JPS61132983A - Metalized 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 (Industrial Application Field) The present invention provides a metal label that can be easily peeled off in an alkaline solution when cleaning collected glass bottles for reuse. Regarding chemical paper.

Among the bottles generally used for beer, Western liquor, sake, soybean oil, sauce, and other soft drinks, glass bottles in particular are used by the final consumer, then returned to the manufacturer and used over and over again. During the collection and reuse process, the bottles are washed and the labels are removed, but in this process, it is very important for workability that the labels can be easily removed.

(Prior Art) Recently, there has been a demand for more beautiful and sophisticated labels, and labels using aluminum foil have been increasing. However, when aluminum foil is used for labels, it has good cosmetic properties and removability of the label during the bottle washing process, but the cleaning liquid used in the bottle washing process is usually an aqueous solution of caustic soda with a temperature of around 70℃ and a IIk degree of 3 to 5X. The caustic soda reacts with the aluminum foil and generates a large amount of hydrogen gas, which poses problems such as the danger of explosion due to ignition and the negative impact on the working environment. Therefore, metal-deposited paper was used as a label instead of aluminum foil.
In particular, aluminum vapor-deposited paper is attracting attention. Compared to aluminum foil, aluminum vapor-deposited paper for labels uses about 11 times less aluminum, and the amount of hydrogen generated during the bottle washing process is hardly a problem.

(Problem to be solved by the invention) The bottle washing process is usually carried out using caustic soda of about 4% at a liquid temperature of 70 to 8.
Generally, bottles are washed at 0°C for 7 to 8 minutes, then washed with water and dried.

In particular, wash the bottle by removing the label as soon as possible, for example 6.
If it is peeled off and removed within minutes, the work can be carried out in a controlled manner within a predetermined time even if there are some variations due to liquid temperature, concentration, etc.

The washing time depends on the cleaning solution penetrating from the label surface through the vapor deposition layer, resin layer, and base paper to dissolve the adhesive rather than penetrating through the cross section of the label and dissolving the adhesive.

Conventionally, melamine alkyd,
There is a method of applying epoxy resin etc. to the base paper and then applying embossing or openings to improve the penetration of alkaline liquid, and a method of coating with an alkali-soluble resin such as shellac, but none of these methods have a glossy finish. There were problems such as the paper falling down, wrinkles and cracks appearing when immersed in water.

The inventors of the present invention have conducted intensive research on labels that can be peeled off within a predetermined time in an alkaline solution, and in particular have studied the characteristics of resin, and have come up with the present invention.0 (Means for solving the problem) That is, the present invention (1) 90 to 99.5 parts of vinyl acetate, 0 chloro/acid
．． 5 to 10 parts of the copolymer, 70 to 95 parts of rosin, 3 to 15 parts of maleic anhydride, and 2 to 15 parts of pentaerythritol were mixed and dissolved at a solid content ratio of 1:1 to 4:1. Resin, (2) A copolymer of 90 to 99.5 parts of vinyl acetate and 0.5 to 10 parts of crotonic acid and 70 to 95 parts of rosin to improve heat resistance, solvent resistance, and water resistance than the resin in (1). Department,
3 to 15 parts of maleic anhydride, 2 to 15 parts of pentaerythritol
15 parts of reactant and R8, nitrified cotton in a ratio of 5 to 8:4 to 2:3 to
The object of the present invention can be achieved by using resins mixed and dissolved at a ratio of 1:1.

Vinyl acetate in this resin is used as a binder for the base paper.

The croton solution is used to improve the adhesion of the deposited film and to make it easier to dissolve in caustic soda.

Rosin is used as a coatability agent and a brightening agent for resins.

Maleic anhydride is used as a heat resistance improver because it makes it soluble in caustic soda and because the melting point of rosin is low.

Pentaerythritol is used as a heat resistance improver like maleic anhydride because it uses rosin and causes burns during vapor deposition.It also improves the hardness of the resin.

R8 nitrified cotton is used to improve water resistance, heat resistance, and solvent resistance.

One of the required qualities for labels is strong water resistance.For this reason, melamine alkyd resin, epoxy resin, etc. are coated on the base paper and then embossed or perforated. Various methods can be considered, such as improving the penetration of the alkaline solution, but all of these methods reduce the gloss. Alternatively, it has drawbacks such as wrinkles when immersed in water.

The metallized paper for labels referred to in the present invention has an undercoat resin layer on one side of a base paper, an aluminum evaporated layer thereon, and an overcoat resin layer thereon, if necessary. When used as a label, the label is printed in 3 to 6 colors using gravure printing, offset printing, etc., and then punched into a predetermined shape.

In order to peel off the label in an alkaline solution, it is preferable that the undercoat layer and overcoat layer other than aluminum and the printing ink dissolve quickly. Of course, these resins must be insoluble or sparingly soluble in water for their purpose.

To produce the metallized paper for labels according to the present invention, the base paper used is wood-free paper, medium-quality paper, pure white roll paper, coated paper, paper mixed with synthetic fibers or synthetic pulp, or the like.

The undercoat resin layer is applied to a coating thickness of 1 to 25 μm, preferably 3 to 10 μm.

The resin layer of the overcoat is provided as necessary, and is coated to a thickness of 0.1 to 15 μm, preferably 0.5 to 7 μm.

The resin is formulated as a solvent-soluble paint, such as Clavia Coater, Percop%! It is coated and dried using a J Perspective coater or the like.

The aluminum layer is usually vacuum-deposited at a vacuum level of 10-10 torr to a thickness of about 200-800λ.

(Effects of the Invention) When the metallized paper for labels of the present invention is used, it is possible to shorten the bottle washing time compared to the conventional paper.

(Example) Next, the present invention will be explained using examples.

Examples 1 to 3, Comparative Examples 1 to 2 98 parts of vinyl acetate and 2 parts of crotonic acid on 732 single-sided coated paper
A mixture of vinyl acetate copolymer, 92 parts of rosin, 5 parts of maleic anhydride, and 3 parts of pentaerythritol maleic acid resin was mixed and dissolved in a solid content ratio shown in Examples 1 to 3 of Table 1. By 5? /l? After coating and drying to a solid content of 500% by vacuum evaporation,
An aluminum layer with a thickness of λ was provided. Furthermore, the maleic acid resin was coated with a gravure coater to 1.0? /rr? (solid content) to obtain metallized paper for labels. Printing ink containing maleic acid resin and nitrified cotton (1:2 ratio) as a vehicle was applied to the obtained metallized paper at a rate of 1 t/rr? (
Solid content) After peta printing (gravure printing), a punched label was obtained.

The resulting label was attached to a peel bottle with casei/base glue and left for one day, then immersed in a 4 part caustic soda solution at 70°C and moved slowly to measure the washing time until the label peeled off. Labels attached to beer bottles were also immersed in water to check for wrinkles and cracks.

In addition, gloss, heat resistance, solvent resistance, and adhesiveness were separately examined in the form of metallized paper. The results are shown in Table 1. In addition, for comparison, Examples 1 to
The same procedure as in 3 was carried out and the results are shown in Table 1.

Examples 4 to 6, Comparative Examples 3 to 5 98 parts of vinyl acetate and 2 parts of crotonic acid were added to 73 pieces of 100 coated paper.
of vinyl acetate copolymer, 92 parts of rosin, 5 parts of maleic anhydride, 3 parts of pentaerythritol maleic acid resin, and R8 nitrified cotton were mixed and dissolved in the solid content ratio shown in Examples 4 to 6 of Table 1. Coating the resin was carried out in the same manner as in Examples 1 to 3. The results are shown in Table 1. For comparison, the same procedures as in Examples 1 to 3 were carried out using the solid content ratios shown in Comparative Examples 3 to 5 in Table 1, and the results are shown in Table 1. was coated with a gravure coater to a fi 5 t/d (hardness, shape), dried, embossed a lattice pattern with an embossing roll, and then provided with an aluminum layer of υ500A by vacuum evaporation.

The following steps were carried out in the same manner as in Examples 1 to 3. The results are shown in Table 1.

Quality test conditions 1. I heated the washing bottle to 70℃! 1 degree K in 4% caustic soda solution,
A beer bottle with a label attached and left for 24 hours is immersed, the bottle is moved slowly, and the time until the metallized paper peels off is measured.2 Visual evaluation of the metallic luster on the surface of the glossy metallized paper λ Wrinkle Peel Bottle After leaving it for 24 hours, immerse it in water for 24 hours, take it out, visually evaluate it as 4, and the same 5 on the crack.After applying adhesive cellophane (manufactured by Chiban) to the surface of the metallized paper, immediately remove cellophane. Quickly peel off the metallized paper and check the peeling condition of the vapor-deposited metal 6. Leave the heat-resistant metallized paper in a blow dryer for 30 seconds at t-too ℃, then visually evaluate the gold gloss on the surface 7. Solvent-resistant metallized paper The paper surface was coated with methanol; ethyl acetate: toluene = 6:6:5fc, and the metallic luster was visually evaluated.

Claims (2)

[Claims] (1) In a metallized paper for labels made by sequentially laminating a base paper, a resin layer, and an aluminum vapor-deposited layer, the resin layer is made of a copolymer of 90 to 99.5 parts of vinyl acetate, 0.5 to 10 parts of crotonic acid, and rosin. 70-95 parts maleic anhydride 3-15 parts and pentaerythritol 2-15 parts reactants at a solid content ratio of 1
A metallized paper for labels, characterized in that it is a mixture in a ratio of :1 to 4:1. (2) The resin layer according to claim 1 is vinyl acetate 90
~99.5 parts of a copolymer of 0.5 to 10 parts of crotonic acid, a reaction product of 70 to 95 parts of rosin, 3 to 15 parts of maleic anhydride, 2 to 15 parts of pentaerythritol, and 5 to 8 parts of nitrified cotton.
A metallized paper for labels, characterized in that it is a mixture in a ratio of 4 to 2:3 to 1.