Radiation imagery chemistry: process – composition – or product th – Microcapsule – process – composition – or product
Reexamination Certificate
2002-03-13
2004-12-28
Chu, John S. (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Microcapsule, process, composition, or product
C430S157000, C430S162000, C430S177000
Reexamination Certificate
active
06835522
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a heat-sensitive recording material and more particularly to a heat-sensitive recording material excellent in lightfastness.
2. Description of the Related Art
In recent years, heat-sensitive recording has made remarkable progress because the recording apparatus for heat-sensitive recording are simple, highly reliable, and maintenance-free. Examples of widely known heat-sensitive recording materials are a heat-sensitive recording material utilizing the reaction between an electron-donating colorless dye and an electron-accepting compound, and a heat-sensitive recording material utilizing the reaction between a diazonium salt compound and a coupler.
However, the heat-sensitive recording material is associated with a problem that, when it is exposed to sunlight for a long time or when it is posted on the wall in an office or the like for a long period of time, its background becomes colored and the image portions may discolor or fade.
Japanese Patent Application Laid-Open (JP-A) No.9-1928 describes a heat-sensitive recording material which uses a precursor of an ultraviolet light absorber in order to prevent the coloration of the background and the discoloration or fading of the image portions and exhibits excellent lightfastness and fixing performance. This precursor of an ultraviolet light absorber functions as an ultraviolet light absorber after it reacts due to the effect of light or heat when irradiated with light whose wavelength is in a region necessary for fixing by irradiation with light in a photo-fixing type heat-sensitive recording layer. For this reason, a large proportion of the light within an ultraviolet region is absorbed by the ultraviolet light absorber and the ultraviolet light transmittance of the heat-sensitive recording material is lowered. Therefore, the lightfastness of the heat-sensitive recording material is enhanced.
However, if the precursor of an ultraviolet light absorber was used alone, the problem encountered was that the efficiency of the ultraviolet light absorber formation was low when the ultraviolet light absorber was formed by irradiation with light.
SUMMARY OF THE INVENTION
The present invention provides a heat-sensitive recording material which is excellent in lightfastness and solves the problem that the efficiency of the ultraviolet light absorber formation is low and thus overcomes the above-mentioned problems.
That is, the first aspect of the present invention is a heat-sensitive recording material containing an ultraviolet light absorber precursor which forms an ultraviolet light absorber by being irradiated with light and a hydrogen donor. Preferably, the ultraviolet light absorber precursor is at least one kind selected from the compounds represented by the following general formulae (1) to (4).
In the general formulae (1) to (4), m represents 1 or 2. A represents —SO
2
—R, —CO—R, —CO
2
—R, —CONH—R, —POR
1
R
2
, —CH
2
R
3
, or SiR
4
R
5
R
6
in the general formula (1) where m is 1 and in the general formulae (2) to (4). A represents —SO
2
R
7
SO
2
—, —CO—, —COCO—, —COR
7
CO—, —SO
2
—, or SO— in the general formula (1) where m is 2. X represents a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, or a halogen atom in the general formulae (1), (3), and (4). X represents an alkylene group, —OR
7
O—, or OCOR
7
CO
2
— in the general formula (2). W represents a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, or a halogen atom in the general formulae (1), (2), and (4). W represents —OR
7
O— or OCOR
7
CO
2
— in the general formula (3). Y represents a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, or a halogen atom in the general formulae (1), (2), and (3). Y represents —OR
7
O—, —OCOR
7
CO
2
—, —CH
2
CH
2
CO
2
R
7
OCOCH
2
CH
2
—, —CH
2
CH
2
OCOR
7
CO
2
CH
2
CH
2
—, or CH
2
CH
2
CON(R
8
) R
7
N(R
8
)COCH
2
CH
2
— in the general formula (4). Z represents a hydrogen atom, a halogen atom, an alkyl group, or an alkoxy group. In the groups listed above, R represents an alkyl group or an aryl group. R
1
and R
2
each represents an alkoxy group, an aryloxy group, an alkyl group, or an aryl group. R
3
represents a phenyl group bearing at least one nitro or methoxy group as a substituent. R
4
, R
5
, and R
6
each represents an alkyl group or an aryl group. R
7
represents an alkylene group or an arylene group. R
8
represents a hydrogen atom or an alkyl group.
It is preferable that the hydrogen donor has at least one group selected from an aromatic OH group, an aliphatic OH group, a heterocyclic OH group, an aromatic SH group, an aliphatic SH group, a heterocyclic SH group, an aromatic NH group, an aliphatic NH group, and a heterocyclic NH group.
Another aspect of the present invention is a heat-sensitive recording material comprising a support, a photo-fixing type heat-sensitive recording layer, an interlayer, and a protective layer, each provided on the support, wherein at least one of these layers contains an ultraviolet light absorber precursor and a hydrogen donor.
Still another aspect of the present invention is a multicolor heat-sensitive recording material which comprises a support and a plurality of photo-fixing type heat-sensitive recording layers provided on the support and contains an ultraviolet light absorber precursor and a hydrogen donor, wherein the photo-fixing type heat-sensitive layers develop the three primary colors for subtractive color mixing, i.e., yellow, magenta, and cyan, respectively, so that full-color recording can be made.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
<Heat-Sensitive Recording Material>
The heat-sensitive recording material of the present invention contains at least one compound selected from the compounds represented by the following formulae (1) to (4) and a hydrogen donor.
The compounds represented by the general formulae (1) to (4) are so-called precursors of ultraviolet light absorbers and form ultraviolet light absorbers by being irradiated with light. The compounds represented by the general formulae (1) to (4) are hereinafter referred to as “ultraviolet light absorber precursors” upon occasion. The heat-sensitive recording material of the present invention contains a hydrogen donor in addition to the ultraviolet light absorber precursor. For this reason, the supply source, which supplies hydrogen to the ultraviolet light absorber precursor is increased and the efficiency of the formation of the ultraviolet light absorber is enhanced. The term “hydrogen donor” as used in the present invention means a compound which donates hydrogen to the ultraviolet light absorber precursor.
(Hydrogen Donor)
Examples of the hydrogen donor include hydroquinone compounds, hydrazide compounds, hydroxy compounds, phenidone compounds, catechol compounds, resorcinol compounds, hydroxyhydroquinone compounds, pyrrologlycinol compounds, phenol compounds, phenylhydrazide compounds, gallic acid compounds, ascorbic acid compounds, and ethylene glycol compounds. These are described in JP-A Nos.3-191341, 3-25434, 1-252953, 2-302753, 1-129247, 1-227145, 1-243048, 2-262649, etc.
Among the hydrogen donors listed above, preferable is a hydrogen donor (an OH group-bearing hydrogen donor) having at least one group selected from an aromatic OH group, an aliphatic OH group, and a heterocyclic OH group; a hydrogen donor (an SH group-bearing hydrogen donor) having at least one group selected from an aromatic SH group, an aliphatic SH group, and a heterocyclic SH group; or a hydrogen donor (an NH group-bearing hydrogen donor) having at least one group selected from an aromatic NH group, an aliphatic NH group, and a heterocyclic NH group.
Examples of the OH group-bearing hydrogen donor include compounds represented by “heterocycle-OH”, “R
10
—COOH”, etc., wherein R
10
represents an aliphatic group, an aromatic group, or a heterocyclic group. Examples of R
10
include octyl, dodecyl, octadecyl, 2-ethylhexyl, oleyl, phenyl, naphthyl, tolyl, cyclohexyl, and pyridyl groups. Examples of the OH group-beari
Minami Kazumori
Takashima Masanobu
Chu John S.
Fuji Photo Film Co. , Ltd.
Sughrue & Mion, PLLC
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