JPS606498B2 - Photosensitized small bubble light and heat sensitive recording material - Google Patents

Description

Detailed Description of the Invention The present invention uses azobisnitrile as a photosensitive and heat-sensitive component,
The present invention relates to a small foam light and heat sensitive recording material using at least one compound selected from anthracene or pyrene and a protonic acid as a photosensitizer.

BACKGROUND ART Conventionally, known small foam recording materials include those in which, for example, a diazonium salt or an azide compound is uniformly dispersed in a thermoplastic polymer, and this is coated on a support such as a plastic film or black paper. In this small bubble photosensitive material,
Irradiation with ultraviolet rays decomposes the diazonium salt used as a photosensitizer in the exposed area and generates nitrogen gas. At the stage of irradiation with light, this gas dissolves into the thermoplastic polymer layer and appears transparent and is indistinguishable from unexposed areas.
When the polymer layer is heated, the polymer softens, and at the same time the nitrogen gas produced by decomposition coalesces and expands to form small bubbles, which have a refractive index different from that of the surrounding medium and scatter incident light. becomes. When the photosensitive material is subsequently irradiated with ultraviolet rays, the photosensitive agent in the exposed areas is decomposed and fixed, resulting in a light-scattering, small bubble-like recorded negative image. However, in this type of recording material, the photosensitizer, diazonium salt, etc.
These photosensitizers have the drawbacks of being unstable to humidity and having a short shelf life. Furthermore, since these photosensitizers are extremely sensitive to light, recording materials using them are difficult to use from the time of manufacture to the time of development of the recording material. It is necessary to always block out external light, and very strict attention is required to manage it. Furthermore, in order to obtain a recorded image using this type of recording material, a fixing process was always required after development. For example, to obtain this positive image, first,
A latent image is formed by exposure, and then a weak heat treatment is applied for a certain period of time to drive out the ultrafine particulate gas that forms the latent image o from the material. (i.e., the previously unexposed area) to form an oak image,
Finally, a heat development and fixing process had to be applied again to bubble the positive latent image. Its operation is extremely complicated and lacks practicality. The inventor of the present invention has repeatedly searched for various photosensitizers with the aim of resolving the various drawbacks of the Koike-like photosensitive recording material, and as a result, it has been discovered that a certain type of azobisnitrile can be used as a photosensitizer that meets the above objectives. I found it, published it, and filed a separate patent application for it (Tokugan 1986-36295).
No.) That's right.

The present invention uses azobisnitrile represented by the general formula [wherein R and R' represent the same or different linear or cyclic alkyl groups] or the formula as a small-foamed light- and heat-sensitive recording material. .

In the recording material using this, azobisnitrile has a temperature of 1. Since it has excellent stability not only against humidity but also against light, it can be stored for a long period of time, and it is easy to manage and handle during production and development.

For example, at a temperature of 7,000 degrees Celsius or lower, almost no decomposition of azobisnitrile, which is used as a photosensitive and heat-sensitive agent, is observed, and even if it is heated to about 9,000 degrees Celsius for a short period of time, its photosensitivity hardly decreases. Regarding light, there is almost no decrease in photosensitivity even if left indoors for several days with only fluorescent lamps as the light source, and even after 30 minutes of direct sunlight, it still remains as expected. There is no adverse effect on the photosensitivity of. Moreover, unlike conventional recording materials, there is no need to perform fixing treatment after exposure and development, and there is an advantage that not only negative images but also positive images can be easily formed by simply adjusting exposure conditions and heat development conditions as appropriate. Therefore, the recording material of the invention is
It can be advantageously used as a general copying material such as copy paper, and as a photographic material for projection in appropriate devices such as overhead projectors and microreaders. When irradiated with light with an intensity that is inversely proportional to the area ratio, it is possible to obtain a recorded image that is clear and has high resolution even if the exposure conditions are weakened.
It is suitable as a photographic material for microfilm.
However, 4. Foamy photosensitive and thermosensitive recording materials of this invention have conflicting photosensitivity and thermal stability (i.e. storage stability of unexposed raw recording materials), so even if the photosensitivity is low, they are not practical. Although it is suitable for reducing the size of microfilm that does not have an original film, for example, when using it as a recording medium for duplication that is printed in close contact with the original film of the subject, in other words, it takes a relatively long time to shoot, so it requires more light. It is desirable to shorten the time required to form a recorded image by increasing the sensitivity.

Therefore, the present invention was achieved through repeated research in order to appropriately increase only the photosensitivity of azobisnitrile used as a photosensitive and heat-sensitive component without impairing its thermal stability.

That is, the present invention contains azobisnitrile represented by the general formula (in which R and R' represent the same or different linear or cyclic alkyl groups) as a photosensitive component and a heat-sensitive component,
The present invention is a photosensitized small foam light and heat sensitive recording material using at least one compound selected from anthracene or pyrene and a protonic acid as a photosensitizer.

The azobisnitrile used in the present invention is that of the previous invention, that is, it is represented by the above general formula [1] or formula [b], and in formula [1], R and R are specifically the same or Differently methyl, ethyl, n-ph.

These are compounds that are lopyl, isopropyl, n-butyl, isobutyl, and cyclopropyl groups. Representative compounds thereof include azobisisobutyronitrile and azopiscyclohexanenitrile. In these azobisnitriles, the absorption of the azo group becomes remarkable when exposed to light with a wavelength around 3,300 to 3,800 Ao.
50A. The azo group has an absorption peak when exposed to light of a nearby wavelength. Therefore, it has the property of being decomposed by light including these wavelengths to generate nitrogen gas. Moreover, it has the feature that it similarly decomposes and generates nitrogen gas even when heated to a temperature exceeding 100 degrees. The recording material of the present invention utilizes the photo-thermal sensitivity peculiar to azobisnitrile. Among these, those having excellent thermal stability and relatively low photosensitivity, such as azobisisobutyronitrile and azobiscyclohexanenitrile, can be particularly preferably used.
When anthracene or pyrene is added to these materials, and a protonic acid is further added, a recording material having particularly enhanced storage stability at room temperature and appropriate photosensitivity can be obtained. This product not only does not require a special external light blocking device such as a darkroom, as long as it is not exposed to external light for a long period of time from the time of manufacturing the recording material until the time of development, it also eliminates the need for a special external light blocking device such as a darkroom. The time taken is greatly reduced, which is particularly meaningful from a practical point of view.
In this way, azobisisobutyi. It is surprising that photosensitizers such as anthracene or pyrene and protonic acid have a high degree of effect on substances such as nitrile, azobiscyclohexanenitrile, etc., which have relatively high decomposition energy and are in a solid solution phase. be. On the other hand, among azobisnitrile, "it has excellent photosensitivity but relatively poor thermal stability. Recording materials made by adding anthracene or pyrene to something like nitrile have further enhanced photosensitivity, so they should be stored in a cold storage from the time of production until the time of development.
Although it is practically inconvenient because it requires blocking external light, it can be useful depending on the purpose because its photosensitivity is significantly improved. The amount of anthracene or pyreso used in the present invention is 3 to 10 parts by weight, preferably 5 to 50 parts by weight, based on 100 parts by weight of azobisnitrile as the photosensitive and heat sensitive component.

If the amount of anthracene or pyrene added is too small, a sufficient photosensitizing effect will not be achieved, and if it is too large, there will be a tendency for the recording material to bleed. Further, as the protonic acid used in the present invention, trichloroacetic acid, phosphoric acid, shelf acid, tartaric acid and other appropriate ones can be mentioned, and the amount used is 3 to 100 parts by weight per 100 parts by weight of azobisnitrile. Preferably it is 5 to 50 parts by weight.

At this time, if the amount of protonic acid used is too large, there is a risk of bleeding or yellowing, and if it is too small, a sufficient effect cannot be expected. The small-shaped light- and heat-sensitive recording material of the present invention, which uses the above-mentioned azobisnitrile as a light- and heat-sensitive agent and at least one compound selected from anthracene or pyrene and a protonic acid as a sensitizer, is generally prepared using a suitable organic polymer. It is used in the form of a thin film using a molecular compound as a medium.

This film is usually prepared by dissolving or dispersing at least one azobisnitrile and the above photosensitizer in a suitable solvent solution of the above-mentioned polymeric medium, and then applying it on a support such as a plastic film or paper according to a conventional method. It can be applied by a coating method, a casting method, etc., or it can be formed by an appropriate film forming method such as a calendar method, an extrusion method, etc. according to a conventional method. Various types of organic polymer compound media can be used as long as they can be formed into a film in a transparent state.
Typically, for example, polymethacrylic resin, polyester resin, cellulose acetate resin, appropriate polymer compounds such as crosslinked products of polymeric polyol and polyisocyanate resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyolefin, etc. Examples include mixtures of the above-mentioned resins and copolymers of the respective monomers constituting these resins. In the present invention, the amount of azobisnitrile used together with these organic polymer compounds etc. is usually about 2 to 8% by weight, preferably about 10 to 5% by weight, based on the recording material. As mentioned above, anthracene or pyrene is used in an amount of 3 to 10 parts by weight, preferably 5 to 5 parts by weight, per 10 parts by weight of azobisnitrile.

. As mentioned above, the desired recording material is obtained by blending 3 to 10 parts by weight, preferably 5 to 5 parts by weight, of tonic acid to 10 parts by weight of azobisnitrile. If the amount of azobisnitrile blended is too small, it will be difficult to obtain a clear recorded image with the resulting recording material, and if it is too large, the compatibility with the organic polymer compound will be poor, making it easy to lead. In addition, a wide variety of solvents can be used when producing a film by the casting method, such as ethyl acetate, methylene chloride, methyl ethyl ketone, tetrahydrofuran, acetonitrile and other esters, alcohols, aromatics, halogenated solvents, etc. Examples include hydrocarbons. In addition to the above-mentioned azobisnitrile, asothracene or pyrene, protonic acid, and organic polymer compound medium, the recording material of the present invention may also contain various additives such as plasticizers, thickeners, and antistatic agents in accordance with conventional methods. It is possible to add additives. Furthermore, when manufacturing a film by a casting method, for example, a wide variety of supports can be used, such as polyethylene terephthalate, polyolefin resins, Transparent film bases such as polyamide resin, cellulose triacetate, paper, glass, etc.
Opaque bodies such as plates and metal plates can be used.

Thus, a polymer formed uniformly contains azobisnitrile as a photosensitive and heat sensitive agent, anthracene or pyrene as a photosensitizer, and a protonic acid. compound film,
The light and heat sensitive recording material of the present invention is obtained which consists of two layers including a support.

The light and heat sensitive recording material of the present invention can be advantageously used as copying paper, projection film, etc. in the form of a resin film containing a light and heat sensitive agent coated on a suitable support as described above. If necessary, it is also possible to peel only the resin film formed on the support to create a single layer film, or to create a three or more layer film with a protective layer on the resin film. be.

In addition, the recording material of the present invention can also be formed into a single-layer film by using a calendaring method, an extrusion method, etc., using a composition containing a photosensitive heat-sensitive agent and its medium as in 1. Of course, if necessary, it can be made into two or three layers by using the above-mentioned support and protective layer.
In the present invention, asobisnitrile used as a photosensitive and heat sensitive agent is “
There is no risk of decomposition at temperatures below 7,000 degrees Celsius, and it has excellent thermal stability. Therefore, when producing recording materials using this material, there is no need for any particular cooling, and instead it is melted in a solvent together with a polymer compound. - When producing a film by the casting method, it is even possible to slightly heat it to improve its solubility. There is no particular limit to the thickness of the recording material film of the present invention, but if it is too thin, the endothermic effect during the heating phenomenon will be so low that it may be difficult to obtain a preferable bubble-like recorded image.

In this case, as described above, it may be used as it is coated on the support, or a protective layer may be provided as the uppermost layer.
To obtain a negative image using the recording material of the present invention described above, the following operation may be performed.In other words, the recording material of the present invention may be used, for example, with colored (non-transparent) image areas and non-image areas. Ayabe exposes the subject with a material that transmits light.As a light source, any light source including light with wavelengths in the vicinity of 3450A (3300 to 3800A) can be used, such as sunlight, mercury lamps, and high-pressure mercury lamps. , carbon arc lamp,
An example is a xenon lamp. Also, when it comes to exposure,
Of course, it is possible to directly project the light from the light source onto the recording material, but it is also possible to use reflected light or convergence using a convex lens or the like. Regarding the exposure time, the azobisnitrile in the portion of the recording material corresponding to the non-image area of the recording material is almost completely decomposed and nitrogen gas is generated. It is preferable that the recording material maintains a transparent state throughout while being fused in the resin. Even if a drug is used,
Decomposition of azopisnitrile and generation of nitrogen gas are not carried out sufficiently, making it difficult to form a clear image. Furthermore, if the exposure is too strong, nitrogen gas generated by decomposition will be dissipated outside the recording material, making it difficult to obtain a clear negative image. In the present invention, heat development treatment is then performed.

As the heating source used here, any of the conventionally known heat sources such as hot gas, hot liquid, hot roll, hot press, high frequency, etc. can be used.In order to obtain a clearer image, it is necessary to A far-infrared heater capable of heating the inside is suitable.The heat development temperature and time using the above heating source are as follows:
It may be determined as appropriate depending on the type and amount of the azobisnitrile and polymer compound medium used as the recording material, the thickness of the recording material, etc. If the heating conditions are too harsh, the azobisnitrile present in the unexposed portions of the recording material may form small bubbles due to rapid thermal decomposition. The nitrogen gas generated during exposure by the heat development coalesces and expands, forming countless small bubbles that can be seen with the naked eye, thus producing a negative image in which the small pond portions have light scattering properties. Further, in order to make the negative image obtained as described above clearer, it is preferable to shorten the time from the start of exposure to the start of development as much as possible.

Although the azobisnitrile in the portion corresponding to the image area of the negative image obtained by the above method remains undecomposed, in the present invention, there is no need to fix this portion by re-exposing or the like. In other words, the azobisnitrile in this part gradually decomposes due to external light, etc., but the extremely fine nitrogen gas that is generated does not expand and coalesce at all to increase its bubbles, but instead escapes into the atmosphere as it is. In order to go
Numerous small ponds that can be observed with the naked eye are not formed on the material surface, and there is no possibility of light scattering occurring at all. The recording material of the present invention can also form a positive image with an easy operation similar to the formation of the above-mentioned negative image.

That is, in order to obtain a positive image, the above exposure should be carried out for a longer period of time or the exposure intensity should be increased to first decompose all the azobisnitrile in the area corresponding to the non-image area, and remove the generated nitrogen. The gas is dissipated into the atmosphere in the extremely fine state as described above. The recording material thus obtained, which remains completely transparent to the naked eye, is then heated with a heating device, such as a far-infrared heater, for a longer period of time than is required to obtain a negative image. By this heating, the azobisnitrile present in the unexposed portions of the recording material is thermally decomposed to generate nitrogen gas, which is foamed by continued heating and forms numerous small ponds on the surface of the recording material. These countless small bubbles are sufficiently visible to the naked eye and are large enough to reflect or refract light, so this portion has light scattering properties and forms a positive image. This no longer requires any subsequent fixing treatment. In addition, there is no problem when forming a self-positive image if the exposure conditions are strong, but in the unlikely event that some azobisnitrile may remain in the exposed area even after exposure, it is preferable to It is preferable to leave the film for an appropriate period of time to completely dissipate the remaining nitrogen gas, and then heat and develop it. In addition, when creating a positive image using the recording material of the present invention, methods according to the prior art,
Of course, it is also possible to create a positive image using other known methods. As described above, the recording material of the present invention can be
By appropriately selecting the time from exposure to development and the intensity of heating during development, both negative and positive images can be easily formed, and in particular the fact that positive images can be obtained by the above operations. This is completely unthinkable from conventional photosensitive materials using diazonium salts and the like.

In addition, by using this recording material, it is particularly useful not only as a microfilm but also as a contact recording medium for duplication (dupe film). Not only does this method have the advantage of being applicable to a wide range of applications, but it can also be expected to significantly shorten the time required to form a bride, resulting in great benefits. Although the method of creating negative images and positive images using the transmission method has been explained above, the self-recording material of the present invention is not limited to this, and similarly clear images can be obtained using the reflection method, etc. When applying the reflection method, there is an advantage that ordinary books, literature, etc. can be copied as is. Examples will be given below to explain the present invention in more detail.

Example 1 Cellulose triacetate4. Chicks and cellulose diacetate were dissolved in 12 parts of methylene chloride, and 41.5 parts of a tetrahydrofuran solution was prepared by dissolving 1.5 parts of pyrene in this.
6 g, and azobisisobutyronitrile 4.

Add 24.55 g of an acetonitrile solution containing 5 spots to each, and add more water.

0.5 g of acetic acid was added, and the mixture was stirred to become homogeneous.
The thus obtained liquid was applied onto a cellulose triacetate film having a thickness of 100 mm using a tabletop hand coater, and the film was left to dry for 3 minutes in a 70 oo temperature dryer. The mixture was then left in a room overnight to obtain a two-layer light and heat sensitive recording material of the present invention. The thickness of this recording medium was 115 mm. On the light- and heat-sensitive recording material obtained above, an original with a colored (non-transparent) image area and a material that transmits light in the non-image area was layered as a subject, and an 18W' high-pressure mercury lamp was used as a light source. A sand exposure was carried out at a distance of 2.5 degrees from the light source. Next, the recording material was left in the basement overnight,
Fine nitrogen gas, which is invisible to the naked eye, generated in the recording material portion corresponding to the non-image area of the original was completely dissipated into the air.
Next, the recording material was heated with a far-infrared heater (800W x 1,
When heat-developed for 6 seconds at a distance of 10 degrees, a clear positive image appeared. Comparative Example 1 A heat-sensitive photosensitive material with a thickness of 115 mm was obtained in the same manner as in Example 1 except that trichloroacetic acid was not included.

In order to obtain a clear positive image comparable to that of the example, the exposure time was 3 hours. Example 2 Using the same recording material as used in Example 1, exposure was carried out for 5 seconds in the same manner as in G.

The document was then immediately heated and developed for 4 seconds using a far-infrared heater, and a negative image of the original appeared. Comparative Example 2 Using the same recording material as that used in Comparative Example 1, "Example 2" was prepared.
In order to obtain a negative image of the same degree of clarity using the same operation as above, an exposure time of 19 seconds was required.

Example 3 Using the same recording material as that used in Example 1, the same subject was superimposed and exposed for 10 seconds at a distance of 2.5 skin from the light source using an 18W skin high pressure mercury lamp as the light source.

Next, the recording material was left on the floor overnight. Then, using the same high-pressure mercury lamp as a light source, the entire surface of the sand was exposed at a distance of 2.5 cm from the light source. Then, it was immediately heated with a far-infrared heater (800 W x 1). When heat development was performed for 6 seconds at a distance of 10 cm, a clear positive contact image was obtained. Comparative Example 3 Using the same recording material as used in Comparative Example 1, Example 3
In order to obtain a close-up image with a positive image of the same level of clarity, the first exposure time was 3 mm, and the next full-surface exposure time was 9 mm.

Example 4 The same recording material as used in Example 1 was used, the same subject was overlapped, and a 54W high-pressure mercury lamp made of quartz glass instead of Pyrex was used as the light source. and 0.5 cm at a distance of 2.5 skin from the light source. Shinsho, exposed.

Next, the recording material was left on the floor overnight. After that, the entire surface of mirror sand was exposed using the same high-pressure mercury lamp as a light source at a distance of 2.5 cm from the light source, and then immediately exposed to far-infrared heat (800 W x When the film was heat-developed for 6 seconds at a distance of 10 cm using a 100° film, a clear positive contact image was obtained.
Example 5 A light and heat sensitive recording material of the present invention was obtained in exactly the same manner as in Example 1 except that anthracene, a substitute for pyrene, was used.

When tested in the same manner, the same clear positive image appeared. Comparative Example 40 Using the same recording material as that used in Comparative Example 1 and performing the same operations as in Example 4, it took an initial exposure time of 2.5 seconds to obtain a close-contact image with a positive image of the same level of clarity. , the next full exposure time is 7.9
It was sand.

Claims (1)

[Claims] 1 General formula ▲ Numerical formula, chemical formula, table, etc. ▼ [In the formula, R and R' represent the same or different chain or cyclic alkyl groups], or formula ▲ Numerical formula, chemical formula It is characterized by containing azobisnitrile represented by ▼ as a photosensitive/thermosensitive component, and using at least one compound selected from anthracene or pyrene and protonic acid as a photosensitizer. A photosensitized small-bubbled light- and heat-sensitive recording material.