JPS61116590A - Thermal transfer recording medium - Google Patents

Abstract

PURPOSE:To provide the titled medium capable of being formed in a small thickness, showing excellent resolution and capable of giving multiple times a fixed printing quality irrespectively of printing energy, wherein a plurality of specified color material layers are provided on a base. CONSTITUTION:Two or more color material layers one of which comprises (A) at least one heat-fusible substance selected from animal, vegetable mineral, petroleum, hydrocarbon and modified waxes, and another of which adjacent to the one layer comprises (B) a heat-fusible substance incompatible with component A (e.g. a polyester compound) are provided on the base, preferably, through an adhesive layer, to obtain the objective medium.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to thermal transfer recording media that can be used multiple times.

Specifically, if the applied energy is above a certain amount, a transferred image with a constant transfer density can be obtained, and a constant print quality can be obtained over many times without being affected by subtle changes in the applied energy. The present invention relates to a thermal transfer recording medium.

[Prior Art] As a heat-sensitive transfer recording medium intended for multi-image use, for example, Japanese Patent Application Laid-open No. 105579/1983 discloses a method in which a microporous layer is formed with a resin.

A technique for impregnating the layer with ink is described, and JP-A-57-160691 describes a technique for forming a network structure using organic or inorganic fine powder and impregnating it with ink. JP-A-57-185192 describes a technique for impregnating porous paper with ink.

All of these technologies were designed to allow the ink to seep out little by little from the porous material, but in these technologies the transfer density changes in response to subtle changes in the applied energy, resulting in a constant print quality. The problem is that it cannot be obtained.

[Problems to be Solved by the Invention] According to the present invention, if energy is applied at a fixed position, a transferred image with a constant transfer density can be obtained.

A technical problem is to provide a thermal transfer recording medium that can obtain constant printing quality over a large number of times without being affected by subtle changes in applied energy.

c. Means for Solving the Problems] As a result of continued research, the present inventor has discovered that in a heat-sensitive transfer recording medium having a heat-fusible coloring material layer on a support, the coloring material layer is a multilayer of two or more layers. It is composed of

One layer of the coloring material layer contains at least one heat-melting substance selected from the following compound group, and the coloring material layer adjacent to the coloring material layer is heat-melting and immiscible with the heat-melting substance. It was discovered that the above-mentioned technical problem could be solved by containing a substance, and the present invention was achieved.

[Compound Group] Animal-based wax Vegetable-based wax Mineral-based wax Petroleum-based wax Synthetic hydrocarbon-based wax Modified wax In the multilayer thermal transfer recording medium, the - coloring material layer contains at least one heat-melting type selected from the above compound group. If at least one coloring material layer adjacent to the striped coloring material layer contains a heat-melting substance that is immiscible with the heat-melting material contained in the striped coloring material layer, the present invention is applicable. However, it is preferable that all adjacent coloring material layers satisfy the above-mentioned conditions of the present invention.

Note that in the present invention, adjacent coloring material layers are not limited to directly adjacent layers, but also include cases where they are indirectly adjacent via a layer other than the coloring material layer.

The present invention will be explained in more detail below.

The thermal transfer recording medium of the present invention has a heat-melting coloring material layer provided on a support. This heat-fusible coloring material layer is preferably formed into a multilayer structure of two or more layers on the support via an adhesive layer. A layer that is melted and transferred to the transfer paper side, and is capable of obtaining printing with the required transfer density in one transfer.

In a preferred layer structure in the present invention, for example, a coloring material layer I1 and a coloring material layer (2) are sequentially coated on a support, and the coloring material layer I is a so-called heat-melting substance with low polarity selected from the above compound group. A multilayer structure may be mentioned, in which the coloring material layer H contains a heat-fusible substance that is immiscible (so-called highly polar) with the heat-fusible substance. With such a structure, one coloring material layer (1) has immiscibility with coloring material layer (I).

The present invention utilizes this immiscibility as a basis for the reduction in breaking strength (coloring material layer weight and coloring material layer!■ releasability). That is, energy is applied to melt one coloring material layer and transfer it to the transfer paper side (peeling 1lll).
) In the process, the pull 3 is applied near the boundary between the color material layer weight and the color material layer
The moon is done. As a result, one coloring material layer is transferred in one transfer.

In the case of the above layer structure, two transfers are possible.

Furthermore, in order to increase the number of transfers, a coloring material layer ■ is placed on top of the coloring material layer H.
, color material Wr11. Layers such as coloring material kW v and coloring material layer (2) in which the overlapping layers are immiscible can be laminated, respectively. In this case, the coloring material layers I, 2, and 2 may have the same composition or may have different compositions, and similarly the coloring material layers I, 2, and 2 may have the same composition, May be different.

In the present invention, it is preferable that the coloring material layer containing at least one kind of heat-melting substance selected from the above-mentioned group of compounds does not contain a heat-melting substance that is substantially immiscible therewith, and even if it contains, The content is preferably 10% by weight or less based on the total weight of the coloring material layer.

The 1 compound group used in the present invention includes waxes that have relatively low polarity and are solid at room temperature, preferably waxes with a melting point or softening point of 40 to 80°C, The waxes listed below are used.

Animal waxes include beeswax and insect wax.

Examples of waxes include shellac wax, spermaceti wax, wool wax, etc.; examples of vegetable waxes include carnauba wax, wood wax, auriculie wax, esparto wax, and canodelira wax; examples of mineral waxes include montan wax, osichelite, ceresin, etc. Petroleum-based waxes include paraffin wax, microglysterin wax, ester wax, petrolatum, etc.1 Synthetic hydrocarbon waxes include Fischer-Tropsch wax, polyethylene wax, low-molecular-weight polypropylene, low-molecular-weight polyethylene, and derivatives thereof. Examples of modified waxes include oxidized waxes, montan wax derivatives, paraffin, and microwax derivatives. These may be used alone or in combination of two or more. In the present invention, hydrogenated waxes such as castor wax and opal wax may also be used.

In the present invention, the heat-fusible substance that is immiscible with the above compound group is preferably a heat-fusible substance that is highly polar and immiscible with respect to the above-mentioned Wanks, which has relatively low polarity.

In the present invention, immiscibility means that when both are mixed by thermal melting or softening, they exhibit a cloudy state, an oil droplet shape, a layer separation, or an incompatible state, which may be detected from the appearance, but is not necessarily detected. You don't have to be able to do it.

As one method of expressing polarity, the solubility parameter δ can be used, and the solubility parameter of the highly polar heat-fusible substance in the present invention is preferably δ≧8.5,
More preferably, δ≧10.0. The solubility parameter of the waxes with relatively low polarity shown in the above compound group is expressed as δ≦8.0.

Heat-melting substances that are immiscible with the above compounds are not materials whose main chain is simply composed of carbon-carbon bonds such as vinyl polymers, but synthetic polymers whose main chain contains bonds that impart polarity. Molecular compounds are preferred.

Typical compounds include polyester compounds, polyether compounds, polyamide compounds, and polyurethane compounds.

Among these, those that are solid at room temperature (25°C).

For example, it is preferable to use a substance with a melting point (1p) or a softening point of 35 to 100°C, more preferably a substance with a relatively low melting point or softening point of 45 to 85°C. In addition, in consideration of breaking strength, the molecular weight is preferably lower, and specifically, it is preferably 500 or more and 50,000 or less, more preferably 500 or more and 15,000 or less.

Specific examples include the following compounds.

(1) Polyester compound A preferred polyester compound has -CO-O- in the main chain.
A linear polyester and its derivatives that are solid at room temperature (25°C) and have a bond, and a polycarbonate that has a 100-0-bond in the main chain.

Contains unsaturated polyester.

These polyesters are synthesized as polycondensates of polyhydric alcohols and polybasic acids or open-door polymers of lactams.

In addition, if the polyester derivative is a copolymer, Pro 1
A polyester copolymer or a kraft copolymer is preferable, and one having a large number of ester bonding moieties is preferable.

Specific examples include ester compounds such as polyethylene glycol fatty acid ester, polyethylene glycol sorbitan fatty acid ester, polyoxyethylene lanolin fatty acid preventive ester, and block copolymers synthesized from polyethylene/glycol and ε-caprolactone. I can do it.

For example, a polyester compound produced by polymerizing a compound having an alcoholic OH group and ε-caprolactone by the reaction described above can also be obtained as a commercially available product.

R-OH+n@e-caprolactone → (I R-0[C(CH2)50 nH Commercial product name; rPlacc@l G-402J, r
Placcsl 240J.

rPlaccel 2B01. rPlaccsl
280J, rPlacasl H-IJ, etc. (Daicel Chemical Co., Ltd. II) (2) Polyether compound A preferable polyether compound has -[C-0-C
It is a compound that is solid at room temperature (25°C) and has an 1-bond, and also includes polyethylene oxide, epoxy resin, etc. that have an 10-bond in the main chain.

The above polyether compound is produced by ring-opening polymerization of cyclic ether,
It is synthesized by ring-opening polymerization of cyclic acetals, high polymerization of aldehydes, polycondensation of glycols, etc.

Preferred representative compounds of the polyether compounds include 4-lyethylene glycol and polyethylene glycol derivatives, and specific examples include polyethylene glycol: polyethylene glycol alkyl ether, polyethylene glycol polypropylene glycol ether, polyethylene glycol furkyl phenol. Ether, polyethylene glycol nonylphenyl ether, polyoxyethylene lanolin alcohol ether.

Among these, polyethylene glycol having a molecular weight of 1,000 to 10,000 or less is particularly preferably used in the present invention.

(3) Polyamide Compound A preferred polyamide compound has a main chain of 1Co-NH-
It is a synthetic polymer compound with The compound is synthesized by polycondensation of a dicarboxylic acid and a diamine or ω-7 aminocarboxylic acid, or by opening the lagtam [111].

Further, the compound may be a saturated or unsaturated compound, or an aromatic compound. The compound can also be obtained as a commercially available product; for example, Sanwa Kagaku's Sanmide series products can be used.

(4) Polyurethane compound A polyurethane compound is a compound containing one NHCOO- in its main chain, and is typically synthesized by a polyaddition reaction between a diisocyanate ester and a glycol.

The polyurethane compound can also be obtained as a commercial product, and for example, HSW-E1 manufactured by Hodogaya Chemical Co., Ltd. can be used.

The layer containing a heat-fusible substance immiscible with the compound group is
Preferably 8 to 8 to the total weight of the color material layer containing this
95i 1% by weight, more preferably 15-90g%.

Examples of heat-fusible substances that are immiscible with the above compound group include resin components described in JP-A No. 54-88253, such as polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, polystyrene, etc. may be included, but in this case it is rather undesirable to use too much.

The thermofusible substances immiscible with the above compounds may be used alone or in combination of two or more.

The coloring agent used in the heat-melting coloring material layer in the present invention is as follows:
The dye may be selected as appropriate from dyes such as direct dyes, acid dyes, basic dyes, disperse dyes, oil-soluble dyes (including alloy metal oil-soluble dyes), and various pigments. Specifically, the following are listed. That is, as the yellow pigment, Kayalon Polyester Light Yellow 5
GS (Nippon Kayaku), Oil Yellow 3-7 (white clay),
Eisen Subiron Yellow GRH Special (Hodogaya)
, Sumiplast Yellow FG (Resident), Eisenspiron Yellow GRH (Hodogaya), etc. are preferably used.
As a red pigment, Gui 7 Seriton Fastred R (
Mitsubishi Kasei), Dianex Brilliant Red BS-
E (Mitsubishi I&), Sumipura Tread FB (resident)
, Sumiplast Tread HFG (Denjin), Kayalon Polyester Pink RCL-E (Nippon Kayaku), Eisenspiron Red GEH Special (Hodogaya), and # are preferably used.

As blue pigments, Diaceritone Fast Brilliant Blue R (Mitsubishi Kasei), Dianics Blue EB-
E C Mitsubishi Kasei), Kayalon Polyester Blue B-3
F Conch (Nippon Kayaku), Sumiplast Blue 3R (Jinja), Sumiplast Blue G (Jinja), etc. are preferably used. In addition, as yellow pigments, Hansa Yellow 3G, Tartrag/Lake, etc. are used, as red pigments, brilliant carmine FB-Pure (Sanyo Dyes), brilliant carmine 6B (Sanyo Dyes), 7 Lizarin Lake, etc. are used, and as blue pigments, As for, cerulean blue,
Sumika blintocyanine blue 〇N-0 (resident), phthalocyanine blue, etc. are used, and the black pigment is carbon black.

Among the colorants used in the present invention, carbon black is most preferred.

The purpose of the present invention is to make the transfer density substantially the same if the applied energy is above a certain level, and within the range that can achieve this purpose, the negative coloring material layer On the other hand, separate color material layers may contain different types of colorants.

In the present invention, a softener may be used, and examples of the softener include low softening point polymers selected from ethylene-ethyl acrylate copolymers, ethylene-vinyl acetate copolymers, and the like.

The composition ratio of the coloring material layer of the present invention is not limited.

For example, when the heat-melting coloring material layer is composed of three layers and the layers are arranged adjacent to each other to obtain the layer structure of the present invention, it is preferable to do as follows.

Coloring material layer ■: 30 to 85 parts (by weight) of a heat-melting substance to 100 parts (parts by weight, the same applies hereinafter) of the solid content w & amount of the coloring material PJI.
More preferably 40 to 80 parts), colorant 5 to 40 parts (
More preferably 10-3! , J), softener is 0-20
parts (more preferably 1 to 15 parts).

Coloring material layer ■: 8 to 95 parts of a heat-melting substance that is immiscible with the heat-melting substance per 1 GG part of the solid content of the other coloring material layer.
More preferably 15 to SO@), 0 to 70 parts (more preferably 1 to 80 parts) of a heat melting substance other than the immiscible heat meltable substance, 5 to 40 parts (more preferably 1 part) of a colorant,
0-35 parts), softener 0-15M (more preferably 1
~10 copies).

Coloring material layer nl [: 30 to 85 parts (more preferably 40 parts
~30 parts), 5 to 40 parts (more preferably 10 parts) of colorant
~35 parts), 0 to 20 parts (more preferably 1 to 20 parts) of softener
15 parts).

As described above, an object of the present invention is to make the transfer density substantially the same if the applied energy is above a certain level, and within the scope of this purpose, -
The content of the coloring agent in the coloring material layer may be different from that in the coloring material layer.

In addition to the above-mentioned components, the heat-melting coloring material layer of the present invention may contain various additives. For example, vegetable oils such as castor oil, linseed oil, and olive oil, animal oils such as whale oil, and mineral oils are preferably used. It's fine.

In the heat-sensitive transfer recording medium of the present invention, in order to apply the heat-melting coloring material layer onto the support, the heat-melting coloring material layer composition may be hot-melt coated.

Alternatively, it can be carried out by dissolving or dispersing the composition in a suitable melt and coating it with a coating solution. As a coating method for the heat-melting coloring material layer of the present invention, any known technique such as a reverse roll coater method, an extrusion coater method, a gravure coater method, a wire bar coating method, etc. can be adopted, but in particular, a layer like the one of the present invention can be applied. In the case of the structure, simultaneous multilayer coating can be carried out in whole or in part. Also, prepare multiple coaters on one line.

It can also be painted.

Note that a heat-sensitive transfer recording medium for multiple uses and for multiple colors can be produced using heat-melting coloring material layer compositions having several different color tones. That is, the longitudinal direction of the support is divided into predetermined intervals. For example, when using heat-fusible colorant layer compositions of ψ color, magenta, cyan, and black, the yellow composition is divided onto the support by a predetermined length in the longitudinal direction. Then, a magenta composition is applied next to it by a predetermined length, and the magenta composition is made into a multilayer structure according to the present invention, and then a cyan composition is applied next to it. A composition is applied over a predetermined length, and the cyan composition is formed into a multilayer structure according to the present invention. Next, a black composition is applied over a predetermined length, and the black composition is formed into a multilayer structure according to the present invention. Then, a multilayer structure layer divided into at least four sections is formed, which is used as one block, and this block is coated repeatedly. It is also preferable to provide a mark for division in each divided living room of a different color. In this way, the number of times of printing of the same color can be reduced to 711 tons, and multicolor printing is also possible.

The thickness of the heat-melting coloring material layer of the present invention is preferably 1 to 1 degrees, more preferably 2 to 7 degrees.

In the present invention, when a subbing layer or adhesive layer is provided between the support and the heat-melt coloring material layer, the subbing layer or adhesive layer may be appropriately selected from 1, for example, a hot melt adhesive. Good specific examples include ethylene-vinyl acetate copolymer, ethylene-7 acrylate copolymer, polyethylene, polyamide, polyester, petroleum resin, nylon, etc., and one or a combination of two or more of these may be used. All you need to do is use the undercoat layer or contact layer, and the thickness of the fake is 0.
．． 5 to 2 pots is preferred.

The support used in the heat-sensitive transfer recording medium of the present invention preferably has heat-resistant strength, and is preferably a support with high dimensional stability and surface smoothness.

It requires strength and dimensional stability to maintain the toughness of a support that does not soften or plasticize due to the heating temperature of a heat source such as a thermal head, and the surface smoothness requires the presence of a heat-fusible substance on the support. It is desired that the color material layer has sufficient smoothness to exhibit a good transfer rate. The smoothness is preferably 100 seconds or more in a smoothness test using a Heck tester (JIS ρ8119), and when it is 300 seconds or more, images with better transfer rate and reproducibility can be obtained. Materials include, for example, papers such as plain paper, condenser paper, laminated paper, and coated paper; resin films such as polyethylene, polyethylene terephthalate, polyester, polystyrene, polypropylene, and polyimide; paper-resin film composites; and aluminum foil. Metal sheets such as the following are preferably used.

In the heat-sensitive transfer recording medium of the present invention, the thickness of the support is generally about 80 mm or less, particularly preferably 2 to 20 mm, in order to obtain good thermal conductivity.

It may have a layer other than the heat-melting coloring material layer such as a wr retention layer, and the structure on the back side of the support may be arbitrary, and a backing layer such as anti-sticking +J may be provided.

[Effects of the Invention] According to the present invention, - a transferred image with a constant transfer density can be obtained as long as the energy is applied on the scaffold, and - constant printing quality can be achieved without being affected by subtle changes in the applied energy. It can be obtained multiple times, and is fundamentally different from conventional thermal transfer recording media that can be used multiple times. Adjacent color material layers are peeled off near the boundary, making it possible to transfer each layer one by one. In particular, in the present invention, the coloring material layers are arranged adjacent to each other, and it is literally possible to perform printing multiple times using just the coloring material layer, compared to the case where an intermediate layer is interposed between one coloring material layer. #l thickness can be made thinner, which has the effect that a transferred image with good resolution can be obtained.

[Example] Examples will be given below, but the present invention is not limited thereto. In the following, "1 part" refers to "parts by weight."

Example 1 The following multilayer composition was deposited on a polyethylene terephthalate film support with a thickness of 4.0 l by solvent method or hot melt method using a wire parr so that the dry film thickness was 1 l in total.
One sample of the thermal transfer recording medium of the present invention was obtained by sequentially laminating and coating the sample to form a g layer.

The composition and thickness of each layer are listed in descending order of thickness from the support.
) ■ = Adhesive layer (1) Composition Ethylene-ethyl 7-acrylate copolymer (NUC807
0B (manufactured by Unicar) 100 copies (2) Thickness: 1ps
(Dry film thickness, the same below) ■Two-color material layer weight (1) Composition Carnauba wax 25 parts Paraffin wax (ap=82°C) 45 parts Carbon black
15 parts ethylene-vinyl acetate copolymer
7 parts Montan wax (sp=83℃) 8
Part (2) Thickness; 5 End ■ Coloring material layer ■ (1) Composition Polyester wax 73 parts (Plug Cell 280 manufactured by Daicel Chemical Co., Ltd.) Carbon black
159i Karuna Power Ix
5 parts ethylene-vinyl acetate copolymer 7 parts (2) thickness;
Prototype a with a thin syA line thermal head,
) was used to apply an applied energy of 0.71 J/dat to write (print) on plain paper. The plain paper used was commercially available high-quality paper (10Qsec).

The results are shown in Table 1.

Example ? A thermal transfer recording medium sample (2) was obtained in the same manner as in Example 1, except that colorant layer I and colorant layer (2) had the following compositions.

(1) Coloring material layer I Carnauba wax 10 parts Polyethylene wax + 5 parts Paraffin wax 20 parts Micro wax
Part 20 Car Pump Chick
15 parts ethylene-ethyl acrylate copolymer 0ffA (2) Coloring material layer■ Paraffin wax 20 parts polyethylene glycol 30 parts carbon black
15 parts oxidized wax
Part 10 Hoechst F 2
511 Thermal transfer zi! , Printing was carried out in the same manner as in Example 1 using recording medium sample ■. The results are shown in Table 1.

Comparative Example 1 A comparative thermal transfer recording medium sample (blade was obtained) in the same manner as in Example 1, except that the coloring material layer (1) was not provided and the thickness of the coloring material layer (I) was top-finished.

Using this thermal transfer recording medium sample (3), printing was performed using a thermal printer in the same manner as in Example 1. The results are shown in Table 1.

Reference 1 [) As is clear from the table above, in the sample of the present invention, the concentration was sufficient in both the first and second tests. Therefore, according to the present invention, multiple printings with substantially the same transfer density can be performed using Dr t#
, it turns out that. On the other hand, in the case of comparative samples,
A high-density image was obtained on the m1th time, but no images were obtained on the second and subsequent times.

Claims (1)

[Scope of Claims] In a heat-sensitive transfer recording medium having a heat-melting coloring material layer on a support, the coloring material layer is composed of two or more multilayers, and one layer of the coloring material layer is selected from the following compound group. at least 1
1. A heat-sensitive transfer recording medium, characterized in that a coloring material layer adjacent to the coloring material layer contains a heat-melting material that is immiscible with the heat-melting material. [Compound group] Animal waxes Vegetable waxes Mineral waxes Petroleum waxes Synthetic hydrocarbon waxes Modified waxes