JPH11235800A - Metallized paper and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metallized paper whose troubles such as creasing, discoloration, luster deterioration or the like occurring during a high temperature step or handling at a high temperature, are eliminated by enhancing the heat resistance, and a method for manufacturing the metallized paper. SOLUTION: In the metallized paper constructed of layers such as a paper base material 1, a polyethylene layer 2, an under layer 3, a deposit layer 4 and a top coat layer 5, the polyethylene layer 2 is formed of an extruded coat layer of a polyethylene composition with a density of 0.930-0.965 (especially 0.936-0.960) comprising a composition of a low density polyethylene with a density of 0.910-0.925 and a high-density polyethylene with a density of 0.941-0.980 at a weight ratio of 2:8-8:2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-resistant vapor-deposited paper suitable for uses such as labels, posters and laminates, and a method for producing the same.

[0002]

2. Description of the Related Art It is preferable to use a sheet having a metallic luster provided with a metal vapor-deposited layer for a label attached to a bottle of a drink, a seasoning, an alcoholic beverage, or the like, from the viewpoint of aesthetic appearance or a sense of quality. Similarly, in the case of poster paper, it is preferable to use a sheet having a metallic luster provided with a metal deposition layer. In the case of cardboard for freshness preservation packaging,
In order to provide oxygen barrier properties and moisture permeability, it is possible to attach a vapor-deposited paper having a metal vapor-deposited layer on the entire surface of the corrugated cardboard, or to use one having a vapor-deposited layer as one of the liners constituting the corrugated cardboard. desirable.

Conventionally, vapor-deposited paper has been known as a material used for this type of label or sheet. Since vapor-deposited paper has a different power of expression than paper, it can be said that it is a modern advertising material that images the luxury of products. In addition, the vapor-deposited paper has excellent oxygen barrier properties and moisture resistance, and can perform high-speed printing as compared with aluminum foil.

The above-mentioned vapor-deposited paper is manufactured by providing an under layer on a base paper, vacuum-depositing a relatively thin layer of about 100 to 500 angstroms thereon, and further providing a top coat (overcoat) layer thereon. Is done.

[0005] The production method, properties, applications, etc. of the vapor-deposited paper are described in, for example, “New Material Utilization Series, Functional Paper, Published by the Industrial Research Institute Co., Ltd., Published: October 1, 1988”, pp. 247-249. There is a commentary.

When using vapor-deposited paper, printing is performed on the surface on the top coat layer side, and gluing is performed on the surface on the base paper side.
Furthermore, after performing processing such as slitting, cutting, and punching as necessary at an appropriate stage, the sheet is attached to an object.

Japanese Patent Application Laid-Open No. Hei 6-316034 discloses a metal-deposited laminate having alkali washing properties, which comprises (a) base paper, (b) an ethylene-ethylene unsaturated carboxylic acid copolymer resin and a tackifier. And a metal vapor-deposited laminate comprising (c) a metal vapor-deposited layer. Here, an example of the ethylene-ethylenically unsaturated carboxylic acid copolymer resin is an ethylene- (meth) acrylic acid copolymer resin. In Comparative Examples, examples using low-density polyethylene and examples using ethylene-vinyl acetate copolymer instead of the ethylene-ethylenically unsaturated carboxylic acid copolymer resin are shown.

Japanese Patent Application Laid-Open No. 9-209 filed by the present applicant
No. 125 discloses a corona discharge treatment on a polyethylene layer side surface of a paper substrate provided with a polyethylene layer by melt extrusion coating, and an under layer, a vapor deposition layer and a top coat layer are formed in this order on the corona discharge treated surface. The method for producing the deposited paper is shown. Here, it is described that as the polyethylene in the polyethylene layer, a polyethylene of a grade for ordinary melt extrusion coating (extrusion lamination), particularly a low density polyethylene having a density of 0.910 to 0.935 (preferably 0.912 to 0.930) is used. . In the embodiment, an example is given in which a low density of 0.919 is melt-extruded and coated on one side of a paper base material.

[0009]

A conventional vapor-deposited paper having a layer structure of base paper / under layer / vapor-deposited layer / top coat layer essentially has a water content that is easily changed and base paper having poor surface smoothness. Since the under layer, the vapor deposition layer, and the top coat layer are provided, it is easy to cause curl or dimensional change and to impair the adhesion of the vapor deposition layer, particularly in the step of vapor deposition under heating vacuum.

The metal-deposited laminate of Japanese Patent Application Laid-Open No. 6-316034 discloses a "resin layer containing an ethylene-ethylenically unsaturated carboxylic acid copolymer resin and a tackifier" on a base paper in order to obtain alkaline washing properties. Therefore, there is a problem that moisture resistance and water resistance are naturally limited and heat resistance is insufficient.

According to Japanese Patent Application Laid-Open No. 9-209125 filed by the present applicant among the documents cited above, a vapor-deposited paper can be industrially advantageously produced, and favorable water resistance can be obtained. However, when exposed to high temperatures under the conditions used in the manufacturing process or the usage conditions and applications of the obtained vapor-deposited paper, the heat resistance is insufficient, causing problems such as wrinkles, discoloration, and reduced gloss. There was a risk of getting up.

Under such a background, the present invention further develops the invention of Japanese Patent Application Laid-Open No. 9-209125 filed by the present applicant and improves heat resistance without impairing the advantages of the invention of the publication. It is another object of the present invention to provide a vapor-deposited paper and a method for producing the same, which eliminate problems such as wrinkling, discoloration, and reduction in gloss during high-temperature processing or high-temperature handling.

[0013]

The vapor-deposited paper of the present invention comprises a paper base (1) / polyethylene layer (2) / under layer (3) / vapor-deposited layer.
(4) In a vapor-deposited paper having a layer configuration of / topcoat layer (5), the polyethylene layer (2) has a density of 0.910 to 0.925.
Characterized by comprising an extrusion coat layer of a polyethylene composition having a density of 0.930 to 0.965 comprising a composition having a weight ratio of a low density polyethylene having a density of 0.941 to 0.980 to a high density polyethylene having a density of 0.98 to 0.980. It is.

The method for producing a vapor-deposited paper according to the present invention comprises the steps of: forming an under layer (3), a vapor-deposited layer (4) and a top coat on a polyethylene layer (2) provided by melt extrusion coating on a paper substrate (1); In producing the vapor-deposited paper by forming the layer (5) in this order, the polyethylene layer (2) has a density of 0.910
Characterized by using a layer of a polyethylene composition having a density of 0.930 to 0.965 comprising a composition having a weight ratio of low density polyethylene having a density of 0.925 to 0.925 and high density polyethylene having a density of 0.941 to 0.980 in a weight ratio of 2: 8 to 8: 2. It is.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

In the present invention, a "paper base (1) / polyethylene layer (2)" in which a polyethylene layer (2) is provided on a paper base (1) by melt extrusion coating as a base sheet.
Is used.

Here, examples of the paper base material (1) include thin paper, high quality paper, medium paper, book paper, art paper, coated paper, cast coated paper, pure white roll paper, and imitation paper. Cardboard, cardboard and the like can also be used. The basis weight or thickness of the paper base material (1) is not particularly limited as long as it has a necessary strength.However, when performing vapor deposition for forming a vapor deposition layer (4) described later with a continuous vacuum vapor deposition machine, Since the thickness of the double-sided adhesive tape for the joint of the paper base material (1) to be added is also increased, it is preferable to use one having a basis weight of about ²⁰ to 80 g / m ² or about that.

In the present invention, the polyethylene layer (2) has a weight ratio of low density polyethylene having a density of 0.910 to 0.925 to high density polyethylene having a density of 0.941 to 0.980 of 2: 8 to 8: 2 (preferably 3: 7-7: 3)
An extruded coat layer of a polyethylene composition having a density of 0.930 to 0.965 made of the following composition is used. In this case, it is particularly preferable that the density of the polyethylene composition is 0.936 to 0.960. The feature of the present invention is that an extrusion coat layer of a polyethylene composition having such a specific composition is used. The thickness of the polyethylene layer (2) is, for example, 1
It is often about 0 to 30 μm.

When the low-density polyethylene is used alone or when the proportion of the low-density polyethylene is higher than the above range, the heat resistance is insufficient. Receive. When the high-density polyethylene alone or the proportion of the high-density polyethylene is larger than the above range, the smoothness is impaired during the extrusion coating, and the layer formed by the extrusion coating becomes opaque and the commercial value is reduced. Become. Further, even when the weight ratio of the low-density polyethylene to the high-density polyethylene is within the above range, when the density of the composition is out of the specified range, dissatisfaction still remains in terms of heat resistance.

It is particularly preferable that the surface of the paper substrate (1) on the side of the polyethylene layer (2) is first subjected to a corona discharge treatment. As is well known, a corona discharge is provided with a minute gap between an electrode connected to a high voltage generator and a metal roll covered with resin or rubber, and has a high frequency of several hundred KC / S and several thousand to several tens of thousands. In this method, a high voltage of V is applied to generate a high-pressure corona in the gap, and the above-mentioned laminated sheet of the paper substrate (1) / polyethylene layer (2) is caused to run in the gap.

On the polyethylene layer (2), an under layer (3), a vapor deposition layer (4) and a top coat layer (5) are formed in this order.

As the under layer (3), phenolic resin, urea resin, melamine resin, polyurethane resin, cellulose resin, maleic acid resin, styrene resin
Various resin layers including a maleic acid resin, a styrene-acrylic resin, an acrylic resin, a chlorinated polyolefin resin, and a natural resin are exemplified. Under layer
(3) The coating agent for formation may be water-based or solvent-based. The thickness of the under layer (3) is suitably about 0.5 to 8 μm.

As the vapor deposition layer (4), Al, Sn, In,
Examples include a metal or metal oxide layer such as ITO, Zn, Ag, Al ₂ O ₃ , and SiOx. Of these, Al is particularly important, and when gas barrier properties are required, A
l ₂ O ₃ and SiOx are also important. The thickness of the vapor deposition layer (4) is 1
About 100 to 600 angstroms, preferably 120
５００500 Å, especially 150-450 Å.

The formation of the vapor deposition layer (4) can be carried out by using an ordinary batch type vacuum vapor deposition apparatus, but the sheet is continuously supplied and the degree of vacuum is increased stepwise by a number of roll pairs. It can be carried out by a continuous vacuum vapor deposition apparatus that performs vapor deposition in a state where the degree of vacuum is brought to a predetermined value. Industrially, the continuous vacuum vapor deposition method is more advantageous.

As the top coat layer (5), various resins such as acrylic resin, epoxy resin, phenol resin, urea resin, melamine resin, maleic acid resin, polyurethane resin, and cellulose resin can be used. Examples include layers of thermosetting or thermoplastic resins. It is also possible to form a layer of an ultraviolet curable resin. Top coat layer (5)
It is appropriate that the thickness is about 0.2 to 2 μm or around that.

Corona discharge treatment on polyethylene layer (2) surface, under layer (3) on polyethylene layer (2), vapor deposition layer
The formation of (4) and the top coat layer (5) is preferably performed in-line using a continuous vacuum vapor deposition machine equipped with a corona discharge device and a coating device.

[0027] A vapor-deposited paper is obtained as described above. The obtained vapor-deposited paper can be subjected to curl prevention processing or embossing processing as required. Then, the surface on the top coat layer (5) side of the vapor-deposited paper is usually printed by an appropriate printing method.

The vapor-deposited paper thus obtained can be used as a product as it is for various purposes such as packaging and posters. For example, by using corrugated cardboard as the paper base material (1), the vapor-deposited paper can be used as a corrugated cardboard for preserving freshness.

The vapor-deposited paper which has been subjected to anti-curl processing, embossing, and printing as required is a paper base material of the vapor-deposited paper.
(1) After gluing the side surface, it can be used for laminating or labeling. Here, for laminating, laminating to the liner on the surface side or the inner side constituting cardboard, laminating to various packaging materials, laminating for dolls and folding screens, laminating to record jackets, laminating to advertising posters Lamination and the like can be mentioned, and it is particularly important to laminate on cardboard for freshness preservation packaging. Labels include labels attached to bottles for drinks, seasonings, alcoholic beverages, and the like.

<Action> According to the present invention, a low-density polyethylene having a density of 0.910 to 0.925 is used as a polyethylene layer (2) provided by melt extrusion coating on a paper substrate (1).
0.941 ~ 0.980 by weight ratio with high density polyethylene 2:
Since a layer of a polyethylene composition having a density of 0.930 to 0.965 consisting of a composition of 8 to 8: 2 is used, a polyethylene layer is used.
(2) ensures extrusion coatability, smoothness and water resistance,
It is also preferable in terms of heat resistance, and does not cause troubles such as wrinkling, discoloration, and reduction in gloss during high-temperature processing or high-temperature handling.

[0031]

The present invention will be further described with reference to the following examples. Hereinafter, "%" is% by weight.

EXAMPLES and COMPARATIVE EXAMPLES FIG. 1 is a process diagram schematically showing one example of a method for producing a vapor-deposited paper of the present invention. In the drawing, (pr) is a printing layer, and (ad) is a glue layer.

Paper substrate (1) made of pure white paper having a basis weight of 50 g / m ²
The following polyethylene or polyethylene composition is melt-extruded and coated on one side to form a polyethylene layer having a thickness of 20 μm.
The one provided with (2) was prepared. The melting temperature was set so as to obtain an appropriate melt viscosity.

Low density polyethylene with a density of 0.920. High density polyethylene with a density of 0.956. Density consisting of a composition of 8.3: 1.7 by weight of the above low density polyethylene and the above high density polyethylene.
0.926 polyethylene composition. Density consisting of a composition of 1.1: 8.9 by weight of the above low density polyethylene and the above high density polyethylene
0.952 polyethylene composition. A density of 0.9 consisting of a 5: 5 composition by weight of the low density polyethylene and the high density polyethylene.
38. A polyethylene composition.

The evaluation at the stage of performing the extrusion coating was as follows. Good surface smoothness of extruded coat layer, transparent extruded coat layer. The surface of the extrusion coat layer is poor, and the extrusion coat layer is opaque. Good surface smoothness of extruded coat layer, transparent extruded coat layer. The surface smoothness of the extrusion coat layer is slightly inferior, and the extrusion coat layer is opaque. Good surface smoothness of extruded coat layer, transparent extruded coat layer.

From the above results, the experiment was stopped at this point in cases where the evaluation result was poor and
The following steps were performed for and cases.

That is, or while the paper substrate (1) with the polyethylene layer (2) is supplied to a continuous vacuum evaporator, the polyethylene layer (2) is first subjected to a corona discharge treatment, and then the polyethylene layer (2) is treated. After coating a 20% concentration solution of chlorinated polypropylene resin on the corona discharge treated surface (C), heat-dry to form an underlayer (3) with a thickness of 1.3 μm, and then perform continuous vacuum deposition. Thickness 3
An evaporation layer (4) consisting of an aluminum evaporation layer of 50 angstroms was formed.

Next, a 30% strength solution of a nitrocellulose-polyurethane mixed resin was cast on the surface of the vapor deposition layer (4) of the vapor deposition film from the continuous vacuum vapor deposition machine, and dried to obtain a 1 μm thick top coat layer. (5) was formed.

The above operation was performed in-line as shown in FIG. As a result, the target vapor-deposited paper was produced at once with high productivity.

After controlling the water content as required, printing was performed on the top coat layer (5) of the vapor-deposited paper.

At this time, a heat resistance test was conducted by blowing hot air at a temperature of 140 ° C. from the side of the top coat layer (5).
The evaluation at this time was as follows. Case: Insufficient heat resistance, wrinkles, discoloration and gloss decrease. Case: Insufficient heat resistance, wrinkles, discoloration and gloss decrease. Case: good heat resistance, no wrinkles, discoloration, or decrease in gloss.

In this case, the surface of the vapor-deposited paper opposite to the printing surface was glued, and then punched to form a label, which was then labeled on a bottle for drinks. If necessary, embossing can be performed by passing the whole paper between embossing rolls after printing and before gluing.

Further, a paste was applied to the surface of the vapor-deposited paper opposite to the printing surface to obtain a poster. Further, the surface of the vapor-deposited paper opposite to the printing surface was glued, and then adhered to one side of a cardboard to form a cardboard for freshness preserving packaging.

[0044]

According to the present invention, as described above, according to the present invention, a low-density polyethylene having a density of 0.910 to 0.925 and a low-density polyethylene having a density of 0.910 to 0.925 are used as a polyethylene layer (2) provided by melt extrusion coating on a paper substrate (1). A density of 0.930 consisting of a composition of 2: 8 to 8: 2 by weight with high density polyethylene of 0.941 to 0.980
~ 0.965 polyethylene composition layer,
The polyethylene layer (2) ensures extrusion coatability, smoothness, and water resistance, and is also preferable in terms of heat resistance, and causes problems such as wrinkling, discoloration, and decrease in gloss during high-temperature processing or handling at high temperatures. Does not occur. Therefore, restrictions on various conditions adopted in the manufacturing process and use and use of the obtained vapor-deposited paper are remarkably relaxed.

According to the present invention, a paper base (1) having a polyethylene layer (2) formed by melt extrusion coating is used as a base sheet, and the polyethylene layer is used as the base sheet.
(2) The side surface is preferably subjected to corona discharge treatment,
Since each layer including the vapor deposition layer (4) is provided from above, the restrictions on the type of paper base material (4) to be used are greatly reduced, and the moisture content is easily changed and the surface is essentially smooth. Even if base paper of inferior degree is used, curling or dimensional change does not occur in the process of vapor deposition under heating vacuum and the adhesion of the vapor deposition layer (4) is not impaired, and the target vapor deposition paper can be produced at a low cost. Advantageously, it can be manufactured with high productivity. Vapor deposition by a continuous vacuum vapor deposition machine is also possible.

[Brief description of the drawings]

FIG. 1 is a process diagram schematically showing an example of a method for producing a vapor-deposited paper of the present invention.

[Explanation of symbols]

 (1)… Paper base material, (2)… Polyethylene layer, (3)… Under layer, (4)… Evaporation layer, (5)… Top coat layer, (pr)… Print layer, (ad)… Glue layer

Claims (4)

[Claims] 1. A metallized paper having a layer structure of paper base (1) / polyethylene layer (2) / underlayer (3) / vapor deposition layer (4) / topcoat layer (5), wherein the polyethylene layer (2 ) Is low density polyethylene with density of 0.910 ~ 0.925 and density of 0.941 ~
2: 8 to 8: 8 by weight with high density polyethylene of 0.980
A vapor-deposited paper comprising an extrusion-coated layer of a polyethylene composition having a density of 0.930 to 0.965, comprising the composition of (2). 2. The density of the layer of the polyethylene composition is from 0.936 to 0.936.
The vapor-deposited paper according to claim 1, which has a value of 0.960. 3. An under layer (3), a vapor deposition layer (4) and a top coat layer (5) are formed in this order from a polyethylene layer (2) provided by melt extrusion coating on a paper substrate (1). In producing a vapor-deposited paper, a composition having a weight ratio of a low-density polyethylene having a density of 0.910 to 0.925 to a high-density polyethylene having a density of 0.941 to 0.980 in a ratio of 2: 8 to 8: 2 as the polyethylene layer (2). Consisting of 0.930 ~ 0.96
5. A method for producing a vapor-deposited paper, comprising using the layer of the polyethylene composition according to 5. 4. A polyethylene layer (2) provided on a paper substrate (1)
Surface is corona-discharge treated, and then the corona-discharge treated surface
The method according to claim 3, wherein an under layer (3), a vapor deposition layer (4) and a top coat layer (5) are formed in this order on (C).