JPH0418426A - Readily bondable film having excellent blocking resistance - Google Patents

Abstract

PURPOSE:To obtain the title film useful as an anchor coating agent having excellent printability and adhesiveness by forming a coating film containing a specific compound on the surface of a thermoplastic film. CONSTITUTION:The objective film obtained by forming a coating film (preferably 0.01-1.0g/m<2> coating build-up) prepared by blending 100 pts.wt. polyethyleneimine with 10-50 pts.wt., preferably 15-20 pts.wt. epoxy compound [e.g. compound shown by the formula (m is 1-3)] and crosslinking on at least one side of a thermoplastic film.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a thermoplastic resin film that has easy adhesion and excellent blocking resistance, and particularly relates to a thermoplastic resin film that is coated with a specific compound on a thermoplastic resin film. This invention relates to an easily adhesive resin film formed by forming a film to improve blocking resistance.

[Prior Art] As a means for improving the printability of synthetic paper, a method is known in which polyethyleneimine or ethyleneimine urea polymer is formed as an anchor coat layer on a thermoplastic resin film such as a polyolefin film.

[Problem to be solved by the invention] However, the above-mentioned polyethyleneimines used as "anchor coating agents" have poor water resistance because they are water-soluble polymers. When stored for a long period of time under high humidity, there is a problem that moisture in the air is absorbed, causing the surface of the coating film to become flattened and cause blocking.

The present invention has been made in view of these problems with the prior art, and its purpose is to provide a thermoplastic 8J resin film that is easy to adhere to and has excellent anti-blocking properties. .

[Means for Solving the Problems] The structure of the film of the present invention that can solve the above problems is such that 10 to 5 parts by weight of an epoxy compound is added to 100 parts by weight of polyethyleneimine on at least one side of the thermoplastic resin film.
The gist is that a coating film is formed by adding 0 parts by weight and crosslinking.

[Function] The present invention is formed by forming a crosslinked coating film on a thermoplastic resin film by adding a specific amount of epoxy compound to polyethyleneimine. To provide an easily adhesive film with excellent blocking resistance even after long-term storage in a high-temperature atmosphere.

As the thermoplastic resin film used in the present invention, general-purpose synthetic resin films such as polyolefin, polyamide, polyester, polyvinyl chloride, and polyvinylidene chloride can be used, but among these, the most common is polyolefin film, especially polyvinylidene. It is an axially stretched polypropylene film.

The polypropylene film can be subjected to a surface treatment such as corona discharge prior to applying the above-mentioned coating liquid to the surface to improve the adhesion of the coating film.

The polyethyleneimine [component A] used in the present invention is:
It is produced by homopolymerizing ethyleneimine using a conventional method, and is highly reactive and easily reacts with acids, isocyanates, epoxy compounds, etc., and is compatible with water and lower alcohols (isopropyl alcohol, methanol,
ethanol, etc.).

In addition, the type of epoxy compound [component B] used for the purpose of crosslinking and curing polyethyleneimine is not particularly limited as long as it has an epoxy group in the molecule, but it is preferable that the epoxy compound has two epoxy groups in the molecule. It is a water-soluble or water-dispersible epoxy compound having the above epoxy group, and the following epoxy compounds are exemplified as representative examples.

(m=1 to 3) Or additional wire hardware of bisphenol A and epichlorohydrin such as H3.

To achieve the object of the present invention, the above epoxy compound is
The content should be 10 to 50 parts by weight, preferably 15 to 20 parts by weight, based on 100 parts by weight of the total solid content of polyethyleneimine in the coating solution. If the proportion of the epoxy compound exceeds 50 parts by weight, the easy adhesion performance of the coating film will be poor, while if it is less than 10 parts by weight, it will not be possible to improve the blocking resistance under high temperature conditions, which is the main objective of the present invention. Can not. The coating agent used in the present invention contains the above-mentioned components [A] and [B] as essential components, but if necessary, a lubricant that acts as an auxiliary agent for preventing blocking of the coating film [component C] may be added as an additional component. The anti-blocking effect can be further enhanced by adding about 0.1 to 0.5% by weight based on the solid weight of the coating liquid. However, if too much lubricant is added, the scratch resistance of the coating film will deteriorate, so the amount should be limited to about 0.5% by weight or less. There are organic and inorganic lubricants used as anti-blocking aids, but organic lubricants may deteriorate the adhesion between the base resin film and the paint film. Preferred are inorganic lubricants, particularly preferred are those obtained by dispersing silica having an average particle size of 10 to 50 μm in water, and more preferred is a colloidal solution of silica. Further, the coating solution may further contain a small amount of a crosslinking reactivity promoter to promote the crosslinking reaction between the polyethyleneimine and the epoxy compound during drying.

In the present invention, a solution containing the above-mentioned components [A] and [B] and optionally component [B] is applied onto a thermoplastic resin film. Although the coating liquid can be used as an organic solvent solution, it is usually used as an aqueous solution or an aqueous emulsion. The concentration of the solution is not particularly limited, but considering the preparation of the coating liquid and the workability of coating, the solid content concentration is set to 0.1.
The amount is preferably adjusted to about 0.5%, and the coating amount is preferably adjusted to about 0.01 to 1.0 g/m2 as a dry coating. As the coating method, any known method can be employed, such as gravure coating, reverse coating, air doctor coating, and spray coating.

When dried after application, the epoxy compound causes a crosslinking reaction between the molecules of polyethyleneimine, providing moisture resistance while maintaining excellent adhesion, resulting in a coating film with excellent blocking resistance. In addition, use moderate heat (50~120℃) during the drying process.
It is preferable to add a temperature of about 10.degree. C.) because it not only accelerates the crosslinking reaction but also shortens the drying time.

The surface film-forming film obtained in this way maintains the excellent adhesion properties of polyethyleneimine, while suppressing the hygroscopicity, which was considered a drawback of polyethyleneimine = i, by crosslinking the epoxy compound, and also has excellent blocking resistance. It will be extremely excellent.

Next, examples of the present invention will be shown. The performance test method adopted in the following examples is as follows.

150m+nx 200mm of thermoplastic resin film with high temperature and high temperature blocking resistant (BL resistant) coating film formed
66.7g/
After applying a load of cm' and leaving it in an atmosphere of 50° C. and 90% RH for 24 hours, the degree of blocking was measured according to the ASTM method.

Color the coating surface of the thermoplastic resin film on which the easily adhesive coating has been formed with an oil-based felt-tip pen, and make 11 straight cuts (1 mI, 11 intervals) on each coating film in the orthogonal direction using a safety razor to reach the film base. to form 100 base pieces. Next, an adhesive tape is strongly pressed onto this base layer, and after the tape is rolled 71", the peeling state of the ink on the base layer is observed, and easy adhesion is evaluated based on the following criteria. The test conditions were 23° C. and 65% RH.

O: Ink transfer rate 0-5% △○: Ink transfer rate -5-2 5%: Ink transfer rate 25-50% △: Ink transfer rate 50-75% ×: Ink transfer rate 75-100% [Example ] Experimental Example 1 Evomin P100OJ manufactured by Nippon Shokubai Kagaku Co., Ltd. was used as the polyethyleneimine, rCR-2LJ manufactured by Dainippon Ink Co., Ltd. was used as the epoxy compound, and Snowtex OLJ manufactured by Nissan Chemical Co., Ltd. was used as the lubricant. An aqueous solution having a solid content concentration of 0.2% by weight was prepared at the ratio shown in the table.

Katana surface * Weight % based on the total coating amount Each of the obtained coating solutions was applied onto a biaxially stretched polypropylene film by gravure coating, and then coated at 100°C for 1
A coating film having a coating weight of 0.045 g/m2 (solid content) was obtained by heat treatment for 5 to 60 seconds.

The blocking resistance and easy adhesion of each obtained coating film are as shown in Table 2, and No. 1.3 and 4.7, which meet the specified requirements of the present invention, have both easy adhesion and blocking resistance. Good, but epoxy compound [component B
] In No. 2, in which the amount is insufficient, the blocking resistance is not sufficiently improved, and in No. 095, in which the epoxy compound [component B] exceeds the specified range, the easy adhesion is poor. Also, No. 6, which did not contain any epoxy compounds.
Although the adhesion property is good, the blocking resistance is extremely poor.

Experimental Example 2 A comparative coating film was obtained in the same manner as in Experimental Example 1, except that a melamine resin (manufactured by Dainippon Ink Co., Ltd. [Hetsukamine PM-NJ]) was used in place of the epoxy compound in Experimental Example 1, and anti-blocking was obtained in the same manner. The properties and adhesion were investigated.

The results are shown in Table 3, and it can be seen that melamine resin has almost no effect on improving blocking resistance.

[Effect of the invention] 1441”. The present invention is configured as described above, thermoplastic Heisei 2 years July 5th day On the resin film surface, to a specific amount of epoxy compound

Claims (1)

[Claims] On at least one side of the thermoplastic resin film, 10 to 50 parts of an epoxy compound is added to 100 parts by weight of polyethyleneimine.
An easy-to-adhesive film with excellent blocking resistance characterized by a coating film formed by crosslinking with the addition of a weight part.