JPS61248791A - Photographic paper for thermal recording - Google Patents

Abstract

PURPOSE:To make possible to obtain high developed color density, by forming a coating layer containing pigment having specific average oil absorption and a specific volume average particle size on a support and impregnating said coating layer with a dye acceptor. CONSTITUTION:A coating layer containing pigment, of which the average oil absorption is 35-140ml/100g and the volume average particle size is 2-20mum, is formed on a support such as high grade paper and impregnated with a dye acceptor, for example, polyester to form a recording layer. By specifying the average oil absorption and volume average particle size of the pigment, the recording layer formed by impregnating the dye acceptor has good dyeability because the dye acceptor, for example, polyester is impregnated in a proper amount and, by forming a proper uneven surface by the pigment particles, thermal fusion is avoided at the time of the printing of an image. As the pigment to be used, for example, barium sulfate, alumina or plastic pigment white or transparent and having heat resistance can be used. The coating amount of the coating layer is desirably 2-20g/m<2> and the impregnation amount of the dye acceptor in the recording layer is desirably 0.5-5g/m<2>.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermal recording photographic paper used when obtaining a hard copy by thermally printing an image captured by a video camera or a television image using sublimation dye, for example. Regarding.

[Summary of the invention]

The present invention is a photographic paper for thermal recording, in which a predetermined coating layer is formed on a support and a paint receptor is impregnated into the coated layer, thereby forming a photographic paper that has sufficient color density and does not cause thermal fusion. It is something.

[Conventional technology]

Hard copy by thermal recording is produced by superimposing an ink ribbon containing a sublimable dye on photographic paper and heating it in a pattern corresponding to the image information, such as image information captured by a video camera or television image information. Obtained by transferring a color dye onto photographic paper. FIG. 3 shows a printer that obtains hard copies by this thermal recording. This printer uses, for example, photographic paper (11 is wrapped around the arrow a).
A platen (2) that rotates in the direction shown in FIG. At the tip of the heating head (4), heating elements (4a) are arranged, for example, by the number of picture elements corresponding to one scanning line of a television image.

The ink ribbon (3) for thermal transfer recording, which is pressed between the heating head (4) and the photographic paper (1), is placed on the sheet-like substrate (9) in the shape of the outline of the screen of the television image. For example, each color yellow, with a corresponding ring shape,
The ink portions of each color having sublimable dyes of magenta, cyan, and black, yellow Y, magenta M, cyan C, and black B, are sequentially and repeatedly arranged, and for example, the ink of each color is placed on one corresponding side edge. Each color ink part position detection mark (5Y) to detect the position of the part
(5M), (5C), and (5B), and a block position detection mark (6) for detecting a combination block of each set of ink portions, that is, adjacent ink portions Y, M, C, and B. .

In this way, for example, in a state where the ink portion Y is in pressure contact with the photographic paper (1), information corresponding to yellow, for example, a color signal corresponding to yellow of a television video signal, is transmitted to each head element (4a ), a pattern corresponding to picture elements for one scanning line is heated, and the yellow sublimation dye of the ink portion Y is thermally transferred to the photographic paper (1) according to this heating pattern. In this way, the platen (2) is rotated intermittently along the arrow a for each line corresponding to each scanning line, and the information on each line is thermally transferred.
One screen of yellow is transferred during one rotation of the platen (2). Next, the same transfer process is performed for magenta M, and then the transfer is repeated for cyan C, black B, and then a color image is created by combining the transferred images of each sublimation dye of yellow Y, magenta M, cyan C, and black B. is projected onto photographic paper to obtain a hard copy. (7) and (8) are each ink portion Y, M, C
and B, the signals corresponding to the respective color signals are transmitted to the head (
Marks (5) ((5Y) (5M) (5C) (5B) as given to the head element (4a) of 4)
) and (6), respectively, constitute a detection means for detecting the light source (for example, an infrared light emitting diode) and the detection element.

As photographic paper for performing the above-mentioned recording, for example, one made of high-quality paper coated with a resin containing a pigment is known (for example, Japanese Patent Application Laid-Open No. 57-91296, Japanese Patent Application Laid-Open No. 57-57- Publication No. 107885, JP-A-58-
209596).

Although efforts have been made to improve color density, that is, dyeability, and fading resistance of such photographic paper, there is a growing demand for these improvements, and in particular, there are problems with the ink ribbon of photographic paper. It cannot be said that this is sufficient in terms of preventing heat fusion.

[Problem that the invention seeks to solve]

The present invention is a photographic paper for thermal recording that has high color density, that is, dyeability, and also aims to improve the above-mentioned problem of thermal fusion during printing.

[Means for solving problems]

In the present invention, on a support such as high-quality paper, the average oil absorption amount is 35 to
140ml/100g, volume average particle size 2-20
．． A coating layer containing a czm pigment is formed, and a recording layer is formed by impregnating this with a pigment receptor such as polyester.

The average oil absorption amount of the pigment here is measured by the method described in JIS K5101, and when a plurality of pigments are used in combination, the following formula (11) is used as the value of the average oil absorption amount.

...(1) (However, A, B, C... and a, b, c...
... is the oil absorption amount (tel) of each pigment using each combination.
/ 100g) and the mixing ratio of each pigment in the pigment composition (%
)).

In addition, the volume average particle diameter is determined by Coulter Electronics, Inc.
Coulter counter model (Cou
The volume fraction (%) distribution and the cumulative volume fraction (%) distribution of the pigment in the coating liquid by particle size were determined using a TA ■ type measurement layer measuring device, and the cumulative volume fraction (%) distribution was determined to be 50%.
The particle size at % was taken as the volume average particle size.

[Effect]

According to the above-described thermal recording paper according to the present invention, excellent color density was obtained, and no thermal fusion was observed during printing. This means that by specifying the average oil absorption and volume average particle size of the pigment, the recording layer formed by impregnating the pigment with a dye receptor can be appropriately impregnated with the dye receptor, such as polyester. It is believed that good dyeing properties, that is, good color density can be obtained by this method, and furthermore, by forming an appropriately uneven surface with pigment particles, thermal fusion during printing can be avoided.

〔Example〕

Next, an embodiment of the present invention will be described in detail together with its manufacturing procedure. First, a pigment and a binder are mixed and homomixer dispersed (hereinafter referred to as H,M dispersion) to obtain a slurry, or a slurry is obtained by sand grinder dispersion (hereinafter referred to as H,M dispersion). (referred to as S, G dispersion) to obtain a slurry.

For H,M' dispersion, 100 parts by weight of the pigment was mixed with 5 parts by weight of polyvinyl alcohol (PVA) as a dispersion binder to obtain an aqueous slurry with a solid content concentration of 30% by weight.
Pigments that are dispersed by a homomixer but have a large oil absorption amount, for example, an oil absorption amount of 170mj! / 100g of sodium aluminosilicate or oil absorption is 300 + wIl / 100
When dispersing H and M when using amorphous silica, the solid content concentration is 25% by weight and 15% by weight, respectively.
Weight%.

In addition, for S and G dispersion, 100 parts by weight of pigment is mixed with 5 parts by weight of polyvinyl alcohol (PVA) as a dispersion binder, but in this case, an aqueous slurry with a solid content concentration of 40% by weight is obtained, which is then processed by a sand grinder. The particle size is reduced by dispersing the particles to obtain a slurry. Also in this case, when sodium aluminosilicate having a large oil absorption amount is used as the pigment, the solid content concentration of the slurry is set to 25 M%.

Next, PVA as a binder was further added to the dispersion slurry obtained by H, M dispersion or S, G dispersion, and the weight ratio of binder to pigment was adjusted to be 8=2. Add water to bring the concentration to 25% (
weight). 160g of the coating solution obtained in this way
10g/nf solids on a support made of high quality paper.
% to form a coating layer.

Next, the coated layer is impregnated with a polyester resin for the dye receptor diluted with methyl ethyl ketone (MEK) or toluene to a solid content of 10%, and dried to a concentration of 2 g/rd, followed by drying. After that, linear pressure 100Kg/
A crosslinking reaction is caused by calendering at 80° C. for 24 hours. In this way, a photographic paper having a recording layer formed on the support is obtained.

For each side of the photographic paper according to the present invention (Examples 1 to 15) using various specified pigments by such a method, the composition of the pigments and the preparation of the slurry are shown in Figure 1. In cases where multiple types of pigments are used, the commonly used dispersion method and the volume average particle size of each pigment are shown, and the volume average particle size Sg (μm) of the pigment as a whole is shown.
The average oil absorption amount (ml/100g), the surface strength Ps as a coating film in each recording layer finally obtained, the whitening state W of the printed area in high density printing, and the thermal fusion state St
Furthermore, the measurement results of saturation density for each color magenta M, cyan C and yellow Y are shown. Examples 1 to 9,
Examples 14 and 15 are cases in which one type of pigment was used alone, and Examples 10 to 13 are cases in which two or more types of pigments were used in combination.

The transfer to each photographic paper, that is, printing, is performed using an ink ribbon, which is brought into contact with the recording layer of each photographic paper, and heated under pressure for 3 seconds from the back side of the ink ribbon using a thermal head set at 200°C. Dye was transferred to the recording layer of paper to develop color. This ink ribbon is a disperse dye with sublimation property (part name manufactured by Nippon Kayaku Co., Ltd., Kayaset Red)...
・6% by weight hydroxypropylcellulose ・・・llit
%Ethylcellulose...5% by weight
Carbon black (average particle size 100 μm): 5% by weight Isopropyl alcohol: 78% by weight
A magenta M ink paint was prepared by kneading a composition consisting of the following, and a yellow ink paint was prepared by using Kayaset Yellow-AG (part name manufactured by Nippon Kayaku Co., Ltd.) dye as a disperse dye in the above composition. , Kayaset Blue-FR (Nippon Kayaku Co., Ltd.) as a disperse dye in the above composition.
Product part name) A cyan ink paint is prepared using the dye, and a black ink paint is further prepared using Kayasent Black 922 (product name manufactured by Nippon Kayaku Co., Ltd.) dye in the above composition as a disperse dye. Each of these magenta.

Yellow, cyan, and black ink paints were each applied to a 20 μm thick capacitor paper using a three-pronged gravure coater.

In addition, FIG. 2 shows the measurement results for Comparative Examples 1 to 11 in the same manner as FIG. 1. In FIGS. 1 and 2, the recording layer surface strength Ps refers to the When a cellophane tape was pasted with an adhesive layer on the heat-treated coating layer, that is, the recording layer, and slowly peeled off in a 180° direction, the coating film constituting the recording layer adhered to the adhesive layer of the cellophane tape. Items in which no loss occurred are indicated by a Q mark, cases in which a small amount was removed are indicated by a Δ, cases in which it was removed uniformly are indicated by an x mark, and cases in which a significant amount was removed are indicated by an ×X mark. It is something.

In addition, high-density printing area whitening (W) refers to when high-energy printing is performed, the dye sublimated and adsorbed on the pigment surface is further diffused into the pigment due to the high energy, and as the dye concentration decreases, the pigment has a hiding effect. This is a phenomenon in which whiteness becomes stronger, and ○ marks indicate cases in which no whitening occurred, and × marks indicate cases in which whitening occurred.

Furthermore, the heat fusion state St refers to whether or not fusion occurred between the dye on the ink ribbon and the measuring photographic paper during similar heating printing, and the mark Q indicates that no heat fusion occurred. △ indicates that there was no occurrence, △ indicates that there was a little occurrence, and × indicates that there was a considerable amount of occurrence.

In addition, the saturation density is determined by transferring and printing the ink portion of each color on the ink ribbon onto measurement photographic paper, and then measuring the saturation density of each color using the Macbeth RD-514 model (Latten gelatin filter, #47 Plue, #25 Left). #58 Green).

The "-" mark in FIG. 2 indicates that the recording layer was so peeled that measurement was impossible.

As is clear from the table in FIG. 1, in each of Examples 1 to 15 according to the present invention, satisfactory results were obtained in terms of surface strength, whitening, and thermal fusion while obtaining high saturation concentrations. As is clear from the measurement results of the comparative example in Figure 2, the average oil absorption of the pigment was 35 to 140 in the present invention
rsj! / Even when selecting a range of 100g, when the volume average particle size Sg is set to 1μm, which is less than 2μm,
Comparative example 1. 3. Heat fusion occurs as in 5, and 2
When it exceeds 0 μm, the saturation concentration decreases as seen in Comparative Examples 2, 4, and 6.8. And these,
Comparative example 2゜4.6. It was observed that in the case of No. 8 and No. 8, the surface of the recording layer became extremely rough. In addition, the volume average particle diameter Sg
Even if the diameter is 2 to 20 μm, the average oil absorption Ab is 10
0mj! / If the weight exceeds 100 g, as seen in Comparative Examples 9, 10, and 11, the surface strength decreases and whitening of the high-density printed area occurs. In addition, the average oil absorption amount is 35
If it is less than 20%, heat fusion occurs as in Comparative Example 7.8, and the saturation concentration decreases.

As is clear from the above, in the case of the present invention, the average oil absorption amount of the pigment is 35 to 140 m
Using 1/100g, the volume average particle size is 2 to 20.
μm, it is possible to obtain high saturation density, that is, high dyeability, high coloring density, and there is no problem of thermal fusion (high surface strength as a recording layer is obtained, and high density Whitening of prints has been improved.In other words, when the average oil absorption is small (less than 35all/100g), the dye receptor penetrates into the coating layer, making it easier to form a film on the surface of the coating layer, resulting in thermal melting. In addition, even if the receptor is impregnated to such an extent that no receptor film is formed on the surface of the coating layer, the sublimated dye tends to remain on the surface, causing fusion when it solidifies. When the amount is sufficient, the color density decreases.

When the average oil absorption takes a large value exceeding 140 mj2/100 g, the amount of binder consumed becomes large, and as in Comparative Example 9.10.11, there is a binder shortage and the surface strength becomes low. In order to obtain sufficient surface strength, it is necessary to consume an extremely large amount of binder, which is economically disadvantageous. Furthermore, since the sublimated dye re-diffuses into the pigment, whitening occurs in high-density printed areas due to the pigment's hiding effect. Furthermore, if the average diameter is less than 2 μm, the surface of the recording layer becomes smooth, reducing the releasability from the ink ribbon and causing thermal adhesion, and if the particle diameter is too small, the required amount of binder is reduced. is the same P/B, the amount P (weight) of the CH material and the amount B of the binder
(ratio to weight)) decreases. If the average particle size is larger than 20 μ-, the surface becomes extremely rough, resulting in point contact between the ink ribbon and the photographic paper, resulting in insufficient heat conduction and insufficient sublimation and adsorption of the dye. If this is not done, the color density will decrease. Furthermore, if the surface is too rough, the reproducibility of dots will be poor and the paper will lack practicality as a photographic paper.

The pigment used in the photographic paper according to the present invention is not limited to the above-mentioned examples, but white or transparent, heat-resistant pigments such as barium sulfate, alumina, and plastic pigments can be used.

In addition to the above-mentioned PVA, the binder may be a protein adhesive such as casein, starch, synthetic latex, cellulose derivative, or the like.

Furthermore, P/
B is preferably selected from 9515 to 65/35. This is because when the binder amount is less than 1.8, the pigment receptor oozes out from the coating layer and forms a film on the surface due to the binder amount being too large, causing thermal fusion, and when it exceeds 19, the surface strength becomes weak.

Furthermore, the coating amount of the coating layer constituting the recording layer is 2 to 20 g/r.
rr is desirable, and if it is less than 2g/rr1, the base material (
Insufficient coverage of the support (support) and lack of ability of the coated layer to absorb the dye receiver may cause thermal adhesion problems.
If it exceeds 20g1rd, the dye will diffuse into the coating layer and the concentration will decrease.

Furthermore, the amount of impregnation in the recording layer of the dye receiver is 0.5 to 5 g/rrr (more preferably 1 to 3 g/rrr).
This is because if desired, it overflows and forms a film on the surface, causing thermal fusion. In addition to the above-mentioned polyester resin, epoxy resin, acetate resin, and nylon resin can be used as the dye receiver.

〔Effect of the invention〕

As mentioned above, the photographic paper of the present invention can obtain high color density and solve the problem of heat fusion with the ink ribbon, so it is possible to obtain hard copies of excellent image quality and to put it into practical use. The benefits are huge.

In addition, in the photographic paper according to the present invention, a transparent cover film can be laminated to cover and protect the recording layer to physically and chemically protect the recording layer and prevent fading. .

Regarding this cover film, please refer to Japanese Patent Application No. 192959 of 1982 filed by the present applicant or Utility Application No. 1983-
This proposal has been made in the application No. 161609.

[Brief explanation of drawings]

Figure 1 is the front page showing the characteristics of each example of the thermal recording photographic paper according to the present invention, Figure 2 is the front page showing the characteristics of each comparative example compared with the photographic paper of the present invention, and Figure 3 is the thermal recording paper. FIG. 2 is a configuration diagram of a recording printer. (1) is photographic paper, (3) is an ink ribbon, and (4) is a heating head. 7. Procedural amendment June 1-4, 1985 Manabu Shiga, Commissioner of the Patent Office, 1985 Patent Application No. 90274 3, Relationship with the case of the person making the amendment Patent applicant address Tokyo Parts Co., Ltd. 6-7-35 name for illustrated items (2
1B) Sony Corporation 4, Agent address: 1-8-1 Nishi-Shinjuku, Shinjuku-ku, Tokyo ↑EL 0
3-343-582H1 (Shinjuku Building) (1) Akira I!
l[l! A, 1st shell, line 17, 1 cephalic receptacle.
Same, page 5, line 9, "pigment" is corrected to "dye." (3) Same, page 9, line 17 “~9, 14.15J”
．． Correct it to 14J. (4) Same, page 12, line 18 "1-15" changed to "1-14"
I am corrected. (5) Same, page 12, line 18 r 100rn1/100
Correct gJ to r 140al/100gJ. (6) Same, p. 15, lines 17-18 “Gassein” is replaced with “
"Casein," he corrected. (7) In the drawings, Figures 1 and 2 will be amended as shown in the attached sheet. that's all

Claims (1)

[Claims] (a) On the support, the average oil absorption amount is 35 to 140 ml/10
0 g, a coating layer containing a pigment having a volume average particle diameter of 2 to 20 μm is formed, and (b) the coating layer is impregnated with a dye receptor.