JP3115142B2 - Sublimation type thermal transfer receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sublimation type thermal transfer image receptor.

[0002]

2. Description of the Related Art Conventionally, synthetic paper, woodfree paper, art paper, coated paper, cast-coated paper, cellulose fiber or various plastic films or sheets have been well known as a substrate of a sublimation type thermal transfer image receiving body. However, when the base material is made of fiber, it is difficult to obtain uniform image quality, and when the base material is made of plastic film, only the surface is heated during printing and the image receiving paper curls. Was.

In order to solve such a drawback, the present inventors have previously used a sheet of a fibrous substance as a substrate of an image receiving medium and embedded polymer particles in the voids between the fibers of the sheet. , Without sacrificing the quality of the sheet,
We have proposed an image receiving medium capable of forming an image record without white spots due to a heat sublimable dye.

[0004] In addition to the above-mentioned functions and effects, this image receiving medium has the advantage that the image is uniform, the image density is high and the image does not curl. It was found that when the color of the polymer particles was yellowish, the surface became yellowish, the whiteness was not sufficient, and the white image was unclear.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances of the prior art, and an object of the present invention is to obtain an image having no white spots without impairing the sheet-like quality of a sheet, and to further reduce the whiteness. It is an object of the present invention to provide a sublimation type thermal transfer image receptor which is sufficient and has excellent white image clarity.

[0006]

According to the present invention, there is provided a sublimation-type thermal transfer image receiver comprising a substrate comprising fibers and polymer particles, and a receptor layer for dyeing a sublimable dye formed on the surface of the substrate. The surface reflection characteristic of the surface coated with the receiving layer is JIS-
Measured by the method specified in Z8722 and JIS-Z
L when displayed by the method specified by 8730,
The values of a and b are each L = 90 or more, and a = −1.5 to +
1.5, b = −5.0 to −0.0. A sublimation-type thermal transfer image receiver is provided, wherein the substrate comprises fibers and polymer particles, and In a sublimation type thermal transfer image receiver having a receptor layer for dyeing a sublimable dye thereon, the surface reflection characteristics of the substrate surface are measured by a method specified in JIS-Z8722 and displayed by a method specified in JIS-Z8730. L is 90
As described above, a is -2.0 to +2.0, and b is -7.0 to -1.
The sublimation-type thermal transfer image receiver is provided, wherein the substrate is composed of fibers and polymer particles, and a resin layer that dyes the sublimable dye is formed on the surface of the substrate. The sublimation type thermal transfer image receiving body, wherein a layer formed between the receiving layer for dyeing the sublimable dye and the substrate contains at least one kind of fluorescent whitening agent or white pigment. A sublimation type thermal transfer image receiver is provided.

Note that L, a, and b in the above are each JIS.
-Z8722 and JIS-Z8730 are symbols representing surface reflection characteristics determined by the method specified in JIS-Z8730. L
Represents lightness, and the larger the numerical value, the higher the lightness.
a represents reddish color. A larger value indicates a stronger reddish color, and a negative value indicates that the reddishness is insufficient, in other words, a greenish color is stronger. The b value is an index of red tint, and a large numerical value indicates that yellow tint is strong, while a negative value indicates that yellow tint is insufficient and blue.
When both a and b are 0, it is expressed as an achromatic color.

The inventors of the present invention have conducted intensive studies on the base constituting the image receiving body in order to solve the above-mentioned problems.
For example, the substrate takes on a yellow tint when the value of a is less than -1.5, a red tint when it exceeds +1.5, and a blue tint when the value of b is less than -5.0. It takes on a yellowish color when the value is 0 or more, and the L value does not affect the color tone. However, when the value is less than 85, the whiteness becomes dull and the formed image becomes dark. did.

Further, as described above, if a dye receiving layer is formed on the surface of a substrate having optimum surface reflection characteristics for normal image formation, even if the substrate has surface reflection characteristics in the above-mentioned range,
Because the resin forming the receiving layer is yellowish,
It has been found that light passing through the receiving layer, reflected on the surface of the substrate, and passing through the receiving layer again causes the naked eye to feel yellow.

Further examination of this point revealed that the value of L in the surface reflection characteristics of the substrate on which the image receiving layer was formed was 90 or more, the value of a was -2.0 to +2.0, and the value of b was-. When it is in the range of 7.0 to -1.5, even if a receptor layer is formed from a yellowish transparent resin on its surface, it passes through the receptor layer, is reflected on the surface of the substrate, and is again formed. The characteristic of the reflected light that reaches the eyes after passing through the receiving layer is L = 85 or more and a = −1.5
To +1.5, b = -5.0 to 0, and the color appearance without turbidity and dullness can be obtained by forming an image receiving body using a substrate having a very white appearance and the above-mentioned surface reflection characteristics. It has been found that a transferred image having excellent properties and transparency can be formed. The present invention has been made based on such findings.

Hereinafter, the present invention will be described in more detail.

The sublimation-type thermal transfer image receptor according to the present invention is a sublimation-type thermal transfer image receptor comprising a substrate comprising fibers and polymer particles, and a receiving layer for dyeing a sublimable dye formed on the surface of the substrate. The surface reflection characteristic of the surface coated with the receiving layer is JI
Measured by the method specified in S-Z8722 and JIS
The values of L, a and b when displayed by the method specified by -Z8730 are each L = 90 or more and a = -1.5
, And b = −5.0 to −0.0, and more preferably, in the image receiving member, the surface reflection characteristic of the substrate surface is determined by a method specified in JIS-Z8722. When measured and indicated by the method specified by JIS-Z8730, L is 90 or more and a is-
2.0 to +2.0, and b is in the range of -7.0 to -1.5, but in order to obtain such an image receiving medium, such a surface reflection characteristic is required. To have
A bleaching treatment, a whitening treatment or addition of a white pigment may be performed on the substrate or the receiving layer, or the surface smoothness may be adjusted by an appropriate means.

As another means for improving the whiteness of the image receiving body, a fluorescent whitening agent or at least one white pigment may be added to the dye receiving layer or the intermediate layer provided between the dye receiving layer and the substrate.
There is a method of containing more than one species.

The whitening agents used in the intermediate layer or the dye receiving layer include the following.

Examples of the white pigment include inorganic pigments such as titanium oxide, zinc oxide, barium sulfate and alumina white.
Extenders such as kaolin, clay, silica, magnesium carbonate and calcium carbonate can be used alone or in combination. Representative titanium oxides among the above include KA-10, KA-20, K
A-30, KA-35, KA-60, KA-80, KA
-90 etc. (above anatase type titanium oxide), KR-31
0, KR-380, KR-460, KR-480, etc. (above, rutile-type titanium oxide), and as kaolin clay, JP-kaolin manufactured by Tsuchiya Kaolin Industries, Ltd., 5M
Kaolin, NN kaolin, Hardsil, ST kaolin and the like are commercially available.

Specific examples of the blue dye include Cassette Blue N (Nippon Kayaku), Cassette Blue FR (Nippon Kayaku), Cassette Blue A-CR (Nippon Kayaku), and Cassette Blue 714 (Japan). Kayaku), Waxolin Blue AP-FW (ICI), Holon Brilliant Blue SR (Sand), MS Blue 100 (Mitsui Toatsu Chemicals), Daito Blue No. 1 (manufactured by Daito Kagaku) or the like can be used. As red dyes, MS Red G (manufactured by Mitsui Toatsu Chemicals), Macrolex RadViole
tr (manufactured by Bayer), Ceress Red 7B
(Manufactured by Bayer AG), SK Rubin SEGL (manufactured by Sumitomo Chemical)
Etc. can be used. As the blue or red colorant, an inorganic pigment or an organic pigment such as a phthalocyanine pigment or an azo pigment can be used. For example, a phthalocyanine blue pigment such as Helige manufactured by BASF is used.
n Blue LBG, manufactured by BASF, Helioge
r Blue BR and the like, and as an azo red pigment, Bayer's Helio Fast
Red BN, Bayer, Helio Fast
Red FG or the like may be used. Focusing on the types of dyes, disperse dyes, acid dyes, gold-containing dyes, and direct dyes can be appropriately used.

Examples of the fluorescent whitening agent include stilbene, distilbene, benzoxazole, styryl / oxazole, pyrene / oxazole, coumarin, imidazole, benzimidazole, pyrazoline, aminocoumarin, distyryl-biphenyl. A system and a fluorescent whitening agent are used, and these fluorescent whitening agents may be used as a mixture of one or more kinds. Specific examples of these optical brighteners include Uviflex-OB and Uviflex-OB manufactured by CIBAGEIGY.
vitex-EBF, Uvitex-ERN-P (benzoxazole type), Uvitex-EHF (styryl / oxazole type), Uvitex-EMT, Uv
itex-EM-V (all pyrene / oxazole-based),
Uvitex-ERT (coumarin-based), Uvitex-
AT (imidazole type), Uvitex-BAC (benzimidazole type), Uvitex-WG (pyrazolin type), Uvitex-WGS (aminocoumarin type), U
vitex-2B, Uvitex-BHT, Uvite
x-MST, Uvitex-CF (above stilbene type), Uvitex-NFW (distyl-biphenyl type), etc., and Kaycall-BS of Shin Nisso Chemical Co., Ltd.
conc, Kayacall-BIconc, Kaya
call-BIL, Kaycall-BAR, Kay
acall-BRAL, Kayall-BRBL,
Kayall-BUL, Kayall-BXc
onc, Kayacall-BXNL, Kayacal
1-BZconc, Kayallall-BZH / C, K
ayacall-CPL, Kayacall-KTL,
Kaycall-PAN, Kaycall-PKc
onc, Kayall-RG, Kayall-
RP, Kaycall-SR, Kaycall-W
G, Kaycall-WS, Kaycall-WS
L-100, Kayall-E, Kayall
—C and the like. In addition, KayalightOS
R, KaylightOS, KaylightB
(Nippon Kayaku) can also be used. Besides these, Eastobrite OB-1 (manufactured by Eastman Chemicals) is also available on the market.

In the image receiving medium of the present invention, a sheet of a fibrous substance which is a main component of the substrate can be produced by forming the fibrous substance into a sheet by a conventional method. Examples of the fibrous substance include natural plant fibers such as wood pulp and bark fiber, synthetic pulp, recycled pulp, synthetic resin fibers such as polyester, polyolefin, and polystyrene, and chemical fibers such as glass fibers. These fibers are preferably white, but may be colored. Among these fibrous substances, those particularly suitable in the present invention are synthetic resins such as PET, which are desirable in terms of availability and cost. These fibrous substances can be obtained by processing the resin into fibrous form by conventional means such as melt spinning.

As the sheet of the fibrous substance used in the present invention, a conventionally known sheet is used, and generally, a porosity:
Those having 20 to 90 vol% are used. The thickness is 5 to 300 μm. Specific examples of such a sheet of fibrous material include Japanese paper, papermaking paper such as Western paper,
Examples thereof include synthetic paper and nonwoven fabric whose surface is formed as paper dust. The substrate used in the present invention can be obtained by embedding polymer particles in the fibrous material sheet. The polymer particles may be solid, but are preferably hollow. Further, it may be porous.
It is preferable that the polymer particles contain a low-boiling substance therein and have a thermal expansion property. Such heat-expandable polymer particles are buried in the inter-fiber voids of the sheet of fibrous material, and then heat-expanded to completely fill the inter-fiber voids and have good bonding with the voids. It can be buried and held in the part.

The polymer particles used in the present invention are conventionally known, and specific examples thereof include the following. (1) Thermoexpandable thermoplastic resin particles: vinylidene chloride
Hollow particles having a capsule wall made of a thermoplastic resin such as an acrylonitrile copolymer and containing a volatile liquid expanding agent such as propane, n-butane, or isobutane inside the particles. When heated, the liquid inside expands to form expanded polymer particles. Such particles are commercially available, for example, Matsumoto Microsphere F30 from Matsumoto Yushi and Expance from Chemo Nobel.
l551 and 642. (2) Microcapsule-shaped polymer particles: These are polymer particles in which a hard resin such as an acryl-styrene copolymer is used as a capsule wall, water is contained therein, and water jumps out during drying and becomes hollow. Particles of this type are also commercially available, for example Rohm and Haas Robake OP-84J.
And the like.

The size of the polymer particles used in the present invention may be any size as long as it is smaller than the size of the pores formed by the fiber voids of the above-mentioned sheet of fibrous material. ~ 1/2, preferably 1/50 to 1/5
It is about. In order to embed the polymer particles in the sheet of the fibrous substance, the adhesive containing the polymer particles may be impregnated into the sheet, and then dried by heating.The content ratio of the polymer particles in the liquid adhesive is as follows. , 5 to 70 vol%, preferably 1
0 to 50 vol%. A conventionally known liquid adhesive is used. In this case, as the adhesive component, carboxymethyl cellulose, sodium alginate,
Starch, casein, polyvinyl alcohol, polyethylene oxide, polyvinylpyrrolidone, acrylate,
Examples include methacrylate, ethylene / vinyl acetate copolymer, polyurethane, and epoxy resin. The ratio of the adhesive component to the polymer particles is 0.1 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 1 part by weight of the polymer building particles. The liquid adhesive can be an aqueous solution, an organic solvent solution or an emulsion. As a method for impregnating the sheet of the fibrous substance with the liquid adhesive containing the polymer particles, a conventionally known method, for example, a dipping method or a roll coating method can be used.

In the liquid adhesive containing the polymer particles, it is preferable to use an organic solvent-resistant adhesive as the adhesive component. When an organic solvent-resistant adhesive component is used, the adhesive component adheres to the polymer particle surface to form an organic solvent-resistant protective layer. Then, when a substrate containing such polymer particles is coated with an organic solvent solution of a resin to form a dye receiving layer, the polymer particles contained in the substrate are dissolved by contact with the organic solvent. Is prevented. The substrate used in the present invention is provided with an organic solvent resistant polymer layer on its surface, thereby preventing the polymer particles from being dissolved by contact with an organic solvent. When such a polymer layer is provided, it is not necessary to use an organic solvent-resistant adhesive component as the adhesive component. The organic solvent-resistant adhesive component or polymer may be any as long as it has excellent film-forming performance and suppresses the penetration of an organic solvent. Specifically, for example, aqueous high-molecular-weight materials such as polyvinyl alcohol, casein, and starch may be used. Examples include molecules, acrylic acid esters, ethylene-vinyl acetate copolymers, and polyethylene having a carboxyl group. Among them, polyvinyl alcohol, casein, and starch are preferably used because of their excellent organic solvent resistance.

In the present invention, in order to improve the whiteness of the substrate, it is preferable to embed a white pigment, a fluorescent whitening agent and a coloring agent such as a blue dye in the fibers of the substrate to whiten them. As the white pigment, inorganic pigments such as titanium oxide, zinc oxide, barium sulfate and alumina white, and extender pigments such as kaolin clay, silica, magnesium carbonate and calcium carbonate can be used alone or in combination. Representative titanium oxides among the above include KA-10, KA-20, KA-30, and KA-35 manufactured by Titanium Industry Co., Ltd.
KA-60, KA-80, KA-90, etc. (above, anatase type titanium oxide), KR-310, KR-380, KR
As the kaolin clay, JP-Kaolin, 5M Kaolin, NN Kaolin, Hardsil, ST Kaolin, and the like are available from the market as kaolin clay. is there. Focusing on the types of dyes, disperse dyes, acid dyes, gold-containing dyes, and direct dyes can be appropriately used.

Examples of the fluorescent whitening agent include stilbene, distilbene, benzoxazole, styryl / oxazole, pyrene / oxazole, coumarin, imidazole, benzimidazole, pyrazoline, aminocoumarin, distyryl-biphenyl. A system and a fluorescent whitening agent are used, and these fluorescent whitening agents may be used as a mixture of one or more kinds. Specific examples of these optical brighteners include Uviflex-OB and Uviflex-OB manufactured by CIBAGEIGY.
vitex-EBF, Uvitex-ERN-P (benzoxazole type), Uvitex-EHF (styryl, oxazole type), Uvitex-EMT, Uv
itex-EM-V (the above is pyrene: oxazole),
Uvitex-ERT (coumarin-based), Uvitex-
AT (imidazole type), Uvitex-BAC (benzimidazole type).

Specific examples of the blue dye include Cassette Blue N (Nippon Kayaku), Cassette Blue FR (Nippon Kayaku), Cassette Blue A-CR (Nippon Kayaku), and Cassette Blue 714 (Japan). Kayaku), Waxolin Blue AP-FW (ICI), Holon Brilliant Blue SR (Sand), MS Blue 100 (Mitsui Toatsu Chemicals), Daito Blue No. 1 (manufactured by Daito Kagaku) or the like can be used. As red dyes, MS Red G (manufactured by Mitsui Toatsu Chemicals), Macrolex RadViole
tr (manufactured by Bayer), Ceress Red 7B
(Manufactured by Bayer AG), SK Rubin SEGL (manufactured by Sumitomo Chemical)
Etc. can be used. As the blue or red colorant, an inorganic pigment or an organic pigment such as a phthalocyanine pigment or an azo pigment can be used. For example, a phthalocyanine blue pigment such as Helige manufactured by BASF is used.
n Blue LBG, manufactured by BASF, Helioge
r Blue BR and the like, and as an azo red pigment, Bayer's Helio Fast
Red BN, Bayer, Helio Fast
Red FG or the like may be used.

Also, Uvitex-WG (pyrazolin type), Uvitex-WGS (aminocoumarin type), Uvitex-WG
vitex-2B, Uvitex-BHT, Uvite
x-MST, Uvitex-CF (above stilbene type), Uvitex-NFW (distyl-biphenyl type), etc., and Kaycall-BS of Shin Nisso Chemical Co., Ltd.
conc, Kayacall-BIconc, Kaya
call-BIL, Kaycall-BAR, Kay
acall-BRAL, Kayall-BRBL,
Kayall-BUL, Kayall-BXc
onc, Kayacall-BXNL, Kayacal
1-BZconc, Kayallall-BZH / C, K
ayacall-CPL, Kayacall-KTL,
Kaycall-PAN, Kaycall-PKc
onc, Kayall-RG, Kayall-
RP, Kaycall-SR, Kaycall-W
G, Kaycall-WS, Kaycall-WS
L-100, Kayall-E, Kayall
—C and the like. In addition, KayalightOS
R, KaylightOS, KaylightB
(Nippon Kayaku) can also be used. Besides these, Eastobrite OB-1 (manufactured by Eastman Chemicals) is also available on the market.

[0027]

The sublimation type image receiving medium of the present invention can provide an image without white spots without deteriorating the paperiness of the sheet, has a sufficient degree of whiteness, and has excellent white image clarity. is there.

[0028]

Next, the present invention will be described in more detail by way of examples.

Example 1 A polyester non-woven fabric (weight: 50.8 g / m ² ) (trade name: 05TH-48, Hirose Paper) was dried with 10 g / m ² of [solution A] having the following composition. It was applied by impregnation so that [Liquid A] Hollow polymer particles (trade name: Matsumoto Microsphere MF30, manufactured by Matsumoto Yushi Pharmaceutical) 29 parts Polyvinyl alcohol (trade name: Kuraray Poval PVA117, manufactured by Kuraray Co., Ltd.) 2 parts Antistatic agent (trade name: 0.6 part Water 80 parts After drying, the whole was heated at 130 ° C. for 3 minutes to expand the hollow polymer particles to form a substrate. [Liquid B] having the following composition was applied to a thickness of 6 μm on the upper surface of the substrate thus obtained. [Liquid B] Vinyl chloride / vinyl acetate / vinyl alcohol copolymer (trade name: Denka Vinyl # 1000GKT, manufactured by Denki Kagaku) 18 parts Silicone resin (trade name: AY42-125 Toray Dow Corning Silicone) 4.5 Part Toluene 20 parts Methyl ethyl ketone 60 parts Fluorescent dye (trade name: MIT-YO, Mitsui Toatsu Dye) 0.05 part Coating was applied and the laminate was dried to prepare an image receiving body of the present invention.

Example 2 The following [Solution C] was used in place of [Solution A] used in Example 1.
Was used in the same manner as in Example 1 except that the following [Solution D] was used instead of [Solution B] to prepare an image receiving medium. [Liquid C] Hollow polymer particles (trade name: Matsumoto Microsphere MF30, manufactured by Matsumoto Yushi Seiyaku) 29 parts Polyvinyl alcohol (trade name: Kuraray Poval, PVA117 Kuraray) 2 parts Antistatic agent (trade name) Name: Chemistat 6300, Sanyo Kasei) 0.6 parts Water 40 parts Fluorescent whitening agent (trade name: Whytex ERN, manufactured by Sumitomo Chemical Co., Ltd.) 0.06 parts Ethanol 40 parts [Solution D] Vinyl chloride / vinyl acetate / Vinyl alcohol copolymer (trade name: Denka Vinyl # 1000GKT, manufactured by Denki Kagaku) 18 parts Silicone resin (trade name: AY42-125, manufactured by Toray Dow Corning Silicone Co., Ltd.) 4.5 parts Toluene 20 parts Methyl ethyl ketone 60 parts

Example 3 A substrate was prepared in the same manner as in Example 1. Next, [Solution E] having the following composition was applied to the substrate to a thickness of 5 μm. [E Solution] Vinyl chloride / vinyl acetate / vinyl alcohol copolymer (trade name: Denka Vinyl # 1000GKT, manufactured by Denki Kagaku) 18 parts Toluene 20 parts Methyl ethyl ketone 60 parts Fluorescent dye (trade name: MIT-YO, Mitsui Higashi) 0.05 parts of the applied laminate was dried, and then [Solution B] of Example 1
Was applied and dried to a thickness of 3 μm to prepare an image receiving medium.

Comparative Example 1 [D] shown in Example 2 in place of [B liquid] in Example 1
Liquid] was used to prepare an image receiving medium in the same manner as in Example 1.

The L, a, and b values of the obtained image receiving medium and the substrate were measured with a color difference meter (trade name: CM-1000, manufactured by Minolta Co., Ltd.). Table 1 shows the results. The white feeling was evaluated by observing it with the naked eye.

[0034]

[Table 1]

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroki Kuboyama 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Yutaka Aruga 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (56) References JP-A-1-115687 (JP, A) JP-A-1-206095 (JP, A) JP-A-2-150389 (JP, A) JP-A-6-191164 ( JP, A) JP-A-6-106866 (JP, A) JP-A-6-155931 (JP, A) JP-A-53-19021 (JP, A) JP-A-5-286260 (JP, A) (58) ) Field surveyed (Int. Cl. ⁷ , DB name) B41M 5/38-5/40 D06P 5/00 114

Claims (3)

(57) [Claims] 1. A sublimation-type thermal transfer image receiver in which a substrate is composed of fibers and polymer particles and a receptor layer for dyeing a sublimable dye is formed on the surface of the substrate, the surface reflection of the surface to which the receptor layer is applied. When the characteristics are measured by the method specified by JIS-Z8722 and displayed by the method specified by JIS-Z8730, the values of L, a, and b are each L = 90 or more, and a = -1.5 to +1. .5, b = -5.0 to -0.0
Sublimation type thermal transfer image receiving member. 2. A sublimation-type thermal transfer image receiver in which a substrate is composed of fibers and polymer particles and a receptor layer for dyeing a sublimable dye is formed on the surface of the substrate, has a surface reflection characteristic of J on the surface of the substrate.
Measured by the method specified in IS-Z8722, and JI
When displayed by the method defined by S-Z8730, L is 90 or more, a is -2.0 to +2.0, b
2. The sublimation type thermal transfer image receiving body according to claim 1, wherein is within a range of -7.0 to -1.5. 3. A sublimation type thermal transfer image receiving body in which a substrate is composed of fibers and polymer particles and a receiving layer for dyeing a sublimable dye is formed on the surface of the substrate. 3. The sublimation type thermal transfer image receiving body according to claim 1, wherein the layer formed between the substrates contains at least one kind of a fluorescent whitening agent or a white pigment.