly, the paperboard that passed the 200 mesh and added the wood powder remaining in the 400 mesh as the extender was not added to the cardboard. The intensity level was improved. This is because, as mentioned earlier, the finer extender particles passing through the 200 mesh wires are responsible for the voids in the fiber network that make up the cardboard because the lignocellulosic extender still contains cellulose and hemicellulose, which can positively affect the interfiber bonding. It also appears to contribute to the improvement of burst strength by participating in hydrogen bonding between fibers and fibers.

Figure 28 shows the change in tear strength of the paperboard added lignocellulosic extender. The tear strength of the paperboard added with organic extenders showed a slight tendency to decrease, but it was not significantly different from the paperboard without any treatment. In general, the tear strength is less affected by the filler than the tensile strength, but in the case of the inorganic filler without the binding force, the larger the amount added, the more negatively it is affected. However, in the case of lignocellulosic bulking agent, unlike inorganic fillers, even if lignin remained, components such as cellulose and hemicellulose had a positive effect on the bonds between fibers.

8-2) Optical Characteristics

29 is a graph showing the change in the opacity of the cardboard according to the particle size of the lignocellulosic extender. Opacity is not significant because cardboard is usually manufactured in high basis weight using unbleached kraft pulp (UKP) or corrugated cardboard. Moreover, in the case of extenders, the meaning of opacity tends to be diluted because they are used as extenders in inner layers in high basis weight cardboard. This same trend can be seen in FIG. 29, but the opacity of the cardboard to which no treatment is applied or the cardboard to which the lignocellulosic extender is added does not appear to be different regardless of the particle size.

Experimental Example 9. Physical Properties of Cardboard According to the Addition Ratio of Lignocellulosic Extender

In order to investigate the physical properties according to the addition ratio of wood powder extender, wood powder passed through 80 mesh and remaining in 100 mesh was used in the experiment. The reason for this is that the bulk and strength properties are better than those of other sizes of wood flour, and to reduce the cost of grinding when used as an extender.

Figure 30 shows the bulk of the cardboard according to the addition ratio of lignocellulosic extender. It was found that the bulk was improved as the rate of addition of the extender increased in both of the cardboard made of UKP and OCC. Coarse-sized extender particles appear to be retained in the fiber network, contributing to the bulk improvement of the cardboard. Therefore, if the bulk of the cardboard can be improved while minimizing the strength reduction of the cardboard, it will be able to contribute greatly to the reduction of the main raw material usage and the manufacturing cost.

31 to 33 is a graph showing the change in thermal shear, pile strength and tear strength of the paperboard with increasing amount of lignocellulosic extender. As the rate of addition of the extender increased, the extender particles interfered with the bonds between the fibers, leading to a decrease in strength. However, the decrease was not large when compared with the raw materials of UKP and OCC. In addition, although the difference in tensile strength and bursting strength was not significant according to the type of pulp, the main raw material, UKP paperboard had a lower value of tensile strength and bursting strength than paperboard made of OCC. It is believed that this is because a large amount of fine fibers offsets the decrease in the inter-fiber bonding distance due to the coarse particles of the extender. On the other hand, in the case of the tear strength, the tear strength value of the paperboard made of UKP and OCC shows a larger difference than the tensile strength and the burst strength. This can be attributed to the fact that UKP made of only hardwood pulp is shorter in fiber length than OCC pulp mixed with softwood and hardwood pulp.

In conclusion, when the lignocellulosic extender was used for the manufacture of the paperboard, it was confirmed that the increase effect can be expected while minimizing the decrease of the strength of the paperboard.

Experimental Example 10 Physical Properties of Multi-layered Cardboard According to the Addition Rate of Filler

In order to examine the effect of wood powder extender on the physical properties of multi-layer board, wood powder passed through 80 mesh and remaining in 100 mesh was added.

34 shows the bulk change of the multi-layered cardboard according to the addition ratio of the wood powder extender. As in the monolayer cardboard of Fig. 30, the bulk of the cardboard was greatly improved as the proportion of the addition of the extender increased.

35 to 37 show the thermal extension, rupture strength, and tearing strength. When 5% was added, there was a slight decrease in strength, but there was almost no change in strength due to the addition of the extender. In conclusion, when the lignocellulosic bulking agent was used, the strength decreased significantly as the addition ratio increased in the single-layer paper. However, when added to the inner layer of the multi-layer paper, it showed little negative effect on the strength of the paperboard.

Through this, it was confirmed that when an organic extender such as a lignocellulosic filler was added as an auxiliary material for the inner layer of the multi-layer paperboard, an excellent effect on bulk improvement could be obtained without reducing the strength of the paperboard.

Experimental Example 11. Dehydration and Turbidity of Paper Stock Added with Lignocellulosic Extender

38 and 39 show the dehydration of the feedstock to which the wood flour extender was added, showing the amount of white water weight discharged through DFS for 60 seconds. FIG. 38 is a dehydration graph of a stock using UKP as a stock, and FIG. 39 is a graph of dehydration of a stock using OCC as a stock. Both UKP and OCC stock showed no significant difference in dehydration rate with the addition of organic extenders. It can be seen that in the high basis weight stock, the addition of the organic extender does not significantly affect the dehydration rate.

40 is a measure of the turbidity of white water dehydrated through DFS, the difference in turbidity according to the ratio of the addition of the organic extender consisting of coarse particles showed little difference, OCC paper containing a large amount of fine powder UKP paper Turbidity was more than three times higher. This may be due to the raw material properties of the main raw material itself, not the difference between the addition of the extender.

Claims

(1) pulverizing wood to prepare wood flour;
(2) bleaching the wood powder; And
(3) mixing the bleached wood powder and the inorganic filler in a weight ratio of 60 to 80: 20 to 40, and adding a polymer electrolyte as a binder to perform surface modification treatment; preparing lignocellulosic paper-based filler Way.

According to claim 1, wherein the step (1) is a method of producing a lignocellulosic paper-based filler, characterized in that after grinding the wood chip, it is ground for 30 to 90 seconds at 20,000 ~ 30,000 rpm.

The method of claim 1, wherein step (2)
(a) adding 4% by weight of 10% sodium hydroxide to the total weight of wood flour and treating it at pH 11.5-12.5, 65-75 ° C. for 90-150 minutes;
(b) adding 1% by weight of 5% sodium hypochlorite to the total weight of wood flour and treating it at pH 11-11.5, 55-65 ° C. for 90-150 minutes;
(c) adding 1% by weight of 10% chlorine dioxide to the total weight of wood meal and treating it for 150-210 minutes at pH 3.5-4.0, 75-85 ° C .; And
(d) adding 3% by weight of 10% hydrogen peroxide (hydrogen peroxide) to the total weight of the wood powder, and processing for 90 to 150 minutes at 75 ~ 85 ℃ of the lignocellulosic paper-making filler comprising: Manufacturing method.

The method of claim 1, wherein the inorganic filler in step (3) is a hard calcium carbonate (PCC) or heavy calcium carbonate (GCC) manufacturing method of lignocellulosic paper-making filler.

The method of claim 1, wherein in step (3), the polymer electrolyte is cationic PAM or cationic starch.

The method of claim 1, wherein when the polymer electrolyte in the step (3) is cationic PAM, the content of the cationic PAM is 0.005 ~ 0.015wt% based on the total weight of the mixture of bleached wood flour and inorganic fillers. The manufacturing method of the lignocellulosic paper-making filler made into.

The method according to claim 1, wherein in the step (3), when the polymer electrolyte is cationic starch, the content of cationic starch is 0.20 to 0.30wt% based on the total weight of the mixture of bleached wood flour and inorganic filler. The manufacturing method of the lignocellulosic paper-making filler made into.

The lignocellulosic paper-making filler manufactured by the method of any one of Claims 1-7.

Paper containing the lignocellulosic paper-type filler of Claim 8.

Cardboard containing the lignocellulosic paper-based filler of claim 8.