JPH06100821B2 - Thin green shading masking film - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a light-shielding masking film mainly used for cutting a required portion in photoengraving to form a transparent image.

[Prior art and its problems]

Conventionally, a light-shielding masking film in which a transparent light-shielding release layer is provided on a plastic support is known. In the field of photoengraving, etc., this product cuts the light-shielding release layer manually or mechanically in order to obtain a desired transparent image, and releases the light-shielding release layer according to the cut line. .

By the way, the light-shielding release layer in such a masking film generally obtains a light-shielding effect by the addition of a colorant, but in the conventional case, most of the colorants for obtaining the light-shielding effect are of a reddish type. However, no green colorant is used. The masking film using the red colorant has a cut line on it,
When performing peeling work, if you engage in the work for a long time,
There was a drawback that the eyes were very tired and the work efficiency was reduced.

On the other hand, the green color is different from the red color,
It is known to reduce eye strain. Therefore, it is clear that the use of the green colorant remarkably ameliorate the above-mentioned drawbacks observed when the red colorant is used. However, unlike the red colorant, the green colorant is significantly inferior in the light-shielding effect, and even if a commercially available green colorant is used, a practical masking film cannot be obtained.

The present inventors previously proposed a specific light-shielding masking film using a mixed colorant having a maximum light-shielding wavelength of 480 nm and composed of a yellow colorant and a blue colorant (Japanese Patent Application No. 62-152).
No. 298).

The color tone of this light-shielding masking film shows a greenish color because a yellowish colorant with a rich orange color was used, but the greenish color is dark and dark. This makes the operator feel that when the masking film is placed on the original drawing and a cut line is applied to the masking film according to the original drawing, the lines of the original drawing are difficult to see through.

[Problems of the Invention]

An object of the present invention is to solve the problems found in the above-described light-shielding masking film colored in a dark green color.

[Means for Solving the Problems]

The present inventors have conducted extensive studies to solve the above problems, using a mixed colorant having a maximum light-shielding wavelength consisting of a light yellow colorant and a blue colorant at about 420 nm or more,
The maximum spectral transmittance in the green light range is 50% or more, and the color tone characteristics specified in a specific range show a light green system color, have practical light-shielding properties, and are very transparent to the original drawing. They have found that they are excellent and have completed the present invention.

That is, according to the present invention, a transparent light-shielding release layer containing a colorant is provided on a transparent support, and the light-shielding release layer comprises a light yellow colorant and a blue colorant. It has a maximum light-shielding wavelength of about 420 nm or more and contains a mixed colorant, has a maximum spectral transmittance of 50% or more in the green light range, and has a blue filter density of 0.9 to 2.0. Filter density is 0.5
Light green light-shielding masking characterized by having the following color tone characteristics such that the density by the red filter is 0.4 or more, and the ratio of the density A by the green filter and the density B by the red filter is 0.7 or less. A film is provided.

The light green color used in the present specification is a term used to distinguish it from a dark green color, and includes a normal green color and a light green color. Further, the maximum light-shielding wavelength means the maximum wavelength of the light-shielded spectral wavelengths in the spectral spectrum chart of the masking film. In the case of the present invention,
The maximum shading wavelength is 420 nm or more, usually in the range of 420 to 470 nm. Furthermore, the light-shielding property referred to in the present specification means that, when a light-sensitive film for a bright room is exposed to ultraviolet light through a masking film, the exposure film does not substantially expose the photosensitive film to light. It means blocking light up to the spectral intensity. Therefore, when the photosensitive film is exposed by using the masking film, the specific light-shielding property required for the masking film needs to be appropriately defined depending on the type of the photosensitive film and the number of exposures. In general, when a small number of exposures (for example, 1 to 2 times), it is not necessary to completely block light, and the photosensitive film is not substantially exposed to light at the number of exposures, usually in the spectral transmittance. Any material having a light-shielding property of 1% or less (particularly 0.5% or less) may be used.
On the other hand, when the number of exposures is large (for example, 10 or more), it is necessary to more completely block the light, and if the spectral transmittance is normally 0.2% or less (particularly 0.1% or less), Good.

The colorant contained in the light-shielding release layer in the masking film of the present invention is a mixed colorant composed of a light yellow colorant and a blue colorant, and has a maximum light-shielding wavelength of about 420 nm or more. In the present invention, the maximum light shielding wavelength of the mixed colorant is usually in the range of 420 to 470 nm. The light yellow colorant used in the present invention has a light yellow color and is a lemon-colored yellow color. Therefore, a light greenish color tone can be obtained by mixing such a yellow colorant with a blue colorant. Regarding the maximum light-shielding wavelength of the yellow colorant, it was initially thought that it was necessary to be 480 nm or more, but in the actual test, a colorant having the maximum light-shielding wavelength in the range of 420 to 470 nm is sufficient for practical use. It was confirmed that it has sex. Further, as the light yellow colorant, those whose maximum light-shielding wavelength is in the range of about 420 to 470 nm are usually used, but not limited to this, mixed coloring mixed with a blue colorant. The maximum light-shielding wavelength of the agent may be in the range of about 420 nm or more.

Showing the specific characteristics of the light yellow colorant used in the present invention,
The maximum shading wavelength needs to be in the range of 420 nm or more as described above, but in addition, the density by the blue filter is in the range of 0.9 to 2.0, and the density by the green filter is 0.5 or less, It can also be shown that the red filter concentration is less than 0.4. In this case, for the concentration measurement, a Macbeth TD904 was used as the densitometer, and the blue filter was wratte for the blue filter.
Two sheets were used, one for each of n47 and CC-40M. One piece of wratten92 was used for the red filter, and one piece of wratten93 was used for the green filter.

Examples of light yellow colorants that can be used in the present invention include, for example, Orasol Yellow 2GL, Saviny 1 Yellow RLS, S
aviny1 Yellow 2GLS, Vali Fast Yellow 4120, Vali Fast
Yellow 1103, Vali Fast Yello 2110, Vali Fast Yello
w 1101, Vali Fast Yellow 1105, Aizen SOT Yellow-1, Mi
hara Oil Yellow 3G, Mihara Oil Yellow 5G, Mihara Oil
Yellow 10G, Kayaset Yellow K-RL, Oil Yellow 101, Oil
Yellow 107, Oil Yellow D, Neo Super Yellow C-131, Ne
o Super Yellow C-132, Neozapon Yellow 018 and so on. These can be used alone or in combination of two or more as long as they have the above-mentioned characteristics. The light blocking wavelength of the blue colorant is not particularly limited as long as it gives a light greenish color tone when mixed with the light yellow colorant. Examples of this are: Oras
ol Blue 2GLN, Orasol Blue GN, Neo Super Blue C-531, N
eo Super Blue C-551, Vali Fast Blue 1505, Vali Fast
Blue 2606, Savinyl Blue GLS, Neozapon Blue 807, Oil B
Examples include lue BO. Two or more of these can be used.

The light-shielding masking film of the present invention has a coloring of a light greenish color, and its specific characteristic is that its maximum light-shielding wavelength is required to be in the range of 420 nm or more as described above, but in addition, green The maximum spectral transmittance in the light range (wavelength 500 nm to 570 nm) is 50% or more, and the density by the blue filter is in the range of 0.9 to 2.0 and the density by the green filter is 0.5 or less (preferably 0.05 to 0.45), the density by the red filter is 0.4 or more (preferably 0.4 to 2.7), and the ratio A / B between the density A by the green filter and the density B by the red filter is 0.7 or less ( It can be shown that it is preferably 0.4 to 2.7). In order for the light-shielding masking film obtained by using the mixed colorant to exhibit a good light green color, it is important to satisfy all the above concentration ranges. For example, if the density of the blue filter is 2.0 or more, it becomes dark green instead of light green. Further, if the ratio of the density of the green filter and the density of the red filter is 0.7 or more, the greenish light yellow is obtained instead of the light green. The concentration measurement conditions in this case are the same as those shown for the light yellow colorant.

The transparent support may be made of a material usually used for a light-shielding masking film, for example, a film made of polyester such as polyethylene terephthalate, polybutylene terephthalate or polyoxybenzoate, or a synthetic resin film such as a polycarbonate film is used. To be These films may be unstretched or stretched. The thickness of the film is usually 25 to 250 μm.

In order to obtain the light-shielding masking film of the present invention, the light-shielding release layer containing the mixed colorant described above may be laminated on the transparent support. In this case, it is advantageous to use an ultraviolet absorber in connection with the use of the mixed colorant composed of the light yellow colorant and the blue colorant, and by using this, a masking film excellent in light-shielding property is obtained. be able to. As the ultraviolet absorber, conventionally known ones, for example,
Although salicylic acid ester-based compounds, benzotriazole-based compounds, and benzophenone-based compounds are used, in the case of the present invention, benzophenone-based compounds do not cause bleeding from the light-shielding release layer, and their use is particularly preferable. The ratio of the ultraviolet absorber used is 0.05 to 1 part by weight of the mixed colorant.
The ratio is 1.0 part by weight, preferably 0.1 to 0.7 part by weight.

The light-shielding release layer contains a polymeric substance such as synthetic rubber or synthetic resin as a binder component in addition to the above-described mixed colorant and ultraviolet absorber. The specific configuration of the light-shielding release layer is well known. However, it can be configured according to a conventionally known technique. For example, in such a light-shielding release layer, in addition to the above components, a nitrile rubber, a vinyl chloride-vinylidene chloride copolymer and any optional additives such as a roughening agent may be contained. You can
Further, a nitrile rubber, a vinyl chloride-vinyl acetate copolymer and any optional additives can be contained. The amount of the colorant added is usually 2 to 50 in the light-shielding release layer.
The amount is preferably 5 to 30% by weight so as not to impair the transparency of the light-shielding release layer.

In the present invention, when the light-shielding release layer is laminated on the transparent support, the light-shielding release layer can be laminated via a pressure-sensitive adhesive layer. In such a light-shielding masking film, the film once peeled can be re-applied to the transparent support. The pressure-sensitive adhesive layer can be formed using, for example, a synthetic resin-based or rubber-based adhesive. Examples of synthetic resin adhesives include acrylic acid ester copolymers, saturated polyester compounds, polyurethanes, and the like, and rubber adhesives include natural rubber, chloroprene rubber, nitrile rubbers, and the like.

A preferred light-blocking release layer for use in connection with the pressure sensitive adhesive layer is one that contains nitrile rubber, nitrocellulose and a plasticizer in addition to the mixed colorant and optionally UV absorber described above. In this case, as the nitrile rubber, for example, acrylonitrile-butadiene copolymer or terpolymer of acrylonitrile-butadiene-carboxyl group-containing monomer, acrylonitrile content of 19 ~ 51 wt% such as It is preferably used. Nitrocellulose has a nitrogen content of 10.7 to 12.2% by weight.
Those of are preferably used. As the plasticizer, fatty acid ester (preferably having a molecular weight of 300 to 500), trimellitic acid ester (preferably having a molecular weight of 500 to 700), epoxidized oil (glyceride) (preferably having a molecular weight of 300 to 1300), Examples thereof include epoxidized fatty acid ester (non-glyceride) (preferably having a molecular weight of 300 to 1300). The weight ratio of nitrile rubber to nitrocellulose is (20:80) to (80:20), preferably (30:70) to (7
0:30). The proportion of the plasticizer used is 0.1 to 30 parts by weight, preferably 0.5 to 20 parts by weight, based on 100 parts by weight of the total amount of nitrile rubber and nitrocellulose. The mixed colorants are
It is 3 to 30 parts by weight, preferably 5 to 20 parts by weight, based on 100 parts by weight of the total amount of nitrile rubber and nitrocellulose.
Furthermore, in the case of a masking film having this pressure-sensitive adhesive layer, it is preferable that the light-shielding release layer contains an incompatible organic compound such as benzoguanamine resin or an inorganic compound such as silica. Addition of the above-mentioned substances not only provides the effect of preventing light reflection but also the effect of reducing stickiness on the surface. Further, the pressure-sensitive adhesive layer may contain a part of the mixed colorant to be contained in the light-shielding release layer.

〔The invention's effect〕

The light-shielding masking film of the present invention exhibits a light green color tone with good transparency. Therefore, in the work of applying a cut line to the masking film of the present invention or peeling the light-shielding release layer according to the cut line,
Unlike the conventional case of using a masking film showing a reddish color, the operator's eye fatigue is remarkably reduced, and the work ability is improved.

Further, in the masking film of the present invention, since the light-shielding release layer is a light green color having good transparency, the original drawing placed thereunder can be clearly seen.

(Example) Next, the present invention will be described in more detail with reference to examples.

Example 1 A uniform mixture having the component composition shown in Table 1 was used as a light-shielding coating liquid.

The colorant A shown in Table 1 is Oil Yellow 101 (manufactured by Orient Chemical Industry Co., Ltd.), and the colorant B is Vali Fas.
t Blue 4120 (manufactured by Orient Chemical Industry Co., Ltd.), the colorant C is Neozapon Blue 807. UV absorber is 2,
It is 2 ', 4,4'-tetrahydroxy-benzophenone.

The acrylonitrile-butadiene rubber is one having an acrylonitrile content of 33% by weight (Nipol 1042, manufactured by Zeon Corporation).

The vinyl chloride-vinyl acetate copolymer is composed of 86% vinyl chloride and 14% vinyl acetate (VYHH, manufactured by Union Carbide Co.).

The surface roughening agent makes the surface rough and eliminates stickiness.
Silica (Cyroid 74, manufactured by Fuji Divison Co., Ltd.).

Next, the coating solution was applied on the surface of a polyethylene terephthalate film (thickness: 100 μm) as a support and dried to form a light-shielding release layer having a thickness of 25 μm.

The masking film thus prepared has a light green color tone, shows the light transmission spectrum chart shown in the drawing, shields wavelengths of 450 nm or less, and between the wavelengths of 530 nm and 570 nm in the green light range ( It has a peak of light transmittance at 545 nm), and the light transmittance of the peak exceeds 50%, which is excellent in transparency.

Example 2 A masking film was obtained in the same manner as in Example 1, except that the coating liquid was applied to the surface of the pressure-sensitive adhesive layer of a polyethylene terephthalate film having a chloroprene-based pressure-sensitive adhesive layer (thickness 3 μm) and dried. .

This masking film also showed the same light transmission spectrum chart as shown in the drawing. This masking film allows the peeled film to be re-applied to the transparent support.

Example 3 As a master coating liquid, a mixed liquid having the component composition shown in the following table was obtained.

Next, the yellow and blue dyes were dissolved in 20 parts by weight of the master coating solution at the addition amounts shown in Table 3 to prepare a coating solution, and the coating solution was applied to the surface of a polyethylene terephthalate film (thickness: 100 μm). After drying, a light-shielding release layer having a thickness of 24 μm was formed.

Next, with respect to the light-shielding masking film thus obtained, its color tone characteristics, color tone and light-shielding property were examined.
The results are shown in Table-3.

The above-mentioned blue dye is Neozapon Blue 807.
Oil yellow 101; dye A and Savinyl yellow RLS (dye B) were used as the yellow dye.

In addition, the measurement of the color tone characteristic was performed using the Magbeth densitometer as described above. The color tone was visually observed.
Regarding the light-shielding property, the one having the maximum light-shielding wavelength in the range of 420 nm or more was judged as “◯”, and the one having a lower light-shielding range was judged as “X”.

Table 4 also shows the color tone characteristics, color tone and light-shielding properties of various yellow dyes.

In Table 4, the color tone characteristics were measured using a Magbeth densitometer as described above. Further, the measurement of the color tone coordinates was performed according to JIS Z 8722-1982. The color tone was visually observed.

[Brief description of drawings]

The drawing is a light transmission spectrum chart of the masking film of the present invention.

Claims (4)

[Claims] 1. A transparent support having a transparent light-blocking release layer containing a colorant, wherein the light-blocking release layer has a maximum light-blocking property including a light yellow colorant and a blue colorant. It consists of a mixture containing a mixed colorant having a wavelength of 420 nm or more, the maximum spectral transmittance in the green light range is 50% or more, the density by the blue filter is 0.9 to 2.0, the density by the green filter is 0.5. Light green light-shielding masking characterized by having the following color tone characteristics such that the density by the red filter is 0.4 or more, and the ratio of the density A by the green filter and the density B by the red filter is 0.7 or less. the film. 2. The masking film according to claim 1, which contains an ultraviolet absorber together with the mixed colorant. 3. The masking film according to claim 2, wherein the ultraviolet absorber is a benzophenone compound. 4. The masking film according to claim 1, wherein the light-shielding release layer is provided on a transparent support via a pressure-sensitive adhesive layer.