KR100979068B1 - Pigmenting method of a paper surface and the produced paper using the same method - Google Patents

Abstract

PURPOSE: A paper surface coating method and the paper manufactured thereby are provided to economically manufacture the paper using a filler for coating the surface of the paper, and to improve the print quality. CONSTITUTION: A paper manufacturing process comprises a dehydration pressing process, a drying process, a surface coating process, another drying process, and an ironing process using a raw material containing pulp, a filler, a drug, and water. The surface coating process uses a coating solution containing starch, fillers(1,1`) and an adhesive(2) to coat the surface of a paper. 30~50wt% of filler is contained in the coating solution.

Description

Surface coating method of paper and paper produced using this method {Pigmenting method of a paper surface and the produced paper using the same method}

The present invention relates to a surface coating method of a new paper and a paper produced using the method, and more particularly, in the manufacture of paper mainly made of pulp, it is possible to apply the surface of the paper by using a filler. The present invention relates to a surface coating method of a paper capable of improving the quality of paper with a reduction in manufacturing cost, and a paper manufactured using the method.

Typically, paper produced from pulp stock through a papermaking process has a high opacity and good printing of the paper, in addition to a cost reduction in the use of fibres, especially in the case of high filling with certain fillers in the manufacturing process. The ability to provide improved product quality, such as properties, has led to established general manufacturing processes in the paper industry.

As mentioned above, fillers that play an important role in the papermaking process are particularly preferred due to their superior light scattering properties, especially when calcium carbonate-based fillers are used. However, in addition to the above-mentioned conventionally known fillers, there is still a need for a filler or a manufacturing process which provides a process for producing paper having an improved papermaking process and better properties, and also superior printing. There is a demand for fillers that enable the production of highly filled papers exhibiting properties and mechanical properties, and research and development are continuing to meet these demands. As described above, highly filled papers have been manufactured according to conventional papermaking processes. As a filler for the preparation, for example, the Republic of Korea Patent Application No. 2006-7012294 in the name of "filler for papermaking process", "cellulose derivative and calcium salt having a total ionic group substitution degree of 0.65 or less, cellulose Or cellulose derivative-treated filler composition free of lignocellulosic or fibrous Water ".

However, the above-described invention merely replaces conventional fillers with fillers including calcium salts and cellulose derivatives, and still lacks in the effective use of fillers and the reduction in manufacturing cost and quality of paper.

Moreover, there is still a need to improve the quality of paper and the method of applying the surface of the paper using the same while reducing the production cost of paper by reducing the amount of pulp used without adversely affecting the papermaking process and quality. It's happening.

Patent Document: Republic of Korea Patent Application No. 2006-7012294

Accordingly, an object of the present invention is to provide a paper surface coating method that can improve the printing quality and surface strength while reducing the amount of pulp used without adversely affecting the process and quality in view of the above-described conventional papermaking process. It is for.

Another object of the present invention is to provide a paper surface coating method that can reduce the manufacturing cost and improve the quality of paper because it provides a new paper making process that allows the filler to be used for surface coating of paper.

It is another object of the present invention to provide a paper having excellent print quality and surface strength obtained by the above method.

The present invention may also be aimed at achieving, in addition to the above-mentioned specific objects, other objects which can be easily derived by those skilled in the art from this and the overall description of the present specification.

Surface coating method of the paper of the present invention for achieving the above object;

In the paper manufacturing process consisting of dewatering and pressing process, drying process, surface coating process, drying process and ironing process from a super support material composed of pulp, filler, medicine and water,

The surface coating process is characterized by coating the surface of the paper with a coating liquid consisting of starch, filler and pressure-sensitive adhesive.

According to another configuration of the present invention, the filler is characterized in that using a heavy calcium carbonate of 1.2 ± 0.5㎛ based on the particle size analyzer of the sedigraph (sedigraph).

According to another configuration of the present invention, the pressure-sensitive adhesive is characterized in that using the PFG part acrylic copolymer obtained by copolymerizing acrylic monomer (acrylic monomer) and polyethylene glycol (PEG).

According to another configuration of the present invention, the filler of the coating solution is characterized in that it is contained in a proportion of 30 to 50% by weight.

According to another configuration of the present invention, the pressure-sensitive adhesive of the coating solution is characterized in that it is contained in a ratio of 1.0 to 3.0% by weight.

Paper produced using the surface coating method of the paper for achieving another object of the present invention;

In the paper manufacturing process consisting of dewatering and pressing process, drying process, surface coating process, drying process and ironing process from a super support material composed of pulp, filler, medicine and water,

The surface coating process is characterized in that the surface of the paper is prepared by coating the coating liquid consisting of starch, filler and pressure-sensitive adhesive.

The surface coating method of the paper of the present invention configured as described above and the paper produced using this method can improve the printing quality and surface strength while reducing the amount of pulp used without adversely affecting the process and quality of the conventional papermaking process. It is a useful invention to provide a surface coating method of a paper, which can reduce the manufacturing cost of paper and improve the quality.

Other features and advantages of the present invention will be described in more detail from the following preferred embodiments and detailed description with reference to the accompanying drawings in which:
1 is a schematic diagram showing an enlarged cross-sectional view of a paper, FIG. 1A is a cross section of a paper manufactured according to a conventional method, and FIG. 1B is a cross section of a paper manufactured according to the present invention.
2 is a flowchart of a papermaking process schematically showing a general paper manufacturing process,
3 is a schematic view showing a surface coating process of paper.

Hereinafter, with reference to the accompanying drawings, the present invention will be described in more detail by preferred embodiments.

FIG. 1 is a schematic enlarged view of a paper cross section, FIG. 1A is a cross section of a paper manufactured according to a conventional method, FIG. 1B is a cross section of a paper manufactured according to the present invention, and FIG. It is a flowchart of the papermaking process which showed the process schematically.

As shown in Fig. 2, typically paper is predominantly pulp, preferably about 56 to 77% by weight, in order to improve color and print quality while maintaining the strength of the paper produced therein above a certain level. Filler, preferably about 15 to 30% by weight, about 4 to 8% by weight of other chemicals and 4 to 6% by weight of water, is added to the dehydration and compression process, drying process, surface coating process, drying process and ironing process. It is manufactured through.

The filler added in the paper manufacturing process typically uses a calcium carbonate-based filler, which is typically added in an amount of 15 to 30% by weight during the manufacture of the paper, as described above. This reduces the manufacturing cost of the paper and also reduces the strength properties of the paper compared to the pulp, but does not compromise the strength sufficient for the paper at this ratio. Because of the advantages of superior quality, the use of the appropriate amount of filler as required is an almost established papermaking process.

As such, the filler 1 is introduced and used in the paper manufacturing process. The use of the filler 1 is generally mixed with the pulp during compounding of raw materials for paper production, as shown in FIG. 1A and 1B; and the coating layer 3 containing starch as a main component was formed on the surface of the paper, thus completing the manufacture of the paper.

According to a preferred embodiment of the present invention, the coating liquid used in the surface coating process of the paper is composed of starch, filler and adhesive. In this case, preferably, the filler is mixed with pulp, which is a raw material for making paper, and a calcium carbonate-based filler is used. More preferably, the particle size is 1.2 ± 0.5 based on a particle size analyzer of a sedigraph. Use of thick calcium carbonate is good in terms of surface strength and printability.

In general, the addition of fillers during the surface coating of paper decreases the surface strength of the paper, but it has been found that such degradation of the surface strength varies according to the type, form, and particle size of the filler, and studies various variables, in particular, Since heavy calcium carbonate having a size of 1.2 ± 0.5 μm is used, printability and economy can be improved without compromising the surface strength. In particular, as a result of a test using a wax pick, which is a surface strength measurement test instrument that melts a wax rod, removes it after attachment, and checks the surface state, hard calcium carbonate having a particle size of 2.5 ± 0.5 μm has a high surface strength. While poorly measured, heavy calcium carbonate shows good surface strength.

In addition, according to another preferred embodiment of the present invention, the filler is not particularly limited thereto, but is preferably contained in 30 to 50% by weight. When the content of the filler is less than 30% by weight, economical efficiency and print quality are drastically lowered, which is not preferable. When the content of the filler exceeds 50% by weight, surface smoothness and printability are deteriorated, which is not preferable.

As the pressure-sensitive adhesive constituting the coating liquid used in the surface coating process of the paper according to the configuration of the present invention described above, an acrylic copolymer is preferably used, and most preferably an acrylic monomer of the following molecular structure I A PFG moiety acrylic copolymer obtained by copolymerizing a monomer) and polyethylene glycol (PEG) is used.

[Formula I]

As shown in Structural Formula I, the PFG moiety copolymer is branched to a molecule around PEG in the process of copolymerizing an acrylic monomer (black moiety) and polyethylene glycol (red moiety). In particular, in order to function as a pigment adhesive, it is preferable that the acrylic monomer should have a weight content range of 20 to 40% and PEG to 60 to 80%. The molecular weight range of the PEG to be used is suitable from 200 to 1000, the n value of the PEG molecule is determined according to the molecular weight.

The pressure-sensitive adhesive composed of the PEG-acrylic copolymer according to the present invention described above has not only affinity with starch, but also has excellent affinity with the calcium carbonate-based filler, which is the filler of the present invention, to act to enhance the surface strength. The molecular weight is 300,000-400,000.

In addition, the pressure-sensitive adhesive is preferably contained 5% by weight or less, more preferably 1.0 to 3.0% by weight. If it is less than 1.0 weight%, adhesive force is weak and printing workability and surface smoothness fall, and it is unpreferable, and when it exceeds 3.0 weight%, it is uneconomical and unpreferable.

As described above, the coating on the paper surface of the surface coating liquid prepared according to the configuration of the present invention is carried out after the drying process of the paper during the papermaking process, in more detail is carried out by the surface coating process as shown in FIG. Lose.

As described above, the method of applying the paper surface by the surface coating according to the present invention is to add a filler to the surface coating liquid to coat the filler on the surface, thereby reducing the amount of expensive pulp used, thereby lowering the production cost of paper. In addition, since the filler is increased on the surface, it does not adversely affect the dehydration and compression processes of paper production. The present invention also provides the additional effect of improving the paper surface smoothness due to the filler applied in an appropriate amount to the surface of the paper.

Hereinafter, although an Example and a comparative example demonstrate this invention in detail, of course, this invention is not limited to these Examples.

Example 1

Paper was prepared by coating the surface of the paper with a paper surface coating composition composed of 58% by weight of starch, 48% by weight of heavy calcium carbonate (trade name; GCC60), and 2% by weight of a PSA part acrylic copolymer.

Example 2

Paper was prepared in the same manner as in Example 1 except that heavy calcium carbonate (trade name; GCC75) was used as the filler.

Example 3

Paper was prepared in the same manner as in Example 1 except that heavy calcium carbonate (trade name; GCC95) was used as the filler.

Comparative Example 1

Paper was prepared in the same manner as in Example 1 except that hard calcium carbonate (trade name; PCC) was used as the filler.

Comparative Example 2

Paper was prepared in the same manner as in Example 1 except that 69% by weight of starch and 29% by weight of filler were used.

Comparative Example 3

A paper was prepared in the same manner as in Example 1 except for using 47% by weight of starch and 51% by weight of filler.

Comparative Example 4

A paper was prepared in the same manner as in Example 1 except that 59.5% by weight of starch and 0.5% by weight of adhesive were used.

Comparative Example 5

A paper was prepared in the same manner as in Example 1 except that 56.5% by weight of starch and 3.5% by weight of pressure-sensitive adhesive were used.

Experimental Example

The printability, surface smoothness, print quality and economical efficiency of the paper prepared according to Examples 1 to 3 and Comparative Examples 1 to 5 were evaluated on a five-point scale, respectively, and the results are shown in Table 1 below.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Printability 2.9 3.3 3.2 2.4 3.0 2.1 2.8 3.3 Surface smoothness 3.9 4.1 3.6 4.0 4.0 3.5 3.9 4.0 Print quality 3.3 3.3 3.1 3.3 3.2 3.4 3.2 3.3 Economics 3.0 3.0 2.5 2.5 2.3 3.8 3.0 2.0 Sum 13.0 13.7 12.4 12.1 12.5 12.8 12.8 12.5

1 --- Internal Filler 1 '--- Surface Filler
2 --- pressure sensitive adhesive
3 --- coating layer

Claims (6)

In the paper manufacturing process consisting of dewatering and pressing process, drying process, surface coating process, drying process and ironing process from a super support material composed of pulp, filler, medicine and water,
The surface coating process is to coat the surface of the paper with a coating liquid consisting of starch, filler and adhesive,
Here, the filler of the coating solution is a surface coating method of the printing paper, characterized in that it is used to contain a heavy calcium carbonate of 1.2 ± 0.5㎛ 30 to 50% by weight based on the particle size analyzer of the sedigraph (sedigraph).
delete The method of claim 1, wherein the pressure-sensitive adhesive is a PFG moiety acrylic copolymer obtained by copolymerizing an acrylic monomer and polyethylene glycol (PEG).
delete The method of claim 1, wherein the pressure-sensitive adhesive of the coating solution is contained in a ratio of 1.0 to 3.0% by weight.
Paper produced using the method of applying the surface of the paper, characterized in that it is prepared according to any one of claims 1, 3 or 5.

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