JPH0510239B2 - - Google Patents

Description

Detailed Description of the Invention [Technical Field] The present invention relates to a heat-sensitive transfer recording material comprising a combination of a heat-sensitive transfer recording medium having a heat-insoluble colorant layer and a recording sheet having a heat-meltable image-receiving layer.
More specifically, the present invention relates to a heat-sensitive transfer recording material that allows transfer recording images of sufficiently high density to be obtained without unevenness and that also has high sensitivity during transfer recording. [Prior art] Dye is transferred from a thermal transfer recording medium onto a recording sheet using a thermal recording device having a heat source such as a thermal head made of thick film resistors, thin film resistors, or semiconductor resistors, and a heat source such as a laser or a xenon lamp. Various technologies for forming recorded images have been proposed in the past, and some have been implemented as thermal printers and thermal facsimile technologies. For example, JP-A-54-68253 and JP-A-57-160691 disclose thermal transfer recording in which a microporous layer containing a resin component as a binder contains an ink component that melts when heated. A technique has been disclosed that uses a medium to form a transferred recorded image multiple times on plain paper, but with this recording method, the formed transferred recorded image has noticeable unevenness and is not suitable for obtaining a so-called solid image. Nakatsuta. On the other hand, JP-A-59-14994 and other documents describe a thermal transfer recording medium using a polymer composition with a melting point or softening point of 100° C. or higher together with a dye, and it is possible to obtain an even transferred recorded image. It is disclosed that it is possible. However, since this recording technique uses a sublimable dye, not only is there a drawback that the storage stability of the thermal transfer recording medium is poor, but also the storage stability of the transferred recorded image obtained by thermal transfer is also poor. [Object of the Invention] The present invention has been made in order to eliminate the above-mentioned drawbacks, and its first purpose is to provide a thermal transfer recording that can form an even transfer recorded image and obtain a so-called solid image. The goal is to provide materials. The second object of the present invention is to have excellent raw storage stability and
It is an object of the present invention to provide a heat-sensitive transfer recording material in which a transferred recorded image obtained by thermal transfer has good storage stability. [Structure of the Invention] The recording material of the present invention that achieves the above object includes a thermal transfer recording medium having a colorant layer containing a colorant and a binder on a support, and a heat-sensitive transfer recording medium that has a colorant layer containing a colorant and a binder on a support; A heat-sensitive transfer recording material consisting of a recording sheet having a heat-fusible image-receiving layer on a support and stacked facing each other, wherein the colorant is non-sublimable and the binder is heat-fusible. The gist is that the heat-fusible image-receiving layer contains a heat-fusible substance that is meltable and has a melting point lower than that of the heat-insoluble binder used in the colorant layer. The present invention will be described in detail below, but first, the thermal transfer recording medium used in the present invention will be explained. The thermal transfer recording medium used in the present invention has at least one colorant layer on a support.
The colorant layer mainly contains a non-sublimable colorant and a heat-non-melting binder. [Colorant] The non-sublimable colorant is a non-sublimable substance that has color and can be dissolved or dispersed in the heat-fusible substance of the image-receiving layer during heating recording. The material may be either a substance that absorbs light at visible wavelengths (400 nm to 800 nm) or a substance that forms a substance that absorbs light in the visible light range. These are generally called dyes and are suitable for thermal transfer recording media.
Among synthetic pigments called dyes and pigments, natural pigments called animal pigments or vegetable pigments, non-sublimable ones are used. The non-sublimable coloring agent used in the present invention is a colorant excluding sublimable colorants (including those that vaporize with melting or dissolution) used in mordant dyes and the like. Specifically, various dyes known in the art (for example, nitroso dyes, nitro dyes, azo dyes, stilbene azo dyes, ketoimine dyes, triphenylmethane dyes, xanthene dyes, acridine dyes, quinoline dyes, methine-polymethine dyes, thiazole dyes) , indamine dye, indophenol dye,
Azine dyes, oxazine dyes, thiazine dyes, sulfur dyes, aminoketone dyes, oxyketone dyes,
Anthraquinone pigments, indigoid pigments, phthalocyanine pigments, etc. ); these leuco dyes, especially colorless or light-colored color-forming substances (e.g., triarylmethane compounds, diphenylmethane compounds, xanthene compounds, thiazine compounds, spiro compounds, etc.); and their color-forming properties. Acidic substances that color substances (e.g., phenol derivatives, aromatic carboxylic acids, etc.); Although they are not pigments, they have light absorption in the visible light range (400 nm to 800 nm) and have a melting point within the range of approximately 45 to 120°C. Examples include certain substances (for example, azobenzene derivatives, nitrobenzene derivatives, thiophenol derivatives, aniline derivatives, etc.) that are non-sublimable. Among these, specific examples of those that are easily available on the market are as follows. That is, the yellow pigments include Oil Yellow S-7 (white clay), Eisenspiron GRH Special (Hodogaya), Stiplast Yellow F5G (Sumitomo), and Eisenspiron Yellow.
GRH (Hodogaya), Hansa Yellow 3G, Tartrazine Lake, etc. are preferably used. Red pigments include Sumiplast Stretch FB (Sumitomo), Sumiplast Pink FF (Sumitomo), and Eisenspiron Red.
GEH (Hodogaya), Brilliant Carmine FB-Piure (Sanyo Shiki), Brilliant Carmine 6B (Sanyo Shiki), Alizarin Lake, etc. are preferably used. As a blue pigment, Eisenspiron Blue
E2BH (Hodogaya), Dia Resin Blue K (Mitsubishi Kasei), Sumiplast Blue 3R (Sumitomo), Sumiplast Blue G (Sumitomo), Cerulean Blue, Sumikaprint Cyanine Blue GN-O (Sumitomo), Phthalocyanine Blue, etc. are suitable. used for. As the black pigment, carbon black, oil black, etc. are used. Particularly preferred are Sumiplast Yellow F5G, Sumiplast Stretch FB, and Sumiplast Blue 3R. [Binder] As the binder used in the colorant layer of the present invention, a thermally non-fusible substance is used. Specific examples of the heat-insoluble binder used in the present invention include polyvinyl chloride, polyvinyl fluoride, polyvinyl butyral, polyvinylidene chloride, polyvinyl alcohol, vinyl chloride/vinyl acetate copolymer, vinyl chloride/vinyl acetate copolymer, Vinyl resins such as vinylidene chloride copolymers; acrylic resins such as acrylic esters and polymethacrylic esters; resins such as ethyl cellulose and cellulose butyrate acetate; others: polystyrene, polyethylene, polyethylene/vinyl acetate copolymers, polyamides, ABS resins Examples include polymer compounds such as, gelatin, gum arabic, and the like. Among these, polyvinyl butyral, polyvinyl chloride, vinyl chloride,
Vinyl acetate copolymers, polyvinyl alcohol, and the like can be particularly preferably used. [Support] The support for the thermal transfer recording medium of the present invention includes:
A support that has heat-resistant strength and high smoothness is desirable. Heat-resistant strength requires strength that maintains the toughness of the support without becoming softened or plasticized by the heating temperature of a heat source such as a thermal head, and surface smoothness requires the strength of the coloring contained in the colorant layer on the support. Sufficient smoothness is desired so that the agent exhibits good transfer rates. The smoothness should be 100 seconds or more in a smoothness test using a Beck testing machine (JIS P 8119).
When the time is 300 seconds or more, images with better transfer rate and reproducibility can be obtained. Examples of materials include:
Papers such as plain paper, synthetic paper, laminated paper, and coated paper, resin films such as polyethylene, polystyrene, polypropylene, and polyimide, paper-resin film composites, and metal sheets such as aluminum foil are all suitable for use. be done. The thickness of the support is preferably about 60 μm or less, particularly 2 to 40 μm, in order to obtain good thermal conductivity. [Additives] The colorant layer of the present invention may contain various additives. For example, additives that are preferably used include oils such as olive oil, castor oil, and silicone oil, fine powders of metal oxides such as zinc oxide, tin oxide, and aluminum oxide, and fine powders of metals such as aluminum, copper, and cobalt. Examples include fine powders of inorganic compounds such as diatomaceous earth and zeolite, organic compounds such as phenolic resins and epoxy resins, and carbon black, which may be used alone or in combination of two or more. Among these, carbon black fine powder with high cohesiveness is most suitable. When these additives are in the form of fine powder, the particle size is
A thickness of 0.01 to 20 μm is preferable. The thermal transfer recording medium used in the present invention may have a known subbing layer, overcoat layer, etc. in addition to the colorant layer. Further, when two or more colorant layers are applied, an intermediate layer may be applied as necessary. Next, the recording sheet used in the present invention will be explained. The recording sheet used in the present invention has at least one heat-melting image-receiving layer on a support.
The image receiving layer contains a thermofusible substance. [Thermofusible substance] The thermofusible substance used in the present invention may be selected from substances such that the solubility of the colorant in the substance is greater than the solubility of the colorant in the binder of the colorant layer. preferable. That is, the solubility ratio is set to X, and when X = solubility of colorant in heat-fusible substance (140°C)/solubility of colorant in binder (140°C), select so that X > 1. However, it is more preferable to select X≧2, particularly X≧5. Here, the solubility of the colorant is measured as follows. While shaking or stirring 100 g of a heat-fusible substance or binder at 140° C., a predetermined amount of a coloring agent is sequentially added thereto. Solubility is the weight (measured in grams) of colorant added up to the point where the colorant can no longer be completely dissolved. The heat-melting substance used in the present invention is preferably selected from among low-melting substances capable of dissolving or dispersing the non-sublimable colorant during melting so as to satisfy the above-mentioned solubility ratio. [Examples of heat-melting substances] Specific examples include vegetable waxes such as carnauba wax, wood wax, auricilla wax, and espal wax, animal waxes such as beeswax, insect wax, serrata wax, spermaceti wax, paraffin wax, and microcrystalline wax. In addition to waxes such as petroleum waxes such as wax, ester wax, and oxidized wax, and mineral waxes such as montan wax, ozokerite, and ceresin; higher fatty acids such as palmitic acid, stearic acid, margaric acid, and behenic acid; palmityl alcohol, Higher alcohols such as stearyl alcohol, behenyl alcohol, marganyl alcohol, myricyl alcohol, eicosanol; cetyl palmitate,
Higher fatty acid esters such as myricyl palmitate, cetyl stearate, myricyl stearate; Amides such as acetamide, propionic acid amide, palmitic acid amide, stearic acid amide, amide wax; ester gum, rosin maleic acid resin, rosin phenolic resin, water Rosin derivatives such as added rosin; softening point of phenolic resin, terpene resin, cyclopentadiene resin, aromatic resin, etc. 50
Polymer compounds with a temperature of ~120°C; higher amines such as stearylamine, behenylamine, and palmitinamine; polyethylene oxides such as polyethylene glycol 4000 and polyethylene glycol 6000; these may be used alone or in combination. It's okay. Among these, waxes such as vegetable waxes, animal waxes, petroleum waxes, mineral waxes, and rosin derivatives are particularly preferred. [Recording Sheet Support] As the support for the recording sheet of the present invention, a support having heat-resistant strength and high smoothness is desirable. The heat-resistant strength and smoothness are the same as those described for the support in the heat-sensitive transfer recording medium. In addition,
Specific examples of the substance include ceramics, porcelain, glassware, and fibers such as cloth.The heat-melting image-receiving layer provided on the support may be partially immersed in the support, A portion may soak in during heating recording. [Other additives] In the layer constituting the thermal transfer recording material of the present invention,
Appropriate additives may be contained, for example, antioxidants, ultraviolet absorbers, color tone modifiers, etc. may be contained in one or more arbitrary layers. [Example of composition of colorant layer] The composition of the colorant layer in the present invention is not limited, and generally, based on 100% of the total composition (weight ratio, same hereinafter), binder is 5 to 95%, colorant is 5%. ~50%, preferably binder 30-75%, colorant 5-25%
%. The thickness of the colorant layer is not limited, and is generally about 1 to 20 μm, particularly preferably about 2 to 8 μm. [Example of Preparation of Recording Material] The thermal transfer recording material of the present invention may be prepared as follows. First, the thermal transfer recording medium of the present invention can be formed by coating a colorant layer on a support.
In order to apply the colorant layer, for example, a non-sublimable colorant is dissolved or dispersed in a solution containing the binder, or a binder is heated and melted without using a solvent. This can be done by preparing a liquid in which a non-sublimable colorant is dissolved or dispersed, and applying this liquid onto a support using a commonly known coating device such as a wire bar, brush, or coater. At this time, a subbing layer may be coated on the support to improve adhesion with the colorant layer. Moreover, an overcoat layer can also be coated on the colorant layer. Next, the recording sheet of the present invention can be formed by coating a heat-melting image-receiving layer on the support.
To apply the image-receiving layer, a molten heat-fusible substance is directly applied, or a liquid obtained by dissolving or dispersing a heat-fusible substance in an appropriate solvent is applied using a generally known coating device such as a wire bar. This can be carried out by coating the support using the following method. The thickness of the image-receiving layer is not limited, as long as it has a thickness necessary and sufficient to melt during heating recording, accept the colorant, and dissolve or disperse it. Generally, the thickness may be several μm. [Recording method] One method of recording using the thermal transfer recording material of the present invention is to use a device that can generate heat, such as a thermal head, a thermal pen, or an iron, to coat the colorant layer on the support. The heating is performed from the side, that is, from the support side, and as the heat source, a laser, a xenon lamp, etc. may be used in addition to the above. Note that heating may be performed from the support side of the recording sheet. Further, it may be carried out from both the support side and the support side of the thermal transfer recording medium. During this recording, the recording medium of the present invention and the recording sheet are stacked with the colorant layer and image receiving layer facing each other. In the present invention, the non-sublimable colorant moves from the colorant layer to the image-receiving layer of the recording sheet through phenomena such as elution in response to the heating temperature and heating time using a thermal pen, etc.; The heat-melting substance contained in the recording medium melts and dissolves or disperses the received non-sublimable colorant, thereby obtaining a recorded image. The image-receiving layer returns to its original solid or semi-solid state when it returns to at least room temperature. The heating temperature when applying thermal energy to the thermal transfer recording material of the present invention in accordance with the image information to be recorded depends on its relationship with the heating time, the melting point of the heat-fusible substance used in the image-receiving layer, and the The temperature is determined by considering the type of sublimable colorant, etc., but the temperature is preferably room temperature or higher, and in practical terms, the temperature is preferably higher than 45°C. [Effects of the Invention] Since the present invention has the above-described structure and operation, the above-described objects of the present invention can be achieved, and so-called solid images can be obtained with high density and evenly, and character images can be obtained with ease of viewing. Furthermore, since it is highly sensitive, it is possible to save the amount of thermal energy required by a thermal pen or the like, or it is possible to perform heating recording in a short time. In particular, according to the present invention, by using a non-sublimable colorant, the thermal transfer recording medium has good shelf life, and the recorded image obtained by thermal transfer has excellent shelf life. [Example] Examples of the present invention will be described below, but the present invention is not limited to these Examples. Example 1 4 g of polyvinyl butyral (softening point: 120 DEG C.) and various coloring materials shown in Table 1 below were dissolved in 40 ml of methyl ethyl ketone to obtain coating solutions 1 to 5. Thickness 6μ
Coat each of coating solutions 1 to 5 using a wire bar on a 3-m condenser paper, and dry to a thickness of 3 μm.
Thermal transfer recording media 1 to 5 having colorant layers were obtained. On the other hand, a coating solution prepared by dissolving 4 g of oleic acid amide in 20 ml of toluene was applied onto plain paper using a wire bar to obtain a recording sheet having an image-receiving layer with a thickness of 2 μm after drying. The colorant layer of each of thermal transfer recording media 1 to 5 and the image-receiving layer of the recording sheet were brought into close contact, and the heat-sensitive transfer recording medium was heated from the support side with an iron at 120° C. for 0.5 seconds to obtain a transferred recorded image. On the other hand, a plurality of thermal transfer recording media 1 to 5 were superimposed and left at 30° C. for one month, and then thermally transferred to a recording sheet in the same manner as above to obtain a transferred recorded image. The optical reflection densities of these transferred recorded images were measured using a reflection densitometer (manufactured by Konica), and the results are shown in Table 1. As is clear from Table 1, it is possible to obtain a transferred recorded image having a high optical reflection density by using the thermal transfer recording method of the present invention, and in the case of the thermal transfer recording medium of the present invention, it is possible to obtain a transferred recorded image having a relatively high optical reflection density. ,
It can be seen that the fresh storage property is excellent. 【table】

Claims (1)

[Scope of Claims] 1. A heat-sensitive transfer recording medium having a colorant layer containing a colorant and a binder on a support, and a heat-melting image-receiving layer that is stacked facing the colorant layer during transfer recording. 1. A heat-sensitive transfer recording material comprising a recording sheet having on a support. wherein the colorant is non-sublimable, the binder is heat-non-fusible, and the heat-fusible image-receiving layer is better than the thermo-non-fusible binder used in the colorant layer. A heat-sensitive transfer recording material characterized by containing a heat-melting substance having a low melting point.