JP2001303483A - Product of papers - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an inexpensive product of papers having excellent water resistance, steam barrier properties and gas barrier properties, preventing adhesion of contents. SOLUTION: This product 10 of papers is constituted of a paper base 14 as a main constituent and has a lower layer 15 and an upper layer 16 on at least one side of the paper base 14. The lower layer 15 is formed by application of a resin-containing lower layer forming coating. A coating having 0.1-100 g/m2 value of water absorption degree to the lower layer forming coating of the paper substrate 14 measured in the manner described in a Cobb method defined by JIS P8140 is used as the lower layer forming coating. The upper layer 16 is formed by application of an upper layer forming coating containing an inorganic or metal alkoxide on the lower layer 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to inexpensive papers having water resistance, water vapor barrier properties and gas barrier properties while maintaining the original recycling characteristics and easy incineration of paper, and in which the adhesion of contents is prevented. The present invention relates to a product and a manufacturing method thereof.

[0002]

2. Description of the Related Art Japanese Patent No. 2992024 discloses that an undercoat is formed by applying a urethane paint to the surface of a tray core made of wood fiber.
A lacquer-like paper tray in which a glass coating portion is formed on the surface of the undercoat portion is described.

[0003] However, the undercoating section of this paper tray is
It is formed to give a predetermined color to the paper tray, and is not intended to enhance water resistance or water vapor barrier properties. Further, since the paint used for forming the undercoat portion is of an organic solvent type, when the paint is applied to the tray core material, the paint penetrates into the inside of the tray core material, and the undercoat portion can be formed with a small application amount. Not economical. In addition, if the penetration of the coating material is large, the surface properties of the formed undercoat portion are deteriorated, so that the function of the undercoat portion may not be sufficiently exhibited. As a means for preventing the penetration of the paint, there is a method of imparting oil repellency to the tray core itself with a fluorine-based additive or the like before applying the paint, but in that case, the number of manufacturing steps is increased. , Again not economic.

Accordingly, it is an object of the present invention to provide an inexpensive paper product having water resistance, water vapor barrier properties and gas barrier properties and in which the adhesion of contents is prevented, and a method for producing the same. Another object of the present invention is to provide a paper product having water resistance and water vapor barrier properties while maintaining the original recycling characteristics and easy incineration of paper, and a method for producing the same.

[0005]

SUMMARY OF THE INVENTION The present invention comprises a paper base as a main component, and has a lower layer and an upper layer on at least one surface of the paper base, wherein the lower layer is a resin-containing coating for forming a lower layer. It is formed by application, and the value of the water absorbency of the paper base material with respect to the lower layer forming paint, measured according to the cup method specified in JIS P 8140, is 0.1 to 100 g / m ² is used, and the above-mentioned upper layer achieves the above-mentioned object by providing a paper product formed on the above-mentioned lower layer by applying a coating for forming an upper layer containing an inorganic or metal alkoxide. Things.

Further, the present invention comprises a paper substrate as a main component, and has a lower layer and an upper layer on at least one surface of the paper substrate.
The lower layer is formed by applying a lower layer forming paint composed of an aqueous resin dispersion or an aqueous resin solution, and the upper layer is formed on the lower layer by applying an upper layer forming paint containing an inorganic or metal alkoxide. The paper substrate provides a paper product having a water absorption value of 0.1 to 100 g / m ² measured according to the cup method specified in JIS P 8140.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The paper products of the present invention widely include papers, paperboards, processed paperboard products, molded articles, and the like manufactured from plant fibers such as wood fibers and non-wood fibers.
The following description is based on a pulp molded product which is a preferred embodiment of the paper product of the present invention. In FIG.
FIG. 1 shows a partially cutaway perspective view and a main part enlarged view of a pulp molded article of the present embodiment.

The pulp molded article 10 shown in FIG.
It is a cylindrical bottle composed of an open mouth and neck 11, a body 12, and a bottom 13. The diameter of the body 12 and the bottom 13 of the molded body 10 are substantially the same, and the diameter of the mouth and neck 11 is smaller than the diameter of the body 12. In the present embodiment, the diameter of the body 12 is 20 to 1
00 mm, especially 40 to 80 mm. on the other hand,
The diameter of the mouth and neck 11 is 10 to 50 mm, especially 15 to 35 mm
It has been done.

The molded body 10 includes a molded body 14 as a paper base formed of pulp fiber as a main raw material, a lower layer 15 formed on the inner surface of the molded body 14, and an upper layer formed on the lower layer 15. 16.

The molded body 14 of the molded body 10 is made of a pulp fiber as a main material by a known pulp molding method, for example, Japanese Patent Application Laid-Open No. H11-31426 according to the earlier application of the present applicant.
It is molded by the method described in Japanese Patent Publication No. Of course, it may be formed from 100% pulp fibers. When other materials are used in addition to pulp, the compounding amount of the materials is 1
-70% by weight, especially 5-50% by weight. Other materials include sizing agents, inorganic substances such as talc and kaolinite,
Examples include inorganic fibers such as glass fibers and carbon fibers, synthetic resin powders such as polyolefin, synthetic fibers, non-wood or vegetable fibers, and polysaccharides.

The thickness of the molded body 14 is substantially uniform in both the longitudinal section and the transverse section, and there is no thick portion. In addition, there is no seam formed by bonding or the like between the body portion of the molded body 12 and the body portion 12 and the bottom portion 13. Thereby, the molded body 1
In addition, the impression of the appearance becomes good as the strength of 0 increases. Further, the adhesion between the molded body 14 and the lower layer 15 and the upper layer 16 is also enhanced.

The molded body 14 has smooth outer and inner surfaces. Thereby, the lower layer 15 and the outer layer 16
In the case where is formed, the adhesion between these layers and the surface of the molded body is improved, and the water resistance and the water vapor barrier property of the molded body 10 are ensured. Further, the appearance of the molded body 10 is further improved. In this specification, “smooth” refers to the molded body 14.
Means that the center line average roughness (Ra) is 50 μm or less and the maximum height (Ry) is 500 μm or less for the surface irregularities on the outer surface and the inner surface (JIS B0601).
Measured in accordance with).

[0013] As shown in FIG.
2 is formed substantially perpendicular to the bottom 13. That is,
The taper angle of the body 12 is about 0 degrees. Also,
The molded body 10 has an overall height of 50 mm or more, particularly 100 mm or more.
mm or more.

Both the lower layer 15 and the upper layer 16 are formed over the entire inner surface of the molded body 14. The lower layer 15 is
It is used mainly for imparting water resistance and water vapor barrier properties to the molded body 10. On the other hand, the upper layer 16 is
It is mainly used to impart gas barrier properties, water vapor barrier properties, and anti-adhesion properties to contents. Both the lower layer 15 and the upper layer 16 are formed by applying a predetermined paint. Hereinafter, the paint used for forming each layer will be described.

The paint for forming the lower layer used for forming the lower layer 15 is a paint containing a predetermined resin. As the lower layer forming paint, the molded article body 1 as a paper base, which was measured according to the cup method specified in JIS P 8140, was used.
4, the value of the water absorption of the paint for forming the lower layer is 0.1 to 10;
0 g / m ^2, preferably is used which becomes 5 to 50 g / m ^2. The water absorption of the glass of the molded body 14 is 100 g
/ M ² , the lower layer coating material penetrates greatly into the molded body 14 and the lower layer 1 has a high surface property.
5 cannot be formed. Further, in order to obtain a sufficiently high surface property, many paints are required, which is not economical. On the other hand, if the water absorption of the glass is less than 0.1 g / m ² , many sizing agents are required when manufacturing the molded body 14, which is not economical.

The above-mentioned water absorption is a value measured by using a lower layer forming paint instead of distilled water used for measuring the water absorption according to the cup method. Even when the same lower layer forming paint is used, the value of the water absorption differs depending on the type of the paper base material to be measured, the surface roughness, the affinity of the paper base material with the lower layer forming paint, and the like. In order to keep the water absorption within the above range, for example, (1) a method of adjusting the composition of the coating material for forming the lower layer, (2) a method of adjusting the water absorption of the molded body 14 by adding a sizing agent and the like, and A method such as a method combining the above (1) and (2) is used. When the paper base to be measured is not flat, the paper base should be φ2
Punched to any size from 0 to 70mm, JIS P
After changing the size of the ring specified in 8140 and performing the same measurement, the water absorption is calculated by converting the area.

As the resin contained in the lower layer forming paint, a resin which imparts water resistance and water vapor barrier properties and can improve the applicability of the upper layer forming paint is used. For example,
As the resin, acrylic, styrene-acrylic, ethylene-vinyl acetate, styrene-butadiene rubber, polyvinyl alcohol, vinylidene chloride, wax, fluorine, silicone resins, copolymers thereof, and these resins And the like. In particular, the use of a styrene-butadiene rubber-based, acrylic, styrene-acryl-based, or polyvinyl alcohol-based resin as the resin improves the applicability of the paint for forming the upper layer, the water resistance and the water vapor barrier property of the lower layer. This is preferred from the viewpoints of improvement in cost and economic efficiency. The lower layer forming paint may be a dispersion containing these resins or a solution.
Further, the lower layer forming paint may be water-based or an organic solvent-based paint. However, in order to prevent the lower layer forming paint from excessively seeping into the molded article body 14 and reduce the amount of use, the lower layer-forming paint is water-based. Preferably, there is. That is, the coating for forming the lower layer is preferably an aqueous resin dispersion or an aqueous resin solution.

When the lower layer forming paint is composed of an aqueous resin dispersion or an aqueous resin solution, the value of water absorption measured according to the cup method specified in JIS P 8140 is used as the molded body 14 as a paper base. (That is, the value of the water absorption of the molded body 14 with respect to distilled water) is 0.1 to 100 g / m ² ,
Preferably, those having a weight of 5 to 50 g / m ² are used. The reason for this is to prevent the lower layer molding paint from seeping into the molded body 14 and to economically form the lower layer 15 having a high surface property.

The paint for forming the upper layer used for forming the upper layer 16 contains an inorganic or metal alkoxide (hereinafter, referred to as alkoxides). Here, the inorganic alkoxide refers to an inorganic alkoxide other than a metal alkoxide. Inorganic or metal alkoxides are denoted by M (OR) _m . M is an inorganic substance atom or a metal atom. Examples of M include Li, Na, Cu, Mg, Ca, Sr, B
a, Zn, B, Al, Ga, Y, Si, Ge, Pb,
P, Sb, Ta, W, La, Nd, Ti, and the like. m is the valence of M. R represents a lower alkyl group, for example, an alkyl group having 1 to 4 carbon atoms.

Specific examples of the alkoxysides include alkoxysilanes such as methyltrimethoxysilane, aluminum propoxide, titanium isopropoxide, zinc t-butoxide, zinc n-butoxide, calcium ethoxide, iron ethoxide, and vanadium isopropoxide. , Tin t-butoxide, lithium ethoxide, beryllium ethoxide, boron ethoxide, phosphorus ethoxide, phosphorus methoxide, magnesium methoxide, magnesium ethoxide and the like.

It is preferable that the coating material for forming the upper layer contains an alkoxide curing agent or a curing accelerator.
As these agents, various generally known metal chelate compounds, acid catalysts, base catalysts and the like are appropriately selected and used depending on the composition of the coating material. The alkoxides are hydrolyzed or condensed by the action of these agents to form an upper layer containing a hydrolyzate or a partial condensate of the alkoxides.

It is preferable that the coating material for forming the upper layer contains an organic polymer from the viewpoint of further improving the water vapor barrier property. In particular, acrylic polymer, polyvinyl alcohol, ethylene vinyl alcohol, preferably contains a hydrophilic resin such as polyamide such as nylon,
In particular, acrylic polymer and polyvinyl alcohol are preferable from the viewpoint of further improving the water vapor barrier property and economic efficiency. Thereby, the hydrolyzate or the partial condensate and the organic polymer can be compounded at the molecular level, so that the film forming property of the upper layer 16 is improved and the upper layer 16 is also given flexibility. Particularly preferred organic polymers are organic polymers having a group capable of reacting with an alkoxide (hydrolysis reaction, condensation reaction, etc.).

Next, the formation of the lower layer 15 and the upper layer 16 using the above-mentioned lower layer forming paint and upper layer forming paint will be described. First, a coating film of a lower layer forming paint is applied to the entire inner surface of the inner surface of the molded body 14 manufactured by papermaking and drying of a slurry containing pulp fibers by an application method such as spray coating, dipping, or brushing. Formed. In this case, since the water absorption of the cup for the lower layer forming paint of the molded body 14 is adjusted to the above-mentioned range, the lower layer forming paint is prevented from excessively seeping into the inside of the molded body, and a small amount of coating is applied. Thus, the lower layer 15 exhibiting sufficient water resistance and water vapor barrier properties is economically formed. In addition, the surface properties of the lower layer 15 are improved,
Effectively exhibits water resistance and water vapor barrier properties. In addition, the property of preventing adhesion of contents is also exhibited. The coating film formed by the application is heated and dried at a predetermined temperature for a predetermined time to form the lower layer 1.
5 are formed. The lower layer 15 is a thin layer mainly composed of the resin. The heating time and heating temperature of the coating film are appropriately adjusted according to the composition of the lower layer forming paint.

Next, a coating film of a paint for forming an upper layer is formed on the lower layer 15. The method of applying the upper layer forming paint can be the same as the lower layer forming paint. As mentioned above,
Since the surface properties of the lower layer 15 are good, the upper layer 16 can be made thinner, more uniform, and have higher surface properties.
As a result, gas barrier properties and water vapor barrier properties are effectively exhibited. The upper layer 16 is formed by heating and drying the coating film formed by the application at a predetermined temperature for a predetermined time. The upper layer 16 is formed of a network structure such as a hydrolyzate or a partial condensate generated by curing (crosslinking) alkoxides. When the above-mentioned organic polymer is contained in the coating material for forming the upper layer, an alkoxide and a network structure composed of the organic polymer are formed. The heating time and heating temperature of the coating film are appropriately adjusted according to the types of the alkoxides and the curing agent contained in the coating material for forming the upper layer.

In the present embodiment, since the lower layer 15 and the upper layer 16 are formed on the main body of the molded article as a paper base previously formed into a predetermined shape, the paper base is formed after forming these layers. There is no danger of cracking of these layers, which may occur in the case of shaping, and the resulting decrease in water resistance, gas barrier properties, water vapor barrier properties, and the like.

The molded article 10 is provided with water resistance and water vapor barrier properties by the lower layer 15 formed by the above-described method. The lower layer 15 has a thickness of 5 to 100 μm,
It is preferable that the thickness is 50 μm from the viewpoints of economy, productivity (drying efficiency), surface properties, and water resistance and water vapor barrier properties.

Further, the upper layer 16 imparts a gas barrier property, a water vapor barrier property, and a property of preventing adhesion of contents to the molded body 10. The upper layer 16 has a thickness of 0.05 to 100.
μm, particularly 1 to 30 μm, is preferable from the viewpoints of economical efficiency, productivity (drying efficiency), gas barrier properties and water vapor barrier properties, and improvement of the adhesion prevention of contents.

The ratio of the thickness of the lower layer 15 to the thickness of the upper layer 16 is as follows: the former: the latter = 1: 0.01 to 10, especially 1: 0.05 to 1
Is preferred from the viewpoints of economy, productivity (drying efficiency), and barrier properties against various substances (various gases and water vapor).

Since the molded body 10 thus obtained has the lower layer 15 and the upper layer 16 formed thereon, it has high water resistance, gas barrier properties, water vapor barrier properties, and the like, and has excellent anti-adhesion properties. I have. Therefore, the molded body 10 is particularly suitably used as a storage container for various liquids and powders. Since both the lower layer 15 and the upper layer 16 are thin layers, the molded body 10 is excellent in recyclability and easy incineration.

The molded article 10 has a glass water absorption (JIS P 8140) as a measure of water resistance of 0 to 50 g.
/ M ² , especially 0 to 5 g / m ² . Further, moisture permeability as a measure of water vapor barrier properties (JIS Z 0208)
Is from 0.05 to 30 g / (m ² · 24 hr), particularly from 0.05 to
20g / become (m ² · 24hr). Further, the oxygen permeability (JIS K 7126) as a measure of gas barrier properties is 0.
01-200cm ³ / (m ² · 24hr · 1atm), especially 0.5 ~
100 cm ³ / (m ² · 24 hr · 1 atm).

The present invention is not limited to the above embodiment.
For example, in the above embodiment, the lower layer 15 and the upper layer 16 are formed on the inner surface of the molded body 14, but a lower layer and an upper layer may be formed on the outer surface of the molded body 14 instead or together with this. The lower layer and the upper layer may not be formed over the entire inner surface and / or outer surface of the molded body 14. For example, in the case of the inner surface, the upper end surface of the content and the upper end surface of the molded body 14 are formed. These layers may be formed so that the upper surfaces of the lower layer and the upper layer are located therebetween.

As the paper base material, in addition to the molded product, paper, paperboard, and a paperboard processed product in which paperboard is preliminarily formed into a predetermined shape can be used, and at least one surface thereof has a lower layer and an upper layer. To form the paper product of the present invention. In particular, after shaping paperboard as a paper base material into a predetermined shape by a predetermined means, a lower layer forming paint is applied to at least one surface of the formed paperboard to form a lower layer, and then an upper layer forming layer is formed on the lower layer. By applying a paint to form an upper layer to form a paper product, a lower layer and an upper layer are formed on the paperboard itself, and thereafter, the paperboard is shaped into a predetermined shape to produce a paper product. In addition, the lower layer and the upper layer are prevented from being damaged such as cracks, and the original performance of these layers is effectively exhibited.

[0033]

[Example 1] A molded body having the shape shown in Fig. 1 was produced from pulp slurry by the method described in JP-A-11-314267. A coating for forming a lower layer was applied to the inner surface of the molded body by dipping to form a coating film. The coating amount was 30 ± 1 g / m ² (based on solid content). Shin Nakamura Chemical Co., Ltd.
Water-based acrylic emulsion MT9000 (trade name)
Was used. The water absorption of a cup for the lower layer forming paint of the molded body can be measured by adding a predetermined amount of a sizing agent [AS-261 (trade name) manufactured by Nippon PMC] to the pulp slurry.
It was adjusted to ± 3 g / m ² . The water absorption of the molded body with respect to distilled water was 20 ± 3 g / m ² . The coating film was dried by heating at 105 ° C. for 5 minutes in a hot-air drying furnace to form a lower layer having a thickness of about 30 ± 1 μm.

On the lower layer, a paint for forming an upper layer was applied by dipping to form a coating film. Examples of the upper layer forming paint include a hybrid inorganic paint Glaska HPC7506 (trade name) manufactured by Nippon Synthetic Rubber Co., Ltd. and a curing agent HP manufactured by the company.
A mixture of C406H (trade name) at 100: 10 was used. The inorganic paint contains an alkoxysilane such as methyltrimethoxysilane and an acrylic polymer containing an alkoxysilyl group. This acrylic polymer is 20 parts by weight based on 100 parts by weight of alkoxysilane.
It is added in parts by weight. The curing agent is made of a zinc compound. The coating film was dried by heating at 105 ° C. for 10 minutes to form an upper layer having a thickness of about 16 ± 1 μm.
This upper layer consisted of a three-dimensional network of polysiloxane and acrylic polymer formed by hydrolysis and partial condensation of alkoxysilane. In this way,
A pulp molded article having a lower layer and an upper layer formed on the inner surface of the molded article body was obtained.

Comparative Example 1 Pulp was prepared in the same manner as in Example 1 except that the amount of the sizing agent added to the pulp slurry was adjusted to make the water absorption of the cup for the lower layer forming paint of the molded body 140 g / m ^2. A molded article was obtained.

Comparative Example 2 A pulp molded article was obtained in the same manner as in Example 1 except that the lower layer was not formed and only the upper layer was formed. The glass had a water absorption of 130 g / m ² with respect to the paint for forming the upper layer of the molded article main body.

Comparative Example 3 A pulp molded article was obtained in the same manner as in Example 1 except that only the lower layer was formed.

[Evaluation of Performance] The moisture permeability of the pulp molded products obtained in Examples and Comparative Examples was measured by the method described above. In addition, the ability to prevent the adhesion of contents on the inner surface of the molded article was evaluated by the following method. Table 1 shows the results.
Table 1 also shows the water absorption of the glass.

[Prevention of Adhesion of Contents] The obtained pulp mold was filled with an oxygen-based powder bleach [Wide Height (trade name) manufactured by Kao Corporation] at 40 ° C. and 80% R.
H was left for 1 day in an environment. The bleach was taken out while gently tilting the container, and it was visually determined whether the bleach had adhered to the inner surface of the molded article. The case where no adhesion was observed was evaluated as ○, and the case where adhesion was observed was evaluated as x.

[0040]

[Table 1]

As is clear from the results shown in Table 1, the pulp molded article of Example 1 (product of the present invention) has a higher moisture permeability than the molded article of the comparative example, and adhesion of contents was also observed. It turns out that there is no. Although not shown in the table, the molded article of Example 1 was easily recyclable and incinerated.

[0042]

According to the present invention, there is provided an inexpensive paper product having water resistance, water vapor barrier properties and gas barrier properties and in which the adhesion of contents is prevented, and a method for producing the same. Further, according to the present invention, a paper product having water resistance and water vapor barrier properties while maintaining the original recycling characteristics and easy incineration of paper, and a method for producing the same are provided.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view and a main part enlarged view of a pulp molded article which is one embodiment of a paper product of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Pulp molded body (paper products) 11 Mouth and neck part 12 Body part 13 Bottom part 14 Mold body 15 Lower layer 16 Upper layer

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) D21H 19/12 D21H 19/14 19/14 19/84 19/84 D21J 3/00 D21J 3/00 B65D 1/00 C BF term (reference) 3E033 BA10 BA13 BA19 BA21 BB08 CA09 CA16 CA20 FA01 FA10 4L055 AA01 AG38 AG71 AG86 AG97 AH37 AJ01 AJ02 BE09 BF09 FA11 FA19 FA20 GA05

Claims (6)

[Claims] 1. A paper base material mainly comprising: a paper base material having a lower layer and an upper layer on at least one surface of the paper base; wherein the lower layer is formed by applying a lower layer forming paint containing a resin; JIS as lower layer paint
A material having a water absorbency of 0.1 to 100 g / m ² with respect to the lower layer forming paint of the paper base, which is measured according to a cup method defined in P8140, is used. Paper products formed on the lower layer by applying an upper layer-forming paint containing an inorganic or metal alkoxide. 2. A paper base material mainly comprising a lower layer and an upper layer on at least one surface of the paper base, wherein the lower layer is formed by applying a lower layer forming paint composed of an aqueous resin dispersion or an aqueous resin solution. The upper layer is formed on the lower layer by applying an upper layer forming paint containing an inorganic or metal alkoxide, and the paper base material is formed according to a cup method defined in JIS P 8140. The value of the measured water absorption is 0.1 to 100 g
/ M ² paper products. 3. The paper product according to claim 1, wherein the paper base material is shaped into a predetermined shape in advance, and the lower layer and the upper layer are formed on the shaped paper base material. . 4. The paper product according to claim 3, wherein the shaped paper substrate is a pulp molded article. 5. A paper base material is formed into a predetermined shape by a predetermined means, and then the lower layer forming paint is applied to at least one surface of the formed paper base material to form the lower layer. A method for manufacturing a paper product in which the upper layer is formed by applying the upper layer forming paint on the lower layer. 6. A pulp molded article having a predetermined shape is formed by papermaking and drying of a slurry containing pulp fibers, and then the lower layer forming paint is applied to at least one surface of the pulp molded article to form the lower layer. And then applying the paint for forming the upper layer on the lower layer to form the upper layer.