JP2002001864A - Oil resistant coating film and method for forming the same and oil resistant paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil resistant coating film having oil resistance, flexibility and biodegradability together. SOLUTION: An undercoating layer is formed of a shellac by coating an ammonia aqueous solution of the shellac on a base material, and then evaporating a solvent. Then, an overcoating layer made of the shellac is formed by again coating the ammonia aqueous solution of the shellac and then evaporating the solvent, and the oil resistant coating film having a two-layer structure is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, an oil-resistant coating film formed on the surface of an oil-resistant paper, a method for forming the same, and an oil-resistant paper.

[0002]

2. Description of the Related Art Shellac is a natural resin secreted by L. chinensis and has properties such as oil resistance, so that it has been widely used as a coating agent for paints and foods. Have been.

However, when an oil-resistant coating film made of shellac is formed on the surface of paper, there has been a problem that sufficient oil resistance cannot be obtained unless the film thickness is extremely large.
Further, when the film thickness is increased to enhance oil resistance, shellac is hard and poor in flexibility, so that there is a problem that the coating film is cracked when the paper is folded.

[0004] By the way, conventionally, synthetic resin-based materials generally used as oil-resistant coating films for paper have not been biodegradable, so that there is a problem of generation of harmful gases during incineration. there were. In particular, in the case of a fluorine-based oil-resistant coating agent, hydrofluoric acid, which is a corrosive gas, was sometimes generated.

[0005] Further, when paper having a synthetic resin-based oil-resistant coating layer is used as recycled paper, the waste discharged in the deinking process contains an oil-resistant coating agent. Since it has no decomposability, there are problems in terms of environment and safety in the treatment of waste and the like.

For the above reasons, a biodegradable oil-resistant coating film has been desired. The present invention has been made in view of the above points, and has sufficient oil resistance, at the same time, has flexibility, does not crack even when bent, and has an oil-resistant coating film which is more excellent in biodegradability and safety than before, and its It is intended to provide a forming method and oil-resistant paper.

[0007]

Means for Solving the Problems and Effects of the Invention (1) The invention of claim 1 provides an undercoat layer formed on the surface side of the base material, and an undercoat layer formed on the surface side of the undercoat layer,
The gist of the present invention is an oil-resistant coating film, which is a multilayer laminated film including a shellac-containing overcoat layer.

A) In the oil-resistant coating film of the present invention, since an undercoat layer is provided on the surface side of the substrate, sufficient oil resistance is exhibited even if the overcoat layer containing shellac is thin. Therefore, the overcoat layer containing shellac can be made thin (for example, the film thickness is 0.1 to 0.5 μm).

[0009] The overcoat layer containing shellac is
For example, as in the above range, when appropriately thin, the oil-resistant coating film of the present invention has sufficient oil resistance,
At the same time, it has excellent flexibility and does not crack even when the substrate is bent. Also, the bent portion has excellent oil resistance. In addition, since the overcoat layer contains shellac, it is superior to conventional oil-resistant coating films made of synthetic resins in terms of biodegradability and safety.

B) Further, in the oil-resistant coating film of the present invention, by selecting the material of the undercoat layer, its properties (for example, water resistance, water absorption, air permeability resistance,
(Moisture permeability) can be controlled. For example, as described below, the characteristics of the oil-resistant coating film of the present invention change depending on the material of the undercoat layer.

When, for example, shellac or natural latex rubber is used as the material of the undercoat layer, it has excellent water resistance. For example, when casein is used as a material for the undercoat layer, it has water absorbency.

When shellac, casein, or natural rubber latex is used as a material for the undercoat layer, for example, the air permeability resistance increases and the moisture permeability decreases. Therefore, in the present invention, by selecting the material of the undercoat layer, in addition to oil resistance, for example, water-resistant, water-absorbing, high air-permeability, oil-resistant coating film having characteristics such as low moisture permeability. Can be formed.

C) Since shellac is a biodegradable material, for example, the overcoat layer is made of shellac, and the other layers are also made of a biodegradable material (for example, shellac, casein, natural). Rubber latex), the oil-resistant coating film of the present invention has biodegradability. Therefore, no harmful gas is generated during incineration.
(For example, hydrofluoric acid, which is a corrosive gas, is not generated as in the case of a fluorine-based oil-resistant coating agent.) Further, when a paper provided with the oil-resistant coating film of the present invention is used as recycled paper, The discharged waste contains the components of the oil-resistant coating film of the present invention, but since these components have biodegradability, there is no problem of environmental destruction in the treatment of the waste.

D) Further, shellac is a material that can be used for foods. For example, the overcoat layer is a layer made of shellac, and other layers can also be used for foods (for example, shellac, casein, natural). Rubber latex), the oil-resistant coating film of the present invention can be used as an oil-resistant coating film for foods.

In the oil-resistant coating film of the present invention, even if both the undercoat layer and the overcoat layer are made of shellac and the two layers are in contact with each other,
Since these two layers are formed separately, they are superior in flexibility and oil resistance at the bent portion as compared with the case where a shellac single layer film having the same thickness as the total film thickness of the above two layers is formed. ing.

The composition of the oil-resistant coating film of the present invention includes, for example, as shown in FIG. 1A, an undercoat layer formed on a substrate and shellac formed thereon. There is a two-layer laminated film composed of an overcoat layer. -Or, as a configuration of the oil-resistant coating film of the present invention, for example, as shown in FIG. 2B, in addition to the undercoat layer and the overcoat layer, another layer (for example, An undercoat layer and an overcoat layer may be provided with an adhesion layer for enhancing the adhesion between the undercoat layer and the overcoat layer, or another layer (for example, a protective layer for protecting the overcoat layer) may be provided on the overcoat layer. ) May be provided.

Examples of the material of the undercoat layer include synthetic resin film agents (eg, paraffin, paraffin Em, polyvinyl alcohol, acrylic resin and derivatives thereof), lipids, proteins, saccharides (eg, gelatin,
There are dextrin, branched dextrin, natural rubber latex, casein, starch), wax (for example, rosin, copal, sandalack, dammar, carnauba wax, candelilla wax, rice wax, beeswax, shellac wax, lanolin), cellulose and derivatives thereof.

The substrate includes, for example, paper, paperboard, nonwoven fabric, and paper containers (including trays). -As shellac, any of three types of shellac (shellac, bleached shellac, white rack) may be used. (2) The invention according to claim 2, comprising an undercoat layer formed on the surface of the base material, and an overcoat layer laminated on the undercoat layer and containing shellac. The gist is the oil-resistant coating film according to item 1.

The present invention exemplifies the constitution of the oil-resistant coating film, and comprises two layers, an undercoat layer and an overcoat layer.
Consists of layers. The oil-resistant coating film of the present invention has oil resistance and flexibility similarly to the oil-resistant coating film according to claim 1, and particularly, the oil-resistant coating film of the present invention is formed of only two layers, so that the film can be easily formed. It has the feature of being.

Further, by selecting the material of the undercoat layer, an oil-resistant coating film having characteristics such as water resistance, water absorption, high air resistance and low moisture permeability can be obtained. Further, the oil-resistant coating film of the present invention can be biodegradable and can be used for food.

(3) The invention according to claim 3 is characterized in that the undercoat layer and the overcoat layer are made of a biodegradable material. I do. Since both the undercoat layer and the overcoat layer have biodegradability, the oil-resistant coating film of the present invention has biodegradability. Thus, no harmful gas is generated during incineration.

Further, when the paper provided with the oil-resistant coating film of the present invention is used as recycled paper, the waste discharged in the deinking process has biodegradability, so that there is no problem of environmental destruction. As the undercoat layer in the oil-resistant coating film of the present invention, for example, shellac, casein, those made of a biodegradable material such as natural rubber latex, and as the overcoat layer, for example, those made of shellac alone, Or, it may consist of shellac and other biodegradable materials. (4) The gist of the invention of claim 4 is that the undercoat layer and the overcoat layer are made of a material that can be used for foods.

Since both the undercoat layer and the overcoat layer are made of a material that can be used for food, the oil-resistant coating film of the present invention can be used for food. As the undercoat layer in the oil-resistant coating film of the present invention,
For example, shellac, casein, there are those composed of materials that can be used in foods such as natural rubber latex, and as the overcoat layer, for example, those composed of shellac alone,
Or it may consist of shellac and other materials that can be used in food. (5) The gist of the invention of claim 5 is an oil-resistant paper characterized in that the oil-resistant coating film according to any one of claims 1 to 4 is provided on the surface.

The oil-resistant paper of the present invention is excellent in oil resistance due to the oil resistance of the oil-resistant coating film provided on its surface. Further, since the oil-resistant coating film provided in the oil-resistant paper of the present invention is rich in flexibility, even when the oil-resistant paper of the present invention is bent, the oil-resistant coating film does not crack. Therefore, the oil-resistant paper of the present invention has excellent oil resistance even at a fold.

Further, the oil-resistant coating film provided in the oil-resistant paper of the present invention can have properties such as water resistance, high water absorption, high air permeability resistance and low moisture permeability by selecting the material of the undercoat layer. You can have it. Therefore, the oil-resistant paper of the present invention can be, for example, oil-resistant paper having the above characteristics.

In addition, in the oil-resistant coating film provided in the oil-resistant paper of the present invention, shellac, which is an essential component of the overcoat layer, has biodegradability. Therefore, when the overcoat layer is made of shellac, or shellac and another biodegradable material, and the other layer is also made of a biodegradable material, the oil-resistant coating film has biodegradability, The oil-resistant paper of the present invention has biodegradability. Therefore, no harmful gas is generated during incineration.

Further, when the oil-resistant paper of the present invention is made into recycled paper, the waste discharged in the deinking process has biodegradability, so that there is no problem of environmental destruction. In addition, since shellac is a material that can be used for food, the overcoat layer is made of shellac, or shellac and another material that can be used for food, and the other layer is also made of a material that can be used for food. Thus, the oil-resistant coating film can be used for foods, and the oil-resistant paper of the present invention can be used for foods.

The oil-resistant coating film may be formed on only one side of the paper, or may be formed on both sides. (6) The invention of claim 6 is a method for forming an oil-resistant coating film, comprising: (1) a step of forming an undercoat layer; and (2) a step of forming an overcoat layer containing shellac. The gist of the invention is a method for forming an oil-resistant coating film.

In the present invention, the step of forming the undercoat layer includes, for example, a solution of the material of the undercoat layer (eg, an aqueous solution, an alkaline aqueous solution (eg, an aqueous ammonia solution, an aqueous sodium carbonate solution, etc.), an alcohol solution,
Or a solution of another organic solvent) on the substrate,
Then, there is a method of evaporating the solvent.

Examples of the method for applying the solution include a method using a bar coater, a dipping method, a spin coating method, and a coating method using a spray. As a step of forming the overcoat layer containing shellac, for example, there is a step similar to the above-described method of forming the undercoat layer.

As a method of forming the oil-resistant coating film of the present invention, for example, there is a forming method comprising the step of forming the undercoat layer and the step of forming the overcoat layer.
Further, in addition to the step of forming the undercoat layer and the step of forming the overcoat layer, another layer (for example, a layer for improving the adhesion between the two layers) is provided between the two steps.
May be provided, or a step of forming another layer (for example, a layer for protecting the overcoat layer) may be provided after the step of forming the overcoat layer.

Since the oil-resistant coating film formed according to the present invention has an undercoat layer, even if the overcoat layer containing shellac is thin, it has sufficient oil resistance. Therefore, the thickness of the overcoat layer can be reduced. When the overcoat layer is appropriately thinned, the oil-resistant coating film formed according to the present invention has oil resistance and flexibility at the same time, and does not crack even when the substrate is bent.

Further, by selecting the material of the undercoat layer, it is possible to form an oil-resistant coating film having characteristics such as water resistance, high water absorption, high air resistance, and low moisture permeability. In addition, the oil-resistant coating film formed according to the present invention can be made of a biodegradable oil-resistant coating by selecting only shellac as a material, or by selecting shellac and another biodegradable material. It can be a coating film.

The oil-resistant coating film formed according to the present invention can be used for food by selecting only shellac as a material, or by selecting shellac and another material usable for food. It can be an oil-resistant coating film.

[0035]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, examples (embodiments) of embodiments of an oil-resistant coating film, a method for forming the same, and an oil-resistant paper according to the present invention will be described. B) First, the oil-resistant coating film, the method for forming the same, and the oil-resistant paper in the examples will be described. (Example 1) a) The configuration of the oil-resistant paper (paper having an oil-resistant coating film on the surface) of Example 1 is a pure white roll paper 1 as shown in FIG.
Undercoat layer 3 made of bleached shellac on one side of
And an overcoat layer 5 made of the same bleached shellac. The areal density of the undercoat layer 3 and the overcoat layer 5 is 2.6 g / cm ² .

B) An oil-resistant paper was manufactured as follows. An aqueous ammonia solution of decolorized shellac (concentration: 28% by weight) was applied to the surface of the pure white roll paper 1 using a bar coater. At this time, the amount of the coating liquid was 9.14 g / m ² .

Using a hot air drier, the solvent was evaporated by heating at 120 ° C. for 30 seconds to form an undercoat layer 3. In the same manner as described above, a decolorized shellac aqueous ammonia solution (concentration: 28% by weight) was applied. At this time, the coating amount is
It was set to 9.14 g / m ² .

In the same manner as described above, the solvent was evaporated to form an overcoat layer 5. c) The oil-resistant paper of Example 1 has oil resistance, does not crack the oil-resistant coating film even when folded, has biodegradability, can be used for food, has water resistance, has transparency. It has the features of high air resistance and low moisture permeability. (Example 2) a) The configuration of the oil-resistant paper of Example 2 is such that an undercoat layer made of natural rubber latex is provided on one side of a pure white roll paper,
It is formed by laminating an overcoat layer made of bleached shellac. Note that the basic configuration of the oil-resistant paper in the second embodiment is the same as that of the oil-resistant paper in the first embodiment, and a drawing showing the configuration is omitted. (The same applies to Example 3 below.) The areal densities of the undercoat layer and the overcoat layer were 4.4 g / cm ² and 2.6 g / c, respectively.
m ² .

B) An oil-resistant paper was manufactured as follows. An aqueous solution of natural rubber latex (concentration: 48% by weight) was applied to the surface of the pure white roll paper using a bar coater. At this time, the amount of the coating liquid was 9.14 g / m ² . In the same manner as in the steps 1 to 3 in the first embodiment, drying,
The decolorized shellac was coated with an aqueous ammonia solution (concentration: 28% by weight) and dried.

C) The oil-resistant paper of Example 2 has oil resistance, does not break the oil-resistant coating film even when bent, has biodegradability, and can be used for food.
It has the features of having water resistance, high air resistance, and low moisture permeability. (Example 3) a) The configuration of the oil-resistant paper of Example 3 is such that an undercoat layer made of casein and an overcoat layer made of bleached shellac are laminated on one side of a pure white roll paper. Incidentally, the areal densities of the undercoat layer and the overcoat layer are 1.4 g / cm ² and 2.6 g / cm ² , respectively.

B) An oil-resistant paper was manufactured as follows. An aqueous casein solution (concentration: 15% by weight) was applied to the surface of the pure white roll paper using a bar coater. At this time, the amount of the coating liquid was 9.14 g / m ² . In the same manner as in the steps 1 to 3 in the first embodiment, drying,
The decolorized shellac was coated with an aqueous ammonia solution (concentration: 28% by weight) and dried.

C) The oil-resistant paper of Example 3 has oil resistance, does not break the oil-resistant coating film when folded, has biodegradability, and can be used for food.
It has the characteristics of having water absorption, high air resistance, and low moisture permeability. B) Next, a comparative example used later in the experimental example will be described. Comparative Example 1 a) The configuration of the oil-resistant paper of Comparative Example 1 is such that a single-layer film of decolorized shellac is formed on one surface of a pure white roll paper at an area density of 2.6 g / m ^2. .

B) An oil-resistant paper was manufactured as follows. An aqueous ammonia solution of decolorized shellac (concentration: 28% by weight) was applied to the surface of the pure white roll paper using a bar coater. At this time, the amount of the coating liquid was 9.14 g / m ² .

The solvent was evaporated as in Example 1 above. Comparative Example 2 a) The configuration of the oil-resistant paper of Comparative Example 2 is such that a single-layer film of natural rubber latex is formed on one surface of a pure white roll paper at an area density of 4.4 g / m ^2. is there.

B) An oil-resistant paper was manufactured as follows. An aqueous solution of natural rubber latex (concentration: 48% by weight) was applied to the surface of the pure white roll paper using a bar coater. At this time, the amount of the coating liquid was 9.14 g / m ² . The solvent was evaporated as in Example 1 above. (Comparative Example 3) a) The configuration of the oil-resistant paper of Comparative Example 3 is such that a single layer film of casein is formed on one surface of a pure white roll paper at an area density of 1.8 g / m ² .

B) An oil-resistant paper was manufactured as follows. An aqueous casein solution (concentration: 15% by weight) was applied to the surface of the pure white roll paper using a bar coater. At this time, the amount of the coating liquid was 9.14 g / m ² . The solvent was evaporated as in Example 1 above. Comparative Example 4 a) The configuration of the oil-resistant paper of Comparative Example 4 is such that an undercoat layer made of a synthetic resin-based oil-resistant coating agent and an overcoat made of the same synthetic resin-based oil-resistant coating agent are formed on one surface of a pure white roll paper. It is formed by stacking layers. The undercoat layer and the overcoat layer each had a surface density of 1.5 g / cm.
²

B) An oil-resistant paper was manufactured as follows. A synthetic resin-based oil-resistant coating agent was applied to the surface of the pure white roll paper using a bar coater. At this time, the amount of coating liquid is
It was set to 9.14 g / m ² . Using a hot air drier, the solvent was evaporated by heating at 120 ° C. for 30 seconds to form an undercoat layer.

In the same manner as described above, the same synthetic resin-based oil-resistant coating agent as described above was applied. At this time, the coating amount was 9.
It was 14 g / m ² . In the same manner as above, the solvent was evaporated to form an overcoat layer. Comparative Example 5 a) The configuration of the oil-resistant paper of Comparative Example 5 is such that a single-layer film of decolorized shellac is formed on one surface of a pure white roll paper at an area density of 9.0 g / m ^2. .

B) An oil-resistant paper was manufactured as follows. An aqueous ammonia solution of decolorized shellac (concentration: 28% by weight) was applied to the surface of the pure white roll paper using a bar coater. At this time, the amount of the coating liquid was 32 g / m ² .

The solvent was evaporated as in Example 1 above. Comparative Example 6 a) The configuration of the oil-resistant paper of Comparative Example 6 is such that a single layer film of decolorized shellac is formed on one surface of a pure white roll paper at an area density of 5.8 g / m ^2. .

B) An oil-resistant paper was manufactured as follows. An aqueous ammonia solution of decolorized shellac (concentration: 28% by weight) was applied to the surface of the pure white roll paper using a bar coater. At this time, the amount of the coating liquid was 20.6 g / m ² .

The solvent was evaporated as in Example 1 above. Comparative Example 7 a) The configuration of the oil-resistant paper of Comparative Example 7 is such that a single layer film of decolorized shellac is formed on one surface of a pure white roll paper at an area density of 3.8 g / m ^2. .

B) An oil-resistant paper was manufactured as follows. An aqueous ammonia solution of decolorized shellac (concentration: 28% by weight) was applied to the surface of the pure white roll paper using a bar coater. At this time, the amount of the coating liquid was 13.7 g / m ² .

The solvent was evaporated as in Example 1 above. Comparative Example 8 a) The configuration of the oil-resistant paper of Comparative Example 8 is such that a single-layer film of decolorized shellac is formed on one surface of a pure white roll paper at an area density of 1.9 g / m ^2. .

B) An oil-resistant paper was manufactured as follows. An aqueous ammonia solution of decolorized shellac (concentration: 28% by weight) was applied to the surface of the pure white roll paper using a bar coater. At this time, the amount of the coating liquid was 6.87 g / m ² .

The solvent was evaporated as in Example 1 above. (Comparative Example 9) a) The configuration of the oil-resistant paper of Comparative Example 9 is such that a single-layer film of a synthetic resin-based oil-resistant coating agent is formed on one side of a pure white roll paper at 5.4 g / m2.
It is formed with an areal density of ² .

B) An oil-resistant paper was manufactured as follows. A synthetic resin-based oil-resistant coating agent was applied to the surface of the pure white roll paper using a bar coater. At this time, the coating liquid amount is 3
It was 2 g / m ² . The solvent was evaporated as in Example 1 above. (Comparative Example 10) a) The configuration of the oil-resistant paper of Comparative Example 10 was such that a single-layer film of a synthetic resin-based oil-resistant coating agent was formed on one side of a pure white roll paper at 3.5 g /
It is formed with an areal density of m ² .

B) An oil-resistant paper was manufactured as follows. A synthetic resin-based oil-resistant coating agent was applied to the surface of the pure white roll paper using a bar coater. At this time, the coating liquid amount is 2
0.6 g / m ² . (Comparative Example 11) a) The configuration of the oil-resistant paper of Comparative Example 11 was such that a single-layer film of a synthetic resin-based oil-resistant coating agent was coated on one side of a pure white roll paper at 2.3 g /
It is formed with an areal density of m ² .

B) An oil-resistant paper was manufactured as follows. A synthetic resin-based oil-resistant coating agent was applied to the surface of the pure white roll paper using a bar coater. At this time, the coating liquid amount is 1
It was 3.7 g / m ² . (Comparative Example 12) a) The configuration of the oil-resistant paper of Comparative Example 12 was such that a single-layer film of a synthetic resin-based oil-resistant coating agent was coated on one side of a pure white roll paper at 1.2 g /
It is formed with an areal density of m ² .

B) An oil-resistant paper was manufactured as follows. A synthetic resin-based oil-resistant coating agent was applied to the surface of the pure white roll paper using a bar coater. At this time, the amount of coating liquid is
6.87 g / m ² . In addition, as decolorization shellac,
PEARL-N811 manufactured by Gifu Ceramics Co., Ltd. was used, and a commercially available fluorine-based oil-resistant coating agent was used as the synthetic resin-based oil-resistant coating agent.

The oil-resistant coating film was formed only on one side. C) Next, a test performed to confirm the oil resistance of the oil-resistant paper manufactured in this example will be described. Oil-resistant papers in Examples 1 to 3 and Comparative Examples 1 to 12 are described in J. Am. TAP
PINo. 41 An oil repellency test was performed by the kit method.

In Examples 1 to 3 and Comparative Examples 4 to 12, the paper was strongly pressed with a finger so that the surfaces provided with the oil-resistant coating film overlap each other (folded portion). The measurement was performed for each of the unbent portions (normal portions). In other examples and comparative examples, the measurement was performed only for the normal part.

Table 1 shows the results. -In Table 1, x shows the kit number 1 or less. -In Table 1,-shows that it has not measured.・ For oil-resistant paper, if you have more than 8 kits,
It can be said that there is sufficient oil resistance.

The blank is paper on which no oil-resistant coating film is formed.

[0065]

[Table 1]

As shown in Table 1, the oil-resistant paper in Examples 1 to 3 has a large number of kits and excellent oil resistance in both the normal portion and the bent portion. Comparative Examples 1-3
The oil resistant paper of the above does not have sufficient oil resistance in the ordinary part. The oil-resistant papers of Comparative Examples 4 and 9 to 12 are inferior in biodegradability and safety because a material containing no shellac is used.

The oil-resistant paper of Comparative Example 5 is excellent in oil resistance in a normal portion, but very poor in oil resistance in a bent portion. Incidentally, in a coating machine currently used by a paper maker, the coating liquid amount is generally 10 g / m ² , and it is difficult to apply the liquid amount in Comparative Example 5.

The oil-resistant papers of Comparative Examples 5 to 8 have very poor oil resistance at the bent portions. Comparative Examples 5 to 8 above
From the results, the shellac single-layer oil-resistant coating film,
It is shown that if the film thickness is not very large, the oil resistance is poor, and even if the film thickness is large, the oil resistance at the fold is poor.

(C) Next, a description will be given of a test performed to confirm the water absorption, the air resistance, and the moisture permeability of the oil-resistant paper manufactured in this example. The test was performed on the oil-resistant paper in Examples 1 to 3 and Comparative Example 4 and a blank.
Table 2 shows the results.

The water absorption test is carried out according to the Cobb method of JIS 8140 and the Stekigt sizing test method of JIS 8122, and the test of air permeability is carried out according to JIS P811.
7: 1998, and the moisture permeability test was performed according to JI.
SZ0208: 1976.

Table 2 shows the results. -The surface in Table 2 means the surface on which the oil-resistant coating film is formed, and the back surface means the surface on which the oil-resistant coating film is not formed. -In Table 2, the symbol "る こ と" indicates that the water absorption was so large that water penetrated to the opposite side of the paper and that measurement was impossible.

The unit of the measurement result of the Cobb method is g / m ² , the unit of the measurement result of the Stekigt size method is second, the unit of the measurement result of the air permeability is second, and the unit of the moisture permeability is The unit of the measurement result is g / cm · 24 hr. -A blank is paper on which no oil-resistant coating film is formed.

[0073]

[Table 2]

As shown in Table 2, the oil-resistant papers of Examples 1 and 2 have very low water absorption. Therefore, it is excellent in water resistance. The oil-resistant paper of Example 3 has the same level of water absorption as Comparative Example 4. Further, all of the oil-resistant papers of Examples 1 to 3 have very high air resistance and very low moisture permeability.

It should be noted that the present invention is not limited to the above-described embodiment at all, and can be implemented in various embodiments without departing from the gist of the present invention. For example, as a substrate on which an oil-resistant coating film is formed, there are paperboard, nonwoven fabric, and paper containers (including trays) in addition to paper.

The method of applying the undercoat layer and the overcoat layer may be, for example, a dipping method, a spin coating method, or a spray coating method. Further, the solvent for applying the undercoat layer and the overcoat layer may be, for example, alcohol or another organic solvent.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an oil-resistant coating film.

FIG. 2 is an explanatory diagram of an oil-resistant coating film in Example 1.

[Explanation of symbols]

 1: Pure white roll paper 3: Undercoat layer 5: Overcoat layer

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) D21H 19/82 D21H 19/82 21/14 21/14 Z // B29K 105: 06 B29K 105: 06 B29L 9:00 B29L 9:00 (72) Inventor Hitoshi Mizutani 1-27 Kano Nishimaru-cho, Gifu-shi, Gifu F-term (reference) 4F100 AD00C AD00H AT00A BA03 BA07 BA10A BA10C DG10A GB23 JB07 JB07A JC00B JC00C JM02F JM02BJM205M AB16 AC06 AH54 GA07 GB02 GB26 GC07 GE02 GE24 GE27 GF03 GF24 GN13 GN21 GW06 GW50 4J038 BA111 BA191 BA211 BA221 CA011 NA04 PB02 PC10 4L055 AG42 AG52 AG53 AG97 AH24 AH37 AJ01 AJ02 BE09 FA19 FA20 GA48

Claims (6)

[Claims] 1. A multilayer laminated film comprising: an undercoat layer formed on a surface side of a substrate; and an overcoat layer formed on the surface side of the undercoat layer and containing shellac. Oil resistant coating film. 2. The undercoat layer formed on the surface of the substrate, and an overcoat layer laminated on the undercoat layer and containing shellac, wherein: Oil resistant coating film. 3. The oil-resistant coating film according to claim 2, wherein the undercoat layer and the overcoat layer are made of a biodegradable material. 4. The oil-resistant coating film according to claim 2, wherein the undercoat layer and the overcoat layer are made of a material usable for food. 5. An oil-resistant paper comprising the oil-resistant coating film according to claim 1 on a surface thereof. 6. A method for forming an oil-resistant coating film, comprising: (1) a step of forming an undercoat layer; and (2) a step of forming an overcoat layer containing shellac. A method for forming an oil-resistant coating film.