JPH1134278A - Manufacture of decorative plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance productivity of a wear resistant decorative plate and to reduce its cost by coating an overlay base sheet with water dispersion liquid containing wear resistance applicator, wet pressing it, then coating it with resin solution, drying it, and molding the overlay sheet formed by impregnating with resin solution and drying it on a decorative plate. SOLUTION: The method for manufacturing the decorative plate comprises the steps of coating an overlay base sheet with water dispersion liquid impregnated with wear resistance applicator, then pressing the base sheet of a wet state to urge the applicator into the sheet to reduce the applicator outputting to its uppermost surface, and distributing it in the sheet. In this case, when it is difficult to be wet pressed only by coating it with the water dispersion liquid, moisture may be supplemented by coating with water at a front stage of coating it with the liquid. Then, the method further comprises the steps of coating the applicator coating surface of the base sheet carried with the applicator with resin solution, drying it to further rigidly fix the applicator, then impregnating it with the solution, drying it, thereby forming the overlay sheet, and then molding the overlay sheet to the decorative sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a decorative plate used as a surface decorative material, and more particularly to a decorative plate provided with an overlay layer having transparency and abrasion resistance. The decorative board is described in a decorative board handbook (issued on October 30, 1973, edited by New Building Materials Laboratory).

[0002]

2. Description of the Related Art In recent years, melamine decorative boards have been used for flooring applications, and in such applications, the wear resistance of the decorative boards has become important. In order to improve wear resistance,
An overlay layer is provided on the decorative board. The overlay layer is required to have not only abrasion resistance but also transparency. In order to improve the abrasion resistance of the overlay layer, various proposals have conventionally been made with respect to an overlay base paper for forming the overlay layer. Representative examples are JP-B-54-10895 and JP-A-6-238.
854 and JP-B-4-23040. In each case, alumina having a high Mohs hardness is used as a wear resistance imparting agent in order to impart wear resistance, and the particle diameter of the alumina is in a specific range. In the above publication, there is a difference in a method of supporting a wear resistance imparting agent on paper.
JP-B-54-10895, JP-A-6-23885
In Japanese Patent Application Laid-Open No. 4 (1995) -4, an aqueous dispersion of an abrasion resistance imparting agent is applied to a felt surface in a wet paper state during the papermaking of an overlay base paper. Tokuhei 4
In Japanese Patent No. 23040, the overlay base paper is formed into three layers, and an abrasion resistance imparting agent is formed into the intermediate layer. The market as a wear-resistant overlay sheet, basis weight 30 to 60 g / m ² according to the required wear resistance level and mainly are used those 40 to 50 g / m ^2.

A proposal for supporting an abrasion resistance imparting agent at the stage of impregnating the overlay base paper with a resin is disclosed in Japanese Unexamined Patent Publication (Kokai) No. 5-57845, although the description is very unclear. It can be understood that this publication discloses two methods for obtaining an overlay-impregnated paper impregnated with a resin using two or three overlay base papers. The first is to apply an abrasion-resistance imparting agent to one side of impregnated paper impregnated with resin on the overlay base paper and laminate the applied surfaces together, or overlay impregnated paper containing no abrasion-resistance imparting agent on the applied surface To obtain a final overlay-impregnated paper. The second is that the overlay base paper is impregnated with a resin solution containing an abrasion resistance imparting agent, and both sides of the overlay impregnated paper are laminated with an overlay impregnated paper impregnated with a resin solution containing no abrasion resistance imparting agent. This is a method for obtaining impregnated paper.

[0004]

[Problems to be solved by the invention] Japanese Patent Publication No. 54-1098
No. 5, JP-A-6-238854, even when an abrasion-resistance imparting agent is sprinkled on the felt surface during the production of the overlay base paper, the wet paper in a portion wider than the paper width is recovered by the circulation system. Since the papermaking material is reused, it is inevitable that the wear resistance imparting agent is inevitably mixed into the papermaking raw material and the wire of the paper machine becomes significantly worn. For this reason, in a form in which wire abrasion is suppressed, for example, wet paper in a portion wider than the paper width must be discarded, and papermaking has to be performed, thereby increasing costs. Further, since the abrasion resistance imparting agent is sprinkled on the felt surface in the wet paper state, the papermaking speed has to be reduced and the papermaking has to be performed, which also increases the cost. In other words,
The overlay base paper made by the method described in Japanese Patent Application Laid-Open No. 4-10985 is expensive, and a decorative board using this overlay base paper is expensive.
The decorative panel market is oriented toward low prices, and there is a demand for inexpensive wear-resistant decorative panels. The problems with the overlay base paper described in JP-B-54-10895 are as follows:
No. 040 publication also describes variously. Tokuhei 4-23
No. 040 mentions problems in the impregnation / molding process, but the abrasion-resistant overlay base paper currently on the market is of the type described in Japanese Patent Publication No. 54-10985. Then, if the process is devised, it can be said that the problem hardly occurs. On the other hand, the three-layered overlay base paper described in Japanese Patent Publication No. 23040/1992 is intended to substantially reduce the wire abrasion of a paper machine. However, there is a problem that it is difficult to make paper, and it is not on the market. The present inventors have also studied, and it is extremely difficult to form three layers of overlay paper of 30 to 60 g / m ² , but it is presumed that the refractive index between the layers is related. It is difficult to obtain transparency when formed into a molding plate required for Further, in the method disclosed in Japanese Patent Application Laid-Open No. 5-57845, since two or three overlay base papers are used, the cost is increased, and even when a thin overlay base paper is used, the transparency of a molded plate is reduced. It is difficult to obtain the property.

[0005]

Means for Solving the Problems The present inventors have studied a method of supporting an abrasion resistance imparting agent at a stage other than the overlay base paper, and as a result, have found that it is sufficient to devise an impregnation step to carry the agent. It is. That is, in the present invention, first, an aqueous dispersion containing an abrasion resistance imparting agent is applied to an overlay base paper, wet-pressed in a wet state, and then a resin solution is applied and dried on the surface to which the abrasion resistance imparting agent is applied. The method further comprises impregnating and drying a resin solution to form an overlay paper, and then molding the decorative paper using the overlay paper.

[0006] The overlay base paper applied to the present invention is not particularly limited, and a type which does not contain a conventional abrasion resistance imparting agent is used. It is preferable that the gap is large and the gap on the surface not coated is small. When the gap on the surface to be applied is large, the wear resistance imparting agent is carried deeper in the paper. Also, the smaller the voids on the non-coated surface are, the less the abrasion resistance imparting agent is removed from the non-coated surface, and it is easier to handle.
The paper is coarser on the wire side, denser on the felt side, and is preferably applied to the wire side. The overlay base paper conventionally used is not calendered, and the felt surface smoothness (Oken air leak type) is about several seconds. The wire surface smoothness is less than the felt surface in the Oken type smoothness of the air leak type. In order to adjust the coatability of the abrasion-resistance imparting agent according to the U.S.P. of the overlay base paper, the average particle size of the abrasion resistance imparting agent, and the amount of the carrier, a calendered overlay base paper may be used. To take advantage of the roughness of the wire surface, calender the surface of the felt. The degree of calendering is up to about 50 seconds in terms of felt surface smoothness. If the calendering is applied more than this, it is not preferable because the paper is easily cut at the calendering stage and the wire surface smoothness becomes too high. To calender with a difference in smoothness between the felt surface and the wire surface, a soft calender may be used. The concentration of the aqueous dispersion containing the wear resistance imparting agent is not particularly limited,
What is necessary is just to adjust suitably according to the target carrying amount, ease of wet pressing, etc.

After applying an aqueous dispersion containing an abrasion-resistance imparting agent, the overlay base paper in a wet state is pressed, and the abrasion-resistance imparting agent is pressed into the paper, so that the abrasion resistance on the outermost surface is obtained. The content imparting agent is reduced and distributed in the paper.
In recent years, the number of impregnation steps has been increasing in two-stage steps of coating and then impregnating and impregnating, and a coating and pressing step of an aqueous dispersion may be provided before such equipment. If it is difficult to perform wet pressing only with the application of the aqueous dispersion, the water may be supplemented by water application or the like before the application of the aqueous dispersion.

Next, a resin solution is applied to the surface of the overlay base paper on which the wear resistance imparting agent is carried, on which the wear resistance imparting agent is applied, and dried to further firmly fix the wear resistance imparting agent. The solution is impregnated and dried to produce overlay paper.

An object of the present invention is to provide a decorative board having a wear-resistant overlay layer at low cost.
The resin solution used for coating and soaking is not particularly limited, and a resin type usually used for the overlay layer may be used, but a melamine resin is usually used from the application. The amount of resin impregnated together with coating and soaking is generally about 100% of the base paper, and if the amount of resin is insufficient, the overlay layer is blurred and transparency is deteriorated. It is well known that too much resin will result in molding failure, and the amount of resin may be appropriately adjusted. It is difficult to provide the required amount of resin only with the first-stage coating resin solution. Further, after the first-stage resin is dried, it is preferable that the surface of the press plate and the abrasion resistance imparting agent hardly come into contact with each other during the molding, and that the press plate is further abraded.

After the resin solution is soaked and impregnated and dried,
When a resin solution containing an abrasion resistance imparting agent is applied and dried, the abrasion resistance imparting agent is not carried deeply in the paper, and the carrying property deteriorates. After impregnating and drying the resin solution, use two pieces of overlay paper coated and dried with the resin solution containing the wear resistance imparting agent so that the surfaces coated with the wear resistance imparting agent are in contact with each other. The method described in Japanese Patent Application Laid-Open No. 5-57845 is also conceivable, but transparency is reduced when two sheets of overlay paper are stacked.

As the abrasion resistance imparting agent, those well-known in the art may be used.
What is described in JP-A-4-10985, JP-A-6-238854 and JP-B-4-23040 may be used, but alumina is generally used. There are various types of particle diameters of the abrasion resistance imparting agent as described in the above-mentioned gazettes. However, among the abrasion resistant overlay base papers currently on the market, those having a large average particle diameter, 10 to 50 microns. is there. The particle size is not particularly limited, and may be appropriately selected depending on, for example, the basis weight of the base paper, the smoothness of the wire surface, and the amount carried. As described in the above-mentioned publications, the loading amount is generally 5% to 50% of the base paper, and, like the average particle size, depending on the target level of abrasion resistance, What is necessary is just to select suitably according to rice tsubo, the smoothness of a wire surface, the average particle size, etc. Next, the overlay paper is molded into a decorative board, preferably with the surface coated with the abrasion resistance imparting agent facing. Abrasion resistance can be easily obtained when the surface coated with the abrasion resistance imparting agent is the surface. Also, when the wear resistance imparting agent coated surface is the back surface, when the amount of the wear resistance imparting agent increases,
There are also problems such as adhesiveness to the pattern paper and damage to the pattern paper, and it is preferable that the coated surface be the upper surface. The usual configuration of high-pressure melamine veneer is overlay paper, pattern paper, core paper, balance paper, but it is applied to all veneer, such as low-pressure melamine veneer without notice. Is described in detail in, for example, a decorative board handbook (published on October 30, 1973, edited by New Building Materials Laboratory).

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments. Example 1 Pulp for overlay base paper having high transparency (NBKP / L
(BPK = 5/5, Canadian freeness 500CC)
Using a fourdrinier paper machine, an overlay base paper containing 40 g / m ² of rice tsubo and not containing an abrasion resistance-imparting agent was produced. Next, this overlay base paper was subjected to coating, pressing and impregnation operations of an aqueous dispersion in a table form. First, an aqueous dispersion containing alumina having an average particle size of 50 microns was applied to the wire surface of the base paper after wet pressing to a loading amount of alumina of 12 g / m 2.
^The composition was applied so as to be ^2, and wet-pressed in a wet state. Further, after the melamine aqueous solution is applied and dried, it is impregnated and dried, so that the amount of the melamine resin is adjusted to 40 g / m ² together with the application, and the overlay paper of the present invention of 92 g / m ² is prepared. I got Next, a high-pressure melamine molded plate was prepared using a pattern paper, a core paper, and a balance paper with the wire side of the overlay paper as the surface. The transparency of the overlay layer of this molded plate was good, and there was no shading. Taber test for wear resistance of molded plate (JI
SK-6902), but it was 2400 times.

Comparative Example 1 After the same pulp as in Example 1 was dried on a Fourdrinier paper machine to form a wet paper web having a rice basis of 40 g / m ² ,
An aqueous dispersion of alumina having an average particle size of 50 μm was applied to the felt side and dried to produce an overlay base paper containing 42 g / m ² (12 g / m ^{2 of} alumina) of an abrasion-resistance imparting agent. . Since the alumina dispersion was applied to the wet paper web, the papermaking speed had to be reduced significantly.
In addition, since the wet paper web exceeding the width was returned to the circulation system and reused, the alumina was mixed with the pulp and the wire was worn. Next, the overlay base paper was impregnated in a table manner. After coating and drying the melamine solution, Dobuzuke impregnation and drying, the amount of melamine resin was adjusted to be 40 g / m ² in conjunction with coating, 92 g / m ²
I got an overlay paper. Next, a high-pressure melamine molded plate was produced in the same manner as in Example 1 with the felt surface facing the surface. The transparency of the overlay layer of this molded plate was good, and there was no shading. The Taber test for abrasion resistance of the molded plate was 2,400. From Example 1 and Comparative Example 1, it is clear that the overlay base paper of the present invention has a high papermaking productivity and that when formed into a molded plate, equivalent abrasion resistance can be obtained.

Example 2 / Comparative Example 2 As Example 2, the overlay base paper prepared in Example 1 was subjected to an average particle diameter using an actual impregnating apparatus provided with an aqueous dispersion application / press step before the impregnation step. After applying an aqueous dispersion containing 50 micron alumina and performing wet pressing,
The coating and drying of the melamine resin solution and the impregnation and drying of the melamine aqueous solution were carried out, and the same as in Example 1 was performed at 92 g / m ^2.
(Alumina 12 g / m ² ) overlay paper was produced. As Comparative Example 2, the overlay base paper produced in Comparative Example 1 was subjected to only the application and drying of the aqueous melamine resin solution and the drying and drying, using the same actual impregnation apparatus as in Example 2.
An overlay paper of ² g / m ² was made. There was no difference in the process speed between Example 2 and Comparative Example 2. From Example 2 and Comparative Example 2, it is clear that the productivity of the impregnation step is not impaired even if the abrasion resistance imparting agent is carried on the overlay base paper before the impregnation step.

[0015]

According to the present invention, the productivity of the overlay base paper is increased because the abrasion resistance imparting agent is supported not at the stage of papermaking the overlay base paper but at the stage prior to the impregnation step. Although the application of the aqueous dispersion and the pressing step are provided before the impregnation step, the speed of the impregnation step itself is sufficiently low, and the final drying after the impregnation becomes rate-determining,
It does not hinder the productivity of the impregnation process. Therefore, it is possible to produce a wear-resistant decorative board at a lower cost than a conventional wear-resistant decorative board.

Claims (2)

[Claims] 1. An overlay base paper is coated with an aqueous dispersion containing an abrasion resistance imparting agent, wet-pressed in a wet state, and then coated and dried with a resin solution on the surface to which the abrasion resistance imparting agent is applied. A method for producing a decorative sheet, comprising: impregnating and drying a resin solution to form an overlay sheet; and then forming the overlay sheet using the overlay sheet. 2. The method for producing a decorative board according to claim 1, wherein an aqueous dispersion containing an abrasion resistance imparting agent is applied to a wire surface of the overlay base paper.