JPH04314538A - Coated paper for decorative plate - Google Patents

Abstract

PURPOSE:To obtain a coated paper for a decorative plate all excellent in smooth ness, surface-hardness, concealment and print luster. CONSTITUTION:The base paper which has the surface-strength of 11-25A defined by JIS P 8129, the smoothness of at least 400sec defined by JIS P 8119 and the permeability to air of 30-80sec is coated with a pigment containing filler and binder, and the resin component in the pigment is caused to permeate through the base paper, and then said base paper is calendered.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to coated paper for decorative laminates, which is used as a building material by being applied to a base material such as plywood after printing and applying a surface protective agent if necessary. .

0002

[Prior Art] Thin paper was used in the past for this type of decorative board paper, but in recent years, base paper with resin added internally to increase the basis weight of the paper to 30 g/m2 has been used. is also known. Furthermore, it is also known to add titanium dioxide in order to improve hiding properties during printing.

On the other hand, JP-A-63-190092 and JP-A-63-190094 similarly disclose impregnation with a resin liquid after papermaking or papermaking.

0004

[Problems to be Solved by the Invention] When printing is performed on conventional base paper for decorative laminates, smoothness, surface strength, concealing properties, and printing gloss are all insufficient. The development of coated paper was urgently needed.

[0005] Accordingly, an object of the present invention is to obtain a decorative laminate paper which is excellent in smoothness, surface strength, concealing property, and printing gloss, and particularly has excellent printability.

[0006]

[Means for solving the problem] The above problem is solved by JIS
Surface strength specified by P 8129 is 11-25A,
Smoothness specified by JIS P 8119 is 400
Filler,
This problem can be solved by applying a paint containing a binder, allowing the resin components in the paint to penetrate into the base paper, and then calendering this. Here, the paint contains 14 to 20 parts by weight of SBR latex and 5 parts by weight or less of esterified starch to 100 parts by weight of filler, and the coating amount is 8 to 2 parts by weight per side.
Desirably, it is 5 g/m2.

[0007]

EXAMPLES The present invention will be explained in more detail below. The inventor is
It has been found that coating a paint containing a filler on a base paper having predetermined characteristics has particularly excellent printability. Furthermore, it has been found that surface strength, smoothness and air permeability are particularly required of the base paper in this case.

[0008] Surface strength and smoothness are determined according to JIS P
8129 and JIS P 8119. The surface strength is 11A to 25A, particularly preferably 14A to 18A. After adhesive tape is attached to the surface of the decorative board for a long period of time, the tape may be peeled off, and a high surface strength is desired mainly for this purpose. To make the surface strength exceed 25A,
This is not preferable because it inhibits other properties. As a means to increase the surface strength, in addition to lowering the freeness, it is also possible to add a paper strength enhancer to the papermaking raw material at a rate of 10.5 kg/T or more, especially 42K.
It is preferable to add more than g/T.

The smoothness is said to be 400 seconds or more. According to the present invention, when the base paper has high smoothness, when a paint is later applied with a blade, the smoothness will be high and the adhesion of printing ink will be good. Conversely, if the smoothness is low, coating unevenness will increase after coating.

The air permeability of the base paper is said to be 30 to 80 seconds. High air permeability means that the base paper is highly dense, which prevents the ink vehicle from penetrating the base paper and makes the print visible. Such an air permeability can be increased by increasing the content of L material to 90% or more in the pulp composition and by lowering the freeness. Freeness is 200 to 300 at 30g/m2
cc is especially 225 to 275 cc, 50g/m2
In this case, 350 cc±50 cc is preferable.

[0011] It is also desired that the base paper has good texture. If the base paper has uneven formation, it will cause uneven coating during coating, resulting in uneven printing. Similar to the air permeability, this means that the pulp composition should be 90% or more of L material,
Even if N material is blended, it is preferably 10% or less. When making base paper, in addition to the above-mentioned paper strength enhancer, size fixing agents such as sulfuric acid are added to the raw pulp.
A pitch remover, a rosin sizing agent, a cationized starch (which functions as a release accelerator from press rolls and wires and a paper strength enhancer during drying), an antifoaming agent, and the like can be added.

[0012] Paper can be made using an ordinary fourdrinier or circular wire paper machine. On the other hand, coated paper for decorative laminates can be obtained by applying a paint containing a filler and a binder to the base paper and calendering it. As the filler, clay, light calcium carbonate, calcium bicarbonate, titanium oxide, etc. 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.
~14/1 is preferred. Increasing the proportion of latex
On the other hand, while the gloss of the print increases, the setting of the ink deteriorates, printing unevenness is more likely to occur (migration occurs easily), and the rigidity tends to decrease. (causing stains on the plate). In addition, from the viewpoint of adhesion between the nitrified cotton type ink and the coating layer, SBR latex with a high blending ratio of acrylonitrile is recommended, especially when the blending amount is 1.
It is preferably 0 parts by weight or more, and the blending ratio of butadiene is small, especially the blending ratio is 30 to 50%,
More preferably 35-45%, particularly preferably 38-4%
2% is preferred. Further, around 40% is optimal. A product that meets these requirements is Sumitomo Nogatta's "P"
-OZ37''. The paint may further contain paper strength additives (PAV, casein, etc.), water resistance agents, lubricants, antifoaming agents, water retention agents, pH adjusters, coloring pigments, and the like. For coating, it is preferable to use a blade such as a chip blade or a bent blade. In roll coating, coating unevenness, especially satin-like unevenness, occurs. The coating amount is preferably 8 to 25 g/m2. On the other hand, the back side can be coated with oxidized starch to prevent curling, a preservative, a waterproofing agent, etc.

[0013] After coating is completed, calendering, particularly supercalendering, is carried out. During this calendering process, the nip pressure is 170 to 250, although it depends somewhat on the relationship with the basis weight of the coated paper to be obtained.
kg/cm2 is preferable, and the number of nip stages is 5.
Levels above are desirable.

<Examples> Examples and comparative examples will be shown below to clarify the effects of the present invention. (Example 1) Printability and tape releasability were investigated based on differences in surface strength, and the results shown in Table 1 were obtained.

[0015]

[Table 1]

It can be seen that both properties deteriorate when the surface strength is low.

(Example 2) The blending amount of SBR latex affects the surface strength of the coated surface. The results are shown in Table 2. When the amount of SBR latex is less than 14 parts, the bonding strength of the pigment becomes weak, the amount of SRB latex that permeates into the base paper decreases, and the surface strength and interpaper strength decrease. If the SBR latex exceeds 20 copies, even if it is good in terms of IGT printing suitability, ink setting becomes slow and migration occurs.

[0018]

[Table 2]

(Example 3) The surface strength after coating is affected by the amount of esterified starch as shown in Table 3.

[0020]

[Table 3]

The contents of the notes are as follows.

(Note 1) Due to its low viscosity, it is difficult for the paint to adhere to the base paper. Furthermore, the mold release effect becomes poor during supercalender treatment, 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 screens. Paint density decreases, paint sets slowly, and image quality deteriorates.

(Example 4) The freeness of the pulp is shown in Table 4.
From the results shown in , it was found that 350 to 200 ml is suitable.

[0024]

[Table 4]

(Example 5) Pulp freeness is 350
~200ml, the surface strength of the base paper is 7~11
Although it is about A, a polyacrylamide-based paper strength enhancer can be internally added to further increase the surface strength. When the freeness is 350ml, as shown in Table 5, 1.05-4.20% (150kg/Ton)
It is desirable to include the above.

[0026]

[Table 5]

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

[0028]

[Table 6]

(Example 7) The coating amount is based on the results in Table 7.
About 8 to 20 g/m2 is good.

[0030]

[Table 7]

(Example 8) Table 8 shows a comparison between two types of coated paper obtained according to the present invention and conventional products A, B, and C. It is clear that the product of the present invention has excellent properties.

[0032]

[Table 8]

[0033]

[Effects of the Invention] As described above, according to the present invention, smoothness,
It has excellent surface strength, hiding properties, and printing gloss, and has particularly excellent printability.

Claims (2)

[Claims] [Claim 1] Surface strength specified by JIS P 8129 is 11-25A, JIS P 8119
Smoothness specified by 400 seconds or more, air permeability 30~
This coated paper for decorative boards is characterized in that a paint containing a filler and a binder is coated on a base paper of 80 seconds, the resin component in the paint is permeated into the base paper, and the coated paper is calendered. 2. The paint contains 14 to 20 parts by weight of SBR latex and 5 parts by weight or less of esterified starch to 100 parts by weight of filler, and the coating amount is 8 to 25 parts by weight per side.
The coated paper for decorative laminates according to claim 1, wherein the coated paper is g/m2.