JP3389355B2 - Heat-developable copy material - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-developable copy material using a photosensitive diazo compound, and more particularly to a heat-developable copy material having improved storage stability at the background. About. 2. Description of the Related Art Copying materials utilizing the photosensitivity of diazo compounds are widely used because they are inexpensive, and are roughly classified into the following three types. The first type is a type known as a wet development type in which a photosensitive layer having a diazo compound and a coupling component as main components is provided on a support. After exposure, development is performed using an alkaline solution. The second type is a type known as a dry development type, which is different from a wet development type in that development is performed with ammonia gas. The third type is known as a heat development type. In addition to a type containing an ammonia gas generating agent such as urea capable of generating an ammonia gas by heating in the photosensitive layer, the photosensitive layer includes Activating a diazo compound and a coupling component by heating and melting a type containing an alkali salt of a compound that loses properties as an acid by heating, such as trichloroacetic acid, as a color development aid using a higher fatty acid amide. There are types used. [0004] The wet type has problems in maintenance and management, such as the need for replenishment and disposal of the developer due to the use of the developer, the large size of the apparatus, and the like. In addition, it has drawbacks such as not being able to be retouched and the copy image not being able to withstand long-term storage. Also, in the case of the dry type, as in the case of the wet type, it is necessary to replenish the developing solution and, in addition, it is necessary to have a gas suction facility to prevent the generated ammonia gas from leaking to the outside. In addition, there is a drawback such as a strong ammonia smell immediately after copying. On the other hand, the heat developing type has a maintenance advantage that a developing solution is unnecessary unlike the wet type or the dry type, but the developing temperature is as high as 150 ° C. to 200 ° C. In addition, if the temperature control is not performed within the range of about ± 10 ° C., the development will be insufficient or the color tone will be changed. Therefore, in order to obtain a good image, the cost of the apparatus must be increased. was there. Also, in order to withstand such high-temperature development, the diazo compound used also needs to have high heat resistance,
Such compounds are often disadvantageous in obtaining high image densities. Therefore, conventionally, low-temperature development (90 ° C. to 1
(30 ° C.), but there is a drawback that the shelf life of the material itself is reduced. Therefore,
At present, the heat development type has not yet occupied the mainstream of the diazo copying system, although the maintenance advantages are expected to be sufficiently higher than those of the wet type and the dry type. [0007] On the other hand, the needs of users are diversifying. For example, there is a need not only to obtain a colored image on a white background as in the past, but also to select the hue of the background and the developed image according to the purpose of use. Has also occurred. This is because when a copy material is used for the purpose of drawing or posting, it becomes necessary for the user to pay attention, and the conventional copy material no longer satisfies the demand. By the way, in order to obtain a desired color density by heating a material provided with a layer containing a diazo compound, a coupling component and a color-forming auxiliary on a support, each component is instantaneously melted by heating. It is necessary to diffuse and react to form a coloring dye. In this case, if the copying material is designed so that a high-density image can be obtained by sufficiently developing a color even at a low heating temperature, the color-forming reaction, of course, slightly increases even during storage at room temperature before copying. The color of the background portion, which must be whitened, must be advanced, causing the background stain. The above-mentioned problem that is seemingly incompatible is that the above-mentioned diazo compound is incorporated into a microcapsule in a copying material provided with a heat-developable photosensitive layer containing a diazo compound, a coupling component and a color-forming auxiliary on a support. The problem was substantially solved by including the compound in the compound (JP-A-59-91438). However, also in this case, when the image density is sufficiently increased, there is a disadvantage that the storability of the copy material before use is not sufficient. The present inventors have already proposed a copying material using a sulfonamide compound or a biphenyl compound as a recording material for solving the above-mentioned drawbacks (JP-A-1-248147 and JP-A-6-148147).
-27581). However, since these compounds have poor dissolution stability to diazo compounds, the copy materials used by encapsulating them in microcapsules containing a diazo compound and mixing them with coupling components cause background fog. There were drawbacks. In addition, the present inventors have already proposed to use a hydroxyphenylsulfone derivative having excellent dissolution stability for a diazo compound in order to solve the above-mentioned drawbacks (Japanese Patent Application Laid-Open No. 5-305767). However, a copy material using the above-mentioned hydroxyphenylsulfone derivative has a drawback that the storage stability after copying is poor because the background is colored after copying. The present inventors have conducted intensive studies to solve the above-mentioned drawbacks. As a result, the present inventors have further added a hydroxyphenylsulfone derivative and a bisphenol derivative in a microcapsule containing a diazo compound. The present inventors have found that extremely good results can be obtained when they are included, and have reached the present invention. Accordingly, an object of the present invention is to prevent background stains from occurring, to provide better storage stability before copying than ever before, to reduce background fog, to provide excellent storage stability after copying, and to achieve a high image density capable of obtaining a high image density. An object of the present invention is to provide a development type copying material. The object of the present invention is to provide a photosensitive diazo compound, a hydroxyphenylsulfone derivative, a bisphenol derivative and a coupling component which reacts with the diazo compound to form a color on a support. Wherein the diazo compound, the hydroxyphenylsulfone derivative, and the bisphenol derivative are encapsulated in microcapsules. Achieved. The photosensitive diazo compound used in the present invention includes a photodegradable diazonium salt, diazosulfonate,
It causes a coupling reaction with a coupling component such as a diazoamino compound to develop color and decompose by light,
It can be appropriately selected from known diazo compounds and used. In the present invention, among these diazo compounds, particularly from the viewpoint of photosensitivity and image density, the general formula Ar
It is preferable to use a diazonium salt represented by N ₂ ⁺ X ⁻ (wherein, Ar represents a substituted or unsubstituted aromatic moiety, N ₂ ⁺ represents a diazonium group, and X ⁻ represents an acid anion. ). Specific examples of the diazonium salt include 4-diazo-1-dimethylaminobenzene and 4-diazo-1
Diethylaminobenzene, 4-diazo-1-dipropylaminobenzene, 4-diazo-1-methylbenzylaminobenzene, 4-diazo-1-dibenzylaminobenzene, 4-diazo-1-ethylhydroxyethylaminobenzene, 4- Diazo 1 diethylamino 3 methoxybenzene, 4 diazo 1 dimethylamino 2 methylbenzene, 4 diazo 1 benzoylamino
2,5-diethoxybenzene, 4-diazo 1-morpholinobenzene, 4-diazo 1-morpholino 2,5
Diethoxybenzene, 4-diazo 1-morpholino
Examples thereof include 2,5-dibutoxybenzene, 4-diazo-1-toluylmercapto-2,5-diethoxybenzene, 4-diazo-1,4-methoxybenzoylamino-2,5-diethoxybenzene and the like. Specific examples of the acid forming the diazonium salt include C _n F _{2n + 1} COOH (n is an integer of 1 to 9) and C _m F _{2m + 1} SO ₃ H (m is 1 to 9). , Boron tetrafluoride, tetraphenylboron, hexafluorophosphoric acid, aromatic carboxylic acid, and metal halides such as zinc chloride and tin chloride. The coupling component used in the present invention is a component which forms a dye by coupling with a diazo compound under heating, and specific examples thereof include resorcin, phloroglucin, 2,3-dihydroxynaphthalene {6-} sulfone. Sodium acid, 1-hydroxy-2-naphthoic acid morphopropylamide, 1,5-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,3-dihydroxy-6-sulfanylnaphthalene, 2-hydroxy-3-naphthoic acid Morpholinopropylamide, 2-hydroxy-3-naphthoic acid anilide, 2-hydroxy
3-naphthoic acid 2'-methylanilide, 2-hydroxy-3-naphthoic acid ethanolamide, 2-hydroxy-3-naphthoic acid octylamide, 2-hydroxy-3
{Naphthoic acid} N {dodecyl} oxypropylamide, 2-hydroxy-3-naphthoic acid tetradecylamide, acetanilide, acetoacetanilide, benzoylacetanilide, 1-phenyl-3-methyl-5-pyrazolone, 1 (2 ′ , 4 ', 6' {trichlorophenyl) {3} benzamide {5} pyrazolone, 1}
(2 ′, 4 ′, 6′─trichlorophenyl) ─3─anilino─5- ゾ pyrazolone, 1─phenyl─3-phenylacetamide─5-─pyrazolone and the like. An image of any color tone can be obtained by using two or more of these coupling components in combination. In the present invention, for the purpose of promoting the coupling reaction by making the system basic during thermal development, it is preferable to add a basic substance that acts as a color-forming aid, if necessary. As such a basic substance, a water-insoluble or water-insoluble basic substance or a substance that generates an alkaline substance by heating is used. Specific examples of the basic substance include inorganic and organic ammonium salts, organic amines, amides, urea and thiourea and derivatives thereof, thiazoles, pyrroles, pyrimidines, piperazines, guanidines, indoles,
Examples include nitrogen-containing compounds such as imidazoles, imidazolines, triazoles, morpholines, piperidines, amidines, formamidines, and pyridines. These basic substances can be used in combination of two or more. In the present invention, a phenol derivative, a naphthol derivative, an alkoxy-substituted benzene, an alkoxy-substituted naphthalene, a hydroxy compound,
Acid compounds, sulfonamide compounds and the like can be further added. These compounds reduce the melting point of the coupling component or the basic substance or improve the heat permeability of the microcapsule wall, and as a result, function as a color-forming aid, thereby obtaining a high color-forming density. . The coloring aid in the present invention includes a heat-fusible substance. Here, the heat-fusible substance is a substance which is solid at normal temperature and melts by heating and has a melting point of 50 ° C. to 150 ° C., and is a substance which dissolves a diazo compound, a coupling component or a basic substance. Specific examples of the heat-fusible substance include fatty acid amides, N-substituted fatty acid amides, ketone compounds, urea compounds, esters, and the like. The hydroxyphenylsulfone derivative used in the present invention is a compound represented by the following formula (1), which is added to prevent background stains. Particularly preferred. Embedded image Embedded image In the formula, R ₁ represents a hydrogen atom, a substituted or unsubstituted lower alkyl group, an alkoxy group or an amino group, or a halogen atom, and R ₂ has a substituent represented by the above R _1. An alkyl group or an aryl group, l is 1 or 2, and m is an integer of 0 to 3. In the formula 2, R ₃ is a hydrogen atom, a substituted or unsubstituted lower alkyl group, an alkoxy group or an amino group, or a halogen atom, and n is an integer of 0 to 3. Specific examples of the hydroxyphenylsulfone derivative include compounds represented by the following chemical formulas (3) and (4). Embedded image Embedded image The amount of the hydroxyphenylsulfone derivative used is 0.0
It is preferably from 5 to ² g / m ² . 0.05g / m
^If it is ² or less, there is no effect in preventing the background stain, and 2 g
/ M ² or more is not preferred because the background density after storage increases. The bisphenol derivative used in the present invention is a compound represented by the following formula (5). Embedded image Wherein R ₁ and R ₄ are a hydrogen atom or a lower alkyl group;
R ₂ and R _{3 each} have 1 to 12 hydrogen atoms or carbon atoms,
It is a substituted or unsubstituted alkyl group. Representative examples of bisphenol derivatives include bisphenol A, and other specific examples include bisphenol F, 1,
1-bis (4-hydroxyphenyl) propane, 2,2
-Bis (4-hydroxyphenyl) -4-methylpentane, 1,1-bis (4-hydroxyphenyl) -2-ethylhexane, 1,1-bis (4-hydroxyphenyl) -cyclohexane and the like. By using at least one of these bisphenol derivatives, the storage stability after copying can be improved. The use amount of the bisphenol derivative is preferably 0.05 to ² g / m ² .
At 0.05 g / m ² or less, the background fog is reduced, and there is no effect of improving the storage stability after copying, and
If it is 2 g / m ² or more, the background density after storage increases, which is not preferable. The hydroxyphenyl derivative and the bisphenol derivative are encapsulated in a microcapsule together with the diazo compound. In the present invention, from the viewpoint of further improving the storage stability of the copy material, the recording layer may contain a reducing metal salt. For more information on these metal salts,
It is described in Japanese Patent Application No. 3-313467. In the present invention, the coupling component is 0.1 to 10 parts by weight, and the coloring aid is 0.1 to 10 parts by weight based on 1 part by weight of the diazo compound.
It is preferred to use 20 parts by weight. The diazo compound is desirably applied at 0.05 to 5.0 g / m ² . The microcapsules of the present invention are prepared by emulsifying a core substance and then forming a wall of a polymer substance around the oil droplets. The reactant that forms the polymeric substance is added inside the oil droplet and / or outside the oil droplet. Specific examples of the polymer substance include polyurethane, polyurea, polyamide, polyester, polycarbonate, urea-formaldehyde resin, and melamine resin. Two or more polymer substances can be used in combination. Preferred polymeric substances are polyurethane, polyurea,
Polyamide, polyester, polycarbonate,
More preferred are polyurethane and polyurea. In the case of polyurethane and polyurea, tolylene diisocyanate trimethanol propane adduct, tolylene diisocyanate isocyanurate, xylylene diisocyanate trimethanol propane adduct, xylylene diisocyanate isocyanurate, hydrogenated xylylene diisocyanate isocyanate It is preferred to use a nullate form. As the physical properties of the polymer substance, a polymer substance having a melting point of 150 ° C. or higher, which does not melt at the temperature during thermal recording, is preferable. Microcapsules can be made from emulsions containing at least 0.2% by weight of the component to be microencapsulated. The microcapsules used in the present invention are:
After dissolving the diazo compound and the coupling component together with the monomer for forming the capsule wall in a non-aqueous solvent having a low boiling point, the microcapsules containing substantially no solvent, such as those obtained by distilling off the solvent during the polymerization reaction. Preferably, there is. The polymer forming the microcapsule wall can be obtained by polymerizing the corresponding monomer by the method described above. The amount of the monomer used is such that the average particle size of the obtained microcapsule is 0.3 to 12 μm. It is determined to be. By enclosing the diazo compound, the hydroxyphenylsulfone derivative and the bisphenol derivative in the microcapsules produced in this way, the background soil at normal temperature is prevented more than ever. The coupling components, basic substances, and other color-forming auxiliaries which are not contained in the microcapsules used in the present invention may be used as a solid dispersion with a water-soluble polymer using a sand mill or the like. Preferred water-soluble polymers include water-soluble polymers used for preparing microcapsules (for example, JP-A-59-19090).
886). In this case, the coupling component and the color-forming aid are added in amounts of 10 to 50% by weight based on the water-soluble polymer solution. The size of the dispersed particles is preferably 10 μm or less. In order to form a substantially transparent recording layer, the above components are dissolved in a water-insoluble or insoluble organic solvent and then mixed with an aqueous phase containing a surfactant and a water-soluble polymer as a protective colloid. And used in the form of an emulsified dispersion. The coating liquid of the present invention can be applied by a well-known coating method such as bar coating, blade coating, air knife coating, gravure coating, doctor coating, slide coating, roll coating coating, spray coating, dip coating, curtain coating and the like. And Yuji Harazaki, "Coating Engineering" 2
It is applied by a method described on page 53 (published by Asakura Shoten in 1973). The photosensitive layer of the present invention is set so that the solid content after coating and drying is 1.5 to 15 g / m ² . In the copying material of the present invention, the diazo compound, the coupling component, the base and the like may be contained in the same layer as described above. it can. In addition, Japanese Unexamined Patent Publication No.
After providing an intermediate layer as described in JP-A-1-54980, a photosensitive layer can be applied. A protective layer can be further provided on the photosensitive layer. When an image is to be formed on the copy material of the present invention, an imagewise exposure corresponding to the original is performed to decompose the diazo compound in the exposed portion, and then the entire copy material is heated and the unexposed portion of the diazo compound is heated. To obtain a colored image by reacting with a coupler, or beforehand, heat recording like an image using a hot pen or thermal head, and then irradiating the entire surface of the copy material with light to decompose the diazo compound in the uncolored part Establish. For the imagewise exposure corresponding to the original, if it is a transparent original, it is easy to perform close exposure, but other methods, for example, exposure with a laser beam may be adopted. As a light source for exposure, various fluorescent lamps, xenon lamps, mercury lamps and the like are used. In this case, it is preferable that the emission spectrum of the light source substantially coincides with the absorption spectrum of the diazo compound used. As the heating means in the step of heating and developing the entire surface of the photosensitive layer of the copying material, an infrared ray, a high frequency wave, a heat block, a heat roller and the like can be used. As described in detail above, the heat-developable copying material of the present invention in which a bisphenol derivative and a hydroxyphenylsulfone derivative are encapsulated in a microcapsule together with a diazo compound has better storage stability before copying than before. In addition to being excellent, there is little background fog and excellent storage stability after copying, and the image density is high. EXAMPLES Examples will be shown below, but the present invention is not limited by these examples. “Parts” indicating the amount of addition represents “parts by weight”. Embodiment 1 Preparation of Microcapsule Solution 2 parts of a diazonium salt represented by the following formula 6, 1 part of a compound represented by the following formula 7, and 1 part of a compound represented by the following formula 8 were added to 5 parts of ethyl acetate and dissolved. . Embedded image Embedded image Embedded image To the solution of the diazo compound and the like, 5 parts of an aromatic isocyanate (Barnock D-750: trade name, manufactured by Dainippon Ink Co., Ltd.) was added and mixed with stirring. Ethyl acetate solution of the diazonium salt, isocyanate and the compound represented by the above formulas (7) and (8) thus obtained was dissolved in 10 parts of water by 1 part of polyvinyl alcohol (PVA217E: trade name of Kuraray Co., Ltd.). The resulting mixture was mixed with the aqueous solution and emulsified and dispersed to obtain an emulsion having an average particle size of 1.0 μm. 10 parts of water was added to the obtained emulsion, and the mixture was heated to 40 ° C. with stirring to react isocyanate, which is a wall-forming substance, for 3 hours. The average particle diameter was 1 μm. Microcapsules containing the compound represented by Chemical formula 8 as a core substance were obtained. The above encapsulation reaction was performed using a water jet pump at 400 mmHg to 500 mmHg.
Under reduced pressure. Preparation of Coupler Dispersion Solution 2 5-Hydroxy-3-naphthoic acid anilide (5 parts) and triphenylguanidine (5 parts) were added to a 5% by weight aqueous solution of polyvinyl alcohol (100 parts) and dispersed in a sand mill for 24 hours to give an average particle size of 2 μm. Was obtained. Preparation of Coating Solution To 10 parts of the above diazonium salt capsule solution, 25 parts of the above coupler dispersion, 10 parts of a 40% by weight calcium carbonate (Univar 70 manufactured by Shiraishi Kogyo) dispersion, and 20% by weight of a stearamide amide dispersion 5 parts and 2 parts of a 40% by weight dispersion of zinc 3,5-di-α-methylbenzylsalicylate were added to prepare a coating solution. Preparation of Copy Material The above coating solution was coated on smooth high-quality paper (76 g / m ² ) using a coating bar so that the dry weight was 5 g / m ^2, and the coating solution was coated at 50 ° C. for 3 minutes. After drying, a copy material was obtained. Evaluation of storage stability Storage stability before recording: The obtained copy material was stored at 40 ° C. for 24 hours in a dark atmosphere at a relative humidity of 90% (90% RH) and subjected to a forced deterioration test. , 10mW / c
After irradiating with a fluorescent lamp having an m ² output for 30 seconds, a hot plate at 150 ° C. was pressed for 5 seconds, and the density of the portion was measured using a Macbeth densitometer. Storage stability after recording: 30 with fluorescent lamp of 10 mW / cm ² output
After irradiating with light for 2 seconds, the recording material having a background portion pressed against a hot plate at 150 ° C. for 5 seconds is sealed for one week in a container filled with exhaust gas (containing NO _x ) of an oil stove, and the background portion before and after the sealing is closed. The density change was evaluated visually. The above results are as shown in Table 1. Embodiment 2 FIG. A coating solution was prepared in exactly the same manner as in Example 1, except that 1 part of the compound represented by the formula 7 was changed to 1.5 parts and 1 part of the compound represented by the formula 8 was changed to 0.5 part. A copy material was prepared and then evaluated for shelf life.
The results are as shown in Table 1. Embodiment 3 FIG. A coating solution was prepared in exactly the same manner as in Example 1 except that 1 part of the compound represented by the formula 7 was changed to 0.5 part and 1 part of the compound represented by the formula 8 was changed to 1.5 parts. A copy material was prepared and then evaluated for shelf life.
The results are as shown in Table 1. Embodiment 4 FIG. Instead of 5 parts of the isocyanate used in Example 1, isocyanate (Sumidur FL)
-2: Example 1 except that 3 parts of Sumitomo Bayer Urethane Co., Ltd.) and 3 parts of isocyanate (Takenate D127N: trade name of Takeda Pharmaceutical Co., Ltd.) were used.
Prepare a coating solution in exactly the same way as in
Next, the storage stability was evaluated. The results are as shown in Table 1. Comparative Example 1 A coating solution was prepared in exactly the same manner as in Example 1 except that the following emulsion was used in place of the emulsion used in the preparation of the microcapsule solution of Example 1, and a copy material was prepared. Was evaluated. The results are as shown in Table 1. The word "impossible" in the table means that the diazo compound cannot be microencapsulated, and the copy material produced using this solution cannot be used because the background density is too high. Emulsified liquid 2 parts of the diazonium salt represented by Chemical formula 6 used in Example 1 was added to and dissolved in 5 parts of ethyl acetate, and the mixture was dissolved in an isocyanate (Barnock D-750: trade name of Dainippon Ink and Chemicals, Inc.). 5 parts were added and mixed with stirring. The thus obtained diazonium salt and isocyanate in ethyl acetate and the compound of formulas 7 and 8 in ethyl acetate were mixed with polyvinyl alcohol (PVA217E:
One part of a product (trade name, manufactured by Kuraray Co., Ltd.) is mixed with an aqueous solution in which 1 part is dissolved in 10 parts of water, and emulsified and dispersed to have an average particle size of 1.0 μm.
m was obtained. Comparative Example 2 The diazonium salt and the isocyanate used in Comparative Example 1 were mixed with the ethyl acetate solution in Example 1
A coating solution was prepared and a copy material was prepared in the same manner as in Comparative Example 1, except that 5 parts of the compound represented by Chemical formula 7 was added, and then the storage stability was evaluated. The results are as shown in Table 1. Comparative Example 3 A coating solution was prepared in exactly the same manner as in Comparative Example 1 except that 5 parts of the compound represented by Chemical Formula 8 used in Example 1 was added to the ethyl acetate solution of the diazonium salt and the isocyanate used in Comparative Example 1, and a copy was prepared. A material was prepared, and then storage stability was evaluated. The results are as shown in Table 1. [Table 1] In the table, ◎ indicates excellent, ○ indicates good, and × indicates bad. The results of the above Examples and Comparative Examples demonstrate the effectiveness of the present invention. Written statement describing chemical formula etc. [Table 1]

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41M 5/28-5/34 G03C 1/52

Claims (1)

(57) [Claim 1] A recording layer containing a photosensitive diazo compound, a hydroxyphenylsulfone derivative, a bisphenol derivative and a coupling component which reacts with the diazo compound to form a color on a support. Wherein the diazo compound, the hydroxyphenylsulfone derivative, and the bisphenol derivative are encapsulated in microcapsules.