JPS5962681A - Sealing of container containing printing ink - Google Patents

Abstract

PURPOSE:To carry out the sealing of the titled container rapidly in high workability and functional efficiency, and to prevent the skin formation on the ink, by charging the printing ink in a container, applying a two-pack type reactive resin to the surface of the ink, and forming a film as an intermediate cover. CONSTITUTION:A printing ink is charged in a container, preferably an organic solvent is applied to the surface of the ink, and a two-pack type reactive resin (preferably a urethane resin composed of polypropylene glycol and an aromatic amine, etc.) is applied to the solvent surface. The container is inclined against the horizontal plane (e.g. by 5-10 deg.) and revolved one or more times to improve the uniformity of the covering film. a covering film acting as an intermediate cover can be formed by this process to effect the objective sealing. A tag to release the formed intermediate cover may be applied before or after the application of the film-forming resin to the surface of the printing ink. EFFECT:The sealing process can be automated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sealing method with excellent workability and functionality for preventing skin formation in containers filled with printing ink.

During storage, the exposed surface of printing inks such as twin ink and letterpress ink becomes hard and changes in quality due to contact with air, causing so-called skinning. Conventionally, in order to prevent printing ink from forming a skin, parchment paper, plastic film, or the like was pasted on the surface of the printing ink inside the container as an inner lid. This process of attaching the inner lid is done by hand, and requires skill to completely expel the loose air and attach the inner cover to the printing ink surface. It became.

Furthermore, the printing ink itself is heated to around 40-50 degrees Celsius, and after applying the inner lid, it returns to room temperature, but part of the inner lid peels off and cannot be completely sealed. It is also said that it lives.

Therefore, as a method for preventing printing ink from forming a skin, manual methods and mechanical methods with good workability are also being considered. For example, as seen in Japanese Patent Publication No. 53-24842, a urethane film is formed by applying a prepolymer having an isocyanate group to the entire printing ink surface and then spraying water or steam. This method is used in place of a lid. This method can be said to be superior in workability compared to the conventional method using an inner lid, but depending on the type of prepolymer, there may be problems with the storage stability of the prepolymer itself; However, there is a problem in that it takes too much time to form a film due to reaction with water or steam, and workability cannot necessarily be said to be good. The presence of water may be a problem depending on the type of printing ink used.

The present invention provides a method of sealing a printing ink filling container IC with excellent workability and functionality. This is a sealing method that can be mechanized, can quickly form a film as an inner lid, and can also provide a complete seal.

That is, this is a method of sealing a container filled with printing ink, in which after filling the container with printing ink, a two-component reactive resin is applied to the surface of the printing ink to form a film as an inner lid.

The film-forming resin according to the present invention is selected from two-liquid reaction resins. In the present invention, the film-forming resin is usually applied as a solvent-free type to the printing ink surface. This is because many solvents for film-forming resins are generally undesirable for printing inks. Examples of the two-component reactive resin include urethane resin, epoxy resin, and polyester resin. A two-component reaction type resin is used, which is easy to break, forms a film quickly, and has a low viscosity before the two-component reaction. By using a material that forms a film quickly, the subsequent work of installing the outer lid and transporting work can be done quickly.

For example, urethane resins include resins using polynoglobylene glycol or adipate-based polyester not toluene diincyanate prepolymers and aromatic amines, or isophorone diisonanate, hydrogenated diphenylmethane diisocyanate, hexamethylene diisocyanate, etc. Examples include resins using an aliphatic diisocyanate compound and a prepolymer of a polyester or polyether type polyol compound and an aliphatic amine.

In the case of a two-part reactive resin, the two parts are mixed before use and applied to the printing ink surface in a container using a nozzle means, a spray means, or the like. There are no particular restrictions on the means for applying the film-forming resin, but any means that can apply the film-forming resin substantially uniformly over almost the entire surface of the printing ink in the container is clever.
By applying it uniformly, it is easy to obtain a uniform film for the inner lid.

Additives such as catalysts for accelerating the reaction can also be added to the two-component reactive resin, if necessary.

The amount of two-component reactive resin applied to the printing ink surface is such that a film can be formed on the entire surface of the printing ink surface and there are no pinholes.
It is desirable that the amount of peeling is as small as possible. Normally, the average thickness of the film formed is 0.1
Apply so that the distance is about 2 m.

In the present invention, before applying the two-component reactive resin to the printing ink surface in a container, an organic bath agent contained in the printing ink or an organic solvent of the same type as the solvent is applied to the printing ink surface in advance. By keeping it in place, the inner lid on which the film has been formed can be easily peeled off, and it is also useful for forming a uniform film (leveling) of the two-component reactive resin.

It is also possible to provide a tongue piece for peeling off the film-formed inner lid. This tongue is usually made of plastic or resin, and is provided either before or after applying the two-part reactive resin. There is no particular shape of the tongue, but it may be one that can at least peel off the membrane-formed medial lid.
A portion of the tongue piece is buried in the two-component reactive resin and is in a state of appropriate size, or it is adhered to such an extent that the inner lid can be peeled off.

Two-component reactive resin applied to the printing ink surface requires leveling to create a uniform film.
As a leveling method, a container with a two-component reactive resin applied to the printing ink surface is tilted (for example, 5 to 10
A preferable method is to rotate it at least once while holding it in place (approximately 100 degrees). This method can be carried out by placing the container on a rotary table having a mounting table inclined with respect to the horizontal plane and rotating it, or by gripping the container with a machine, tilting it, and rotating it.

A two-component reaction type resin is preferred as the film-forming resin according to the present invention, but it is also possible to apply a thermoplastic resin such as polyethylene, polypropylene, polybutene, nylon, etc. in a molten state to the printing ink surface. For example, a method is to use a molding machine to mix thermoplastic resin, mold it into a shape that fits the inner lid, and apply it to the printing ink surface in a semi-molten state.

Next, the present invention will be explained with reference to Examples.

Example 1 Printing ink (Toyo Ink Mfg. Co., Ltd. Offset Ink TKU70G Eye) was filled into a 1 kg Hitomaru can using a filling machine, approximately 2 g of spindle oil was applied to the entire surface of the printing ink using an air spray method, and then thickness 2
mm, r1] A polyethylene tongue piece with a length of 40 mm and 10 holes was placed so that it was partially hooked on the can wall and partially resting on the printing ink surface. Brepolymer 352 having urea bonds obtained by reacting at a quantitative ratio of 3:1
．． 8 parts by weight, 267.8 parts by weight of PTGloo (a polyhydroxy compound manufactured by Nippon Polyurethane Industries Co., Ltd.), and 60.3 parts by weight of trimethylolpropane. Approximately 10 grams was applied evenly. Next, the round can was placed on a mounting table tilted 5 degrees from the horizontal plane of a rotary table that can be rotated with a center line tilted 5 degrees from the vertical line, and rotated twice at a speed of 300 rotations per minute. I let it happen.

Put the outer lid on and seal it.

A very uniform film with an average thickness of l Tnn is formed.
t. Approximately 24 hours later, by pulling the polyethylene tongue, the film serving as the inner lid was peeled off, and no skin was observed on the surface of the printing ink.

No skinning of the printing ink was observed even after one month of being shattered.

patent applicant Toyo Ink Manufacturing Co., Ltd.

Claims (1)

[Claims] 1. After filling a container with printing ink, on the printing ink surface,
A method for sealing a container filled with printing ink, characterized by applying a two-component reactive resin and forming a film as an inner lid. 2. A method for sealing a printing ink-filled container according to claim 1, wherein an organic solvent contained in the printing ink is applied to the printing ink surface, and then a two-component reactive resin is applied to the printing ink surface. 3. The printing ink surface The method for sealing a printing ink filling container according to claim 1 or 2, wherein a tongue piece is provided for peeling off the inner lid on which the film has been formed before and after the film-forming resin is applied to the container. 4. Printing. 4. A printing ink filling container sealing method according to any one of claims 1 to 3, wherein the container whose ink surface is coated with a two-component reactive resin is rotated one or more times in an inclined state with respect to a horizontal plane. 5. The method for sealing a printing ink filling container according to claim 1, wherein the 52-liquid reaction type resin is a urethane resin.