KR101535522B1 - Preparation method of filler containing cellulose and the paper containing the filler thereby - Google Patents

Abstract

Provided is a preparation method of a paper filler, which comprises: (step 1) preparing a mixture by mixing a raw material of nanocellulose and a calcium compound; and (step 2) injecting carbon dioxide into the mixture prepared in the step 1. According to the present invention, the preparation method of a nanocellulose-containing paper filler has an effect of preparing a stable filler which has the large aspect ratio, is flexible, and is highly resistant to even strong vortex. Furthermore, the paper containing the paper filler attached with calcium carbonate to the nanocellulose raw material prepared by the method of the present invention has improved bulk, and excellent tensile strength.

Description

The present invention relates to a method for producing a papermaking filler comprising nanocellulose and a papermaking filler prepared thereby,

The present invention relates to a method for producing a papermaking filler comprising nanocellulose and a paper comprising the papermaking filler produced thereby.

Wood pulp, fillers, and other additives are used as raw materials in the manufacture of paper. Among them, wood pulp is used as the main raw material and then the filler content is high. Fillers are also used to improve paper quality such as paper opacity, brightness, and printability, but since the price of filler is lower than that of wood pulp, it can be expected to reduce costs by replacing pulp. have.

Recently, in the paper industry, not only the prices of pulp raw materials but also the prices of petroleum have been increasing. Therefore, in the paper industry, it is very important to develop efficient utilization technology of fillers which is more advantageous than pulp It is an assignment. However, the use of fillers is limited because these fillers have disadvantages such as inhibiting the formation of interfiber hydrogen bonds and reducing the stiffness of the paper.

Due to the above-mentioned problems, various measures have been sought to overcome this. Many techniques such as fiber-filler composite, preflocculation, and lumen loading have been developed to increase the filler content and to prevent the paper from lowering in strength, but they have also been applied in practice.

Preflocculation technology is a technique to form a stabilized preflocculant (Prefloc) with a certain size by forming a mass between calcium carbonate particles by mixing calcium carbonate and a polymer and then forming a strong vortex. it means. Such a pre-agglomerate is used as a raw material for papermaking, and when a pre-agglomerate is added to a papermaking raw material to produce a paper, a paper having a higher tensile strength than that of paper using ordinary calcium carbonate can be produced.

As described above, Korean Patent Laid-Open No. 10-2009-0040682 discloses a method for producing paper in which packing aggregation using a positive polyacrylamide is applied according to the prior art for producing a papermaking filler. Specifically, a cationic polyacrylamide having a molecular weight of 1 to 8 million g / mol and a charge density of 0.1 to 5.0 meq / g is added to pre-flocculate the filler, and the filler pre- The present invention also provides a method for producing a paper to which a filler pre-agglomeration using a positive polyacrylamide is applied.

Korean Patent Publication No. 10-2005-0023824 discloses a method for producing paper using cationic starch. In detail, the process is carried out by dispersing the filler with the process water containing fine fibers or adding fine fibers or long fibers to the filler diluted with fresh water, adding the cationic starch having a degree of substitution of 0.04 to 0.4 to the filler Pre-agglomerating, and adding the pre-agglomerated filler to the pulp-containing paper stock.

On the other hand, as a technique to compete with such a pre-agglomeration technique, there is used a method of mixing fine calcium carbonate with fine particles of wood pulp and then using fine particles and calcium carbonate by using a polymer. However, it exhibits proper physical properties without significantly differing from the physical properties of the paper produced by the pre-agglomeration technique.

The inventors of the present invention have found out that, while studying a method for producing a papermaking filler, it has been found that preparing a filler using nanocellulose can be a method of producing a filler that is very excellent and mixing a nano- The present inventors have developed a method for producing a papermaking filler by reacting with a calcium compound by injecting carbon dioxide into a mixture prepared after the preparation of the mixture and finding that the heat shrinkage and the bulk are improved when the mixture is used as a raw material for producing paper, Thus completing the present invention.

It is an object of the present invention to provide a method for producing a papermaking filler comprising nanocellulose and a paper comprising the papermaking filler produced thereby.

In order to achieve the above object,

Mixing the nanocellulose raw material and the calcium compound to prepare a mixture (step 1); And

And injecting carbon dioxide into the mixture prepared in the step 1 (step 2).

In addition,

A papermaking filler prepared by the above production method and having calcium carbonate adhered to a raw material of nano cellulose is provided.

Further,

The papermaking filler; And

Natural pulp or recycled pulp.

Further,

Mixing the nanocellulose raw material and the calcium compound to prepare a mixture (step 1);

(Step 2) of injecting carbon dioxide into the mixture prepared in step 1 to prepare a papermaking filler;

Mixing the papermaking filler prepared in step 2 with natural pulp or recycled pulp (step 3); And

And a step of adding the mixture of step 3 to a paper machine to produce paper (step 4).

The method for producing a papermaking filler containing nanocellulose according to the present invention has the effect of producing a stable filler that has a large length / width ratio, is flexible, and can withstand even strong vortices. Also, the paper comprising the papermaking filler with calcium carbonate adhered to the raw material of nanocellulose produced by the manufacturing method according to the present invention has an effect of improving the bulk of paper, decreasing the drying energy, and having excellent heat shrinkage.

1 is a graph showing the bulk of the paper prepared in Example 3, Example 4, Comparative Example 1, Comparative Example 2, Comparative Example 4, Comparative Example 5, Comparative Example 8 and Comparative Example 9 according to the present invention;
FIG. 2 is a graph showing heat deflection of the paper prepared in Examples 3, 4, Comparative Example 1, Comparative Example 2, Comparative Example 4, Comparative Example 5, Comparative Example 8 and Comparative Example 9 according to the present invention.

The present invention

Mixing the nanocellulose raw material and the calcium compound to prepare a mixture (step 1); And

And injecting carbon dioxide into the mixture prepared in the step 1 (step 2).

Hereinafter, the method for producing a papermaking filler according to the present invention will be described in detail for each step.

First, in the method for producing a papermaking filler according to the present invention, step 1 is a step of preparing a mixture by mixing a nanocellulose raw material and a calcium compound.

By adding calcium carbonate in the production of paper, it improves the opacity, printability, whiteness, etc. of paper and replaces some wood pulp with calcium carbonate, thereby reducing the cost of paper by reducing the use of expensive wood pulp. However, since calcium carbonate is not bonded to wood pulp and density is higher than that of wood pulp, the strength of paper is lowered and the density of paper is increased as the amount of calcium carbonate is increased. The lowering of the stiffness of the paper caused by the lowering of the strength of the paper or the higher the density of the paper results in a condition that can not contain a lot of calcium carbonate in the paper. Therefore, it is very necessary to develop a technique for keeping the physical properties of paper and containing a lot of calcium carbonate.

In this situation, the technique of applying calcium carbonate in the paper making process of paper has been proposed. Recently, calcium carbonate was mixed with fine particle of preflocculation technique or wood pulp, and then fine particles and calcium carbonate were combined using polymer The method used is being used. Although the paper produced using such a technique exhibits relatively high heat shrinkage, it is in fact difficult to incorporate more calcium carbonate into the paper.

Thus, in step 1, the mixture is prepared by using the nanocellulose raw material and the calcium compound. By using the nano-cellulose raw material, it is possible to form a filler different from the method of forming the pre-agglomerates and the method of applying calcium carbonate to the fine particles of the wood pulp.

That is, the nanocellulose raw material is an elongated flexible cellulosic material having a very large aspect ratio, and when the calcium carbonate is formed thereon, an elongated flexible filler is formed. On the other hand, the pre-agglomeration technique is an agglomerate of calcium carbonate in the form of a circle or an ellipse, and a method of applying calcium carbonate to the fine particles of wood pulp is also formed with a round or elliptical filler in which the calcium carbonate and the fine particles are connected by the polymer . Unlike the nano-cellulose, the fine powder is formed when the wood fiber is excessively beaten, and its shape is amorphous. The average shape is often circular or elliptical. Therefore, when calcium carbonate is adhered to the fine powder, A filler in the form of a circle or ellipse along the shape is produced.

Specifically, the nanocellulose raw material of step 1 is preferably nanofibrillated cellulose (NFC). When nano-fibrillated cellulose is used as the raw material of the filler, it has an advantage of being able to produce a flexible filler having a large aspect ratio and a flexible filler having such a shape. Lt; / RTI > That is, it was possible to produce aragonite-type calcium carbonate as a hard calcium carbonate (PCC) as a filler in a long and rigid form, but a long and flexible filler as in the present invention could not be produced.

The nanocellulose raw material of step 1 may be nanofibrillated cellulose treated with a colloid mill or a fludizer. As a specific example, a super mass colloid can be used as the colloid mill, and a micro-fludizer can be used as the fluid flow, but the present invention is not limited thereto. As a more specific example, nano-fibrillated cellulose can be prepared by repeatedly passing wood pulp through the supermeth colloid or micro-tiller, and the nano-fibrillated cellulose does not have a fiber shape, lt; RTI ID = 0.0 > nm. < / RTI >

The nano-fibrillated cellulose may be 100% passed through a 200-400 mesh screen. The nano-fibrillated cellulose may have a width of 300 nm or less and an aspect ratio ) Is 10 or more, and it is more preferable that the nano-fibrillated cellulose has a width of 1 to 300 nm and a length / width ratio of 10 to 1,000.

If the ratio of the length to the width is less than 10 without passing through the 200 to 400 mesh screen as described above, the nanofibrillated cellulose may not be properly formed. It is necessary to prepare nano-fibrillated cellulose. The filler prepared from the nano-fibrillated cellulose as a raw material for nano-cellulose is an elongated and flexible filler, and the filler for papermaking in which calcium carbonate is adhered to the finally prepared nano-cellulose raw material has a width ranging from nano size to tens of microns It can grow and reach hundreds of microns in length.

The calcium compound of step 1 may be calcium oxide, calcium hydroxide, calcium chloride, calcium sulfate, calcium phosphate or the like, and calcium oxide and calcium hydroxide may be used as the calcium compounds, but the present invention is not limited thereto.

At this time, when calcium hydroxide is used as the calcium compound, calcium hydroxide produced by reacting sodium hydroxide with calcium chloride may be used. That is, since sodium hydroxide and calcium chloride are reacted to form calcium hydroxide, calcium carbonate can be formed by reacting with carbon dioxide even if calcium hydroxide is not directly added. The reason for directly forming calcium carbonate in the nanocellulose is that the mutual adhesion of calcium carbonate and nanocellulose is excellent, so that the retention ratio of calcium carbonate is increased, and the elongated shape of the filler can be maintained well.

The mixing ratio of the nanocellulose raw material and the calcium compound in step 1 is preferably 1: 1 to 1:70 by weight. If the ratio of the mixture of the nanocellulose raw material and the calcium compound in the step 1 is less than 1: 1 by weight, there is a problem that carbon dioxide is added afterwards to perform carbonation reaction. If it exceeds 1: 70, There is a problem that excessive calcium carbonate that does not adhere to the raw material of nanocellulose is formed when calcium carbonate is formed by an autocatalytic reaction.

Further, the nanocellulose raw material of step 1 above may be one in which hard calcium carbonate (PCC) or heavy calcium carbonate (GCC) is preliminarily adhered.

At this time, an ionic polymer may be used to attach the hard calcium carbonate (PCC) or the heavy calcium carbonate (GCC) to the nanocellulose raw material.

The ionic polymer may be an anionic polymer, a cationic polymer, an anionic polymer, or a cationic polymer.

Examples of the cationic polymer include polyamidoamine-epihalohydrin polymers, polyalkyldialylamine-epihalohydrin polymers, polyethyleneimine, polyacrylamides, polyamines, polyvinylamines, and cationic starches. Polymers can be used,

Examples of the anionic polymer include polysaccharides, proteins, polyvinyl alcohol, polyvinyl acetate, cellulose derivatives, epoxy acrylates, polyesters, polyurethanes, polyester acrylates, polyether acrylates, polyolefin dispersions, polyamides, vinyl copolymers , Polyacrylate, and the like.

Examples of the polysaccharide include agar, sodium alginate, modified starch (carboxymethylated starch, hydroxyethylated starch, oxidized starch, etc.), and if calcium carbonate can be easily attached to the nanocellulose raw material, The cationic polymer and the anionic polymer are not limited thereto.

In the case where calcium carbonate is adhered to the raw material of nanocellulose in advance as described above, calcium carbonate is added together with calcium carbonate. Therefore, when calcium carbonate is added with carbon dioxide in the later reaction with calcium carbonate, Calcium carbonate is more firmly formed and has a stable effect that can withstand strong vortices.

Next, in the method for producing a papermaking filler according to the present invention, Step 2 is a step of injecting carbon dioxide into the mixture prepared in Step 1 above.

In the step 2, carbon dioxide is injected into the mixture prepared in the step 1 to bond the mixture to a raw material of nanocellulose through a carbonation reaction between a calcium compound and carbon dioxide, thereby producing a padding filler having a stable size even in a strong vortex .

Specifically, the calcium contained in the calcium compound component in the mixture of step 2 is dissolved in the form of a salt such as calcium hydroxide. Calcium carbonate can be synthesized through carbonation by blowing carbon dioxide thereinto. At this time, in step 2, carbon dioxide is generally preferably reacted until the pH of the diluted solution reaches 7.0, preferably until the injected carbon dioxide does not react. The temperature at which the carbon dioxide is injected into the mixture in the step 2 and reacted with the mixture is preferably 10 to 80 ° C.

In addition,

A papermaking filler prepared by the above production method and having calcium carbonate adhered to a raw material of nano cellulose is provided.

By adding calcium carbonate in the production of paper, it improves the opacity, printability, whiteness, etc. of paper and replaces some wood pulp with calcium carbonate, thereby reducing the cost of paper by reducing the use of expensive wood pulp. However, since calcium carbonate is not bonded to wood pulp and density is higher than that of wood pulp, the strength of paper is lowered and the density of paper is increased as the amount of calcium carbonate is increased. The lowering of the stiffness of the paper caused by the lowering of the strength of the paper or the higher the density of the paper results in a condition that can not contain a lot of calcium carbonate in the paper. Therefore, it is very necessary to develop a technique for keeping the physical properties of paper and containing a lot of calcium carbonate.

In this situation, the technique of applying calcium carbonate in the paper making process of paper has been proposed. Recently, calcium carbonate was mixed with fine particle of preflocculation technique or wood pulp, and then fine particles and calcium carbonate were combined using polymer The method used is being used. Although the paper produced using such a technique exhibits relatively high heat shrinkage, it is in fact difficult to incorporate more calcium carbonate into the paper.

Accordingly, the present invention provides a papermaking filler having calcium carbonate adhered to a nano-cellulose raw material. Thus, by using the nanocellulose raw material, it is possible to form a filler different from the method of forming the pre-aggregate or the method of applying calcium carbonate to the fine particles of the wood pulp.

In the papermaking filler according to the present invention, the papermaking filler preferably has an aspect ratio of 1.5 or more, more preferably 1.5 to 10.0. If the length / width ratio of the papermaking filler is less than 1.5, excellent bulk and heat shrinkage can not be exhibited.

Further,

The papermaking filler; And

Natural pulp or recycled pulp.

The paper according to the present invention includes the papermaking filler, natural pulp or recycled pulp, and particularly includes a padding filler in a form in which calcium carbonate is adhered to the nano-cellulose raw material, It can exhibit excellent quality in which whiteness of the paper is not lowered even though it is replaced with a filler. In addition, conventional conventional pre-coagulation techniques can exhibit higher heat shrinkage and bulk as compared to paper used. When the papermaking filler in the form of calcium carbonate adhered to the nano-cellulose raw material according to the present invention is mixed with recycled pulp, the whiteness of the recycled pulp can be increased, dehydration and drying energy can be reduced, and the bulk can be increased So that the quality of a paper product made of recycled pulp can be improved.

Wherein the paper comprises 1 to 80% by weight of a papermaking filler; And 20 to 99% by weight of natural pulp or recycled pulp, preferably 5 to 50% by weight of the papermaking filler.

Further,

Mixing the nanocellulose raw material and the calcium compound to prepare a mixture (step 1);

(Step 2) of injecting carbon dioxide into the mixture prepared in step 1 to prepare a papermaking filler;

Mixing the papermaking filler prepared in step 2 with natural pulp or recycled pulp (step 3); And

And a step of adding the mixture of step 3 to a paper machine to produce paper (step 4).

Hereinafter, the method for producing paper according to the present invention will be described in detail for each step.

First, in the method for producing a paper according to the present invention, step 1 and step 2 are steps for producing a papermaking filler.

The above steps 1 and 2 are the steps of producing the papermaking filler according to the present invention and can be produced by the production method described above.

At this time, in the step 1 and the step 2, a filler capable of increasing the strength of the paper to be produced can be produced.

Specifically, a mixture of a mixture of a nano-cellulose raw material and a calcium compound is prepared, and carbon dioxide is injected into the mixture thus prepared, whereby calcium carbonate is bonded to the nano-cellulose raw material through the carbonation reaction between the calcium compound and carbon dioxide, A padding filler having a stable size even in a vortex can be produced.

Next, in the method for producing paper according to the present invention, Step 3 is a step of mixing the paper filler prepared in Step 2 with natural pulp or recycled pulp.

Generally, when only wood pulp is used as a raw material for producing paper, there is a problem that the manufacturing cost of paper is increased due to high price. Thus, by replacing some wood pulp with a filler, the amount of wood pulp that is expensive can be reduced to reduce the manufacturing cost of the paper. However, since the filler is not bonded to the wood pulp and has a density higher than that of the wood pulp, the strength of the paper is lowered, and the density of the paper is increased. The lowering of the stiffness of the paper thus formed results in a condition in which a lot of filler can not be put on the paper.

In the step 3, the papermaking filler prepared by the production method according to the present invention, which can add a large amount while maintaining the physical properties of paper, is mixed with natural pulp or recycled pulp as raw materials for paper. By using the papermaking filler as a raw material of paper, it is possible to maintain the performance of paper such as whiteness and improve bulk and heat shrinkage.

The mixing of step 3 may be performed at a ratio of 1 to 80% by weight of the papermaking filler and 20 to 99% by weight of the natural pulp or regenerated pulp, preferably 5 to 50% by weight of the papermaking filler, Natural pulp or recycled pulp can be carried out at a ratio of 50 to 95% by weight.

The more the papermaking filler is used as a raw material in the production of paper, the lower the amount of natural pulp or recycled pulp used, thereby reducing the manufacturing cost of paper. However, when excessive padding filler is used, the performance of the paper may be deteriorated. In step 3, the padding filler is included in an amount of 5 to 50 wt%.

Next, in the paper making method according to the present invention, step 4 is a step of putting the mixture of step 3 into a paper machine to produce paper.

The papermaking filler mixed in step 3 and the natural pulp or recycled pulp are put into a paper machine, which is a general paper making machine, and through the initial machine, paper containing a papermaking filler and natural pulp or recycled pulp can be manufactured .

The paper produced by the manufacturing method according to the present invention can be produced at a low manufacturing cost as it contains a large amount of papermaking filler and can be easily combined with wood pulp by using a more rigid papermaking filler. This makes it possible to produce a paper showing a high heat deflection and bulk.

Hereinafter, the present invention will be described in detail with reference to the following examples and experimental examples.

It should be noted, however, that the following examples and experimental examples are illustrative of the present invention, but the scope of the invention is not limited by the examples and the experimental examples.

≪ Preparation Example 1 > Production of nanocellulose raw material

The bleached wood bleached chemical pulp was put into a super masscolloider and repeatedly passed through for 30 times. All of them were passed through a 200 mesh screen to prepare nano-fibrillated cellulose as a raw material of nano-cellulose.

Their electron micrographs showed that most of the nanofibrilated cellulose had a width of 300 nm or less and an aspect ratio of 10 or more.

≪ Example 1 > Preparation of padding filler 1

Step 1: The mixture of nano-fibrillated cellulose prepared in Preparation Example 1 was mixed with calcium oxide in an amount of 25 times the weight of nano-fibrillated cellulose.

Step 2: The mixture prepared in step 2 was diluted to 5% concentration in water at 30 degrees Celsius, and then carbon dioxide was continuously fed under vortexing to prepare a padding filler until the pH reached 7.0.

≪ Example 2 > Preparation of padding filler 2

A papermaking filler was prepared in the same manner as in Example 1 except that the mixture was prepared by mixing calcium oxide in an amount of 50 times the weight of nano-fibrillated cellulose in the step 1 of Example 1 above.

≪ Example 3 > Preparation of Paper Containing Paper Filler 1

Step 1: As a pulp for making paper, bleached softwood pulp and bleached hardwood pulp were mixed at a ratio of 1: 1, and the degree of freeness was 500 CSF (Canadian Standard Freeness). The filler and the pulp were mixed in a weight ratio of 30:70.

Step 2: A paper was prepared according to the paper test method (ISO 5269/1) using the papermaking fillers and pulp mixed in step 1 above.

At this time, cationic polyacrylamide (PAM, Korea Shiba Chemical Co., Ltd.) was used as a retaining agent to improve the retention rate of the filler as a whole by 0.1% of dry weight of the ground.

Example 4 Production of Paper Containing Paper Filler 2

The paper was prepared in the same manner as in Example 3, except that the paper-making filler prepared in Example 1 and pulp were mixed in a weight ratio of 50:50 in the step 1 of Example 3.

≪ Example 5 > Production of paper containing papermaking filler 3

The paper was prepared in the same manner as in Example 3, except that the paper-making filler prepared in Example 2 and pulp were mixed in a weight ratio of 30:70 in the step 1 of Example 3.

Example 6 Production of Paper Containing Paper Filler 4

The paper was prepared in the same manner as in Example 5 except that the paper-making filler prepared in Example 2 and pulp were mixed in a weight ratio of 50:50 in the step 1 of Example 5 above.

≪ Comparative Example 1 &

Step 1: As the pulp for making paper, bleached softwood pulp and bleached hardwood pulp were mixed at a ratio of 1: 1, and the degree of freeness was 500 CSF (Canadian Standard Freeness) Calcium carbonate (GCC) and pulp were mixed at a weight ratio of 30:70.

Step 2: Paper was prepared according to the paper test method (ISO 5269/1) using heavy calcium carbonate and pulp mixed in step 1 above.

At this time, cationic polyacrylamide (PAM, Korea Shiba Chemical Co., Ltd.) was used as a retaining agent to improve the retention rate of the filler as a whole by 0.1% of dry weight of the ground.

≪ Comparative Example 2 &

A paper sheet was prepared in the same manner as in Comparative Example 1, except that heavy calcium carbonate (GCC) having an average particle size of 3 to 4 μm and pulp were mixed in a weight ratio of 50:50 in Step 1 of Comparative Example 1.

≪ Comparative Example 3 &

Step 1: 50 g of heavy calcium carbonate (GCC) was mixed with 500 ml of water to prepare a diluted solution.

Step 2: The cationic polymer, polyacrylamide (PAM, Korea Shiba Chemical) was added to the diluent prepared in step 1 to make the overall zeta potential, that is, the charge slightly cationic, and the anion Polymer micropolymer (Korea Eka Chemical) was added to maintain the overall zeta potential, that is, charge neutrality. The exact addition of ionic polymer was based on the zeta potential.

Thereafter, the diluted solution was stirred at a rotation speed of 2,000 RPM for 10 minutes to prepare a heavy calcium carbonate pre-agglomerate having a size of about 35 to 40 탆.

≪ Comparative Example 4 &

Step 1: As a pulp for making paper, bleached softwood pulp and bleached hardwood pulp were mixed at a ratio of 1: 1, so that the degree of freeness was 500 CSF (Canadian Standard Freeness), and the heavy carbonic acid Calcium (GCC) pre-agglomerates and pulp were mixed at a weight ratio of 30:70.

Step 2: Paper was prepared according to the paper test method (ISO 5269/1) using the heavy calcium carbonate pre-aggregates and pulp mixed in step 1 above.

At this time, cationic polyacrylamide (PAM, Korea Shiba Chemical Co., Ltd.) was used as a retaining agent to improve the retention rate of the filler as a whole by 0.1% of dry weight of the ground.

≪ Comparative Example 5 &

A paper was prepared in the same manner as in Comparative Example 4, except that the heavy calcium carbonate (GCC) pre-aggregate prepared in Comparative Example 3 and pulp were mixed in a weight ratio of 50:50 in Step 1 of Comparative Example 4 .

≪ Comparative Example 6 >

Step 1: Bleached hardwood pulp was finely pulverized to a fineness of 100 CSF or less, and calcium oxide was mixed in an amount of 25 times the weight of the fine particles to prepare a mixture.

Step 2: The mixture prepared in step 2 was diluted to 5% concentration in water at 30 degrees Celsius, and then carbon dioxide was continuously fed under vortexing to prepare a padding filler until the pH reached 7.0.

≪ Comparative Example 7 &

A padding filler was prepared in the same manner as in Comparative Example 3, except that the amount of calcium oxide in the step 1 of Comparative Example 6 was 50 times the weight of the fine powder to prepare a mixture.

≪ Comparative Example 8 >

Step 1: As a pulp for making paper, bleached softwood pulp and bleached hardwood pulp were mixed at a ratio of 1: 1, and the degree of freeness was 500 CSF (Canadian Standard Freeness). The filler and the pulp were mixed in a weight ratio of 30:70.

Step 2: A paper was prepared according to the paper test method (ISO 5269/1) using the papermaking fillers and pulp mixed in step 1 above.

At this time, cationic polyacrylamide (PAM, Korea Shiba Chemical Co., Ltd.) was used as a retaining agent to improve the retention rate of the filler as a whole by 0.1% of dry weight of the ground.

≪ Comparative Example 9 &

A paper sheet was prepared in the same manner as in Comparative Example 8 except that the paper-making filler prepared in Comparative Example 6 and pulp were mixed in a weight ratio of 50:50 in Step 1 of Comparative Example 8.

≪ Comparative Example 10 &

The paper was prepared in the same manner as in Comparative Example 8 except that the paper-making filler prepared in Comparative Example 7 and the pulp were mixed in a weight ratio of 30:70 in the step 1 of Comparative Example 8.

≪ Comparative Example 11 &

A paper was prepared in the same manner as in Comparative Example 10, except that the paper-making filler prepared in Comparative Example 7 and pulp were mixed in a weight ratio of 50:50 in Step 1 of Comparative Example 10.

<Experimental Example 1> Characterization of paper

The following experiments were conducted to analyze the characteristics of paper made with papermaking fillers according to the present invention.

(1) Bulk analysis of paper

In order to evaluate the effectiveness of the paper produced in the examples according to the present invention and the comparative examples, the bulk of the produced paper was analyzed and the results are shown in Table 1 and FIG. The bulk is the volume per unit mass of the thickness divided by the basis weight.

As shown in the following Table 1 and FIG. 1, in the case of Comparative Example 1 in which general heavy calcium carbonate was used as a filler and the paper and the pulp were produced in a weight ratio of 30:70, a bulk of about 1.62 cm ³ / g , A bulk of about 1.75 cm &lt; ³ &gt; / g in the case of Comparative Example 2, in which general heavy calcium carbonate was used as the filler, and the paper in which the filler and pulp were produced in a weight ratio of 50:50.

In the case of Comparative Example 4 in which the heavy calcium carbonate preaggregate prepared in Comparative Example 3 was used as a filler and the filler and pulp were prepared in a weight ratio of 30:70, the bulk was about 1.67 cm ³ / g, In the case of Comparative Example 5 in which the heavy calcium carbonate preaggregate prepared in Example 3 was used as a filler and the filler and pulp were produced in a weight ratio of 50:50, a bulk of about 1.59 cm ³ / g was exhibited.

Further, in the case of Comparative Example 8 and Comparative Example 10 in which the filler and the pulp were prepared in a weight ratio of 30:70 by using the filler containing the fine particles prepared in Comparative Example 6 and Comparative Example 7, about 1.90 and about 1.95 cm &lt; ³ &gt; / g and Comparative Example 9 and Comparative Example 11 in which the filler and the pulp were produced in a weight ratio of 50:50 by using the filler containing the fine particles prepared in Comparative Example 6 and Comparative Example 7 And a bulk of about 1.89 and about 1.95 cm &lt; ³ &gt; / g.

On the other hand, in the case of Examples 3 and 5 in which the papermaking filler comprising nano-cellulose according to the present invention prepared in Example 1 and Example 2 and the paper in which the pulp was produced in a weight ratio of 30:70, Example 4 in which the papermaking filler comprising nanocellulose according to the present invention produced in Examples 1 and 2 and the pulp exhibiting a bulk of about 1.98 cm ³ / g were paper made in a weight ratio of 50:50, And about 2.05 and about 1.99 cm &lt; ³ &gt; / g in the case of Example 6.

As described above, it was confirmed that the paper made from the papermaking filler containing nanocellulose according to the present invention had a high bulk and a high bulk even though the content of the filler was increased.

(2) Thermal analysis of paper

In order to evaluate the effectiveness of the paper produced in the examples according to the present invention and the comparative examples, the heat treatment of the paper was analyzed, and the results are shown in Table 1 and FIG.

The heat front is a kind of marking method for indicating the tensile strength of paper. The heat front end fixes the end of a specimen cut into a prescribed size of paper, and when the load is gradually increased to one end, Lt; / RTI &gt; (ISO 1924-2).

As shown in the following Table 1 and Fig. 2, in the case of Comparative Example 1 in which general heavy calcium carbonate was used as a filler and the paper and the pulp were produced in a weight ratio of 30:70, a heat shrinkage of about 2.04 km was exhibited, In the case of Comparative Example 2 in which heavy calcium carbonate was used as the filler and the paper was produced in a weight ratio of 50:50 of the filler and pulp, the heat shrinkage was about 0.99 km.

In addition, Comparative Example 4, in which the heavy calcium carbonate preaggregate prepared in Comparative Example 3 was used as a filler, and the paper in which the filler and pulp were prepared in a weight ratio of 30:70, exhibited a heat shrinkage of about 2.44 km, In Comparative Example 5 in which the heavy calcium carbonate preaggregate prepared in Example 1 was used as a filler and the paper prepared in a weight ratio of 50:50 of filler and pulp was about 1.14 km.

Further, in the case of Comparative Example 8 and Comparative Example 10 in which the filler and the pulp were prepared in a weight ratio of 30:70 by using the filler containing the fine particles prepared in Comparative Example 6 and Comparative Example 7, about 2.52 and about 2.58 in the case of Comparative Example 9 and Comparative Example 11 in which the filler and the pulp were produced in a weight ratio of 50:50 by using the filler containing the fine particles prepared in Comparative Example 6 and Comparative Example 7, About 1.41 and about 1.36 km, respectively.

On the other hand, in the case of Examples 3 and 5, in which the papermaking filler comprising nano-cellulose according to the present invention prepared in Example 1 and Example 2 and the pulp were produced in a weight ratio of 30:70, The papermaking filler containing nanocellulose according to the present invention produced in Examples 1 and 2 and the paper made in a weight ratio of 50:50, which exhibited a heat shrinkage of about 3.14 km, 6 showed a heat shrinkage of about 1.85 and about 1.86 km.

As described above, it was confirmed that the paper made from the papermaking filler containing the nanocellulose according to the present invention had excellent heat shielding.

Bulk also exhibited the same tendency as heat shrinkage, and the examples using fillers using nanocellulose showed high values.

Therefore, the paper containing the papermaking filler according to the present invention has the effect of improving the bulk of the paper and having excellent heat shrinkage.

Type of filler Filler: Pulp bulk
(cm &lt; ³ &gt; / g) Heat gauge
(km) Calcium carbonate
(%) Example 3 Example 1 30:70 1.96 3.21 28.8 Example 4 Example 1 50:50 2.05 1.85 49.9 Example 5 Example 2 30:70 1.98 3.14 30.1 Example 6 Example 2 50:50 1.99 1.86 49.3 Comparative Example 1 GCC 30:70 1.75 2.04 31.8 Comparative Example 2 GCC 50:50 1.62 0.99 51.8 Comparative Example 4 Comparative Example 3 30:70 1.67 2.44 32.8 Comparative Example 5 Comparative Example 3 50:50 1.59 1.14 51.9 Comparative Example 8 Comparative Example 6 30:70 1.90 2.52 31.3 Comparative Example 9 Comparative Example 6 50:50 1.89 1.41 49.1 Comparative Example 10 Comparative Example 7 30:70 1.95 2.58 30.1 Comparative Example 11 Comparative Example 7 50:50 1.95 1.36 48.6

Claims (12)

Nanofibrillated cellulose (NFC) having a width of 1 to 300 nm and a length / width ratio of 10 to 1,000 and being diluted in water is prepared, and then the nanofibrillated cellulose Preparing a mixture by mixing a calcium compound at a weight ratio of 1: 1 to 1: 70 (step 1); And
(Step 2) of injecting carbon dioxide into the mixture prepared in step 1 under a temperature condition of 10 to 80 占 폚.
delete delete delete The method according to claim 1,
Wherein the calcium compound of step 1 is at least one kind of calcium compound selected from the group consisting of calcium oxide, calcium hydroxide, calcium chloride, calcium sulfate and calcium phosphate.
The method according to claim 1,
Wherein the nanocellulose raw material of step 1 is attached with light calcium carbonate (PCC) or heavy calcium carbonate (GCC).
The method according to claim 6,
Wherein an ionic polymer is used to adhere the hard calcium carbonate (PCC) or the heavy calcium carbonate (GCC) to the nanocellulose raw material.
A papermaking filler prepared by the manufacturing method of claim 1, wherein calcium carbonate is adhered to the nano-cellulose raw material.
9. The method of claim 8,
Wherein the papermaking filler has an aspect ratio of 1.5 to 10.0.
A papermaking filler according to claim 8; And
Natural pulp or recycled pulp.
11. The method of claim 10,
Said paper comprising 1 to 80% by weight of a papermaking filler; And
Characterized in that it comprises 20 to 99% by weight of natural or recycled pulp.
Nanofibrillated cellulose (NFC) having a width of 1 to 300 nm and a length / width ratio of 10 to 1,000 and being diluted in water is prepared, and then the nanofibrillated cellulose Preparing a mixture by mixing a calcium compound at a weight ratio of 1: 1 to 1: 70 (step 1);
(Step 2) of preparing a papermaking filler by injecting carbon dioxide into the mixture prepared in step 1 under a temperature condition of 10 to 80 캜;
Mixing the papermaking filler prepared in step 2 with natural pulp or recycled pulp (step 3); And
And adding the mixture of step 3 to a paper machine to produce paper (step 4).

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