JP3001650B2 - Coated paper for decorative board with excellent printing gloss - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a decorative plate having excellent printing gloss, which is to be printed afterwards, further coated with a surface protective agent if necessary, and adhered to a base material such as plywood for use as a building material. For coated paper.

[0002]

2. Description of the Related Art Thin paper has been used as this type of decorative paper in the past, but in recent years, a base paper in which a resin is internally added to the base paper to increase the basis weight of the paper to 30 g / m ² is used. It is also known. It is also known to add titanium dioxide in order to enhance the concealing property during printing.

On the other hand, JP-A-63-190092 and JP-A-63-19
[0094] Japanese Patent Application Publication No. JP-A-2004-133125 discloses that a paper-liquid reinforced base paper similarly containing a resin liquid and a pigment (particularly titanium dioxide) is internally impregnated with a resin liquid after papermaking or a resin liquid containing no pigment is clear-coated. ing.

[0004]

As described above, the conventional base paper for decorative board uses a paper-reinforced base paper internally containing a resin liquid and a pigment, or as described in the above-mentioned publication, further after the base paper is formed. A resin liquid is impregnated or a resin liquid containing no pigment is clear-coated and is subjected to a supercalender treatment, and does not form a coating layer by coating a base paper with a paint containing a filler and a binder. And, as described in Table 1 of JP-A-63-190094,
A resin solution containing no pigment was clear-coated and subjected to a super calendering treatment. Among these, the smoothness was 550 seconds at the maximum (when the coating amount of the rear coat was 40 g), and the smoothness was evaluated to be sufficiently high. It has been.

Therefore, in the prior art, there is no idea that the base paper is coated with a paint containing a filler and a binder, and the surface strength, smoothness and air permeability of the base paper when forming this coating layer are considered. It does not focus on the degree.

[0006] Therefore, when this is printed, decorative paper is not satisfactory in all of the smoothness, surface strength, concealing property, and print gloss, and in particular, the printability is not sufficient, and furthermore, the decorative paper is excellent in these properties. The development was urgent.

Accordingly, an object of the present invention is to provide a decorative paper sheet which is excellent in all of smoothness, surface strength, concealing property and print gloss, and particularly excellent in printability.

[0008]

[Means for Solving the Problems] The above problems are described in JIS P 8129
The surface strength specified in 11 to 25A, the smoothness specified in JIS P 8119 is 400 seconds or more, and the air permeability is 30 to 80 seconds. The problem can be solved by applying a coating layer of 8 to 25 g / m ² on a single-side basis to form a coating layer, and infiltrating a resin component in the coating material into a base paper and calendering the resin component.

Here, it is desirable that the paint contains 14 to 20 parts by weight of the SBR latex and 5 parts by weight or less of the esterified starch based on 100 parts by weight of the filler.

[0010]

The present invention will be described in more detail below. The inventor has
It has been found that applying a paint containing a filler to base paper having predetermined characteristics is particularly excellent in printability. Furthermore, in this coating, what is required as the base paper is
In particular, the surface strength, smoothness, and air permeability were found.

[0011] The surface strength and smoothness are specified in JIS P 8129 and JIS P 8119. As the surface strength, 11
A to 25A, and particularly preferably 14A to 18A. The decorative plate may be peeled off after the adhesive tape is stuck on the surface thereof for a long time, and it is mainly desired that the surface strength is high. It is not preferable that the surface strength exceeds 25 A because other properties are impaired. As a means of increasing the surface strength, not only lowering the freeness, but also using a paper strength enhancer in the papermaking raw material of 10.5 kg / T or more,
It is preferable to add 42 kg / T or more.

The smoothness is set to 400 seconds or more. When the base paper has a high degree of smoothness according to the present invention, when the coating material is later blade-coated, the smoothness becomes high and the adhesion of the printing ink becomes good. Conversely, if the smoothness is low, coating unevenness increases after coating.

[0013] The air permeability of the base paper is 30 to 80 seconds. High air permeability means that the base paper has high density, which prevents the ink vehicle from penetrating into the base paper,
The print will look good. As means for increasing the air permeability, in addition to making L material 90% or more as a pulp blend,
It can be obtained by lowering the freeness. As the freeness, in the case of 30 g / m ² , 200 to 300 cc, especially 225 to 2
In the case of 75 cc and 50 g / m ² , 350 cc ± 50 cc is preferable.

It is also desired that the base paper has good formation. If there is unevenness in the formation of the base paper, coating unevenness occurs during coating, resulting in printing unevenness. This is because, like the air permeability, the pulp content of L material is 90% or more,
Even if a material is blended, it is preferred that the content be 10% or less. When making the base paper, in addition to the above-mentioned paper strength enhancer, a size fixing agent such as a sulfuric acid band, a pitch remover, a rosin sizing agent, a cationized starch (a release accelerator from press rolls and wires, (Which functions as a paper strength agent during drying), an antifoaming agent, and the like.

The paper can be made by a usual paper machine such as a long net or a round net. On the other hand, a coated paper for decorative board can be obtained by applying a paint containing a filler and a binder to the base paper and subjecting the base paper to a calender treatment.
As the filler, clay, calcium light carbonate, calcium bicarbonate, titanium oxide and the like can be used. The binder preferably contains 14 to 20 parts by weight of SBR latex, preferably 5 parts by weight or less of esterified starch, and the latex / starch ratio is 16/3 to 1%.
4/1 is preferred. When the ratio of latex is increased, the gloss of the print is increased, but the ink setting property is deteriorated, printing unevenness is likely to occur (migration is likely to occur), and the rigidity tends to decrease. Dropping (causing stains on the calendar and printing plate) is caused. As the SBR latex, those having a large mixing ratio of acrylonitrile from the viewpoint of the adhesion between the nitrifying cotton type ink and the coating layer, and particularly having a compounding amount of 1
It is preferably 0 parts by weight or more, and the mixing ratio of butadiene is small, especially the mixing ratio is 30 to 50%,
More preferably 35 to 45%, particularly preferably 38 to 4%
2% is preferred. The optimum is around 40%. An example of a device that conforms to this point is “P-OZ37” manufactured by Sumitomo Nogatack Co., Ltd. To the paint, a paper strength enhancing aid (PVA, casein, etc.), a water-proofing agent, a lubricant, a defoaming agent, a water retention agent, a pH adjuster, a coloring pigment, and the like can be further added. The coating is preferably performed by a blade such as a tip blade or a vent blade. In roll coating, coating unevenness, particularly, satin-like unevenness occurs. The coating amount is preferably from 8 to 25 g / m ² . On the other hand, oxidized starch for preventing curling, a preservative, a waterproofing agent, and the like can be applied to the back surface side.

When the coating is completed, a calendar process, particularly a super calendar process, is performed. At the time of this calendering treatment, the nip pressure is 170 to 250 kg / cm ² , although it slightly depends on the relationship with the basis weight of the coated paper to be obtained.
Is preferable, and the number of nip stages is desirably 5 or more.

<Examples> Examples and comparative examples are shown below to clarify the effects of the present invention. (Example 1) According to the difference in the surface strength, the printability and the tape releasability were examined. The results shown in Table 1 were obtained. The paint used was 100 parts by weight of filler (60 parts of the first clay, 2 parts of the second clay 2).
0 parts, heavy calcium carbonate 5 parts, light calcium carbonate 1
5 parts) with SBR latex (“P-OZ3
7 "), 1 part of starch, and 1.5 parts of other additives.

[0018]

[Table 1]

It can be seen that when the surface strength is low, both properties are reduced.

Example 2 The amount of the SBR latex affects the surface strength of the coated surface. The results are shown in Table 2. If the SBR latex is less than 14 parts, the bonding strength of the pigment becomes weak, and the amount of SRB latex penetrating into the base paper decreases,
Surface strength and inter-sheet strength decrease. If the SBR latex exceeds 20 parts, the ink setting becomes slow and migration occurs even if the suitability for IGT printing is good.

[0021]

[Table 2]

Example 3 The surface strength after coating has an effect as shown in Table 3 depending on the amount of esterified starch.

[0023]

[Table 3]

The contents of the notes are as follows.

(Note 1) Since the viscosity is low, the paint does not easily adhere to the base paper. In addition, the releasing effect is deteriorated during the super calendering, and the pigment adheres to the calender roll.
(Note 2) The load on the blade increases, and the coated surface deteriorates. Paint does not pass through high vibration screen. The paint concentration decreases, the paint setting is delayed, and the image quality deteriorates.

(Example 4) The freeness of the pulp was 35% based on the results shown in Table 4.
0-200 ml has been found to be suitable.

[0027]

[Table 4]

(Example 5) When the freeness of the pulp is 350 to 200 ml, the surface strength of the base paper is about 7 to 11 A. To further increase the surface strength, a polyacrylamide-based paper strength enhancer is used. Can be attached. If the freeness is 350ml,
As shown in Table 5, it is desirable to add 1.05 to 4.20% (150 kg / Ton) or more internally.

[0029]

[Table 5]

(Example 6) As shown in Table 6, the air permeability of the base paper is preferably 30 to 80 seconds.

[0031]

[Table 6]

Example 7 The coating amount is preferably about 8 to ²⁰ g / m ^{2 based} on the results shown in Table 7.

[0033]

[Table 7]

Example 8 Table 8 shows a comparison between coated papers of two kinds of coating amounts obtained according to the present invention and conventional products A, B and C. It is clear that the products of the invention have excellent properties. The reason why the surface strength column is blank is that the measurement is impossible because the coating material is melted.

[0035]

[Table 8]

[0036]

As described above, according to the present invention, smoothness,
It is excellent in surface strength, hiding power and print gloss, and particularly excellent in printability.

Claims (2)

(57) [Claims] (1) After printing on a surface, it is attached to a base material to form a decorative board, wherein the surface strength specified in JIS P8129 is 11 to 25A, JIS P81
A base paper having a smoothness of 400 seconds or more and an air permeability of 30 to 80 seconds specified in 19 is coated with a paint containing a filler and a binder at a coating amount of 8 to 25 g / m ² on a single-side basis. A coated paper for decorative board excellent in printing gloss, characterized in that the coating layer is formed by coating and the resin component in the coating material is permeated into the base paper and calendered. 2. The paint is SBR based on 100 parts by weight of filler.
The coated paper for decorative board excellent in printing gloss according to claim 1, comprising 14 to 20 parts by weight of latex and 5 parts by weight or less of esterified starch.