Radiation imagery chemistry: process – composition – or product th – Microcapsule – process – composition – or product
Reexamination Certificate
2000-04-24
2002-02-12
Chu, John S. (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Microcapsule, process, composition, or product
C430S163000, C430S179000, C430S182000, C544S282000, C544S287000, C544S293000
Reexamination Certificate
active
06346359
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a novel pyrrolopyrimidineone compound. Further, the present invention relates to a heat-sensitive recording material using a diazonium salt and a coupler as color forming components. More specifically, the present invention relates to a novel purple to cyan color forming type diazo heat-sensitive recording material with excellent color forming property.
2. Related Art
In a color forming reaction system using a coupler and a diazonium salt, color forming reaction rate (coupling rate) often presents a problem. In particular, in a diazo coupling heat-sensitive recording material, it is usually necessary to improve the coupling rate from the standpoint of improving color forming property. Normally, for a particular diazonium salt, the coupling rate is roughly determined by the skeleton of the coupler. The coupling rate can be raised by appropriately changing the substituent group which is at a position other than the coupling position. This change, however, impairs the stability of the coupler and therefore will bring about various defects, such as increase of background coloration due to exposure to light, in a heat-sensitive recording material. That is, coupling activity and coupler stability tend to be incompatible with each other. Accordingly, an effective method, which remarkably increases coupling activity of a coupler skeleton without significant impairment of coupler stability, has not yet been found.
With the increased efficiency of the heat-sensitive material, there has been a strong demand for a heat-sensitive recording material which has sufficient purple to cyan color forming property and also has a long shelf life, improved image storability, and improved image fixation.
A diazonium salt compound is a compound having a very high chemical activity. Because of this chemical activity, the diazonium salt compound easily forms an azo dye by reacting with a coupler which is a phenol derivative, a compound having an active methylene group, or the like. In addition, the diazonium salt compound is photosensitive, and when irradiated with light decomposes and becomes inactive. Because of these properties, a diazonium salt compound has been long utilized as a photo-recording material represented by diazo copy (“Principles of Photographic Science and Engineering-Non-Silver Salt Photographs” edited by the Photographic Society of Japan, 1982, pp.89-117, pp.182-201, published by Corona Publishing Co., Ltd.).
Further, by utilizing the property where a diazonium salt compound is decomposed by light and then becomes inactive, recently the diazonium salt compound is also being used in a recording material requiring the fixation of images. As a typical example of this recording material, there has been proposed a photo-fixation type heat sensitive recording material in which a diazonium salt compound and a coupler are heated in accordance with an image signal so as to form an image by the reaction therebetween, and the image thus formed is then fixed by irradiation with light (for example, H. Sato et al., Journal of the Image Electronics Society of Japan, Vol. 11(1982), No.4, pp.290-296).
However, these recording materials utilizing a diazonium salt compound as a color forming component have been associated with the drawback that the shelf life of the recording material is short. This is because the activity of the diazonium salt compound is so high that the diazonium salt compound undergoes a gradual thermal decomposition even in a dark place and the diazonium salt compound becomes non-reactive. One of the measures to be taken to alleviate this drawback is a method in which the diazonium salt compound is enclosed in microcapsules. Since this method enables the diazonium salt compound to be separated from compounds, such as water or a base, which accelerate the decomposition of the diazonium salt compound, it has become possible to remarkably increase the shelf life of the recording material (T. Usami et al., Journal of the Electrophotographic Society of Japan, Vol. 26(1987), No.2, pp.115-125).
If the microcapsules are composed of a wall, which like a urea resin or a urethane resin, has a glass transition temperature, and if that glass transition temperature is slightly higher than room temperature, the capsule wall is impermeable to materials at room temperature but permeable to materials at a temperature greater than or equal to the glass transition temperature. Therefore, such microcapsules are called heat-responsive microcapsules and are useful in a heat-sensitive recording material. That is, a recording material including a substrate and a heat-sensitive recording layer formed thereon, wherein the heat-sensitive recording layer contains heat-responsive microcapsules enclosing a diazonium salt compound, a coupler, and a base, enables the diazonium salt compound to be kept for a long period of time in a stable state. This recording material also makes it possible to easily form a colored image by heating, and to fix the image by irradiation with light.
As stated above, it has become possible to remarkably improve the stability of the diazonium salt compound by encapsulation.
It has been known that the use of 2-hydroxy-3-naphthoic acid anilide as a coupler results in a particularly excellent color forming material for heat-sensitive recording and that the 2-hydroxy-3-naphthoic acid anilide forms a blue dye when subjected to a coupling reaction with a 4-substituted amino-2-alkoxybenzenediazonium salt compound (Japanese Patent Application Laid-Open (JP-A) No. 2-225,082).
However, if a diazonium compound having &lgr;
max
on a longer wavelength side is used as the diazonium salt, the drawback that the raw stock storability of recording material (resistance to background coloration during storage before copying) is reduced has been observed. Meanwhile, when the above-mentioned 2-hydroxy-3-naphthoic acid anilide is used, fixation by irradiation with light is inhibited and the color formed is shifted to a longer wavelength side(cyan region) in the color hue and further the storability (lightfastness) of colored images is insufficient. That is, the drawbacks associated with the use of a diazonium compound having &lgr;
max
on a shorter wavelength side are observed.
As stated above, a heat-sensitive material, which exhibits sufficient purple to cyan color forming property but little absorption of yellow and which has a long shelf life, and exhibits excellent image storability and image fixation, has yet not been obtained.
SUMMARY OF THE INVENTION
In view of the foregoing, the object of the present invention is to provide a novel purple to cyan color forming diazo type heat-sensitive recording material with a long shelf life, excellent image storability and image fixation and to provide a coupler usable in the heat-sensitive recording material.
After extensive studies on couplers, the present inventors have found that a pyrrolopyrimidineone compound represented by the following general formula (1) is useful as a coupler providing a good purple to cyan color hue and a sufficient coloration density. Further, they have found that the heat-sensitive recording material using the pyrrolopyrimidineone compound and the following diazonium salt compound has improved shelf life, image lightfastness, and image fixation as well as excellent purple to cyan color forming property. Based on these findings, they have achieved the present invention.
The present invention is:
<1> a pyrrolopyrimidineone compound represented by the following general formula (1):
General formula (1)
wherein R
1
and R
2
each independently represents a hydrogen atom, a halogen atom, an aryl group, an alkyl group, a cyano group, an acyl group, a carbamoyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylsulfonyl group, or an arylsulfonyl group; R
3
represents an amino group, a substituted amino group, a hydroxyl group, an acyloxy group, an arylcarboxyl group, an alkoxy group, an aryloxy group, an alkylthio group, or an a
Nigorikawa Kazunori
Tsurumi Mitsuyuki
Yamada Hisao
Chu John S.
Fuji Photo Film Co. , Ltd.
Sughrue & Mion, PLLC
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