Record receiver having plural interactive leaves or a colorless – Having a colorless color-former – developer therefor – or...
Reexamination Certificate
2002-09-23
2004-08-24
Hess, Bruce H. (Department: 1774)
Record receiver having plural interactive leaves or a colorless
Having a colorless color-former, developer therefor, or...
C427S152000, C503S226000
Reexamination Certificate
active
06780819
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a heat sensitive recording material, and particularly to a heat sensitive recording material of high image quality suitable for a medical recording medium or the like.
2. Description of the Related Art
A heat sensitive recording method has advantages in that: (1) no development is needed; (2) when a support is paper, a recording material is close to plain paper; (3) handling is simple; (4) a color formation density is high; (5) a recording device is simple, highly reliable and inexpensive; (6) no noise is made at the time of recording; and (7) no maintenance is required. Therefore, the heat sensitive recording method has been recently developed in various fields and has been used extensively in, for example, the field of facsimile machines or printers, or the field of labeling such as Point of Sale (POS).
As a heat sensitive recording material used for the aforementioned heat sensitive recording, a material using a reaction between an electron-donating colorless dye and an electron-accepting compound, a material using a reaction between a diazo compound and a coupler, or the like has been conventionally and widely known.
Further, in recent years, there has been demanded development of heat sensitive recording material having a heat sensitive recording layer on a transparent support, which allows direct recording by a thermal head for the purpose of projecting an image or the like by an overhead projector, or directly observing an image or the like on a light table. Particularly, transparent heat sensitive recording material used for producing a diagnostic image for medical use has attracted the attention of those involved.
Such transparent heat sensitive recording materials have excellent transparency, but when printing is carried out therefor by a heat sensitive recording device such as a thermal printer, there exists a problem that sticking or noise is apt to be caused. Particularly, when a transparent heat sensitive recording material is used for medical application, a high transmission density is required. For this reason, heat energy applied by a thermal head increases, and problems such as sticking, noise generated at the time of recording, abrasion of a thermal head, and the like become serious. Accordingly, a protective layer containing, as principal components, a pigment and a binder is provided on a heat sensitive recording layer for the purpose of improving sticking and noise.
When a diagnostic image for medical use is prepared using a transparent heat sensitive recording material, an accurate diagnosis can be given so long as the image is clearly legible down to the smallest detail. However, a minute coating defect, which is caused when the protective layer is formed by coating, may have an adverse effect on an image to be formed. Thus, it is required that a so-called surface state is improved by preventing the aforementioned minute coating defect.
Further, when plastic material (vinyl chloride resin or the like) containing a plasticizer contacts an image portion after an image is formed on a heat sensitive recording material, the plasticizer contained in the plastic material transfers to the image portion and an image density may be lowered or color fading may be caused. Accordingly, the heat sensitive recording material needs to have resistance to a plasticizer (chemical resistance).
Japanese Patent Application Publication (JP-B) No. 1-17479 discloses that, due to 0.01 to 5 mass % of alkylsulfosuccinic acid being added to a heat sensitive recording material having a heat sensitive recording layer and a water-soluble resin layer on a support, coating property is improved while preventing a coating liquid from excessively permeating into the heat sensitive recording layer in the case of forming by coating the water-soluble resin layer. However, the aforementioned publication does not disclose a heat sensitive recording material having a heat sensitive recording layer formed on a transparent support. Further, there is not suggested therein that extremely strict surface state characteristics are required by a heat sensitive recording material for medical diagnosis, which is an example of the heat sensitive recording material.
SUMMARY OF THE INVENTION
The present invention has been devised in view of the aforementioned drawbacks, and an object of the present invention is to provide a heat sensitive recording material which has a good surface state and excellent solvent resistance, and also has excellent light resistance (in a background portion and an image portion) and storage characteristics of an image portion.
The present invention provides a heat sensitive recording material having, on a support, at least a heat sensitive recording layer and a protective layer in that order, which protective layer contains an ammonium salt of alkylsulfosuccinic acid.
The heat sensitive recording material of the present invention contains an ammonium salt of alkyl sufosuccinate in the protective layer, and therefore, minute coating defect caused when the protective layer is formed by coating is prevented and the surface state improves. Further, chemical resistance of the heat sensitive recording material according to the present invention is improved. Moreover, the heat sensitive recording material of the present invention has excellent light resistance in a background portion and an image portion, and also has image storability at a high temperature and under high humidity.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A heat sensitive recording material of the present invention will be hereinafter described in detail.
The heat sensitive recording material of the present invention has, on a support, a heat sensitive recording layer and a protective layer in that order, and if necessary, it also has other layers. The protective layer contains an ammonium salt of alkylsulfosuccinic acid. In the heat sensitive recording material of the present invention, since the protective layer contains an ammonium salt of alkylsulfosuccinic acid, minute coating defect caused when the protective layer is formed by coating is prevented and the surface state improves. Further, the heat sensitive recording material of the present invention is improved in chemical resistance. Moreover, the heat sensitive recording material of the present invention has excellent light resistance in a background portion and an image portion, and also has excellent image storability at a high temperature and under high humidity.
[Protective Layer]
The aforementioned protective layer is formed on the heat sensitive recording layer. Alternatively, when an intermediate layer is formed, as the other layer, on the heat sensitive recording layer, the protective layer is formed on the intermediate layer.
The protective layer is formed by applying a coating liquid for a protective layer thereto. As the ammonium salt of alkylsulfosuccinic acid to be added to the coating liquid for a protective layer, one represented by the following structural formula is particularly preferably used.
R
1
OOC—CH
2
—CH(COOR
2
) (SO
3
NH
4
)
Wherein R
1
and R
2
each represent an alkyl group. The aforementioned alkyl group is not particularly limited, but preferably has 3 to 15 carbon atoms, and more preferably has 4 to 8 carbon atoms. Specific examples thereof include an isobutyl group, an amyl group, a hexyl group, a cyclohexyl group, an octyl group, 2-ethylhexyl group and the like. Among them, an octyl group and 2-ethylhexyl group are particularly preferable from the standpoint of obtaining a predetermined effect of the present invention. Further, a so-called symmetrical ammonium salt of alkylsulfosuccinic acid in which R
1
and R
2
are the same is preferable from the standpoint of obtaining a predetermined effect of the present invention.
The ratio of the ammonium salt of alkylsulfosuccinic acid to the total dry amount of the protective layer coated is not particularly limited, and preferably in the range of 5 to 21 mass %. If it is less than 5 mass
Fuji Photo Film Co. , Ltd.
Hess Bruce H.
Sughrue & Mion, PLLC
LandOfFree
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 Heat sensitive recording material, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Heat sensitive recording material will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3336593