JPS60141775A - Backing for thin material to be printed - Google Patents

Abstract

PURPOSE:The titled backing preventing deformation such as curl, expansion and contraction, etc., even if printing on a material to be printed and drying under heating are repeated, by using an ethylene-vinyl acetate copolymer containing vinyl acetate in a specific ratio as a releasable layer coated with an adhesive. CONSTITUTION:One side of base material of plastic film (preferably made of polyester resin, having 20-100mu) having no stretchability is coated with an ethylene-vinyl acetate copolymer (preferably 2-55/10min melt index) containing 40- 90wt% vinyl acetate in a melted state by heating or in a solution in an organic solvent, dried and a coated layer is formed to give the desired backing. EFFECT:Backing application can be carried out at normal temperature, neither melting and bonding operations under heating nor device for them are required. The backing is reusable after releasing, and the adhesive will not remain after releasing.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for printing (including painting) on the surface of a thin printed member and then heating and drying the surface to prevent its expansion and contraction.
In order to prevent deformation such as curling, it is pasted on the back side at room temperature prior to the printing process, and is used as a backing material for thin printed materials that will be peeled off after the printing process is completed. Sekiura sticker.

Conventionally, this type of backing material is made by forming a coating layer of acrylic or rubber adhesive on a plastic film base material with little elasticity. When used by pasting it on the back side, the adhesive tends to protrude from the edge of the printed material, contacting printing equipment and contaminating it, and is also subject to repeated printing and heating drying of printing ink in the multicolor printing process. In this case, it is not possible to sufficiently prevent the printing member from being deformed by stretching, curling, or the like. Furthermore, when the adhesive is peeled off from the printed material after printing, a portion of the adhesive may remain on the back surface of the printed material, resulting in other inconveniences. Instead of such adhesives, it is possible to heat a hot-melt adhesive and apply it to the back side of the printed material, but heating bath melting is cumbersome and requires heating equipment, making it unnecessary. A removable adhesive that is economical, can be bonded at room temperature, and can be peeled off cleanly is desired.

The present invention provides a thin backing material 0a for printed materials that satisfies such requirements and eliminates the above-mentioned drawbacks, and includes a plastic film base material with little elasticity and a removable adhesive applied to the base material. In the thin backing material for printed materials formed by forming a coating layer of It is characterized by

The above ethylene-vinyl acetate copolymer preferably has a melt index (MI) of 2 to 55 r/10 minutes.

Next, examples of the backing material of the present invention will be described.

As the plastic base material with low elasticity, one made of polyester resin is preferable. Usually wall thickness 10~1501
1F+1. Preferably tj: 20 to 100 μm, one side of the base material has a specific vinyl acetate content of 40 to 90 μm.
A coating layer of ethylene-vinyl acetate copolymer having a weight ratio is formed. For its application, it is heated to a molten state or dissolved in an organic bath agent and applied uniformly to the desired thickness.
! Apply a coating film. Its thickness is in the range of 5 to 50 .mu.m, preferably 10 to 30 .mu.m, and its surface has adequate room temperature adhesiveness.

According to the present invention, it is important to specify the content of vinyl acetate in the ethylene-acetic acid-vinyl copolymer within the above range VC, and if either the upper or lower limit is exceeded, the adhesiveness etc. at room temperature will be poor. I found out that it will happen.

Next, an example will be shown in which the backing material of the present invention is used for a thin printed member to be printed in multiple colors.

Example 1 On one side of a long polyester film base material with a wall thickness of 25 μm, 20% of an adhesive resin prepared by dissolving a copolymer (MI25flO) of ethylene-vinyl acetate-10% by weight:90% by weight in an organic solvent was applied. The adhesive is applied to the back side of a long, smooth polyester film with a wall thickness of 25 μm to be printed in multiple colors. After press-bonding at room temperature through the coating layer, complete printing is performed on the surface of the printing target material, and then 7
After repeating heating and drying in the range of 0°C to 120°C and printing in 10 colors, there was no deformation such as partial shrinkage or curling of the printed material at all, and the printing condition was accurate. was gotten. Thereafter, the backing material was removed, but no adhesive remained on the layered surface of the printing member. Also, when the backing material is attached to the printed material,
The adhesive did not leak out at all, and the printing machine was not contaminated by this, allowing the work to be carried out smoothly. The above-mentioned room temperature peel strength was 200F/25m.

Example 2 Example i1. The adhesive for the backing material in /c is ethylene-
Vinyl acetate - 13% by weight: 87% by weight copolymer (MI
The procedure was the same as in Example 1, except that the adhesive resin was used (30 f/10 min).

Example 3 The adhesive for the backing material in Example 1 was replaced with ethylene-vinyl acetate-55% by weight: 45% by weight copolymer (MI2f7
The procedure was the same as in Example 1, except that the adhesive resin was used for 10 minutes). However, the surface of the thin printing member used was an embossed surface.

Example 4 The adhesive for the backing material in Example 1 was a copolymer of ethylene-vinyl acetate = 60% by weight: 40% by weight (MI51M
Example 1 was carried out in the same manner as in Example 1, except that the adhesive resin was changed to a tacky resin (1/10 minutes), except that the surface of the thin printing member was an embossed surface.

Comparative Example 1 The adhesive for the backing material in Example 1 was replaced with an ethylene-vinyl acetate-8wt%:92wt% copolymer (MI24M/
An attempt was made to make a backing material with the same structure except that it was replaced with a tacky resin (10 minutes), and to attach it to the back side of the printed material used in Example IK, but it was not possible to attach it at room temperature.

Comparative Example 2 Example IVc & Copolymer of ethylene-vinyl acetate = 67 wt %: 33 wt % copolymer (M I
30 f / 10 minutes) backing material with the same composition except for changing to adhesive resin? Attempts were made to attach the material to the surface of the printed material used in Example 31C, but the adhesive could not be attached at room temperature.

The above test results are shown in the table below. An example of similar implementation using a conventional rubber adhesive as well as an acrylic adhesive will be shown as a conventional example.

As described above, according to the present invention, an ethylene film containing vinyl acetate with a polymerization ratio of 40 to 90 is used as an adhesive coating layer of a backing material that prevents deformation such as expansion, contraction, curling, etc. of a thin printed member.
Since it is made of vinyl acetate copolymer, it can be backed at room temperature, eliminating the need for heat-melting adhesive work and all equipment, and even printing on printed materials and repeated heat-drying. , it is possible to prevent deformations such as curling and shrinkage, and to obtain a product with precise predetermined printing.Also, since there is no adhesive extrusion, multicolor printing and coating can be smoothly performed without contaminating the machine. When the printing member is peeled off, the adhesive does not remain on the back side of the printing member, resulting in a good product, and the printing member can be reused after being peeled off.

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Claims (1)

[Claims] 1. A thin backing material 0a for a printed member consisting of a plastic film base material with little elasticity and a coating layer of a releasable adhesive on the base material, and the releasable adhesive is 4
Thin backing material for printed materials characterized by being an ethylene-vinyl acetate copolymer containing 0 to 90% vinyl acetate by weight