JP2001089994A - Converted paper, production thereof and paper product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production process for converted paper that can produce converted paper having excellent rigidity, water resistance and water repellency by forming the resin layers on the surface of the converting paper, even when the converting paper does not have the coating layers on its surface. SOLUTION: The objective converted paper is formed by laminating the filler layer 2 and the resin layer on the converting paper 1 in order in which the filler layer 2 is insoluble in the solvent that is used in the formation of the resin layer 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processed paper in which a resin layer is provided on the surface of paper to improve rigidity, water resistance and water repellency of the surface, a method for producing the same, and a paper product.

[0002]

2. Description of the Related Art In recent years, interest in environmental issues has been greatly increased, and it has been required to reduce the weighing of base paper by providing rigidity to base paper constituting a paper container.

[0003] As a method for imparting rigidity to base paper, a method of coating and impregnating a base resin with a solution resin in a well-known coating device such as a gravure or a dip, a method of extruding a thermoplastic resin to form a film, and a method of forming a film. There is generally a method of simultaneously or once forming a film and then bonding the film to the surface of the base paper.
Further, the same method as described above is used as a method for imparting water resistance and water repellency to the paper surface.

However, when a solution-type resin is applied by a well-known method, the solution-type viscosity is increased to prevent permeation into paper and to improve the film-forming property of the resin. I do. If the solution resin is diluted to lower the viscosity of the solution in order to improve the coatability, the solution resin penetrates into the paper and the resin film does not form on the paper surface. , Water resistance and water repellency are not sufficiently exhibited.

In order to improve the film forming property of the resin to be coated,
There is also a method of applying a resin in the form of a solution on the clay coat layer of existing base paper.However, not all base papers are provided with such a layer. It is often provided only for Moreover, since such a layer has good appearance and printability, it becomes a printing surface when forming a paper product such as a tray, a paper box, and a multi-pack, and is used for applying a solution resin for imparting rigidity. There is a problem that it cannot be used.
Some base papers have a clay coat layer on both sides, but many of them are expensive and it is difficult to switch from existing base papers.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in the prior art. Even if the base paper does not have a coat layer on its surface, the rigidity can be improved by providing a resin layer on the surface. It is an object to provide a processed paper excellent in water resistance and water repellency and a paper product using the processed paper.

[0007]

Means for Solving the Problems In order to achieve the above object in the present invention, first, in the invention according to claim 1, a filler layer and a resin layer are sequentially provided on the surface of paper to form a filler. The agent layer is a processed paper characterized in that it does not show solubility in volatile components used in forming the resin layer.

[0008] In the invention according to claim 2, the resin layer comprises:
The processed paper according to claim 1, wherein the processed paper is formed from a resin dispersed or emulsified in a volatile liquid.

In the invention of claim 3, the filler layer is made of one or more materials selected from starch, polysaccharides, water-soluble polymers such as polyvinyl alcohol, and olefin resins. The processed paper according to claim 1 or 2, wherein the processed paper is formed.

[0010] In the invention according to claim 4, the resin layer comprises:
4. It is formed of one or more resins selected from acrylic resin, styrene resin, polyethylene resin, vinyl chloride resin, isocyanate resin, urethane resin and expo resin. The processed paper according to any one of the above.

In the invention of claim 5, a filler which does not dissolve in volatile components such as a solvent contained in a liquid resin having fluidity at room temperature is coated on the surface of the paper. A process characterized by comprising a step of forming a stopper layer, and a step of further coating a liquid resin having fluidity at room temperature on the surface of the paper on which the filler layer is formed to form a resin layer. This is a method for producing paper.

According to a sixth aspect of the present invention, there is provided a paper product formed by molding a blank of a predetermined shape formed of the processed paper according to any one of the first to fourth aspects. .

[0013]

Embodiments of the present invention will be described below.

In the method for producing a processed paper according to the present invention, as shown in FIG. 1, a filler is applied to the surface of a base paper 1 to form a filler layer 2, and then the surface of the filler layer 2 is formed. The resin layer 3 is formed by applying a liquid resin having fluidity at room temperature to prevent the resin from penetrating into the base paper 1 even if there is no coat layer on the surface. For this reason, the film forming property of the resin is improved, and a continuous resin layer 3 is formed. As a result, in the processed paper of the present invention, the properties such as rigidity, water resistance, and water repellency of the coated resin are sufficiently exhibited.

The base paper 1 used in the present invention is not particularly limited, but it is preferable to use base paper having a surface having no coat layer 4 on both sides or one side.

The sealant layer 2 formed on the base paper 1 before coating with a liquid resin having fluidity at room temperature is formed for the purpose of sealing the coated surface on which the resin layer 3 of the base paper 1 is formed. The material may be any material as long as it does not exhibit solubility for volatile components contained in the liquid resin forming the resin layer 3. For example, the volatile component of the resin layer 3 may be alcohol,
In the case of an organic solvent, examples of components that form the filler layer 2 include starch and polysaccharides, water-soluble polymers such as polyvinyl alcohol dissolved in water, and a polyolefin resin dispersion in water. One or a combination of a plurality of them can be mentioned. If necessary, a powdery substance which is equal to or larger than the pulp fiber voids on the base paper coated surface may be added. The viscosity of the filler may be freely selected within a range that can be applied by an existing coating apparatus according to a desired degree of sealing of the base paper.

The resin layer 3 is a liquid resin having fluidity at room temperature, and is not particularly limited as long as it has fluidity at room temperature and does not contain water.
As an example, acrylic resin, styrene resin, polyethylene resin, vinyl chloride resin alone or mixed and dissolved in alcohol, organic solvent, etc., isocyanate resin, urethane resin, epoxy resin dissolved in organic solvent, etc. Alternatively, a resin or the like having thermoplasticity which is not dissolved in alcohol, an organic solvent or the like may be powdered or granulated and dispersed in a volatile component such as an alcohol or an organic solvent.

When the resin layer 3 is an isocyanate resin, urea bond is formed at the coated interface with the moisture contained in the filler forming the filler layer 3 to form the filler layer 2.
May be improved.

An anchor agent may be used, if necessary, in order to increase the adhesiveness between the filler layer 2 and the resin layer 3 formed of a liquid resin having fluidity at room temperature.

As a method of forming the filler layer 2 and the resin layer 3 on the base paper 1, first, the filler is coated on the surface of the base paper 1 by a known coating device and dried to form the filler layer 2. After the formation, the liquid resin having fluidity at the room temperature is applied by a known coating device and dried to form the resin layer 3. In addition, if necessary, after the coating of the filler layer 2 coating agent, humidity control is performed to control the moisture content of the filler, and the resin layer 3 is coated thereon, and has fluidity at room temperature. The reaction at the interface with the liquid resin may be performed.

[0021]

Embodiments of the present invention will be described below in detail.

<Embodiment 1> Court ball 31 as base paper
0 g / m ² , a 30% aqueous solution of a polyvinyl alcohol resin as a filler layer, and a liquid resin having fluidity at room temperature as a resin layer (hereinafter referred to as a liquid resin). Using a 25% solution for 3 minutes, the coating amount of the filler is 3 g / m
² (solid content), drying temperature 120 ° C., drying time 1 minute, coating amount of liquid resin 10 g / m ² (solid content), drying temperature 120
Under a condition of a drying time of 3 minutes at a temperature of 0 ° C., the uncoated surface of the base paper was coated to form a filler layer and a resin layer, thereby obtaining a processed paper shown in FIG.

The processed paper of this example was evaluated for water absorption and taper stiffness. The degree of water absorption is JIS P 8140
According to the Cobb method according to (1), the coated surface was brought into contact with water and evaluated. Taper stiffness is JIS P81
In accordance with No. 25, evaluation was made by performing a stiffness test on the base paper in the plain paper direction.

Comparative Example 1 A processed paper of Comparative Example 1 was obtained in the same manner as in Example 1 except that no filler layer was provided. The evaluation of the processed paper of this comparative example was performed in the same manner as in Example 1.

Comparative Example 2 Court Ball 31 as Base Paper
0 g / m ² alone was used as Comparative Example 2. The evaluation of the base paper of Comparative Example 2 was performed in the same manner as in Example 1 except that water was brought into contact with the uncoated surface and the water absorption was measured.

Comparative Example 3 Court Ball 40 as Base Paper
0 g / m ² alone was used as Comparative Example 3. Evaluation of the base paper of Comparative Example 3 was performed in the same manner as Comparative Example 2.

The above results are shown in Table 1 for Example 1 and Comparative Example 1, and Table 2 for Comparative Examples 2 and 3.

[0028]

[Table 1]

[0029]

[Table 2]

From Tables 1 and 2, it can be seen that Example 1 exhibited excellent performances in all of rigidity, water resistance and water repellency, and succeeded in reducing the weight of the base paper.

[0031]

According to the present invention, even in a base paper having no coat layer on the surface, a filler is applied to the surface of the base paper to form a filler layer on the base paper, and then has fluidity at room temperature. By coating the liquid resin, the penetration of the resin into the base paper is suppressed, the film forming property of the resin is improved, and the resin layer of the continuous film is obtained. , Water repellency and the like can be sufficiently exhibited. Therefore, there is an effect that a processed paper excellent in rigidity, water resistance and water repellency and a paper product using the same can be provided, and further, it is useful for reducing the weight of the base paper of the processed paper and the paper product using the same. There is also an effect.

[Brief description of the drawings]

FIG. 1 is a sectional view of a processed paper according to a first embodiment of the present invention.

[Explanation of symbols]

 1: Base paper 2: Filler layer 3: Resin layer 4: Coat layer

Claims (6)

[Claims] 1. A structure in which a filler layer and a resin layer are sequentially provided on the surface of paper, wherein the filler layer does not show solubility for volatile components used in forming the resin layer. Processed paper characterized by the following. 2. The processed paper according to claim 1, wherein said resin layer is formed of a resin dispersed or emulsified in a volatile liquid. 3. The method of claim 1, wherein the filler layer is formed of one or more materials selected from starch, polysaccharides, water-soluble polymers such as polyvinyl alcohol, and olefin resins. The processed paper according to claim 1 or 2, wherein 4. The resin layer is formed of one or more resins selected from acrylic resin, styrene resin, polyethylene resin, vinyl chloride resin, isocyanate resin, urethane resin and expo resin. The processed paper according to any one of claims 1 to 3, characterized in that: 5. A filler agent having no solubility for volatile components such as a solvent contained in a liquid resin having fluidity at room temperature is coated on the surface of paper to form a filler layer. A process for producing a processed paper, comprising a step of further applying a liquid resin having fluidity at room temperature to the surface of the paper on which the filler layer has been formed to form a resin layer. 6. A paper product obtained by molding a blank of a predetermined shape formed of the processed paper according to claim 1. Description: