JPS6227375B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bubble photographic photoreceptor.
More specifically, the present invention relates to a bubble photographic photoreceptor that provides images that are extremely easy to see and have high contrast by coloring the colored portions.

A bubble photographic photoreceptor is one in which a photosensitive layer consisting of a photosensitive substance and a vehicle is formed on a base material such as a polyethylene terephthalate film, and when this photosensitive layer film is exposed and developed, it becomes extremely An image is formed consisting of small air bubbles.
These bubbles scatter light and create opacity in specific areas depending on the pattern of the light applied to them.

The photosensitive substance has the property of decomposing upon exposure to light and generating gas at room temperature, and is uniformly dispersed in the vehicle. Generally, development is carried out by heating the bubble photographic photoreceptor to relax the vehicle, thereby diffusing these gas molecules and forming bubbles, usually about 1 μm in size.

The bubble photography method using this bubble photography photoreceptor not only provides moderate sensitivity and high resolution, but also
Because it uses light scattering to form images, it is more effective than silver halide photography or diazo photography, which utilize light absorption.
Unique and wide-ranging photographic properties can be obtained, and it is currently widely used for reproduction by close contact with a transparent original, especially for reproduction of microfilm.

However, when a conventional bubble photographic photoreceptor is used, the image formed on the transparent bubble photographic film is made of white bubbles, so the image is unclear when viewed with reflected light. However, there was a drawback that the contrast (the difference between the maximum density and the minimum density) was not sufficient.

Conventionally, a method to improve these problems has been to add dyes to the photosensitive layer, but adding dyes to the photosensitive layer greatly increases the maximum density, but also increases the minimum density, so the contrast is sufficiently high. was not obtained, and even by adding this dye, the blurring of the bubble photographic image due to reflected light could not be resolved.

In view of this point, the present inventors conducted extensive research and found that
The inventors have discovered that this drawback can be overcome by using a specific polymer as a vehicle and further containing a specific dye precursor that develops color at the same time as the formation of a bubble image in the photosensitive layer, resulting in the present invention.

That is, the gist of the present invention is that aromatic diazonium salts, leuco bases, polyvinyl chloride, polyvinylidene chloride, polyvinyl fluoride, polyvinylidene fluoride, vinylidene chloride-acrylonitrile copolymers, vinyl chloride-acrylonitrile copolymers, etc. Polymer, halogen-containing polymer selected from vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, or tetrabromobutane, styrene dichloride, styrene dibromide, 1, 1, 1, 4
-tetrabromo-3-phenylpropane, 1-
The base material is a photosensitive layer containing a polymer in which an organic halide selected from (α-chloroethyl)naphthalene, 1-(β-bromoethyl)naphthalene, 1-(1,2-dibromoethyl)naphthalene, and stilbene dichloride is dispersed. The air bubbles formed on the photographic photoreceptor.

The present invention will be explained in detail below.

The photosensitive layer of the bubble photographic photoreceptor of the present invention generally contains an aromatic diazonium salt stabilized with an acidic substance as a photosensitive material. It is generally well known that aromatic diazonium salts used as photosensitive substances are stabilized with acidic substances.

Examples of acidic substances that stabilize this aromatic diazonium salt include zinc chloride, boron trifluoride, cadmium chloride, and phosphorus pentafluoride.

The diazonium salt stabilized with a commonly acidic substance used in the present invention is soluble in an organic solvent or an organic solvent containing a small amount of water, homogeneously mixed with the vehicle-forming polymer, and decomposed by exposure to light. Any substance that generates nitrogen gas may be used, preferably one that forms a double salt or a complex salt with a Lewis acid. Specifically, for example, p-N.N-dimethylaminobenzenediazonium chloride/zinc chloride double salt, p-N.N-diethylaminobenzenediazonium tetrafluorophorate, p-
N・N-diethylaminobenzenediazonium hexafluorophosphate, 4-morpholino-
2,5-diethoxybenzenediazonium sulfate, 4-N-morpholino-2,5-diethoxybenzenediazonium chloride/zinc chloride double salt, p-N-hydroxyethyl-N-ethylaminobenzenediazonium chloride/zinc chloride Double salts, sodium 1-oxy-2-diazonaphthalene-5-sulfonate, 4-(p-tolylmercapto)-2,5-diethoxybenzenediazonium/zinc chloride double salts, and the like. These aromatic diazonium salts are used so that the content in the photosensitive layer is in the range of 1 to 20% by weight.

The photosensitive layer of the bubble photographic photoreceptor of the present invention contains a leuco base so that the foamed portions of the bubble photograph are colored. Leuco base is known as a precursor of carbonium-based dyes, and is a compound that develops color when it is oxidized and converted into a carbonium ion salt with acid. The most typical leuco base has the general formula () (In the formula, R ¹ , R ² and R ³ represent phenyl groups,
At least two of R ¹ , R ² and R ³ are phenyl groups substituted with an electron-donating group such as an alkoxy group or an amino group. Particularly suitable for the photosensitive layer of the body is polymethoxytriphenylmethane, which is a precursor of red dyes. Specifically, polymethoxytriphenylmethane includes 4,4',4''-trimethoxy, 2,4,2',4'-
Tetramethoxy body, 3,4,3',4'-tetramethoxy body, 2,4,2',4',2''-pentamethoxy body, 2,4,6,2',4',6'- Hexamethoxy, 2, 4, 6, 2', 4', 6', 2''-heptamethoxy, 2, 4, 6, 2', 4', 6', 3''-heptamethoxy, 2, 4,6,2′,4′,6′,4″-heptamethoxy form, 2,4,6,2′,4′,6′,2″,3″-octamethoxy form, 2,4,6・2′・4′・6′・2″・
Examples include 4″-octamethoxy form.
The amount of the leuco base to be used is not particularly limited, but if it is too small, the effect cannot be expected, and if it is too large, there will be various adverse effects, so it is preferable to use it in an amount of 0.5 to 10% by weight in the photosensitive layer.

As the vehicle component polymer contained in the photosensitive layer of the bubble photographic photoreceptor of the present invention, it is necessary to use a halogen-containing polymer or a polymer in which an organic halide is dispersed. The polymer of the vehicle component is appropriately selected depending on the photosensitive material, and is usually selected from hydrophobic, water-insoluble, thermoplastic, and non-crystalline polymers. In addition, the permeability of nitrogen gas at 30℃ is 8.6×10 ^-16 to 8×10 ^-10 cc・cm/cm ² sec・
cmHg, especially 8.6×10 ^-16 to 1.0×10 ^-12 cc・cm/cm ²
It is preferable that the polymer has a range of sec/cmHg.

The halogen-containing polymer is a polymer that satisfies the above conditions, such as polyvinyl chloride, polyvinylidene chloride, polyvinyl fluoride, polyvinylidene fluoride, vinylidene chloride-acrylonitrile copolymer, vinyl chloride-acrylonitrile copolymer, chloride vinyl
It is selected from vinyl acetate copolymer and vinyl chloride-vinylidene chloride copolymer.

When a halogen-containing polymer is not used as the vehicle component polymer, it is necessary to disperse the organic halide in the polymer, particularly in a polymer that satisfies the above conditions.

These organic halides include tetrabromobutane, styrene dichloride, styrene dibromide, 1.1.
1,4-tetrabromo-3-phenylpropane,
1-(α-chloroethyl)naphthalene, 1-(β-
bromoethyl)naphthalene, 1-(1,2-dibromoethyl)naphthalene, and stilbene dichloride.

Examples of polymers containing dispersed organic halides include polystyrene, phenoxy resin, polymethyl methacrylate, etc.
Any material may be used as long as it is soluble in organic solvents and has excellent film-forming properties. Of course, it is also possible to use a dispersion of an organic halide in the above-mentioned halogen-containing polymer.

Various substrates can be used for the bubble photographic photoreceptor of the present invention, but films include polyester, polyethylene, polypropylene,
and polyvinyl acetate films are preferred;
Paper, metal and glass are also useful for some purposes. When a film is used as the base material, the photoreceptor of the present invention becomes a bubble photographic film (vesicular photographic film).

A bubble photographic photoreceptor is produced by dissolving the above-mentioned photosensitive substance, leuco base, and vehicle component in an organic solvent, and applying the solution to a base material to form a photosensitive layer.

Organic solvents include benzene, methanol, methyl ethyl ketone, tetrahydrofuran, acetonitrile, nitromethane, dimethyl sulfoxide,
Dimethylformamide, N-methylpyrrolidone are used. The vehicle component polymer is dissolved in an organic solvent together with the photosensitive material and the leuco base and applied to the substrate to form a photosensitive layer. However, between this photosensitive layer and the substrate, there is another polymer layer (hereinafter referred to as an intermediate layer). (referred to as a layer) may be applied. Examples of the polymer for the intermediate layer include copolymers of vinylidene chloride and acrylonitrile; thermoplastic polymers such as phenoxy resins and synthetic rubber; thermosetting resins such as epoxy resins used together with crosslinking agents. This intermediate layer strengthens the adhesion between the substrate and the photosensitive layer.

The bubble photographic photoreceptor of the present invention has been described in detail above, but when, for example, 2,4,2',4',2'',4''-hexamethoxytriphenylmethane is used as the leuco base in the photoreceptor of the present invention, An image is obtained in which the foamed areas are red and the non-foamed areas are colorless.

As described above, when the bubble photographic photoreceptor of the present invention is used, it is possible to obtain a foamed image area and a non-image area with clearly different colors, so that a bubble photographic image can be clearly seen even with reflected light. Furthermore, an image with sufficiently high contrast can be obtained.

The present invention will be described in more detail below based on Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded. In addition, "parts" and "%" in the examples represent "parts by weight" and "% by weight."

Example 1 Both solutions A and B having the following compositions were first prepared. To prepare each liquid, mix the following components in the following proportions,
This was done by uniformly dissolving it.

[Liquid A]

Vinylidene chloride-acrylonitrile copolymer (manufactured by Dow Chemical Company, trade name "Saran F-120")
100 parts 2, 4, 6, 2', 4', 6'-hexamethoxytriphenylmethane 5 parts Methyl ethyl ketone 400 parts Benzene 100 parts [Liquid B] p-N-N-dimethylaminobenzenediazonium chloride/zinc chloride double salt 10 parts acetonitrile 65 parts methanol 65 parts Next, solution B was filtered through a 0.2μ Millipore filter, and gradually added to solution A and mixed. The obtained homogeneous solution is spread on a polyester film with a thickness of 100μ for 25~
Apply with a doctor blade with a gap of 200μ65
It was dried at 115°C for 5 minutes, followed by 5 minutes at 115°C.

The original image of the silver halide film was brought into close contact with the photosensitive layer side of the bubble photographic photoreceptor film obtained in this way,
Expose from the silver halide film side with a high pressure mercury lamp, and then continue
When developed by passing through a hot roll at 140°C to form an image, a crimson foam image emerges on the background of the colorless non-foamed area, creating an extremely clear image that cannot be seen in conventional bubble photographs. I got something that was easy to see.

2, 4, 6, 2', 4', 6' - In the case of a bubble photographic photoreceptor that does not use hexamethoxytriphenylmethane, the foamed area is white and the non-foamed area is colorless, resulting in images that are difficult to see with the naked eye. Ta.

Example 2 Both solutions A and B having the following compositions were first prepared. To prepare each liquid, mix the following components in the following proportions,
This was done by uniformly dissolving it.

[Liquid A]

Vinylidene chloride-acrylonitrile copolymer (manufactured by Dow Chemical Company, trade name "Salan F-120")
100 parts 40% methyl ethyl ketone solution of polymethyl methacrylate (manufactured by Rohm and Haas, trade name "Acryloid A101") 53 parts 2, 4, 2', 4', 2''-pentamethoxytriphenylmethane 5 parts methyl ethyl ketone 400 Part benzene 100 parts [Liquid B] 4-(p-tolylmercapto)-2,5-diethoxybenzenediazonium chloride/zinc chloride double salt 10 parts Methyl ethyl ketone 70 parts Acetonitrile 30 parts Methanol 30 parts The above composition for both A and B A bubble photographic film was produced in the same manner as in Example 1 except that a foamed photographic film was used, and then an image was formed.A very clear image was obtained in which the foamed areas were reddish-purple and the non-foamed areas were colorless. .

Example 3 In Example 1, 2,4,6,2',4',6'-hexamethoxytriphenylmethane was replaced with 2,4,
A bubble photographic photoreceptor film prepared using 6, 2', 4', 6', 2''-heptamethoxytriphenylmethane was exposed in the same manner as in Example 1, and developed by passing it through a heated roll at 160°C. However, a clear image in which only the foamed image area was colored crimson was obtained.

Example 4 In Example 3, 2, 4, 6, 2', 4', 6', 2''-
2. instead of heptamethoxytriphenylmethane
A clear image in which only the foamed image area was colored deep red was obtained in the same manner as in Example 3 except that 4,6,2',4',6',3''-heptamethoxytriphenylmethane was used.

Example 5 In Example 3, 2, 4, 6, 2', 4', 6', 2''-
2. instead of heptamethoxytriphenylmethane
A clear image in which only the foamed image area was colored crimson was obtained in the same manner as in Example 3 except that 4,6,2',4',6',2'',3''-octamethoxytriphenylmethane was used. Ta.

In addition, 2. used in Examples 3, 4, and 5.
4,6,2',4',6',2''-heptamethoxytriphenylmethane, 2,4,6,2',4',6',3''-heptamethoxytriphenylmethane, and 2,4,
6,2',4',6',2'',3''-octamethoxytriphenylmethane was produced according to Synthesis Examples 1, 2 and 3 shown below.

Synthesis Example 1 3.36 g (20 mmol) of 1,3,5-trimethoxybenzene and 1.36 g (10 mmol) of 2-methoxybenzaldehyde were dissolved in 10 ml of ethanol, and mixed with concentrated hydrochloric acid while stirring under a nitrogen stream. When 2 drops were added and stirring was continued, a large amount of white precipitate was formed in 1 hour. When the crystals were filtered and recrystallized with an ethanol-benzene mixed solvent, 3.75 g (82.6%) of white crystals of 2, 4, 6, 2', 4', 6', 2''-heptamethoxytriphenylmethane were obtained. Ta.

The melting point of this compound was 204°C, and the elemental analysis values were as follows.

Calculated value as C H C ₂₆ H ₃₀ O ₇ 68.71% 6.65% Actual value 68.57% 6.31% Synthesis Example 2 Except for using 3-methoxybenzaldehyde instead of 2-methoxybenzaldehyde in Synthesis Example 1. In exactly the same way, 2, 4, 6, 2', 4',
6′·3″-heptamethoxytriphenylmethane was obtained. The yield was 1.78 g (39.2%).

The melting point of this compound was 152°C, and the elemental analysis values were as follows.

Calculated value as C H C ₂₆ H ₃₀ O ₇ 68.71% 6.65% Actual value 68.98% 6.70% Synthesis Example 3 Instead of using 2-methoxybenzaldehyde in Synthesis Example 1, 1.66 g (10 mmol) of 2. 3-
2, 4, 6, 2', 4', 6',
2″·3″-octamethoxytriphenylmethane was obtained. The yield was 4.16g (94.5%).

The melting point of this compound was 158.5°C, and the elemental analysis values were as follows.

Calculated value as C H C ₂₇ H ₃₂ O ₈ 66.93% 6.66% Actual value 66.71% 6.71%

Claims (1)

[Claims] 1. Aromatic diazonium salt, leuco base, and polyvinylidene chloride, polyvinylidene chloride, polyvinyl fluoride, polyvinylidene fluoride, vinylidene chloride-acrylonitrile copolymer, vinyl chloride-acrylonitrile copolymer, A halogen-containing polymer selected from vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, or tetrabromobutane, styrene dichloride, styrene dibromide, 1.
1,1,4-tetrabromo-3-phenylpropane, 1-(α-chloroethyl)naphthalene, 1-
(β-bromoethyl)naphthalene, 1-(1,2-
A bubble photographic photoreceptor in which a photosensitive layer containing a polymer in which an organic halide selected from dibromoethylnaphthalene and stilbene dichloride is dispersed is formed on a base material. 2. The aerated photographic photoreceptor according to claim 1, wherein the leuco base is polyalkoxytriphenylmethane.