JPH0326824B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a photosensitive peel-off film with an improved colored synthetic resin film layer (hereinafter referred to as peel coat layer), and more specifically, it relates to a photosensitive peel-off film with improved etching properties,
The present invention provides a photosensitive peel-off film having a peel coat layer with excellent peelability. The photosensitive peel-off film according to the present invention is formed by sequentially providing a peel coat layer and a photosensitive photoresist layer on a transparent support. After exposing and developing the photosensitive peel-off film, the peel coat layer is etched with an etching solution. By doing so, a relief image is formed. Generally, a photosensitive peel-off film is exposed, developed, etched, washed, and dried to create film cut lines corresponding to the original image lines, and the areas surrounded by the film cut lines are separated to create a mask plate. be done. This mask plate is commonly used in the printing and plate making industry.For example, in order to print only lakes and marshes in a map with a color or pattern that is distinct from other parts, a hole in the shape of a lake is printed. It is necessary to create a negative or a corresponding positive and create a printing plate for only that part, or to overlap it with a pattern negative and print only the lake area onto a printing plate. The negative or corresponding positive used in this case with a certain shape of area aperture is a mask plate. Conventionally, the method for creating these mask plates is to use a peel-off film, which is a photosensitive material with a colored synthetic resin film that has excellent light-shielding properties against active light and is easy to peel off from the base film, using a knife to adhere to the original image. Another method is to cut around the cut line and peel off the inner membrane with the tip of a needle. In this method, a peel-off film is overlaid on the original drawing and the knife cuts are made by hand, so the work can only be carried out by an experienced person. Moreover, it takes a long time and relies on manual labor, so the reproducibility of the original drawing is poor. Attempts have also been made to improve these using photographic techniques. The first type is a photosensitive peel-off film in which a light-shielding dye or pigment is mixed in advance with a resin composition that undergoes a polymerization reaction and becomes insolubilized upon exposure to light and is coated on the film. A positive line drawing original is placed on this film and after exposure, the unexposed areas are eluted and washed with a solvent to obtain film defect lines corresponding to the original image. In this method, the photosensitive wavelength range of the photo-insolubilized film itself overlaps with the absorption wavelength range of the light-shielding dyes and pigments coexisting in the film, resulting in surprisingly low sensitivity, and the required baking time becomes extremely long. This has the drawback that it absorbs a large amount of heat rays, causing thermal dimensional changes in the original and the peeling material, resulting in deterioration of accuracy. Also, it is dangerous because flammable organic solvents are used during the treatment process. The second type is a material in which a soluble and highly light-shielding peel coat layer is provided on a film support, and a silver halide gelatin emulsion is coated on the upper layer. After exposure, tanning development is carried out to dissolve the gelatin corresponding to the imaged areas of the document, followed by washing with water and drying, followed by dissolving the peel coat layer in the gelatin-dissolved areas with a solvent that dissolves the underlying peel coat layer. After elution, the sample is washed and dried, and the film surrounded by the film removal line is removed using a needle tip. In this method, the exposure time is shortened compared to the first type, but the process is complicated and takes a long time, so it is not satisfactory. The third type is as described in Japanese Patent Publication No. 50-27402, which consists of polyvinyl alcohol, which is a water-soluble polymer material, and a photoinsolubilizing agent such as diazonium, tetrazonium compound, dichromate, etc., on a film support. A method for making a mask plate is known, which comprises the steps of providing a photosensitive film, exposing the film to light through a line drawing original, and then dyeing, washing with water, and drying. This method has the advantage of not using a solvent in the processing solution, but since it uses a water-soluble photosensitive resin, it is easily affected by humidity, and it is also difficult to peel, and because it is a dyed type, it requires a dyeing process. However, it also has drawbacks such as uneven density and decreased density. A fourth type of film that attempts to solve these problems is a photosensitive peel-off film in which an alcohol-soluble polyamide layer is provided as a peel coat layer on a transparent support, and a photoresist layer is sequentially provided on top of this. There is. This type forms an image by etching the alcohol-soluble polyamide layer after exposure and development. Conventionally, the alcohol-soluble polyamide layer is etched using a mixed aqueous solution of lower alcohol and aromatic alcohol. Etching methods that contain alcohol, such as a method of treating with an aqueous solution containing an aromatic neutral salt and alcohol (Japanese Patent Application Laid-open Nos. 55-137524 and 1987-137527), etc. Although there are methods of processing with liquid, these methods tend to change the etching performance due to evaporation of the alcohol, lack stability, and pose a risk of ignition. In contrast, it is treated with water-soluble sodium salicylate, chloral hydrate, or bromal hydrate (Japanese Patent Publication No. 49-45321), or with an aqueous solution of an alkali metal compound of halogenated phenol or an alkali metal compound of halogenated benzoic acid. A method of processing with an etching solution that does not contain alcohol, such as the method (Japanese Patent Application Laid-open No. 124349/1982), has also been proposed, and the etching properties are almost satisfactory. However, the strength of the photosensitive peel-off film using this alcohol-soluble polyamide in the peel coat layer is still not satisfactory. In other words, because the strength of the film is weak during peeling work,
It has the disadvantage that the film tends to break during peeling and workability is poor. Increasing the thickness of the peel coat layer made of alcohol-soluble polyamide increases the strength of the film, but this is not a preferred method since it increases the time required for etching and reduces image reproducibility. In order to solve these problems, the inventors of the present invention have conducted extensive research on materials for the peel coat layer that have excellent etching and peel properties, and have developed a peel coat containing a polyvinyl formal resin and a polyester resin that is compatible with the polyvinyl formal resin. The inventors have discovered that by using this layer, a photosensitive peel-off film with superior etching and peeling properties can be obtained compared to conventional peel-coat layers using alcohol-soluble polyamide, and the present invention has been achieved. That is, the present invention relates to a photosensitive peel-off film comprising a transparent support, a peel coat layer containing a polyvinyl formal resin and a polyester resin compatible therewith, and a photoresist layer thereon. Conventional photosensitive peel-off films using alcohol-soluble polyamides in the peel coat layer have the drawback of poor peel workability due to low film strength and large film elongation.
In order to solve this problem, measures such as increasing the thickness of the film or adding a hard resin that suppresses the elongation of the film are taken, but if the thickness of the film is increased, the time required for etching will increase, and side etching will be reduced. If a hard resin is mixed, the film may easily lift off from the support due to the shock during handling, and there is a risk that it will no longer function as a photosensitive peel-off film. However, this method does not give favorable results and is not preferred as a means for improving peeling workability. However, when using the material of the peel coat layer according to the present invention, a relatively thin film can be obtained due to the film strength, appropriate elongation, and etching properties of the polyvinyl formal resin, and the film strength, etching properties, and affinity for the support of the polyester resin. It is possible to obtain a photosensitive peel-off film that has high film strength, good peeling workability, and excellent etching properties without lifting of the film from the support, and is different from the conventional photosensitive peel-off film using alcohol-soluble polyamide. In comparison, peeling workability can be significantly improved. Further, a layer containing alcohol-soluble polyamide resin (copolymerized nylon) as a main component is provided between the peel coat layer containing the polyvinyl formal resin and polyester resin according to the present invention and the support, resulting in a two-layer peel coat layer, A photosensitive peel-off film having a structure in which a photosensitive photoresist layer is provided on this peel coat layer may also be used. In this case, the disadvantages of the peel coat layer made only of alcohol-soluble polyamide, such as low film strength and large film elongation, are improved, and the photosensitive peel-off film has good peel and etching properties. can be obtained. Transparent supports used in the present invention include films and glass plates made of polyester such as polyethylene terephthalate, polycarbonate, cellulose acetate, etc., which have good flexibility and are not affected by etching processing solutions, and in particular, films made of biaxially oriented materials such as cellulose acetate. A polyethylene terephthalate film is preferred because it has excellent strength, dimensional stability, transparency, and the like. As for the polyvinyl formal resin used in the peel coat layer of the present invention, the molecular weight, degree of saponification, and degree of formalization of the raw material polyvinyl acetate can be selected depending on the mechanical strength and chemical properties of the required film. Formal component 75-85wt%,
A polymerization degree of 300 to 1100 is preferred. Next, as the polyester resin, a polyester resin that is compatible with polyvinyl formal resin is used, and an example thereof is a linear saturated polyester resin having a molecular weight of 2,000 to 20,000. The composition, degree of polymerization, etc. may be determined based on the adhesion to the support, the toughness of the film, the physical properties of the film, the chemical properties of the film related to etching properties, etc. In the present invention, polyester resin plays an extremely important role. When polyvinyl formal resin is used alone as a peel coat layer, the film is difficult to get stuck to the edge of a knife during peeling, resulting in poor workability. However, mixing polyester resin It can be improved by In addition, the peel coat has a two-layer structure that improves adhesion to the support and prevents the film from peeling off easily due to shocks during handling, and has a layer containing alcohol-soluble polyamide as the main component underneath. When used as a layer, it improves adhesion with this layer and prevents peeling between the layers. Furthermore, by using an alkali-soluble polyester resin, the etching time can be significantly shortened. The mixing ratio of polyvinyl formal resin and polyester resin is in the range of 95:5 to 50:50, especially 90:10.
A range of ~60:40 is preferred. If the mixing ratio is less than 95:5, the adhesion to the support or lower layer will be poor, and the film will easily peel off and will no longer function, and it will be difficult to start peeling off the film with the edge of a knife when working with beer. Furthermore, the time required for etching becomes longer, which may reduce workability. On the other hand, if the polyester resin is more than 50:50, the etching time will be shortened, but the strength of the film will be reduced, the elongation will be too high, and if it is applied directly to the support, it will not adhere well to the support. If it becomes too thick, peeling becomes difficult. Further, a third component resin may be mixed in order to more finely control physical properties such as hardness of the film. In this case, various resins with physical properties suitable for the purpose can be selected from resins that are compatible with the polyvinyl formal resin and the polyester resin. One example is the mixing of phenolic resin, nitrocellulose, etc. for the purpose of improving the hardness of the film. In that case, the mixing amount is 40% of the total resin solid content.
% is appropriate. When the peel coat layer has a two-layer structure, the performance of the peel coat layer mainly composed of an alcohol-soluble polyamide resin is further improved when an alkali-soluble acrylic resin or the like is mixed with the alcohol-soluble polyamide resin. This is because by mixing an alkali-soluble acrylic resin with an alcohol-soluble polyamide resin, it is possible to improve the poor peelability caused by the fact that the film is soft and easy to stretch, which is an essential property of the polyamide resin. The mixing ratio of polyamide resin and acrylic resin is
A range of 90:10 to 50:50 is preferred. Mixing ratio: 90:
If the acrylic resin content is less than 10:1, the purpose of mixing acrylic resins will not be achieved, and conversely, if the acrylic resin content is more than 50:50, the flexibility of the film may be impaired, resulting in a brittle film and reduced peelability. There is. In addition to acrylic resins, resins that meet the above purpose may be appropriately selected and used in combination. By providing a peel coat layer made of a mixture of the above-mentioned polyvinyl formal resin and polyester resin on this peel coat layer, the film strength is increased, and even with a relatively thin film thickness, it has excellent etching properties and image reproducibility. A peel coat layer can be obtained. Further, in order to form a light-shielding colored image, it is necessary to incorporate a coloring substance such as a dye or a pigment into this peel coat layer. In order to form a colored image with sufficient light-shielding properties using a thin peel coat layer, a high coloring substance compounding ratio is inevitably required. Use is preferred. Further, as the material for forming the photosensitive photoresist layer used in the present invention, when forming a positive-positive type photosensitive photoresist layer, for example, O
- There are photosensitive resin compositions that use quinonediazide as a photosensitizer, and when forming a negative-positive photosensitive photoresist layer, for example, 2,6-di-
There is a photosensitive composition in which an azide-based photosensitizer such as (4'-azidobenzal)cyclohexanone is mixed with a phenol novolak, but the composition is not limited thereto. Note that the development of the photosensitive photoresist layer using these photosensitive materials is done using sodium hydroxide,
This can be carried out using an alkaline aqueous solution such as tertiary sodium phosphate or sodium carbonate. The method of forming an image on a photosensitive peel-off film according to the present invention involves first superimposing an original film on the film surface of a photosensitive photoresist layer, and then applying active light using a carbon arc lamp, mercury lamp, chemical lamp, metal halide lamp, etc. Expose to light. Next, the photosensitive photoresist layer is removed by developing with an alkaline aqueous solution such as sodium hydroxide, tribasic sodium phosphate, sodium carbonate, or sodium silicate (which may also contain alcohol, surfactant, etc.). . For the peel coat layer in the exposed portions due to development, an aqueous solution of a salt such as sodium salicylate or sodium trichloroacetate, toluenesulfonic acid, sulfosalicylic acid, etc. that can dissolve the peel coat layer without dissolving the remaining photoresist layer, The image is dissolved and removed by treatment with an aqueous solution of an acid such as maleic acid, acetic acid, or formic acid, an aqueous solution of chloral hydrate, an etching solution such as cresol, or ethylene dichloride. Regarding the formed image, any part surrounded by the film removal line can be selectively peeled off with the edge of a knife or the like. After exposure, the photoresist layer and the underlying peel coat layer are dissolved at once by treatment with an aqueous solution containing an alkali and a salt such as sodium salicylate, or a treatment solution containing a small amount of alcohol if necessary. It can also be removed to form an image. In this way, a photosensitive peel-off film in which a peel coat layer mainly composed of polyvinyl formal resin and polyester resin of the present invention is provided on a transparent support, or a photosensitive peel-off film with an alcohol-soluble polyamide resin as a main component further under the peel coat layer. The photosensitive peel-off film consists of a two-layered peel coat layer with a peel coat layer, which has high film strength, low film elongation, good adhesion to the support film, excellent peelability, and is photosensitive. It can be said to be an epoch-making photosensitive material, which has excellent etching properties after exposure and development, which is important for a peel-off film, and eliminates all the drawbacks seen in conventional technology. The present invention will be explained in more detail with reference to Examples below. Examples 1 to 3 A film forming liquid having the following composition was coated on a biaxially stretched polyethylene terephthalate film (100 μm thick) using a knife coater so that the dry film thickness was 8 μm.
Dry in an oven at 100°C for 2 minutes to form a peel coat layer. Polyvinyl formal resin (PVF82% by weight)
PVA 6% by weight PVAC 12% by weight Average degree of polymerization approx. 950)
Part A Polyester resin (Terephthalic acid 25 mol% Isophthalic acid 25 mol% 1,4-butanediol 50
Polyester with a weight average molecular weight of 16,000 (mol%) B Weight part Neozapon Red GE (red dye manufactured by BASF)
20 parts by weight Ethyl cellosolve 70 parts by weight Methanol 125 parts by weight Toluene 485 parts by weight (Additional amounts of each resin A and B are listed in the table.) Next, apply the following resist forming solution on the peel coat layer to a dry film thickness of 2 μm. The photoresist layer was coated with a wire bar and dried for 2 minutes in an oven at 100°C to obtain a photosensitive peel-off film. Alkali-soluble phenol novolak 5 parts by weight Condensate of 1,2-naphthoquinone diazide-5-sulfonyl chloride and alkali-soluble phenol novolac resin 10 parts by weight Butyl acetate 108 parts by weight Cyclohexanone 27 parts by weight This photosensitive peel-off film was coated with an original film. were exposed for 40 seconds from a distance of 1 m using a 2KW ultra-high pressure mercury lamp, and then treated with a developing and etching solution with the following formulation at a temperature of 30°C to dissolve and remove the photoresist layer and peel coat layer in the exposed areas. form. Then, rinse under running water for 30 seconds and dry. Sodium salicylate 35 parts by weight Sodium hydroxide 0.3 parts by weight Water 64.7 parts by weight Development and etching time, physical properties of the film, peelability, etc. are shown in the table. Note that Comparative Examples 1 to 3 are also shown for comparison. Examples 1 to 3 exhibit good peelability because the film strength is high and elongation is low. Furthermore, the film does not lift off from the support during handling. Comparative Example 1 had poor adhesion to the support, and the film easily peeled off. Also, the etching time is long. Furthermore, in Comparative Example 2, the film had low strength and elongation was large, so the peelability was poor. In Comparative Example 3, although the elongation of the film was reduced, the strength of the film was insufficient, so that the peelability did not reach a satisfactory level. Also, the etching time becomes longer. Example 4 A film forming solution having the following composition was applied onto a biaxially stretched polyethylene terephthalate film (100 μm thick) using a wire bar so that the dry film thickness was 3 μm.
Dry for 2 minutes in an oven at °C to form a peel coat layer. Copolymer of caprolactam, hexamethylene diamine adipate and 4,4'-diaminodicyclohexylmethane adipate 80 parts by weight Acrylic acid/methacrylic acid ester copolymer
20 parts by weight Neozaponredo GE 20 parts by weight Ethyl cellosolve 80 parts by weight Methanol 600 parts by weight Next, the film forming solution of Example 2 was applied on top of this peel coat layer using a knife coater so that the dry film thickness was 5 μm. Dry in an oven at 100°C for 2 minutes to form a two-layer peel coat layer. Thereafter, a photoresist was formed in the same manner as in Examples 1 to 3, and images were formed by exposing, developing and etching. The results are shown in the table. As shown in the table, a photosensitive peel-off film with good peelability and a short etching time could be obtained.

[Table] Example 5 On the peel coat layer obtained in Example 2, a negative resist forming solution with the following composition was applied with a wire bar to a dry layer thickness of 2 μm, and dried in an oven at 100°C for 2 minutes. A photosensitive photoresist layer was then formed to obtain a photosensitive peel-off film. Alkali-soluble phenolic novolak resin
10 parts by weight 2,6-di-(4'-azidobenzal)cyclohexane 2 parts by weight Butyl acetate 86 parts by weight cyclohexanone 22 parts by weight The obtained photosensitive peel-off film was prepared in Example 1.
When an image was formed by exposure, development and etching in the same manner as in Example 2, it showed good peelability as in Example 2.

Claims (1)

[Scope of Claims] 1. A colored synthetic resin film layer and a photosensitive photoresist layer are sequentially laminated on a transparent support, and the colored synthetic resin film layer comprises a polyvinyl formal resin, a polyester resin compatible with the polyvinyl formal resin, and a light-shielding resin. 1. A photosensitive peel-off film characterized by comprising a color dye and a pigment. 2. A colored synthetic resin film layer containing alcohol-soluble polyamide resin and a light-shielding dye and pigment as main components is provided on a transparent support, and is further layered with a polyvinyl formal resin, a polyester resin compatible with this, and a light-shielding resin. 1. A photosensitive peel-off film comprising a colored synthetic resin film layer comprising dyes and pigments and a photosensitive photoresist layer in this order.