JPS59152483A - Metal evaporated paper for label - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to metallized paper for labels used for liquor bottles, beer bottles, etc. Among bottles generally used for beer, Western liquor, sake, soy sauce, sauce, cider, and other soft drinks, etc. In many cases, glass products are collected by the manufacturer after being used by the final consumer and then used again. In this case, if a label is attached to the bottle, the bottle is washed and the label is removed.

The base materials used as labels include paper such as high-quality paper and coated paper, or printed on plastic film such as polypropylene or cellophane, and the above-mentioned paper or plastic film laminated with aluminum foil, or paper or Plastic films coated with metal vapor deposited or even resin overcoat layers are used.

However, in the bottle washing process that is carried out after the bottles are collected, it is necessary that the labels are dissolved and peeled off in a short period of time while the bottles are washed.

Normally, a bottle washing machine removes and cleans dirt and foreign matter adhering to bottles through 5 to 10 cleaning liquid tanks.
It is used after being heated to ℃.

Compared to labels made of only paper or paper laminated with aluminum foil, the most effective means in terms of time is for the cleaning liquid to penetrate perpendicularly to the label surface and reach the adhesive layer of the label. However, it is difficult for the cleaning solution to penetrate into substrates such as overcoated paper with resin paint, plastic film, metal foil laminated film, metallized film, and metallized paper. It took a long time to prepare and could not be used for this type of label.Also, in the case of aluminum foil-laminated paper, the aluminum foil is dissolved by the cleaning solution, but since the aluminum foil has a thickness of 6 to 10 mm, it cannot be used for this type of label. Metal-metalized paper, which is made by vacuum-depositing aluminum or other materials onto the paper, has come to be used because it generates a large amount of hydrogen gas, which poses a risk of explosion and worsens the working environment, and also because it has poor workability during printing. However, since the surface gloss of aluminum vapor-deposited paper is inferior to that of aluminum foil-laminated paper, it is common to form an undercoat layer before vapor deposition.However, the resin used for the undercoat layer is Many liquid-reactive thermosetting or thermoplastic resins do not dissolve easily in alkaline liquids, and conventionally these resins have generally been solvent-soluble resins, which have problems such as air pollution caused by solvents and the resins themselves being expensive. There's a problem.

In order to avoid these problems, attempts have been made to use aqueous resin dispersions. The present inventors also have patents (Application No. 57, 8, 9, etc.) As a result of intensive study by the present inventors to further shorten the bottle washing time for label paper using such an aqueous resin dispersion, the present inventors have found that:
We have arrived at the present invention.

In the present invention, the undercoat layer of metal-metalized paper contains a pigment in which the surface of alkaline earth metal powder is modified to be hydrophilic, so that alkaline solution for bottle washing can easily penetrate through the alkaline earth metal of the undercoat layer. The present invention relates to a metal-deposited paper for labels, which has excellent suitability for bottle washing and has a good metallic luster on the surface.

The present invention will be specifically explained below.

The alkaline earth metal powder of the pigment used in the undercoat layer of the present invention is preferably a fine metal powder such as aluminum zinc, lead, iron, etc., and the surface thereof is coated with a surfactant in order to impart hydrophilicity to it. The amount of the pigment added is preferably 3 to 50% by weight based on the undercoat layer resin.

Furthermore, as the synthetic resin, aqueous polymers having carboxyl groups are mainly used, but aqueous dispersions of other synthetic resins can also be used. Examples of the metal for forming the metal vapor deposition layer include aluminum and zinc. Cellulose derivatives, such as nitrocellulose lacquers, are used as overcoat resins. Nustyrene maleic acid resins are also used. Since jj and j47, which are generally used in the overcoat layer, are relatively easily soluble in an alkaline solution, the label can be easily peeled off if the undercoat layer has good permeability to the alkali solution.

That is, in the present invention, since the undercoat layer uses a paint in which a pigment obtained by modifying the surface of alkaline earth metal powder to be hydrophilic is dispersed in an aqueous solution of a water-soluble synthetic resin or an aqueous dispersion of a synthetic resin. The pigment is easily and uniformly dispersed, and there is no problem with unevenness or deterioration of the gloss after vapor deposition (on the contrary, the gloss increases).And in the bottle washing process, the alkaline liquid erodes and dissolves the gradient, causing the surrounding It penetrates the undercoat layer while attacking the resin and is deposited on the base material.On the other hand, if you try to disperse alkaline earth metal powder that has not been surface-treated into an aqueous dispersion or solution of a synthetic resin, it will not be possible to disperse it uniformly. If the amount of metal powder is increased to improve the bottle washing effect, the dispersibility will become worse, and the gloss on the deposited surface will become uneven, reducing the overall gloss, so water-based undercoat paints are not treated. metal powder is difficult to use.

(Publication of Patent Publication No. 56-9776) Furthermore, when the underfoot layer of the metal-deposited paper of the present invention contains a polyvalent metal complex or a polyvalent metal chelate compound, the metallic luster is further improved, the water resistance is excellent, and the underfoot layer of the metallized paper of the present invention is improved. Metal-deposited paper is obtained which is resistant to solvents in the coating layer and the printing ink layer and has good bottle washing suitability.

Suitable polyvalent metal ions include zinc, aluminum, titanium, zirconium, barium, calcium, magnesium, strontium, lead, cobalt, copper, bismuth,
There are antimony, iron, and nickel ions, especially zinc ions.

Preferred polyvalent metal chelate compounds or polyvalent metal complexes include zinc carbonate ammonia, glycine zinc ammonia, malate zinc ammonia, hydroxyacetate zinc ammonia, and ethylenediaminetetraacetic acid disodium zinc chelate.

The polyvalent metal complex or polyvalent metal chelate compound is an aqueous polymer dispersion or an alkaline water-soluble polymer with a solid content of 100%.
It is desirable to use 0.1 to 20 parts by weight, preferably 0.2 to 15 parts by weight, of the metal. If the amount added is less than 0.1 part by weight, the expected effect will not be obtained, and 2
If it exceeds 0 parts by weight, polymer coagulation will precipitate, which is not preferable.

By having the above-described structure, the metallized paper for labels of the present invention can significantly shorten the label peeling time during cleaning when collecting and reusing bottles, and furthermore, the metallized paper for labels has excellent water and solvent resistance. It has been found that paper can be produced in a well-produced manner (and obtained without causing environmental pollution).

The present invention will be further explained with reference to Examples below, but the present invention is not limited to these Examples. In the Examples, "parts" indicate parts by weight.

Example Using 64φ single-sided coated paper as the base material, pigment and zinc ammonia carbonate were coated on the surface of aluminum in an aqueous dispersion of acrylic synthetic resin so that the coating amount was 5 tYrrt (solid content) on the 2nd and 2nd sides of the core. After coating and drying a material dispersed in the ratio shown in Table 1 to form an undercoat layer, vacuum vapor deposition of aluminum/nium is performed to form a metal vapor deposited layer with a film thickness of 40 to 5 Qgg, and then 1 coat of nitrocellulose lacquer on
It was coated with φ and dried to form an overcoat layer. In the bottle washing test, the overcoat layer was floated on the surface of a 4% concentration caustic soda solution at 80° C., and the time until the alkaline solution reached the back surface was measured. The vapor deposition surface and overcoat surface were evaluated visually and ranked in the order of ◎→○→△→×.

Table 1 shows the results.

Comparative Example Gold N3 vapor-deposited paper was manufactured in the same manner as in the example except that the weight ratio of the acrylic synthetic resin aqueous dispersion and aluminum powder in the undercoat layer was changed as shown in Table 2, and various tests were conducted. was conducted and used as a comparative example.

Examples (Table 1) Comparative Examples (Table 2) The penetration time of the additives is short, and the vapor deposition surface and overcoat surface are equivalent to or better than those without the additives.

Comparative samples Nα2 and N with aluminum powder added
With α3, the penetration time is very short (although it is much worse on the vapor-deposited surface and the overcoated surface than when it is not added).

In addition, example sample Nα5 with zinc carbonate and ammonia added
Although the penetration time was slightly slower, the overcoated surface was very good.

From the above, the effects of the present invention are clear.

Claims (2)

[Claims] (1) In metallized paper for labels, in which an undercoat layer, a metallized layer, and an overcoat layer are sequentially provided on a base material, the underfoot layer is obtained from an aqueous dispersion or solution of a synthetic resin. Metal-deposited paper for labels, which is a synthetic resin layer containing a pigment in which the surface of alkaline earth metal powder is modified to be hydrophilic in the undercoat layer. (2) The metal-deposited paper for labels according to claim 1, wherein the undercoat layer contains a polyvalent metal complex or a polyvalent metal chelate compound.