JPH08197854A - Photographic paper - Google Patents

Abstract

PURPOSE: To obtain a photographic paper capable of forming an image with excellent preservation properties such as a lightfastness, anti-darkness and discoloration property, skin fat resistance, and plasticizer prooflng property, In a photographic paper to be used in a sublimation type thermal transfer recording method. CONSTITUTION: A photographic paper 1 consists of a sheet base material 2 and dyes reservoir layer 3 wherein it is allowed to contain a polymer having a phenoxyethylate unit as a main component in the dyes reservoir 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing paper suitable for sublimation type thermal transfer recording. More specifically, by incorporating a polymer having a phenoxyethyl methacrylate unit in the dye receiving layer of photographic paper, the image formed on the dye receiving layer can be preserved in terms of sebum resistance, plasticizer resistance, light resistance, etc. The present invention relates to photographic printing paper having improved properties.

[0002]

2. Description of the Related Art An ink ribbon having an ink layer made of a sublimable or heat-diffusible dye and a printing paper having a dye receiving layer are superposed on each other, and the ink layer of the ink ribbon is subjected to image information by a thermal head or the like. There is known a sublimation type thermal transfer recording method in which an image is formed by heating by heating and transferring a dye from an ink layer to a dye receiving layer of a printing paper. According to this method, a full-color image with continuous gradation can be formed, and therefore, it has attracted attention as a method for hard copying a video image.

FIG. 1 is a sectional view of a general printing paper 1 used for sublimation type thermal transfer recording. As shown in the figure,
The photographic printing paper 1 has a laminated structure of a sheet-shaped substrate 2 and a dye receiving layer 3. Here, the dye receiving layer 3 is a layer that receives the dye transferred from the ink ribbon during thermal transfer recording and holds the image formed by the dye. Such a dye receiving layer 3 is conventionally formed of a dyeing resin such as polyester, cellulose ester, polycarbonate, polyvinyl chloride or the like.

By the way, in recent years, the photographic paper as shown in FIG. 1 is required to have the following properties so as to be compatible with high-speed printers. (i) High sensitivity and high dyeability, capable of forming a clear image with high density and gloss, (ii) Good storage stability of the image, that is, (a) Excellent fingerprint resistance and sebum resistance That the dye forming the image does not agglomerate or discolor when the image comes into contact with a part of the human body such as hands or fingers, and (b) excellent plasticizer resistance. Specifically, when the image comes in contact with a plastic eraser containing a plasticizer or its eraser, the dye forming the image does not aggregate or fade, and (c) when exposed to light. It should have high light resistance so as not to cause discoloration or discoloration of images, and (d) it should have excellent resistance to dark fading.

In order to meet such demands, various proposals have been made for the construction of photographic printing paper. For example, above
To meet the requirement of (i), it has been proposed to use a polyvinyl acetal resin as the main component of the dye receiving layer (JP-A-4-10339).

[0006]

However, in the conventional photographic paper in which the dye receiving layer is formed of a dyeing resin such as polyester, the light resistance, dark fading resistance, sebum resistance and resistance of the image formed thereon are reduced. There is a problem that the plasticizer property is not sufficient and thus the image storability is low. Further, even in photographic paper using a polyvinyl acetal resin as the main component of the dye receiving layer, it cannot be said that the storability is sufficient, and further improvement has been desired.

[0007] Regarding such a problem of storage stability, it has been proposed to add a storage stability improving agent such as a UV absorber or an antioxidant to the dye receiving layer, but a sufficient effect has not been obtained. . Further, in order to improve the resistance to sebum and the resistance to plasticizers, a cover film is also laminated on a printing paper on which an image is formed. However, there is a problem that it is necessary to add a laminating step in addition to the conventional image forming step of thermal transfer recording, and there is also a problem in the appearance and thickness of the cover film after lamination.

The present invention is intended to eliminate such drawbacks of the prior art, and to form an image excellent in storage characteristics such as light resistance, dark fading resistance, sebum resistance, and plasticizer resistance. The purpose is to provide a photographic paper that can be used.

[0009]

The inventor of the present invention uses a polymer having a phenoxyethyl methacrylate unit as a resin constituting a dye receiving layer of a photographic printing paper to obtain an image formed on the photographic printing paper. They have found that the storage characteristics can be greatly improved, and have completed the present invention.

That is, the present invention provides a photographic printing paper comprising a sheet-like substrate and a dye receiving layer, wherein the dye receiving layer contains a polymer having a phenoxyethyl methacrylate unit. provide.

The present invention will be described in detail below.

The photographic printing paper of the present invention basically has a laminated structure of a sheet-like base material and a dye receiving layer, like the photographic printing paper shown in FIG. 1, but the dye receiving layer comprises a phenoxyethyl methacrylate type unit. It is characterized by being formed from a polymer having a main component. Here, the phenoxyethyl methacrylate-based unit has a structure represented by the following formula (1) as a basic structure.

[0013]

Embedded image In the present invention, the polymer having a phenoxyethyl methacrylate-based unit as a main component is represented by the formula (1)
A polymer having a derivative unit of formula (1) or an analog unit in addition to the unit of formula (1) can be used. For example, a polymer having a unit of formula (2) can be used.

[0014]

Embedded image Moreover, the polymer having a phenoxyethyl methacrylate unit preferably has a molecular weight of about 10,000 to 1,000,000. If the molecular weight is too large, the coating liquid (coating containing a polymer having a phenoxyethyl methacrylate unit) used at the time of forming the dye receiving layer will have a high viscosity, while if it is too small, the coating properties will be deteriorated, which is not preferable.

Commercially available products can be used as the polymer having the phenoxyethyl methacrylate unit as the main component as described above.

If desired, the dye-receiving layer of the photographic printing paper of the present invention may contain, in addition to the polymer having a phenoxyethyl methacrylate unit as a main component, a resin compatible with this polymer. . Examples of such a resin include resins having an ester bond (polyester, polyacrylic acid ester, polycarbonate, polyvinyl acetate, styrene acrylate, vinyltoluene acrylate, polyvinyl aromatic carboxylic acid ester, etc.), polyurethane resin, polyamide resin, Urea resin,
Examples thereof include polycaprolactone resin, polystyrene resin, polyvinyl chloride or copolymers thereof.

When such a resin is contained in the dye receiving layer together with the polymer having the phenoxyethyl methacrylate unit, the polymer having the phenoxyethyl methacrylate unit is contained in an amount of 40% by weight or more of the dye receiving layer. Preferably. If the content of the polymer having the phenoxyethyl methacrylate unit is too small, the effect of the present invention cannot be obtained.

Various additives can be added to the dye receiving layer of the photographic paper of the present invention in addition to the above-mentioned resins. For example, in order to improve the whiteness of the dye-receptive layer to improve the sharpness of the image, to give the image surface writability, and also to prevent retransfer of the image formed by thermal transfer, a fluorescent whitening agent is added. (Fluorescent dye) or white pigment may be contained. As such a fluorescent whitening agent, a commercially available product such as Ubitex OB manufactured by Ciba-Geigi can be used.
Further, as the white pigment, titanium oxide, zinc oxide, kaolin, clay, calcium carbonate, fine powder silica and the like can be contained. These may be used alone or in combination of two or more.

Further, in the dye receiving layer, one or more kinds of ultraviolet absorbers, light stabilizers, antioxidants, surface modifiers and the like can be used in order to further improve the light resistance of the image. .

Further, the dye receiving layer may contain a releasing agent in order to improve the releasing property from the ink ribbon at the time of thermal transfer. As the release agent, polyethylene wax, amide wax, solid wax such as Teflon powder, fluorine-based or phosphate-based surfactant, silicone oil, high melting point silicone wax, etc. can be used. Above all, it is preferable to use silicone oil from the viewpoint of releasing property and durability.

In this case, as the silicone oil, an oily one and a reaction (curing) type can be appropriately selected and used. Here, as the reaction (curing) type silicone oil, a reaction cured product of an alcohol-modified silicone oil and an isocyanate, an epoxy-modified silicone oil (epoxy / polyether-modified silicone oil) and a carboxy-modified silicone oil (carboxy
Reaction cured product with polyether modified silicone oil),
Amino-modified silicone oil (amino-polyether-modified silicone oil) and carboxy-modified silicone oil (carboxy-polyether-modified silicone oil)
It is possible to use a reaction-cured product or the like.

Further, the dye receiving layer may contain various curing agents in order to improve the film characteristics. As such a curing agent, for example, an epoxy curing agent, an isocyanate curing agent or the like can be used, and among them, a non-yellowing type polyfunctional isocyanate compound is preferable. Examples of such polyfunctional isocyanate compounds include aliphatic polyisocyanates such as hexamethylene diisocyanate (HDI) and biuret, and aromatic polyisocyanates such as toluene diisocyanate (TDI) and xylene diisocyanate (XDI). . These may be used alone or in combination of two or more.

Further, the dye receiving layer may contain an antistatic agent in order to suppress the generation of static electricity during the process of processing the printing paper or during running in the printer. As the antistatic agent, a cationic surfactant (4th
Use of various surfactants such as primary ammonium salt, polyamine, etc.), anionic surfactant (alkylbenzene sulfonate, sodium alkyl sulfate ester, etc.), zwitterionic surfactant, nonionic surfactant, etc. You can Such an antistatic agent may be contained in the dye receiving layer or may be applied to the surface of the dye receiving layer by coating or the like.

The method for forming the dye-receptive layer is as follows: the respective components forming the dye-receptive layer are mixed uniformly with a solvent if necessary to prepare a coating material, and the coating material is applied to a sheet-shaped substrate, or Alternatively, it can be formed by applying a hot melt of each component onto a sheet-shaped substrate and curing.

On the other hand, in the present invention, as the sheet-like substrate, papers such as high-quality paper, coated paper, synthetic paper, various plastic sheets, or composite sheets of these can be used.

On the surface of the sheet-shaped substrate opposite to the dye-receptive layer, an acrylic resin or silicone is used in order to improve the running property of the printing paper in the printer and to prevent the printing paper from being double fed. A back coat layer made of resin or the like may be formed.

The image forming method for the photographic printing paper of the present invention is not particularly limited, and for example, sublimation type thermal transfer recording can be carried out by using a commercially available video printer or the like using an ink ribbon for sublimation type thermal transfer recording.

[0028]

In the photographic printing paper of the present invention, since the dye receiving layer is composed of a polymer having a phenoxyethyl methacrylate unit, the light resistance and the dark fading resistance of the image formed on the dye receiving layer by the sublimation type thermal transfer recording method. , Storage resistance such as sebum resistance and plasticizer resistance are remarkably improved. Also,
The water resistance is also greatly improved. Further, it becomes possible to form an image with high sensitivity.

[0029]

EXAMPLES The present invention will be specifically described below based on examples.

Examples 1 and 2 and Comparative Examples 1 and 2 As a sheet-shaped substrate, a 150 μm thick synthetic paper (FPG-150 manufactured by Oji Yuka Co., Ltd.) was prepared. On the other hand, the total of each component in Table 1 is methyl ethyl ketone / toluene (1 /
1% by weight) of a mixed solvent to prepare a dye-receiving layer-forming coating solution so as to be a 20% solution, which is applied on the surface of a sheet-shaped substrate so that the dry film thickness is 3 to 6 μm, In 4
A photographic printing paper was prepared by carrying out curing for 8 hours.

[0031]

(Table 1) (parts by weight) Example Comparative Example 1 2 12 Phenoxyethyl methacrylate resin (* 1) 100 100-Polyester resin (* 2)-100-Cellulose acetate butylate resin (* 3) --- 100 Isocyanate compound (* 4) 5-5 5 〃 (* 5) -5 --- Silicone oil (* 6) 5 5 5 5 5 (* 1) Scientific Polymer Products (MW = 100,000) (* 2) Byron # 200, Toyobo (* 3) CAB500, E.I. Kodak (* 4) Takenate D110N, Takeda Pharmaceutical Co., Ltd. (* 5) Takenate D160N, Takeda Pharmaceutical Co., Ltd. (* 6) SF8427, Toray Dow Corning (evaluation) On the other hand, sublimation type thermal transfer ink ribbons (UP-7000, manufactured by Sony Corporation) of yellow (Y), magenta (M) and cyan (C) are used.
Standard test printer manufactured by Machiles Co., Ltd. (print pulse width 5
12 steps of stairstep printing and black solid printing were performed at msec / line). Then, the light resistance, dark fading resistance and sebum resistance of the obtained image were evaluated as follows, and the results are shown in Table 2. (i) Light resistance The image formed on the photographic paper is irradiated with 90,000 KJ / m ² with a xenon fade meter (manufactured by Suga Test Instruments) (30
C, 65% RH), the optical density before and after irradiation in this case was measured using a Macbeth reflection densitometer (TR-924),
The residual dye ratio was calculated according to the following formula.

Dye residual ratio (%) = (optical density after irradiation /
(Optical density before irradiation) × 100 (ii) Dark fading resistance The photographic printing paper on which the image is formed is kept in a constant temperature bath (60 ° C, 85% RH).
Then, the optical densities of the images before and after the storage were measured in the same manner as above to determine the dye residual ratio. (iii) Sebum resistance One drop of artificial sebum is dropped on the image formed on the photographic paper and 3
After leaving it at 5 ° C. for 10 minutes, it was wiped off, and the optical densities of the images in this case before the artificial skin oil was dropped and after the artificial skin oil was wiped off were measured in the same manner as above to obtain the dye residual ratio.

[0033]

[Table 2] Light resistance, dark fading resistance, sebum resistance (dye residual rate%) (dye residual rate%) (dye residual rate%) Y M C Y M C Y M C Example 1 84 75 83 89 82 83 91 95 93 Example 2 80 74 79 95 83 81 93 98 96 Comparative example 1 61 52 72 73 72 81 68 71 70 Comparative example 2 81 74 61 85 79 65 45 51 46 From Table 2, the photographic printing papers of the examples of the present invention have high dye residual ratios in all evaluation items of light resistance, dark fading resistance, and sebum resistance, as compared with the photographic papers of comparative examples containing no phenoxyethyl methacrylate resin. It can be seen that the image storability is excellent.

[0034]

According to the photographic paper of the present invention, it is possible to form an image having excellent storage characteristics such as light resistance, dark fading resistance, sebum resistance, and plasticizer resistance.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a general printing paper.

[Explanation of symbols]

 1 photographic paper 2 sheet-like substrate 3 dye receiving layer

Claims (3)

[Claims] 1. A photographic printing paper comprising a sheet-shaped substrate and a dye receiving layer, wherein the dye receiving layer contains a polymer having a phenoxyethyl methacrylate unit. 2. The printing paper according to claim 1, wherein the dye receiving layer contains a resin compatible with a polymer having a phenoxyethyl methacrylate unit. 3. The printing paper according to claim 1, wherein the polymer having a phenoxyethyl methacrylate unit is contained in an amount of 40% by weight or more of the dye receiving layer.