JPH0751641B2 - Method for producing scratch-resistant composite film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a method for producing a scratch-resistant composite film.

[Conventional technology]

In recent years, synthetic resin films have been widely used as a base material for decorative materials such as interior materials and light-shielding films for automobile window glass.

Conventionally, as a decorative material based on a synthetic resin film,
The one in which an adhesive layer was provided on the back surface after simply printing on a synthetic resin film and the one in which an adhesive layer containing a colorant was provided on the back surface of a transparent synthetic resin film were used.
Since the synthetic resin film is easily scratched, the decorative material having only the adhesive layer on the back surface of the synthetic resin film has a drawback that the beautiful appearance cannot be maintained for a long time. Therefore, instead of a mere synthetic resin film, a composite film in which a surface protective layer made of a thermoplastic resin is provided on the surface of the synthetic resin film has been used as a base material used for applications such as cosmetics.

[Problems to be solved by the invention]

However, the surface hardness of conventional composite films provided with a surface protective layer made of a thermoplastic resin is not always sufficient, and it is not possible to reliably prevent the synthetic resin film from being scratched. When it is used as a base material, the surface protection layer softens due to the temperature rise in the automobile compartment, especially in summer, and it is easily damaged.

The present invention has been made in view of the above points, and a scratch-resistant composite film having a surface protective layer having excellent surface hardness and heat resistance, which can be used as a base material for interior materials, light-shielding films, or other decorative materials, and It is an object to provide a manufacturing method thereof.

[Means for solving problems]

As a result of earnest research to explain the above problems, the present inventors have found that
When a synthetic resin film substrate is coated with an ionizing radiation-curable resin and cured, the substrate is wrapped around the surface of the heat roll at least partially, and the ionizing radiation is applied while heating the coated layer to a temperature of 30 ° C to 100 ° C. By irradiating and curing the coating layer to form a surface protective layer, distortion due to curing shrinkage of the ionizing radiation curable resin is prevented, and an excellent scratch-resistant composite film having a surface protective layer with excellent adhesion is obtained. As a result, they have completed the present invention.

The gist of the present invention is to form an ionizing radiation-curable resin coating layer on one side or both sides of a synthetic resin film substrate, and then wind the substrate at least partially around the surface of a heat roll and the temperature of 30 to 100 ° C. with the coating layer. The method for producing a scratch-resistant composite film is characterized in that the surface protective layer is formed by irradiating with ionizing radiation while heating to harden the ionizing radiation curable resin.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the composite film 1 of the present invention comprises a synthetic resin film substrate 2 and a surface protective layer 3 provided on one surface of the substrate 2 and made of a three-dimensional crosslinked cured film.

As the film substrate 2, polyester film, polyethylene film, polypropylene film, polyvinyl chloride film, polyvinylidene chloride film, polycarbonate film, nylon film, polystyrene film, ethylene-vinyl acetate copolymer film, etc. are used. A film, a polycarbonate film and a polyvinyl chloride film are preferable.

The surface protective layer 3 is formed by curing an ionizing radiation curable resin. The ionizing radiation used for curing is emitted from various electron beam accelerators such as Cockloft-Walton type, Van de Graaff type, resonant transformer type, insulating core transformer type, linear type, dynamitron type, high frequency type, etc., and 50 to 1000 KeV Electron beam having energy of preferably 100 to 300 KeV, ultra high pressure mercury lamp, high pressure mercury lamp, low pressure mercury lamp, carbon arc,
Examples include ultraviolet rays emitted from a light source such as a xenon arc or a metal halide lamp. As the ionizing radiation curable resin that is cured by these electron beams and ultraviolet rays, unsaturated polyester, polyether acrylate, epoxy acrylate, urethane acrylate, spiro acetal acrylate, polybutadiene resin, polythiol polyene resin, etc. can be used. Trifunctional monomers such as trimethylolpropane triacrylate and pentaerythritol triacrylate for improving curing; Bifunctional such as neopentyl glycol diacrylate, tripropylene glycol diacrylate, diethylene glycol diacrylate, and 1,6-hexanediol diacrylate Monomer; other polyfunctional monomers such as dipentaerythritol hexaacrylate can be mixed and used. When ultraviolet rays are used as ionizing radiation, acetophenones, benzophenone, Michler's ketone, benzoin, benzylmethyl ketal, benzoylbenzoate, α-amyloxime ester, tetramethylthiuram monosulfide, thioxanthones, and photosensitizers are used as photopolymerization initiators. For example, n-butylamine, triethylamine, tri-n-butylphosphine, etc. can be mixed and used.

Although the case where the surface protective layer 3 is provided on one surface of the base material 2 has been described in the above embodiment, the surface protective layer 3 may be provided on both surfaces of the base material 2.

Next, a method for producing the scratch-resistant composite film of the present invention will be described.

First, one side or both sides of the synthetic resin film base material 2 is coated with an ionizing radiation curable resin. However, if the coating thickness is too thin, sufficient scratch resistance cannot be obtained, and if it is too thick, the curing speed decreases and during curing. Since the base material 2 is likely to be distorted such as curl,
It is preferable to apply it to a thickness of 50 μ, particularly 1.5 to 10 μ. As the coating method, a blade coating method, a gravure coating method, a rod coating method, a knife coating method, a reverse roll coating method, a kiss coating method, a spray coating method, an offset gravure coating method, etc. are adopted, but the accuracy of the coating thickness,
The gravure coating method, the reverse roll coating method, and the offset gravure coating method, which are excellent in the smoothness of the coated surface, are preferable.

Next, the ionizing radiation-curable resin applied to the substrate 2 is irradiated with ionizing radiation to cure the ionizing radiation-curable resin. In the present invention, the substrate 2 is heated with the ionizing radiation-curable resin coating layer while the ionizing radiation is cured. It is necessary to irradiate and cure the resin, and heating with ionizing radiation prevents the occurrence of distortion due to curing shrinkage, and a surface made of a three-dimensional cross-linked cured film formed by curing the ionizing radiation curable resin. The protective layer 3 has excellent adhesion to the base material 2. If the heating temperature is too low, the surface protective layer 3
If the adhesion is low and if it is too high, the base material 2 tends to shrink and wrinkle easily when a thin film having a low softening point is used as the base material 2. Therefore, in the present invention, heating is performed at a temperature of 30 to 100 ° C, and particularly 40 to 80 ° C is preferable. In the method of the present invention, in order to prevent the base material 2 from shrinking, as a heating method, the base material 2 on which the ionizing radiation-curable resin coating layer is formed is partially or substantially completely wound around the surface of the heat roll and heated. adopt.

In the present invention, the base material 2 may be cut into a desired size, but the long base material 2 is used while being wound in a roll shape, and the base material 2 wound in a roll shape is rolled out. While continuously applying the ionizing radiation curable resin on the base material 2 and then curing the ionizing radiation curable resin while heating, a long scratch-resistant composite film is continuously wound. It is preferable.

Hereinafter, the present invention will be described in more detail with reference to specific examples.

Example 1 A 50 μ thick polyester film (Toray mirror T-60) was used as a film substrate, and a polyester acrylate-based UV-curable resin coating (manufactured by Dainichi Seika:
SEIKA BEAM PHC) was applied by the gravure coating method. Three types of coating thickness were prepared: 1μ, 2μ, and 10μ. Next, each film substrate coated with the ultraviolet curable resin coating material was wound up to about half the circumference of the roll surface rotating at a surface speed of 5 m / min, and while being heated by the roll, ultraviolet rays were applied to cure the ultraviolet curable resin. The ultraviolet irradiation was performed using two 160 W / cm output ultraviolet lamps provided 12.5 cm above the roll. The heating by rolls was performed at roll surface temperatures of 30 ℃, 50 ℃, and 100 ℃ for different thicknesses of UV-curable resin coatings.

The scratch resistance of each composite film obtained as described above,
The adhesion test of the surface protective layer was carried out under the following conditions.
Compared with those of μ and 10μ, there is a tendency to be more easily scratched.
Although it was observed that the adhesion of the surface protective layer was slightly lower than that of the one heated at ℃, both had sufficient scratch resistance,
It was excellent in the adhesiveness of the surface protective layer.

Scratch resistance test conditions The surface of the surface protective layer was rubbed 20 times with steel wool # 0000 and observed for scratches.

Adhesion test conditions for surface protection layer Nichiban Cello tape (industrial type) with a width of 24 mm was pasted on the surface protection layer that had been cross-cut with a cutter in advance, and the cloth was rubbed 10 times back and forth to adhere. After that, this was left in a room for 1 minute, and it was observed whether or not the surface protective layer was adhered to the tape and peeled off when the tape was peeled off by pulling the tape abruptly upward from the front side.

Comparative Example 1 A film substrate coated with a UV-curable resin coating in a thickness of 1 μ, 2 μ, and 10 μ in the same manner as in Example 1 was wound around the same roll surface as in Example 1 without heating the roll. The UV-curable resin was cured by irradiating it with UV light at roll surface temperatures of 10 ℃ and 20 ℃, respectively.

The scratch resistance of each composite film obtained as described above,
The adhesion of the surface protective layer was tested under the same conditions as in Example 1, but the scratches and the peeling of the surface protective layer were severe, and the scratch resistance and the adhesion of the surface protective layer were poor.

〔The invention's effect〕

As described above, the manufacturing method of the present invention, in curing the ionizing radiation curable resin coating layer, the base material is at least partially wound around the surface of the heat roll and the coating layer together with the coating layer 30
By adopting the method of irradiating ionizing radiation while heating to a temperature of ~ 100 ° C, distortion due to curing shrinkage of the ionizing radiation-curable resin is effectively prevented, and it has an excellent surface protection layer with excellent adhesion. A scratch resistant composite film can be produced. The scratch-resistant composite film obtained by the method of the present invention has a surface protective layer made of a three-dimensional crosslinked cured film obtained by curing an ionizing radiation curable resin, and thus the surface protective layer is excellent in heat resistance and hardly scratched, and has excellent resistance. When the film has scratch resistance and is used as a base material for cosmetics, the aesthetic appearance of a decorative material such as an interior material and a light-shielding film can be retained for a long period of time.

[Brief description of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a longitudinal sectional view showing one embodiment of the scratch resistant composite film of the present invention. 1 ... Scratch resistant composite film 2 ... Synthetic resin film substrate 3 ... Surface protection layer

Claims (1)

[Claims] 1. A synthetic resin film substrate having an ionizing radiation-curable resin coating layer formed on one or both sides thereof, and then the substrate is at least partially wrapped around the surface of a heat roll and heated to a temperature of 30 to 100 ° C. together with the coating layer. A method for producing a scratch-resistant composite film, which comprises irradiating ionizing radiation while heating to cure an ionizing radiation curable resin to form a surface protective layer.