JP5730923B2 - Decorative board base paper and decorative board - Google Patents

Description

  The present invention relates to a decorative board base paper used as a surface decorative material for a thermosetting resin decorative board such as a melamine decorative board, a polyester decorative board, and a dapp decorative board. More specifically, the present invention relates to a decorative board base paper for printing a pattern or the like by ink jet printing.

The high-pressure melamine decorative board has a configuration in which a decorative layer is provided on a core layer serving as a support by hot pressing. The core paper used for the core layer is usually kraft paper with a brown hue, but white core paper with a white hue containing titanium oxide is also used to enhance the design of the decorative layer. For the decorative layer, a decorative base paper having a concealing property is used for surface decoration. When the covering board base paper used for the face makeup is weak, the decorative board white base paper having a strong covering ability may be used as the makeup layer using the back face of the face makeup.

Since a plurality of white core papers are laminated and used as a support, it has a structure that has a higher basis weight and a smaller amount of titanium oxide than the decorative base paper.

In many cases, an overlay base paper having excellent transparency is used for the outermost layer of the decorative layer in order to protect the surface makeup. Since the overlay base paper is required to have transparency when formed into a molded board, the pulp blending and the chemical blending are designed with priority on transparency. For this reason, the paper is weak in strength. As a basic weight, 18-50 g / m < ² > is common. The lower the basis weight, the better the transparency, but the lower the strength.

Finally, since the laminate is laminated in a state highly impregnated with the thermosetting resin and is heated and pressed to be processed into a decorative board, the decorative base paper is required to be impregnated with the thermosetting resin. If the impregnation property of the thermosetting resin is poor, the productivity of the impregnation process is lowered.
Therefore, the decorative board base paper does not have an internal size or surface size using a sizing agent. This is a special paper with no size processing .

In order to conceal the base when the decorative board base paper used for surface makeup is molded, titanium oxide, pigments, dyes and the like are incorporated according to the hue. The decorative board base paper is roughly classified into white base paper (decorative board white base paper) and color base paper (decorative board color base paper) from the viewpoint of hue. Further, from the viewpoint of printing, it is broadly classified into printing for printing and monochrome printing for use as it is. The difference between printing and single color is in the smoothness setting of the decorative board base paper, and the decorative decorative board base paper is smoothed by a calendar.

  Printing of a wood grain pattern, an abstract pattern, etc. on a decorative decorative board base paper is carried out in order to give a decorative property to the decorative board. Gravure printing is the mainstream printing method. For the reason that gravure printing is not suitable for low-volume production, a printing layer is also formed on printing decorative board base paper by inkjet printing. However, even if a decorative decorative base paper for gravure printing is used for inkjet printing, the printing finish of inkjet printing is not fully satisfactory.

  In order to improve the inkjet printing suitability of the decorative board base paper, it has been proposed to provide an ink-receiving layer on the surface (smooth surface side) of the decorative board base paper by coating (for example, see Patent Document 1). In the example of Patent Document 1, an ink receiving layer containing amorphous silica is provided on the surface of a monochromatic white base paper.

In general uses other than decorative sheet base paper, not only so-called coated paper type inkjet recording paper provided with an ink receiving layer but also non-coated paper type inkjet recording paper provided with no ink receiving layer have been studied. Yes. If the ink receiving layer is not provided, the raw material cost is low. In order to provide the ink receiving layer, a separate coating process is required after paper making.

For example, Patent Documents 2 and 3 are cited as documents of non-coated paper type ink jet recording paper for general use. Claim 1 of Patent Document 2 states that “an inkjet recording sheet characterized in that 0.2 to 2.0 g / m ^{2 of} zinc sulfate is adhered to the support as a dry adhesion amount”. Claim 1 of Patent Document 3 states that “an inkjet recording sheet characterized by having 0.2 to 2.0 g / m ^{2 of} magnesium sulfate adhered to a support as a dry adhesion amount”.

Patent Document 4 proposes that inkjet printing is performed on the overlay base paper, not the base paper of the decorative board, in the melamine decorative board.

Patent Document 5 proposes a polyester decorative board having a configuration in which a commercially available inkjet-coated paper is subjected to ink jet printing and concealed with decorative base white paper.

JP 2007-212390 A JP-A-9-267546 JP-A-9-290556 JP 2003-1781 A Japanese Patent Laid-Open No. 2004-195731

  In general-purpose inkjet recording paper, the suitability of impregnation with a thermosetting resin is an unrelated characteristic. The inkjet recording paper is sized. Therefore, the impregnation suitability is difficult. Moreover, it is inferior in concealment property when using it for the surface decorative material of a decorative board.

Since the overlay base paper used for the decorative board is required to be transparent, generally a very thin one with a basis weight of about 20 g / m ² is used, but there is no paper stiffness and paper jams occur in the inkjet printer. Easy to wake up. In addition, there is a drawback that wrinkles are likely to occur depending on the printed pattern.

Patent Document 1 relates to a decorative sheet base paper, but examines a coated paper type provided with an ink receiving layer. Further, no mention is made of the suitability of the thermosetting resin for impregnation.

The non-coated paper type is less expensive in terms of raw materials than the coated paper type, but it is also possible to impart ink jet printing suitability with a paper machine that makes a decorative board base paper.

An object of the present invention is to provide a decorative base paper for inkjet printing of a non-coated paper type. The impregnation suitability of the thermosetting resin and the suitability for inkjet printing are problems.

The subject of the present invention is a decorative board base paper that is not sized, and is achieved by incorporating a white inorganic filler and externally adding a water-soluble metal salt.
That is, the present invention
(1) it was impregnated with thermosetting resins need use in the thermosetting resin decorative plate, a decorative laminate base paper which are not sized as a white inorganic filler ash other than the titanium oxide in the veneer sheet 18 An aqueous solution containing at least 1% by mass and further containing at least one neutral water-soluble metal salt consisting of calcium chloride, magnesium chloride, magnesium sulfate and calcium acetate, and no water-soluble polymer binder. Is applied externally to at least the printing surface, and 0.5 to 3.0 g / m ² of dry adhesion amount of the water-soluble metal salt is applied , and the water-soluble polymer binder is not externally added. Base paper.
(2) A decorative base paper for ink-jet printing, wherein the white inorganic filler of item 1 is at least one selected from the group consisting of talc, calcined kaolin and calcium carbonate.
(3) A high-pressure melamine decorative board using a melamine resin as the thermosetting resin of the decorative layer, wherein the decorative layer impregnated with the thermosetting resin and the core layer impregnated with the thermosetting resin are laminated by heat and pressure molding. in the as a surface decorative material used for the decorative layer to item 1 or 2 wherein the inkjet printing veneer base paper is subjected to ink jet printing and the surface decorative material, containing titanium oxide on the back surface of the surface decorative material to the decorative layer or using a decorative laminate white base paper, and / or high pressure melamine decorative plate having a layer structure impart opacity by using a white core sheet as a core sheet to the core layer.

INDUSTRIAL APPLICABILITY According to the present invention, there is provided a non-coated paper type decorative board base paper for ink-jet printing, which has the suitability for impregnation with a thermosetting resin and has improved ink-jet printing ability. It can be applied not only to white base paper but also to color base paper.

Hereinafter, the present invention will be described step by step.
In the present invention, the physical properties and raw materials of the decorative printing board base paper for ink jet printing are based on the conventional decorative printing board base paper. The basis weight of decorative printing board base paper is generally in the range of 60 g / m ^{2 to} 110 g / m ² , the Oken smoothness is in the range of 50 seconds to 200 seconds, and the Oken air permeability is A range of 15 seconds or more and 30 seconds or less is common although it depends on the tsubo and the smoothness. This range is also preferable for the base paper for inkjet printing of the present invention.

The decorative board base paper for printing includes pulps such as L BKP and NBKP (the drainage degree of the pulp is preferably 400 to 600 ml CSF), titanium oxide, coloring pigments, coloring dyes, wet paper strength enhancers, coagulants such as sulfuric acid bands, A pH adjusting agent such as sodium aluminate is appropriately combined depending on the required hue and concealment, and the paper is produced by a long paper machine. However, in order to highly impregnate the thermosetting resin, an internal size and an external size using a sizing agent are not used. The same applies to the present invention. The decorative decorative board base for printing is calendered and is designed on the premise of calendering. The ash content of white base paper for printing is generally 20% by mass or more and 40% by mass or less (substantially corresponding to titanium oxide).

In the present invention, as a filler, white inorganic fillers other than titanium oxide such as talc, clay, kaolin, calcined kaolin, calcium carbonate and the like are mixed in an amount of 13% by mass or more, preferably 18% by mass or more as ash. is there. Of these, talc, calcined kaolin and calcium carbonate are preferred. Titanium oxide may be blended when more concealment is required or for adjusting the hue. The upper limit of the ash content is 40% by mass or less, preferably 35% by mass or less, and more preferably 30% by mass or less from the viewpoint of paper quality.

A method for applying a water-soluble metal salt composed of at least one of calcium chloride, magnesium chloride, magnesium sulfate, and calcium acetate to the surface of the decorative board base paper is not particularly limited, and a known external addition method can be applied. As a method of external addition in a process separate from papermaking, not only coating with an air knife coater, bar coater, roll coater, etc., but also impregnation by dipping impregnation can be applied. Examples of the external addition method during papermaking include spray coating in a press part and impregnation by a size press. The external addition during paper making is preferable not only in terms of cost, but also because the hue and physical properties are easy to manage. Among these, it is preferable that spray coating is performed on wet paper at the press part in the process of the paper machine following the wire part, the press part, and the dryer part because there is no extra drying step compared to the size press.

  Calcium chloride, magnesium chloride, magnesium sulfate, and calcium acetate used in the present invention are water-soluble metal salts having high solubility in water. In general, the neutrality of an aqueous solution refers to a pH of 6.0 or more and 8.0 or less. The aqueous solution of the four types of water-soluble metal salts of the present invention is neutral. Because it is neutral, it hardly affects the moldability of the decorative board.

In the present invention, the application amount of the veneer sheet of water-soluble metal salt, 0.5 g / ^{m 2} or more 3.0 g / ^{m 2} preferably in the following range in solids (dry coverage).

If the applied amount of the water-soluble metal salt is less than this, sufficient color developability may not be obtained.

If the application amount of the water-soluble metal salt is larger than this, the thermosetting resin impregnation property may be deteriorated.

Since water-soluble polymer binders such as starch and PVA may deteriorate the impregnation property of the thermosetting resin, in the present invention, it is preferable that the water-soluble polymer binder is not added to the water-soluble metal salt coating solution or impregnation solution.

In the present invention, ink jet printing is not particularly limited. For example, the pigment ink may be either a solvent-based pigment ink or a water-based pigment ink, and a pattern or the like can be inkjet printed on a decorative board base paper using a conventionally known inkjet printing apparatus.

  In the present invention, the decorative board base paper can be printed by inkjet printing, and the decorative board can be produced by a known method. The obtained decorative board is not particularly limited, and can be used as a surface decorative material for a high-pressure melamine decorative board, a low-pressure melamine decorative board, a polyester decorative board, and a dup decorative board.

In the high-pressure melamine decorative board, when the concealing property of the ink-jet printing decorative board base paper subjected to ink-jet printing is weak, the decorative board white base paper or white core containing titanium oxide having a strong concealment directly under the layer structure of the decorative board A layer structure in which paper is laminated can be taken. Since white core paper is used for the core layer instead of brown core paper, the number of layers is large. Moreover, the layer structure which laminates | stacks both the decorative board white base paper and white core paper containing a titanium oxide with strong concealment property can also be taken.

Hereinafter, the present invention will be described in detail with reference to examples.
This example and comparative examples were evaluated by the following methods.
As printing veneer sheet, using KJ a printing white base paper special paper made of 80 g / ^{m 2} dishes Product No. KSH-801P. The basis weight of KSH-801P used was 80 g / m ² , the smoothness was 120 seconds, the air permeability was 25 seconds, and the ash content was 32% by mass (substantially equivalent to titanium oxide).

(1) Thermosetting resin impregnation property The thermosetting resin impregnation property uses a 55% by mass aqueous solution of melamine formaldehyde resin as a thermosetting resin, and is adjusted to 20 ° C. and then immersed in the paper surface. Visual observation was performed until the melamine formaldehyde resin was uniformly infiltrated into the back of the film, and the time taken was measured with a stopwatch. The lower the value, the better the impregnation of melamine formaldehyde resin. In consideration of the impregnation property of uncoated KSH-801P (25 seconds), in the present invention, 100 seconds or less, more preferably 50 seconds or less were considered good.

(2) Inkjet printing suitability <Sharpness evaluation>
Using PX-V630 (manufactured by Seiko Epson) as an ink jet printer, printing was performed using pure water-based pigment ink. The sharpness was measured by observing the dot diameter with a microscope: VHX-500 (manufactured by Keyence). A smaller dot diameter results in a sharper image. In the present invention, a dot diameter of 60 μm or less is considered to be excellent in sharpness.

(3) Finishing evaluation of decorative board The printed matter printed in (2) above was molded into a decorative board by the following method, and the hue of the decorative board was measured with a Macbek spectrophotometer: CE-3100 (manufactured by Sakata Inx). In the present invention, it is assumed that the printing finish is excellent when the a value is 20 or more.

<Production of decorative board>
100% by weight of melamine formaldehyde resin, 0.2 part by weight of curing agent, and 1 part by weight of penetrating agent are dipped and impregnated with an impregnating solution of 55% by weight solution, and the impregnation rate is from 100% by weight based on the printed matter. A 130% by weight melamine formaldehyde resin impregnated paper was obtained.
Next, overlay paper impregnated with melamine formaldehyde resin: Trade name Melamine impregnated overlay paper (made by Ota Sangyo) and tea core paper impregnated with phenol formaldehyde resin: Trade name Ota Core (made by Ota Sangyo) Overlay one sheet of decorative board base paper (KSH-801P) impregnated with melamine resin as a white barrier, and further laminate the printed matter impregnated with melamine formaldehyde resin on top of it, and overlay paper impregnated with melamine formaldehyde resin. After the lamination, a high-pressure melamine decorative board was obtained by hot pressing with a heating and pressing machine.

Example 1
100 parts by weight of hardwood bleached kraft pulp (LBKP) was beaten with a double disc refiner to make 400 ml CSF. To this was added 50 parts by mass of talc, inorganic coagulant, wet paper strength agent: polyacrylamide epichlorohydrin, and the pH was adjusted to 8.3 with sodium aluminate. This was handmade with a handmade sheet machine to obtain paper.

The paper was impregnated with a 2% by weight aqueous solution (pH = 7.5) of calcium chloride (manufactured by Wako Pure Chemical Industries) as an impregnating solution. The adhesion amount was 1.1 g / m ² . To obtain a paper by performing a smoothing process further test calendar.

(Example 2)
A paper was obtained in the same manner as in Example 1 except that 35 parts by mass of talc and the impregnating solution were a 4% by mass aqueous solution (pH = 7.6) of magnesium chloride (manufactured by Wako Pure Chemical Industries, Ltd.).

Example 3
A paper was obtained in the same manner as in Example 1 except that 50 parts by mass of calcined kaolin instead of talc and a 6% by mass aqueous solution (pH = 7.6) of magnesium sulfate (Wako Pure Chemical Industries, Ltd.) as the impregnating solution.

Example 4
A paper was obtained in the same manner as in Example 1, except that 50 parts by mass of calcium carbonate instead of talc and the impregnating solution was a 2% by mass aqueous solution (pH = 7.1 ) of calcium acetate (Wako Pure Chemical Industries ) .

( Reference Example 5)
A paper was obtained in the same manner as in Example 1, except that 20 parts by mass of talc and the impregnating solution were 2% by mass magnesium sulfate aqueous solution (pH = 7.3).

(Comparative Example 1)
Comparative Example 1 was a commercially available non-coated paper type inkjet paper (manufactured by Epson, double-sided plain plain paper, exclusive for inkjet).

(Comparative Example 2)
Overlay paper: 23 g / m ² (made by KJ Special Paper) was used as Comparative Example 2.

(Comparative Example 3)
10 parts by weight of softwood bleached kraft pulp (NBKP) and 90 parts by weight of hardwood bleached kraft pulp (LBKP) were beaten with a double disc refiner to obtain 470 ml CSF. 10 parts by weight of calcium carbonate, 0.8 parts by weight of amphoteric starch, 0.6 parts by weight of aluminum sulfate, sizing agent AS-263 (manufactured by Arakawa Chemical), wet paper strength agent: polyacrylamide epichlorohydrin Was added as a preparation seed and hand-made with a hand-made sheet machine to obtain paper.

As impregnating liquid 6 wt% aqueous solution (pH = 7.6) of magnesium sulfate in this paper (manufactured by Wako Pure Chemical), impregnated to give a paper with a smooth treated with test calendar. Comparative Example 3 assumes a general non-coated paper type ink jet paper (the decorative board base paper is a special paper that is not sized by a sizing agent).

(Comparative Example 4)
The white base paper for printing KSH-801P was used as the decorative board base paper of Comparative Example 4.

Table 1 shows the evaluation results of Examples 1 to 4, Reference Example 5, Table 2 to Comparative Examples 1 and 2, Table 3 to Comparative Example 3, and Table 4 to Comparative Example 4.

From the results of Tables 1 and 2, it can be seen that Examples 1 to 4 corresponding to the present invention are excellent in ink jet printing suitability, excellent in thermosetting resin impregnation properties, and have a good print finish when used as a decorative board. In Comparative Example 1, it can be seen that the thermosetting resin impregnation property is inferior.
Since Comparative Example 2 was jammed by an ink jet printer and poor in transportability, the paper of Comparative Example 1 was used as a mount, and the overlay paper of Comparative Example 2 was printed with cellophane tape and reinforced. Moreover, it turns out that the coloring property after making a melamine decorative board is inadequate.
It turns out that the comparative example 3 is inferior in thermosetting resin impregnation property.

The base paper for ink-jet printing of the present invention is excellent in ink-jet printing suitability and impregnated with a melamine resin such as melamine formaldehyde resin, and is expected to be used in a high-pressure melamine decorative board using an ink-jet printed material as a surface decorative material. it can. In addition to high-pressure melamine decorative boards, it can be expected to develop into low-pressure melamine decorative boards, polyester decorative boards, and dup decorative boards.

Claims (3)

Was impregnated with thermosetting resins need use in the thermosetting resin decorative plate, size the process is not a decorative laminate base paper, the white inorganic filler other than titanium oxide veneer base paper is 18 wt% or more ash In addition, an aqueous solution containing at least one neutral water-soluble metal salt consisting of the group of calcium chloride, magnesium chloride, magnesium sulfate, and calcium acetate, and not containing a water-soluble polymer binder, A decorative base paper for ink-jet printing which is externally added to the printing surface and provided with 0.5 to 3.0 g / m ² as a dry adhesion amount of the water-soluble metal salt, and no water-soluble polymer binder is externally added . A decorative base paper for ink-jet printing, wherein the white inorganic filler of claim 1 is at least one selected from the group consisting of talc, calcined kaolin and calcium carbonate. In the high-pressure melamine decorative board using a melamine resin as the thermosetting resin of the decorative layer, wherein the decorative layer impregnated with the thermosetting resin and the core layer impregnated with the thermosetting resin are laminated by heat and pressure molding, subjected to inkjet printing and surface decorative material as a surface decorative material according to claim 1 or inkjet printing veneer sheet according to claim 2 for use in the decorative layer, containing titanium oxide on the back surface of the surface decorative material to the decorative layer decorative or using Itashiro base paper, and / or high pressure melamine decorative plate having a layer structure impart opacity by using a white core sheet as a core sheet to the core layer.