JPS6351875B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to stamping foils. More specifically, the present invention aims to provide a stamping foil with excellent gloss and processability. Stamping foil is a plastic molded product,
It is used to stamp metal-colored patterns or letters on leather, wood products, paper products, or other objects to make the product look luxurious and increase its commercial value. As shown in FIG. 1, stamping foil is usually made by laminating a release layer 2, a protective layer 3, a light reflective layer 4, and an adhesive layer 5 on a base film 1.
Then, as shown in Fig. 2, the adhesive layer side of the stamping foil is placed on the article 8 to be printed and pressed from the base film side with a heated mold 7, so that the adhesive on the mold part melts and bonds. However, when the mold and stamping foil are separated from the article, only the portion stamped by the mold is separated from the base film and stamped and printed on the article. From the viewpoint of printing decorative effects, aesthetic effects, etc., it is desired that the gloss is excellent, and for this purpose, it is desirable that the light reflecting layer be as smooth as possible. The light-reflecting layer is provided after coating a release layer and a protective layer on the surface of the base film, but these layers are thin and the surface roughness of the base film appears on the coated surface almost as is, so the light-reflecting layer is In order to make the surface smooth, it is necessary to smooth the surface of the base film. However, when the surface of the base film is made smooth, the slipperiness of the film deteriorates, and the winding appearance of the film during the process of processing into stamping foil deteriorates significantly. As shown in the appearance of the winding film roll schematically shown in Figure 3, bump-like protrusions occur on the winding roll of film with poor slipperiness, and the coating layer in those areas is damaged or peeled off, resulting in the stamping foil being damaged. This will result in defects. Therefore, from the viewpoint of processability, stamping foils have been manufactured using base films whose surfaces have been roughened to some extent, sacrificing gloss. As a result of intensive research in order to obtain a stamping foil with excellent gloss and workability, the present inventor found that if an oriented polyester film containing a specific amount of inert material with a specific average particle size range is used as a base film. It was discovered that excellent workability can be imparted without impairing gloss, and the present invention was achieved. That is, the present invention provides a release layer on one side of an oriented polyester film containing 0.01 to 0.15% by weight of an inert substance with an average particle size of 1.0 to 4.0μ, and further includes a light reflecting layer and an adhesive layer on the outside thereof. This is a stamping foil characterized by being provided with a covering layer. The coating layer of the present invention includes a protective layer, a colored layer, a light-reflecting layer, and an adhesive layer, and the light-reflecting layer and the adhesive layer are essential constituent layers. The polyester used in the present invention is polyethylene terephthalate or polyethylene naphthalene dicarboxylate. Even if these are non-copolymerized polymers, 90 mol% or more (preferably 95 mol% or more) of the dicarboxylic acid component is terephthalic acid or naphthalene dicarboxylic acid,
It may be a copolymer in which 90 mol% or more (preferably 95 mol% or more) of the glycol component is ethylene glycol. Further, the polyester accounts for 90% by weight or more (preferably 95% by weight or more) and other polymers (for example, polyamide, polyolefin, polycarbonate, other types of polyester, etc.) account for 10% by weight or less (preferably 5% by weight or less). Polymer blends such as these may also be used. The polyester used in the present invention may contain stabilizers, colored layers, antioxidants, lubricants, matting agents,
Other additives may also be included. The oriented polyester film used in the present invention is
It is necessary to contain 0.01 to 0.15% by weight of inert substances with an average particle size of 1.0 to 4.0 μm. When using particles with an average particle size smaller than 1μ, it is necessary to contain more than 0.15% of the inert substance in the film in order to obtain good processability, and in this case, the transparency of the film itself becomes poor. This is not preferable because the gloss of the stamping foil itself deteriorates. On the other hand, if the average particle size is 4.0 μm or more, unevenness will become noticeable on the film surface and/or the light reflecting layer provided on the film surface, and the gloss of the printed matter will deteriorate, which is not preferable. From this point of view, the average particle size of the inert substance is
1.5μ or more and 3.0μ or less, preferably 0.18μ or more and 2.5μ
The following are more preferred. In addition, the content of inert substances should be 0.025% by weight or more and 0.10% by weight in order to improve the gloss and processability of the stamping foil.
Up to % by weight is preferred. The oriented polyester film used in the present invention has a surface roughness of 0.010 to 0.030μ expressed as center line average roughness, especially 0.015μ to 0.028μ.
It is preferable that it is within the range of . Examples of inert substances include silica, clay, kaolin, and calcium carbonate. Here,
Silica may be crystalline or amorphous. The inert material can be obtained in a variety of ways that can be performed by those skilled in the art, including milling and mixing operations of the additives. For example, calcium carbonate, silica, etc. can be obtained by classifying a slurry of ethylene glycol using a classifier (eg, Tomoe Kogyo P-660 Super Decanter) or the like. Note that the particle size referred to in the present invention is Stokes.
(described later), and the average particle size is determined by the particle size (Stokes
diameter), calculate the composition ratio, create an integration curve, and calculate the integration rate of 50.
Particle size expressed in %. The resulting inert material is added to the polyester. The addition time may be before polyester polymerization,
It may be added during the polymerization reaction, or it may be kneaded in an extruder when pelletizing after the completion of polymerization, or it may be added during melt extrusion into a sheet, dispersed in an extruder, and extruded, but it may be added before polymerization. It is preferable to add The polyester film that is the object of the present invention is a biaxially oriented film. The film is stretched in biaxial directions (for example, vertical and horizontal directions) at a stretching temperature (70 to 120°C), a stretching ratio (3 to 5 times), and an area ratio (8 to 22 times). 245℃) at (1
~30 seconds) obtained by heat fixing. The stretching ratios in the biaxial directions may or may not be the same, and may be obtained by longitudinal stretching and transverse stretching, by adding longitudinal re-stretching or re-transverse stretching to a biaxially oriented film, or by four-stage stretching in the longitudinal and lateral directions. It also includes those obtained by Film thickness is 3-100μ, preferably 4-50μ
Those having a diameter of 8 to 25 μm are most preferably used. In the present invention, a release layer is provided on one side of the oriented polyester film containing an inert substance as described above in contact with the film surface, and a release layer is provided on the outside (upper side) of the oriented polyester film.
A light-reflecting layer is provided on the surface of the stamping foil, and an adhesive layer is provided on the outer side of the light-reflecting layer to form a stamping foil. The outside here refers to the side opposite to the film base material side when viewed from each of these layers. In the stamping foil of the present invention, a protective layer or a protective layer and a colored layer can be provided between the release layer and the light-reflecting layer, if necessary. When providing a protective layer and a colored layer, it is preferable to place the latter on the outside. The release layer is provided so that the protective layer, light reflection layer, adhesive layer, etc. can be easily peeled off from the base film during printing, and any known release layer material may be used, such as wax. It can be formed by dissolving a synthetic drying oil, a cellulose derivative resin (for example, cellulose nitrate, cellulose acetate, butyrate, etc.) in a solvent, applying the solution, and then evaporating the solvent. The protective layer covers the light reflective layer to prevent the light reflective layer transferred to the article to be printed from being damaged by external friction, etc., and may be made of any known protective layer material. For example, it can be formed by dissolving a cellulose derivative resin (for example, cellulose nitrate, cellulose butyrate, cellulose acetate, cellulose acetate butyrate, etc.) in a solvent, applying the solution, and then evaporating the solvent. Addition of a thermosetting resin such as acrylic or epoxy resin can improve the abrasion resistance of the protective layer.
It goes without saying that when a material that can be used for the protective layer is used as a material for the release layer, the release layer can also serve as the protective layer. The colored layer is provided for coloring printed matter and is formed by dispersing or dissolving dyes, pigments, etc. in a binder, and often uses a polymer that can be used in the protective layer as the binder. The light reflective layer is often a vapor deposited layer of metal, but may also be a vapor deposited layer of metal oxide, a reflective layer formed by chemical plating, or the like. The adhesive layer is provided so that only the part pressed by the mold adheres to the printed article during printing, and may be any heat-sensitive adhesive layer, such as vinyl acetate, chloride, etc. Vinyl-based, acrylic-based, etc. adhesives are often used. Since the stamping foil of the present invention uses an oriented polyester film containing the above-mentioned inert substance as a base film, it is characterized by excellent processability and excellent gloss of printed matter. Next, methods for measuring the main substances employed in the present invention will be described. 1 Particle size and composition of the inert substance Using the Shimadzu automatic sedimentation balance, use the Stokes equation T = 18ηh/G (ρp - ρo) × d ² In the formula, T: sedimentation time (sec) η: medium Viscosity (g/cm・sec=poise) h: Sedimentation distance (cm) G: Acceleration of gravity (980cm/sec ² ) ρp: Density of inert substance (g/cm ³ ) ρo: Density of medium (g/cm ³ ) d: Calculate the settling time corresponding to each particle size using the particle size (diameter/cm) of the inert substance, find the settling time range corresponding to each particle size range, and calculate the settling time range. The weight of the inert material in the total weight of the inert material is determined, and the proportion to the total weight of the inert material is expressed as a percentage and used as the composition ratio. 2 Average particle size Determine the composition ratio using the method described in measurement method 1, and integrate from the larger particle size to the smaller particle size (particle size 0 μ
Create an integration curve (100% in m) and set the integration rate to 50
The particle size expressed in % is defined as the average particle size (μm). 3 Center average roughness: According to the method specified in JIS B-6601, the cut-off length is 0.25 mm and the measuring stylus has a radius of 3 μ. In the following Examples and Comparative Examples, a surface roughness meter Surfcom Model 3B manufactured by Tokyo Seimitsu Co., Ltd. was used. 4 Volume appearance: Graded from 1st grade to 5th grade. Width 500mm, length 2000
After providing a release layer and a protective layer on the film of m,
Rolled up into a roll. The appearance of this winding roll was inspected in detail, and the number of lump-like protrusions with a major diameter of 1 mm or more as schematically shown in FIG. 3 was counted and graded as follows. 0 pieces 1st grade 1-2 pieces 2nd grade 3-5 pieces 3rd grade 6-10 pieces 4th grade (fail) 11 or more pieces 5th grade (fail) 5 Gloss: Gloss meter GM-3M manufactured by Murakami Color Research Institute was used to measure the gloss of the surface printed by the stamping foil. Since the surface printed with stamping foil has a very high gloss, the specular reflectance of a black glass standard plate (refractive index 1.5275) was set to 10.0, and the gloss was compared with this value to display the gloss. Note that the incident angle and reflection angle are 60 degrees. The present invention will be further explained below using specific examples. Examples 1 to 8 and Comparative Examples 1 to 4 Polyethylene terephthalate was produced by a conventional method using dimethyl terephthalate and ethylene glycol as raw materials, manganese acetate as a transesterification catalyst, antimony trioxide as a polymerization catalyst, and phosphorous acid as a stabilizer. did. At that time, by dispersing silica or calcium carbonate as an inert substance in ethylene glycol, a predetermined amount of the inert substance was contained in the polymer (see Table 1). The obtained polymer was melt-extruded using a conventional method to form a film, and the stretching temperature was 90 to 120°C, longitudinal magnification was 3.5 times, and transverse magnification was 3.5 times.
Biaxially stretched at 3.7 times and heat set at 220℃ to a film thickness of 12μ
A biaxially oriented film was obtained. Cellulose acetate butyrate was coated on one side of the film to a thickness of 5 μm to serve as both a release layer and a protective layer, and the film was wound up into a roll to determine the roll shape. Next, on the release layer of the film, aluminum was vapor-deposited to a thickness of about 300 Å as a light-reflecting layer, and then a vinyl acetate-based heat-sensitive adhesive was applied as an adhesive layer on top of this, used as a stamping foil, and an ABS molded plate. It was used for printing. The results obtained are shown in Table 1. In addition, it was found that the part of the winding roll where the bump-like protrusion was formed was a defective part in which printing could not be performed normally in the case of stamping foil.

[Table] From the above results, the examples have excellent gloss and winding appearance, while the comparative examples have good gloss but extremely poor winding appearance with grade 5, and those with good winding appearance have poor gloss. It turns out that it is significantly inferior. Examples 9 to 13 and Comparative Examples 5 to 7 Using the inert substances shown in Table 2, polyethylene terephthalate used in Example 1 was replaced with polyethylene-2, which was produced in the same manner.
Using 6-naphthalene dicarboxylate, the film stretching temperature was 120 to 140℃ and the heat setting temperature was 230℃.
A biaxially stretched film and a stamping foil were produced in the same manner as in Example 1 except that the temperature was changed to .degree. The results obtained are shown in Table 2.

【table】 [Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing the basic structure of stamping foil, Figure 2 is a schematic diagram showing printing using stamping foil, and Figure 3 is a problem that occurs when a film with poor slipperiness is rolled up. FIG.

Claims (1)

[Claims] 1. An inert substance with an average particle size of 1.0 to 4.0μ
A stamping foil comprising a release layer provided on one side of an oriented polyester film containing 0.15% by weight, and a coating layer provided on the outside of the release layer. 2. The stamping foil according to claim 1, which uses an oriented polyester film having a surface roughness of 0.010 to 0.030μ as expressed by center line average roughness. 3. The stamping foil according to claim 1 or 2, wherein the coating layer comprises a protective layer, a light reflecting layer, and an adhesive layer, and the adhesive layer is the outermost layer. 4. The stamping foil according to claim 1 or 2, wherein the coating layer is comprised of a protective layer, a colored layer, a light reflective layer, and an adhesive layer in this order.