Record receiver having plural interactive leaves or a colorless – Having a colorless color-former – developer therefor – or... – Method of use – kit – or combined with marking instrument or...
Reexamination Certificate
2001-11-13
2004-06-01
Hess, Bruce H. (Department: 1774)
Record receiver having plural interactive leaves or a colorless
Having a colorless color-former, developer therefor, or...
Method of use, kit, or combined with marking instrument or...
C503S215000, C503S217000
Reexamination Certificate
active
06743750
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a heat-sensitive recording material using a diazo compound and a coupler as color-forming components, and more particularly, to a heat-sensitive recording material which is excellent in photo-fixing property when a light source emitting light having a wavelength longer than 400 nm is used, and which has low color formation in background areas.
2. Description of the Related Art
In general, diazo compounds have very high chemical activity. Diazo compounds react with a compound (so-called coupler) having an active methylene group or a phenol derivative, and readily form azo dyes. Also, diazo compounds are photosensitive and are decomposed when exposed to light, thereby losing their chemical activity. For these reasons, diazo compounds have been used for a long time as photo-recording materials such as for diazo copies (see “Fundamentals of Photographic Engineering: Non-Silver Salt Photography Edition”, published by Corona Co., Ltd., pp. 89-117 and pp. 182-201 (1982)).
Further, by utilizing the property of diazo compounds whereby their chemical activity is lost by being decomposed by light, diazo compounds have recently been applied to recording materials which require image fixation. As a typical example, a photo-fixing type heat-sensitive recording material has been proposed wherein a diazo compound and a coupler are reacted by heating in accordance with image signals to form an image, and then exposed to light to fix the image (see Koji Sato, et al., Journal of The Institute of Image Electronic Engineers of Japan, Vol. 11, No. 4, pp. 290-296 (1982), etc.).
These recording materials using a diazo compound as a color forming component are generally exposed to an ultra violet ray having a wavelength of about 360 nm in a fixing process in order to effectively performing photo-fixing. However, the ultra violet ray requires a special light source, and there are problems in that it may have a harmful effect on eyes, and the like. Therefore, there has been a need for a recording material using a diazo compound with which fixing can be effectively performed when a light source which emits visible light having a wavelength longer than 400 nm is used.
However, there has been a problem with a conventional recording material using a diazo compound in that fixation proceeds slowly and therefore a long time is required in order to deactivate the diazo compound with a light source emitting light having a wavelength longer than 400 nm. Another problem has been that, if photo-fixing is carried out for a long time in order to complete the fixing, a product generated by the photo-fixing also reacts and this may result in a color-formed image having low whiteness in background areas.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a heat-sensitive recording material which is excellent in photo-fixing property when a light source emitting light having a wavelength longer than 400 nm is used, and has which low color-formation in background areas.
The object of the present invention can be accomplished by the following means.
First aspect of the present invention is a heat-sensitive recording material comprising a support and at least one heat-sensitive recording layer. The heat-sensitive recording layer comprises at least one diazo compound and at least one coupler, and the at least one diazo compound is encapsulated in microcapsules and is represented by the following general formula (1):
wherein R
1
, R
2
, R
3
, R
4
, R
5
, R
6
, R
7
and R
8
each independently represents a hydrogen atom, a halogen, an alkyl group, an alkoxy group, an alkylthio group or an arylthio group; R
9
represents a hydrogen atom, an alkyl group or an alkoxy group; and X
−
represents an anion.
Second aspect of the present invention is a heat-sensitive recording material comprising a support and at least one heat-sensitive recording layer. The heat-sensitive recording layer comprises at least one diazo compound and at least one coupler, and the at least one diazo compound is encapsulated in microcapsules and is represented by the following general formula (2):
wherein R
9
represents a hydrogen atom, an alkyl group or an alkoxy group; R
10
and R
11
each independently represents an alkyl group; R
12
and R
13
each independently represents a hydrogen atom, a halogen, an alkyl group or an alkoxy group; and X
−
represents an anion.
Third aspect of the present invention is a heat-sensitive recording method. The method comprises the steps of:
preparing a heat-sensitive recording material comprising a support and at least one heat-sensitive recording layer, the heat-sensitive recording layer comprising at least one diazo compound and at least one coupler, the at least one diazo compound being encapsulated in microcapsules and being represented by the following general formula (1):
wherein R
1
, R
2
, R
3
, R
4
, R
5
, R
6
, R
7
and R
8
each independently represent a hydrogen atom, a halogen, an alkyl group, an alkoxy group, an alkylthio group or an arylthio group; R
9
represents a hydrogen atom, an alkyl group or an alkoxy group; and X
−
represents an anion;
heating a recording surface of the heat-sensitive recording material imagewise to cause a reaction between the diazo compound and the coupler to form a color; and
irradiating light to decompose the remaining diazo compound which has not formed a color.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
<<Heat-Sensitive Recording Material>>
A heat-sensitive recording material of the present invention comprises a heat-sensitive recording layer containing a diazo compound and a coupler on a support thereof, wherein the diazo compound is encapsulated in microcapsules, and is represented by the following general formula (1):
wherein R
1
, R
2
, R
3
, R
4
, R
5
, R
6
, R
7
and R
8
each independently represent a hydrogen atom, a halogen, an alkyl group, an alkoxy group, an alkylthio group or an arylthio group, and R
9
represents a hydrogen atom, an alkyl group or an alkoxy group. X
−
represents an anion.
By including the compound represented by general formula (1) in the heat-sensitive recording layer of the heat-sensitive recording material of the present invention in a state in which it is encapsulated in the microcapsules, a heat-sensitive recording material which is excellent in photo-fixing property when a light source emitting light having a wavelength longer than 400 nm is used, and which has low color formation in background areas can be provided.
<Heat-Sensitive Recording Layer>
[Diazo Compound]
The diazo compound according to the present invention is characterized in that it is represented by the above-described general formula (1). Since the diazo compound according to the present invention is highly soluble in an organic solvent, a uniform emulsified dispersion can easily be obtained. Further, since the diazo compound exhibits an excellent photo-decomposition rate when exposed to light having a wavelength longer than 400 nm, photo-fixing property can be significantly improved.
In general formula (1), R
1
, R
2
, R
3
, R
4
, R
5
, R
6
, R
7
and R
8
each independently represents a hydrogen atom, a halogen, an alkyl group, an alkoxy group, an alkylthio group or an arylthio group. As the halogen represented by the above R
1
, R
2
, R
3
, R
4
, R
5
, R
6
, R
7
and R
8
, a chlorine atom or a bromine atom is preferable.
The alkyl group represented by the above R
1
, R
2
, R
3
, R
4
, R
5
, R
6
, R
7
and R
8
preferably has 1 to 30 carbon atoms, and more preferably has 1 to 12 carbon atoms. The alkyl group may have at least one substituent, and preferable examples of the substituent include a phenyl group, a halogen, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an acyloxy group, an acylamino group, a carbamoyl group, a cyano group, a carboxylic acid group, a sulfonic acid group, and a heterocyclic group.
Particularly preferable examples of the alkyl group represented by the above R
1
, R
2
,
Jimbo Yoshihiro
Nagase Hisato
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