JPH03130199A - Hard coat transfer foil - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a hard coat transfer foil, and more specifically, a hard coat transfer foil that has high hardness, scratch resistance, abrasion resistance, stain resistance, etc. on the surface of various resin molded products. This invention relates to a hard coat transfer foil that can easily provide an excellent surface layer.

(Prior art) Acrylic resins, polystyrene resins, polycarbonate resins, and other synthetic resins have traditionally had various advantages such as good moldability, excellent transparency, light weight, and low cost. It is widely used as molded products for various industrial materials, building materials, decorative materials, optical materials, weak electrical materials, cosmetic materials, household materials, etc.

On the other hand, although such resin molded products have various advantages as mentioned above, their surface hardness is lower than that of glass, metal, etc., so the surface is easily scratched (and transparency is reduced). There are problems such as high contamination.

A method for imparting a surface layer with excellent hardness, scratch resistance, abrasion resistance, stain resistance, etc. to the surface of various resin molded products as described above is to apply and cure an ionizing radiation-curable resin paint. Alternatively, a method is known in which a hard coat layer made of an ionizing radiation-curable resin paint is transferred from a transfer foil.

The above-mentioned hard coat transfer foil is made by laminating a hard coat layer on the surface of a base sheet via a release layer, and further laminating a pattern layer and a heat-sensitive adhesive layer as necessary. The hard coat layer is either placed on the surface and transferred by a conventional method, or placed in a mold and transferred by an in-mold coating method in which a resin is injected into the mold. In this case, peeling during transfer occurs at the interface between the release layer and the hard coat layer, and the hard coat layer is located on the surface of the transferred layer.

In the case of the above-mentioned conventional hard coat transfer foil, it is desirable that the hard coat layer on the surface is as hard as possible, but a resin molded plate etc. onto which such a hard hard coat layer has been transferred is remolded by compression molding etc. to create a curved surface. If a part of the hard coat layer or corner is formed, cracks will occur in the transferred hard coat layer, which is not only unfavorable in appearance, but also exposes the base layer and pattern layer covered with the hard coat layer, making it difficult to effectively use the base layer and pattern. The problem is that it cannot be protected. Of course, if a soft hard coat layer is used, the above problem will not occur, but the original performance of the hard coat layer cannot be obtained.

Therefore, an object of the present invention is to solve the various problems of the prior art as described above, and to improve the appearance of various articles due to cracks etc. even when remolded not only on flat surfaces but also on curved surfaces and corner parts. It is an object of the present invention to provide a hard coat transfer foil capable of transferring an excellent bird coat layer without deterioration of physical properties such as deterioration or abrasion resistance.

(Means for solving problems) The above objects are achieved by the present invention as described below.

That is, in the present invention, a hard coat layer made of a hard ionizing radiation curable resin and a hard coat layer made of a soft ionizing radiation curable resin are laminated on one surface of a base sheet in the order described above. This is a hard coat transfer foil featuring the following.

(Function) When a hard coat layer is transferred to an arbitrary article using the transfer foil of the present invention, a soft hard coat layer is placed inside and a hard hard coat layer is placed on the surface. When such an article is remolded to form a curved surface or part of a corner, cracks may occur in the hard hard coat layer on the surface, but since the hard coat layer on the surface is thin, the cracks that occur are not visible to the naked eye. There are no problems with the appearance. Furthermore, since the cracked portion is in close contact with the underlying soft hard coat layer, it will not peel off. Furthermore, the base and pattern to be protected are covered with an internal soft hard coat layer that does not cause cracks, so they are sufficiently protected.

(Preferred Embodiments) The present invention will now be described in more detail with reference to the accompanying drawings which schematically show preferred embodiments.

As shown in the first diagram, the hard coat transfer foil of the present invention has a hard coat layer 2.3 formed on one side of a base sheet 1 via a release layer (not shown) provided as necessary. This hard coat layer 2.3 is composed of a layer 2 made of a hard ionizing radiation curable resin and a layer 3 made of a soft ionizing radiation curable resin. Furthermore, if necessary, a brimer layer 4 and a decorative layer 5 such as a pattern layer or a metal vapor deposition layer are applied to the surface.
and/or a heat-sensitive adhesive layer 6 can be provided. The pattern layer may be any pattern such as a natural pattern such as wood grain or stone grain, a letter, a symbol, an abstract pattern, or an all-over solid pattern, and the metal vapor deposition layer may be provided on the entire surface or only partially. Good too.

The base sheet l used in the hard coat transfer foil of the present invention may be any conventionally known base sheet, such as polyester films of polyethylene terephthalate, polyethylene terephthalate/isophthalate copolymer, polybutylene terephthalate, etc. Single layer or laminate of polyolefin film such as polyethylene, polypropylene, polymethylpentene, polyvinyl chloride film, polyvinylidene chloride film, ethylene/vinyl alcohol copolymer film, polycarbonate film, polyamide film, etc., on high quality paper. Any base sheet used for conventional hard coat transfer foils, such as various processed papers such as those formed with polyolefin as a release layer, can be used in the present invention, but particularly preferred are sheets with a thickness of 10 to 1100 u. It is a biaxially stretched polyethylene terephthalate film with a thickness of about

A release layer can be provided on the surface of the base sheet 1, if necessary. Such a release layer can be formed from any conventionally known release resin.

The hard coat layers 2 and 3 provided on the base sheet 1 or the release layer as described above are formed from an ionizing radiation-curable paint. Particularly preferred ionizing radiation-curable paints are electron beam-curable paints and ultraviolet-curable paints.

Electron beam-curable paints and ultraviolet-curable paints are similar in composition, except that the latter contains a photopolymerization initiator and a sensitizer, and generally their structure is the film-forming component. The main component is a polymer, oligomer, monomer, etc. that has a radically polymerizable double bond or epoxy group, and contains non-reactive polymers, organic solvents, wax, and other additives as necessary. be.

Particularly preferred for the purpose of the present invention are those in which the film-forming component has an acrylate functional group, such as relatively low molecular weight polyester resins, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, Spiroacecool resin, polybutadiene resin, polythiol polyene resin, oligomers or prepolymers such as (meth)acrylates of polyfunctional compounds such as polyhydric alcohols, and reactive diluents such as ethyl (meth)acrylate, ethylhexyl (meth)acrylate, and styrene. ,
Monofunctional monomers such as methylstyrene and N-vinylpyrrolidone as well as polyfunctional monomers such as trimethylolpropane tri(meth)acrylate, hexanediol(meth)acrylate, tribrobylene glycol di(
Comparison of meth)acrylate, diethylene glycol (meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol(meth)acrylate, etc. It contains a large amount.

By using such a polyfunctional (meth)acrylate-based ionizing radiation-curable paint, surface hardness, transparency,
A hard coat layer with excellent abrasion resistance, scratch resistance, etc. can be formed.

Furthermore, if such a hard coat layer is required to have high flexibility or shrinkage resistance, an appropriate amount of thermoplastic resin such as non-reactive acrylic resin or various waxes may be added to the above-mentioned curable coating. These demands can be met by adding .

In addition, in order to convert the above-mentioned curable paint into an ultraviolet curable paint,
Among them, photopolymerization initiators such as acetophenones, benzophenone, Michler benzoyl benzoate, α-amyloxime ester, tetramethylthiuram monosulfide, thioxanthone, and photosensitizers such as n-butylamine, triethylamine, trilobylphosphine, etc. Can be used in combination.

Various grades of ionizing radiation curable coatings such as electron beam or ultraviolet ray curable coatings as described above are known, all of which are readily available on the market and can be used in the present invention.

A feature of the present invention is that the hard coat layers 2 and 3 are formed separately into a hard hard coat layer 2 and a soft hard coat layer 3.

The hard hard coat layer 2 is formed by using a relatively large amount of a polyfunctional monomer as a component of the above-mentioned ionizing radiation curable resin. The preferred hardness is AS
When formed on a molded article with a thickness of 10 μm, the pencil hardness is 2H or more, and the elongation is preferably in the range of 1 to 30%. If the pencil height is less than 2H, the function as a hard coat layer cannot be obtained.

The thickness of this hard hard coat layer 2 is 0.4-2μ.
The thickness is preferably about 1.5 ft (1.8 m) thick. If it is too thin, it will be difficult to apply uniformly and the hardness will be insufficient, and the surface protection effect of the transferred article will be insufficient. Whitening is noticeable due to the occurrence of cracks on curved surfaces such as parts of corners, which is unfavorable in terms of appearance.

On the other hand, the soft hard coat layer 3 can have its hardness reduced by reducing the ratio of polyfunctional monomers as constituent components of the above-mentioned ionizing radiation curable resin or by mixing a non-reactive resin with excellent flexibility. can be formed by adjusting.

The preferred hardness is a pencil hardness of about 3B to H when formed on an AS molded product with a thickness of 10 μm, and the elongation is preferably 25% or more. If it is too hard, the soft hard coat layer 3 itself will whiten or crack during remolding, making it impossible to achieve the object of the present invention. Moreover, if it is too soft, it cannot function as a hard coat layer.

The thickness of the soft hard coat layer 3 is preferably about 1 to 50 μm; if it is too thin, the surface protection effect of the transferred article will be insufficient, while if it is too thick, the deformability of this layer will be reduced. This is transmitted to the hard layer 2, thereby reducing the hardness of the hard layer 2.

The total thickness of the above-mentioned hard and soft hard coat layers is preferably about 1 to 50 μm.

Conventional techniques can be used as is for the curing method of the hard coat layer 2.3. For example, in the case of electron beam curing, Cockroft-Walton type, Bumpgraph type, resonant transformer type, insulated core transformer type, linear type, Quinamidron type, etc. 50 to 000K emitted from various electron beam accelerators such as type and high frequency type
An electron beam or the like having an energy of eV, preferably 100 to 300 eV is used, and in the case of ultraviolet curing, ultraviolet light emitted from a light source such as an ultra-high pressure mercury lamp, high pressure mercury lamp, low pressure mercury lamp, carbon arc, xenon arc, metal halide lamp, etc. etc. are used.

The above-mentioned curable paints include, for example, a blade coating method, a gravure coating method, a rod coating method, a knife coating method, a reverse roll coating method, a spray coating method, an offset gravure coating method, a moss coating method, etc.
Coated on the above release layer by any coating method,
In particular, gravure coating methods, gravure reverse coating methods, reverse roll coating methods, offset gravure coating methods, etc., which are excellent in coating thickness accuracy, coating surface smoothness, etc., are suitable. Further, the hard coat layer may be cured before or after the transfer or during the transfer.

The hard coat transfer foil of the present invention basically has the above-mentioned structure, but if necessary, any pattern, etc., can be printed on the surface of the hard coat layer 3 using ordinary gravure ink or the like, via the brimer layer 4. A decorative layer 5 can be applied, and
A heat-sensitive adhesive layer 6 can be formed thereon or directly.

Any adhesive can be used, including heat-sensitive adhesives, pressure-sensitive adhesives, solvent-activated adhesives, and ionizing radiation-curable adhesives, but preferred adhesives are those that are not tacky at room temperature, but It is preferable to use a heat-sensitive adhesive that shows adhesive properties when heated. By using such a heat-sensitive adhesive, it is possible to continuously produce a base sheet on which a hard coat layer and an adhesive layer are formed, without winding it into a roll or the like. This is preferable from the viewpoint of productivity.

The method of using the hard coat transfer foil of the present invention is carried out, for example, as shown in the second figure. The hard coat transfer foil of the present invention shown in FIG. Glue. Next, by peeling off the base sheet 1, the layers including the hard coat layers 2 and 3 are transferred onto the transfer material 7.

The 8-do coated transfer foil of the present invention, which does not have an adhesive layer, can be used when the transfer material itself has heat-sensitive adhesive properties, such as thermoplastic resin molded products or in-mold coating method. Alternatively, it can be advantageously used when an adhesive layer is previously provided on a transfer material.

The materials to which the hard coat layer is transferred by the hard coat transfer foil of the present invention include synthetic resin molded products, metals, wood,
It is not limited to ceramics, glass, etc.

(Effect) According to the present invention as described above, using the transfer foil of the present invention,
When a hard coat layer is transferred to an arbitrary article, a soft hard coat layer is placed inside and a hard hard coat layer is placed on the surface. Such an article can be reshaped as shown in Figure 3 to create curved surfaces and corners. If a part of the surface is formed, fine cracks may occur in the hard hard coat layer on the surface, but since the hard coat layer on the surface is thin, the cracks that occur cannot be seen with the naked eye and there is no problem with the appearance. The cracked area is in close contact with the soft hard coat layer underneath, so it will not peel off.Furthermore, the base and pattern to be protected are covered by the internal soft hard coat layer that will not cause cracks, so the cracks will not peel off. protected.

(Example) Next, the present invention will be explained in more detail by giving examples and comparative examples.

Example 1 Ionizing radiation curable resin HC-A (manufactured by Moryo Ink) was coated on the surface of a polyethylene terephthalate film (T-60, manufactured by Toshi ■) to a thickness of 2 μm when dried, and heated at 100°C.
After drying for 1 minute, an ionizing radiation curable resin HC-C (manufactured by Moryo Ink) was applied to the surface to a dry thickness of 8 μm, and dried at 100° C. for 1 minute. Furthermore, a 1 μm thick brimer (manufactured by Shoshyo Ink) was formed on the surface.

The hard coat layer was cured by irradiating the coated film with an electron beam using a scanning type electron beam irradiation machine at an acceleration voltage of 175 KV, a beam current of 36 mA, and an irradiation dose of 10 Mrad.

After that, acrylic resin gravure ink (Showa Ink)
A pattern is printed using the acrylic heat-sensitive adhesive solution (Showa Ink (manufactured in China)) on the surface, which is gravure-coated to a dry thickness of 1 μm, and dried at 100°C for 1 minute to form the hard coat transfer of the present invention. Got the foil.

Comparative Example 1 A hard coat transfer foil of a comparative example was obtained in the same manner as in Example 1 except that the hard coat layer was formed with a hard ionizing radiation curable resin (HC-A) to a thickness of 10 μm.

Comparative Example 2 A hard coat transfer foil of a comparative example was obtained in the same manner as in Example 1 except that the hard coat layer was formed with a soft ionizing radiation curable resin (HC-C) to have a thickness of 10 μm.

Using the hard coat transfer foils of the above examples and comparative examples, 2
The hard coat layer was transferred to the surface of the AS molded product under the conditions of 00° C. x 3 m/min and x 15 kg/cm (pressure). Thereafter, after the AS molded product had cooled down, the base sheet was peeled off, and the layer including the hard coat layer was transferred to the surface of the AS molded product. When the obtained molded article was remolded, the physical properties of the transferred hard code layer were as shown in Table 1 below.

1. Moldability: A molding process of 10R was performed and visually evaluated.

○: Cracks and whitening are not noticeable. membrane No falling off.

×: Cracks and whitening are noticeable. Partial membrane There is some falling off.

2. Pencil hardness; evaluated under a load of 500 g.

3. Scratch resistance: evaluated by rubbing lightly <100 times using 5oooo steel wool.

○: Whitening is not noticeable.

×: Whitening is noticeable.

[Brief explanation of the drawing]

FIG. 1 schematically shows a cross section of the Bartco-1 transfer foil of the present invention, FIG. 2 is a diagram schematically explaining a transfer method using the hard coat transfer foil, and FIG. 3 shows a transfer article. It is a figure explaining the state where it was remolded. Base sheet 2: Rigid hard coat layer 3: Soft hard coat layer 4 Nib primer layer 5: Pattern layer 6: Adhesive layer 7: Transfer material Figure 2

Claims (3)

[Claims] (1) A hard coat layer made of a hard ionizing radiation curable resin and a hard coat layer made of a soft ionizing radiation curable resin are laminated on one surface of the releasable base sheet in the order described above. Features hard coat transfer foil. (2) The hard coat transfer foil according to claim 1, wherein the hard hard coat layer has a thickness of 0.1 to 2 μm, and the soft hard coat layer has a thickness of 1 to 50 μm. (3) The hard coat transfer foil according to claim 1, wherein a decorative layer such as a pattern layer or a metal vapor deposition layer and/or a heat-sensitive adhesive layer are formed on the surface of the hard coat layer.