JPS6312649A - Film for protecting card - Google Patents

Abstract

PURPOSE:A film for protecting cards, consisting of a blend of a copolymer of ethylene and (meth)acrylic acid with a copolymer of ethylene and a specific monomer having a specific softening point in a specific proportion and having strong hot adhesive force to mounting paper and hardly peeling. CONSTITUTION:A film obtained by blending (A) 10-90pts.wt., preferably 30-70 pts.wt. copolymer of ethylene and (meth)acrylic acid with (B) 90-10pts.wt., preferably 70-30pts.wt. copolymer of <=70 deg.C softening point prepared from ethylene and another copolymerizable monomer, e.g. vinyl acetate, ethyl acrylate, etc., except the (meth)acrylic acid forming the film. The surface of the resultant film is preferably subjected to heat bonding property imparting treatment, e.g. corona discharge or plasma treatment.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a film for protecting cards.

In particular, the present invention relates to a card protective film that has a strong thermal adhesive strength with a mount and does not easily peel off as an ID card protective film.

Conventional technology and its problems In recent years, cards in which a plastic film is adhered to a mount have been widely used to prevent contamination and damage to the mount, especially as ID cards, which are printed and/or handwritten. A mount, or a portion of it with photographic paper pasted on it, is commonly used for driver's licenses and other identification documents. In these cards, a transparent thermoplastic film is layered on the surface of the mount immediately after handwriting, printing, or photo pasting, and the film is thermally bonded between hot rolls, and the plastic film used for this is mainly polyester film. A film laminated with Surlyn A (manufactured by DuPont, ionomer resin) or ethylene ethyl acrylate film was in practical use. However, when such plastic films are thermally bonded at a temperature of 110° C. or lower, the thermal adhesion between the film and the mount, especially photographic paper, is weak and the film easily peels off. For this reason, it could only be used to protect ID cards in response to demands such as prevention of tampering with handwriting and printing, and prevention of replacement of pasted photos.

Therefore, in order to improve the above-mentioned drawbacks, the present inventor previously disclosed in JP-A-55-25327 that unsaturated carboxylic acid or We proposed the use of a film made of a resin obtained by grafting the anhydride, but even with this, there are cases in which satisfactory adhesive strength cannot be obtained, especially in terms of thermal adhesion to ID cards with photographic paper attached. I discovered that.

Means for Solving the Problems The present invention was completed in order to improve the above-mentioned drawbacks, and its main points are as follows.

In a card protection film made of a synthetic resin film, the synthetic resin is a copolymer of ethylene and acrylic acid or methacrylic acid (hereinafter referred to as A resin).
0 parts and 90 to 10 parts of a copolymer of ethylene with a softening point of 70°C or less and other polymerizable monomers other than the above acrylic acid and methacrylic acid (hereinafter referred to as B resin). This is a card protection film that is characterized by:

It is preferable that the surface of the card protection film according to the present invention is subjected to a heat adhesive treatment by a known means,
As a result, -M low-temperature thermal adhesion is improved, and an excellent card protection film can be provided.

As resin A in the present invention, a commercially available copolymer of ethylene and acrylic acid or methacrylic acid can be used. The proportion used is at least 10 parts or more in the middle of all resin components.

90 parts or less, particularly preferably 30 to 70 parts.

As resin B in the present invention, many commercially available copolymers of ethylene with a softening point of 70°C or less and other polymerizable monomers except acrylic acid and methacrylic acid can be used. Particularly preferred are copolymers of ethylene and vinyl acetate, ethylene and alkyl acrylates, especially ethyl acrylate, and the proportion used is 90 to 10 parts, particularly 70 to 3 parts.
0 parts is preferred and the A resin is less than 10 parts.

When resin B exceeds 90 parts, the adhesive force is weak and the desired adhesive strength cannot be obtained, while when resin A exceeds 90 parts and resin B is less than 10 parts, it will not bond unless it is at a high temperature. Heat sealing at high temperatures, for example around 130°C, causes foaming on the surface of the photographic paper, which is undesirable.Furthermore, it is preferable to heat seal at a constant temperature, for example 110°C or lower, but if the softening point of the B resin exceeds 70°C. It has been found that maintaining this temperature is disadvantageous.

In the present invention, the desired mixture is obtained by mixing the above A and B resins in a predetermined ratio, adding known compounding agents as necessary, and blending by ordinary means. The desired film can be obtained by forming the film using a plastic film molding machine such as an extruder. Note that the film in the present invention is not limited to a single film made of the above-mentioned composition, but may be a support film such as polyester coated with the above-mentioned composition with or without an intermediate layer. A desired film can be formed by laminating.

Furthermore, in addition to corona discharge on the surface of the obtained film,
The excellent adhesive strength of the film can be further enhanced by thermal adhesion imparting treatment by known means such as plasma treatment or application of an agent consisting of an organic metal salt such as an alkyl titanate.

Example Hereinafter, the present invention will be described in detail with reference to Examples.

These are examples and do not limit the present invention in any way.

The following table shows the main resins A@ fat and B resin used in the present invention.

Table 1 Example 1 The above A and B resins were blended in the proportions shown in Table 2 below, and using an extrusion laminator with a 65 m extruder,
A polyester film having a thickness of 0.05 mm was extruded and simultaneously laminated at a die temperature in the range of 180 to 200° C. and a winding speed of 30 to 50 m/min to form a film having a thickness of 0.05 mm. This film was subjected to surface treatment by generating a corona discharge in-line using a pillar P-6° OKV type generator with a primary power of 1°3 KV.

The obtained film was coated with photographic paper (Bora Color Film 6
99, Polaroid Company! When heat sealing was performed on the 1K) surface at 110 DEG C. and a peel test was performed after 3 hours, all of the photographic papers were torn, indicating that the adhesive strength of the film was satisfactory.

Example 2 Using the above EAA-XO-2375:33 as the AI resin and the above DQDJ-1868 as the B resin, Example 1
．． A film was obtained in the same manner as above, using photographic paper (BORA COLOR FILM 699) and a Fuji Lami Packer at 95°C and a speed of 1.5C! Heat sealing was carried out at l/min. A peel test was carried out on five of each sample, and the average value of the percentage (%) of the damaged area of the photographic paper surface upon peeling is shown in Table 3 together with a comparative example (sample 6).

Example 3 Example 2 except that DPDJ-6169 was used as the B resin and Fuji Photorama was used as the photographic paper.
Example and comparative example (sample 6) conducted in exactly the same manner as
The test results are shown in Table 4.

Table 4 Example 4 Using resin A and resin B in the composition ratios shown in the table below, Example 1. A film was formed using the same method as above, and the surface treatment of the film was performed. The wet tension of the film is 45-48 dyne/
(It was 2m. This film was used as a Polaroid type 66
The photographic paper photographed using 9ER was heat-sealed at 110° C., and a peel test was performed after 3 hours. The results are shown in Table 5.

Table 5 Example 5 A 5% ethyl acetate solution of Toyo Morton EL364A was added to a 0.1 m thick polyester film as a hardening agent.
4 g of isocyanate resin solution containing L364B
A 30% ammonia solution of Primercol 4990 as resin A and Sumikaflex 7 as resin B were applied to a polyester film that had been anchor coated with a coating amount of lrd.
A film was prepared by coating a composition consisting of 53EVA emulsion (50% solids) to a thickness of 0.03. This film was used in Example 4. in the same way as (
Photographic paper (photographed using Polaroid Type 669ER) was heat-sealed and a peel test was performed after 3 hours.

The results are shown in Table 6.

Effects of the Invention As shown in the above test, it is clear that all the films according to the present invention exhibit excellent adhesive strength, especially when the adhesive strength of resin A is 3.
A film using 0 to 70 parts of resin B and 70 to 30 parts of resin B is excellent, and its adhesion is improved by further thermal adhesion imparting treatment, eliminating the conventional drawback of weak adhesive strength and easy peeling. It is also shown that the mounts of the photographic paper used were damaged. As described above, the present invention can provide a card protection film with excellent adhesive strength.

Claims (1)

[Claims] In a card protection film made of a synthetic resin film, the synthetic resin contains 10 to 90 parts of a copolymer of ethylene and acrylic acid or methacrylic acid and has a softening point of 70°C.
A card protective film characterized by being a mixture of 90 to 10 parts of the following copolymer of ethylene and other polymerizable monomers other than the above acrylic acid and methacrylic acid.