Radiation imagery chemistry: process – composition – or product th – Microcapsule – process – composition – or product
Reexamination Certificate
2000-03-29
2001-06-19
Chu, John S. (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Microcapsule, process, composition, or product
C430S157000, C430S177000, C430S179000
Reexamination Certificate
active
06248497
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a light-sensitive and heat-sensitive recording material, and particularly to a diazo compound based light-sensitive and heat-sensitive recording material on which an image can be fixed.
2. Description of the Related Art
A diazonium salt compound is a compound having extremely high chemical activity, and reacts with a compound (which is called a coupler) having a phenol derivative or an active methylene group, to easily form an azo dye. Further, a diazonium salt compound also has photosensitivity, and is decomposed by irradiation with light and loses its activity. Therefore, diazonium salt compounds have been conventionally used for a long time as light recording materials as represented by diazo copy (see “Shashin-Kougaku no Kiso—Hi-gin-en Shashin Hen (Fundamentals of Photographic Engineering—Non-silver Salt Photography Section)”, pp. 89 to 117, 182 to 201, edited by the Photographic Society of Japan, Corona Publishing Co., Ltd. 1982).
Further, in recent years, diazonium salt compounds are also applied to recording materials on which fixation of an image is required, by utilizing its nature in which it is decomposed and loses activity due to action of light. As a typical example, there has been proposed a light fixation type light-sensitive and heat-sensitive recording material in which a diazonium salt compound and a coupler are heated in accordance with an image signal so as to be reacted to form an image, and thereafter, the image is fixed by irradiation with light (Hirotsugu Sato et al., Bulletin of the Image Electronics Society, Vol. 11, No. 4 (1982) pp. 290 to 296, and the like).
However, this recording material in which a diazonium salt compound is used as a color forming element has a drawback in that a shelf life thereof as a recording material is short since the activity of the diazonium salt compound is extremely high and the diazonium salt compound is thermally decomposed gradually to lose its reactivity even in a dark place. As one of the means for solving the drawback, there is suggested a method in which a diazonium salt compound is enclosed in a micro capsule. In this method, the diazonium salt compound can be isolated from materials which promote decomposition, such as water, a base, and the like. Therefore, the shelf life of the diazonium salt compound as a recording material can be greatly increased (Tomomasa Usami et al., Bulletin of the Electronic photography Society, Vol. 26, No. 2 (1987), pp. 115 to 125).
In a case in which a micro capsule has a wall composed of a material having a glass transition temperature such as a urea resin or urethane resin, which glass transition temperature is slightly higher than room temperature, this micro capsule is called a heat-responsive micro capsule and is useful for a light-sensitive and heat-sensitive recording material since the capsule wall is impermeable with respect to materials at room temperature and is permeable with respect to materials at a temperature equivalent to or greater than the glass transition temperature thereof. Namely, by preparing the recording material in which a heat-sensitive recording layer including a coupler, a base, and the heat-responsive micro capsule which contains a diazonium salt compound is applied to a substrate, the diazonium salt compound can be stably kept for a long period of time, and a color formation image can be easily formed by heating. Further, an image can be fixed by irradiation with light.
As described above, stability of a diazonium salt compound can be remarkably improved by enclosing the compound in a micro capsule.
However, even in the light-sensitive and heat-sensitive recording material in which the compound is enclosed in a micro capsule, various photo-dissociative reaction products are formed during diazo decomposition in a fixing process, and coloring (so-called photo-dissociative stain) having an absorptivity, particularly in a visible region, may occur. Further, when such recording materials are exposed to the sun or a fluorescent light for a long time after fixing of an image, the density of the non-image portion (a base portion) also becomes higher and the whiteness of the recording paper may remarkably decrease.
Further, heat development-type recording materials using diazonium salt compounds also have a drawback in that after optical writing and heat development, photo-dissociative stain occurs in a non-image portion to thereby cause deterioration in the whiteness of the base portion, in the same manner as in the above-described light-sensitive and heat-sensitive recording material.
In order to improve the whiteness of the base portion, for example, Japanese Patent Application Laid-Open (JP-A) No. 62-55188, discloses that a micro capsule containing a diazo compound and a compound which forms free radicals by irradiation with light (that is, aromatic ketones such as benzophenone, 4,4′-bis(dimethylamino)benzophenone, and the like, cyclic aromatic ketones such as fluorenone, anthrone, and the like, quinones such as benzoquinone, 2,3,5-trimethyl-6-bromobenzoquinone, and the like, benzoin, benzoin ethers, aromatic polycyclic hydrocarbons, azos such as azobisisobutyronitrile, organic sulfides such as thiuramdisulfide, and acyloxime esters). By using the above-described compound, which forms free radicals, the whiteness of the base portion after fixing was improved to a certain degree.
However, as advanced light-sensitive and heat-sensitive recording materials have been desired, further improvement has been demanded for the whiteness of the base portion in a fixed light-sensitive and heat-sensitive recording material.
An object of the present invention is to provide a light-sensitive and heat-sensitive recording material containing a diazo compound and a coupling component, in which a density of an image recorded thereon and the whiteness of a base portion are both improved.
SUMMARY OF THE INVENTION
In accordance with a preferred embodiment of the present invention, a light-sensitive and heat-sensitive recording material is provided. The light-sensitive and heat-sensitive recording material includes a substrate and a heat-sensitive recording layer disposed on the substrate. The recording layer contains micro-capsules having a diazonium salt compound therein, along with an acylphosphine compound. The recording layer further contains a coupler reactive with the diazonium salt compound.
The acylphosphine oxide compound is preferably at least one of the compounds represented by the following general formulae (1) and (2):
In the above-described general formulae (1) and (2), R
1
, R
2
, and R
5
each represent an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a heterocyclic group. R
3
, R
4
, and R
6
each represent an alkyl group, an aryl group, or a heterocyclic group.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A light-sensitive and heat-sensitive recording material of the present invention is formed in such a manner that a heat-sensitive recording layer, which contains at least a diazonium salt compound and a coupler reacting with the diazonium salt compound, is applied onto a substrate, the diazonium salt compound being, together with an acylphosphine oxide compound, contained in micro capsules. Since the acylphosphine oxide compound is contained in micro capsules, a light-sensitive and heat-sensitive recording material in which a density of an image recorded thereon, and the whiteness of a base portion are both improved. The acylphosphine oxide compound is preferably selected from the previously-described general formulae (1) and (2) in the summary.
In the foregoing-described general formulae (1) and (2), an alkyl group, an aryl group, a heterocyclic group, an alkoxy group, and an aryloxy group represented by R
1
, R
2
, R
3
, R
4
, R
5
, and R
6
may each be substituted by an alkyl group, an aryl group, a hydroxy group, a nitro group, a cyano group, a halogen atom, an alkyl sulfonyl group, an aryl sulfonyl group, an alkoxy group, an alkoxycarbonyl gro
Sano Shojiro
Takashima Masanobu
Chu John S.
Fuji Photo Film Co. , Ltd.
Sughrue Mion Zinn Macpeak & Seas, PLLC
LandOfFree
Light-sensitive and heat-sensitive recording material does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Light-sensitive and heat-sensitive recording material, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Light-sensitive and heat-sensitive recording material will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2493885