JPS60137691A - Thermal transfer recording medium - Google Patents

Abstract

PURPOSE:To provide the titled recording medium in which sticking, contamination of a thermal head and the like are prevented from occurring, wherein a coloring material layer comprising a heat-fusible substance is provided on one side of a film base, and a backing layer comprising a hardenable resin and a specified heat-fusible substance is provided on the other side. CONSTITUTION:(A) The backing layer comprising (i) a hardenable resin, preferably, a heat-resistant resin such as an epoxy resin, preferably, in an amount of 70-99.9wt% and (ii) a heat-fusible substance which is (semi)solid at normal temperature and preferably has a melting point of 50-120 deg.C, e.g., bees wax, preferably, in an amaount of 0.1-30%, is provided on one side of the film base, e.g., a polyethylene terephthalate film, and (B) the coloring material layer comprising (i) a heat-fusible substance, preferably, having a melting point of 40-120 deg.C, e.g., carnauba wax, in an amount of, e.g., 50-90% and (ii) a coloring agent, e.g., carbon black, in an amount of 5-20%, or the like is provided on the other side to obtain the objective recording medium.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a thermal transfer recording medium, and more particularly, the present invention relates to a thermal transfer recording medium that does not cause blocking during storage, does not contaminate or abrade a thermal head during use,
The present invention relates to a thermal transfer recording medium that can prevent the sticking phenomenon from occurring.

[Prior Art] As one of the technologies related to heat-sensitive recording media, thermal paper is widely known due to its ease of handling (see, for example, Japanese Patent Application Laid-Open No. 57-2795). Thermal paper used for printing cannot prevent tampering of the printed (recorded) image, and is easily colored by heat or organic solvents.
Record) The disadvantage was that the image had poor preservation. On the other hand, a type of thermal transfer recording medium using a heat-melting substance is known as a recording medium with excellent tampering resistance and storage stability.

However, in the melt transfer type thermal transfer recording medium using a polymer film such as a polyethylene terephthalate film as a support, a part of the film support is melted and fused to the thermal head by the heated thermal head during recording. Sometimes. This phenomenon, called a sticking phenomenon, significantly reduces the recording quality and eventually causes the film support to become stuck to the thermal head, making it impossible to feed the thermal transfer recording medium.

In order to prevent this sticking phenomenon, it is possible to use paper with excellent heat resistance such as condenser paper for the support, but if such paper is used, heat conduction from the thermal head is poor, resulting in .

The power applied to the thermal head must be increased, resulting in a drawback that the life of the thermal head is significantly shortened.

On the other hand, as a technique for preventing the sticking phenomenon, there is a technique using a backing layer. For example, □Unexamined Japanese Patent Publication No. 55-7
Japanese Patent No. 467 proposes a heat-resistant protective film placed on a film support, but this method has the disadvantage that the thermal head will wear out during long recording due to large friction with the thermal head. Therefore, JP-A-58-17
In the 1992 publication, in order to improve the slipperiness of the backing layer.

The use of waxes in combination with thermoplastic resins has been proposed, but this approach not only has the disadvantage of staining the head, but also causes blocking of the thermal transfer recording medium during storage. Also, JP-A-56-15579
Although Publication No. 4 proposes providing a resin layer containing a highly slippery inorganic pigment on the film support-1-, it is difficult to separate the resin layer from the resin layer.

The drawback was that the separated inorganic pigments contaminated the thermal head.

[Object of the Invention] The present invention has been made in view of the above points, and it is possible to not only effectively suppress the occurrence of the sticking phenomenon, but also prevent debris from adhering to the thermal head even after long-term use. It is an object of the present invention to provide a thermal transfer recording medium in which a thermal head is not worn out and does not have an adverse effect on thermal performance. ,' Other objects of the present invention are 1. To provide a thermal transfer recording medium that does not cause blocking phenomenon during storage.

□ Other objects of the present invention will become clear from the following description of the present specification.

[Summary of the Invention] As a result of intensive research, the present inventor has discovered that a heat-sensitive transfer recording medium having a colorant layer containing a heat-melting substance on one side of a film support and a backing layer on the other side, It has been found that the above object can be achieved when the backing layer contains a curable resin and a heat-fusible substance that is solid or semi-solid at room temperature, leading to the present invention.

That is, the present inventor believes that in order to prevent the sticking phenomenon and thermal head wear, it is better to improve the lubricity than by applying a backing layer to improve heat resistance or impart matte properties. The inventors discovered that means for improving the temperature of the thermal head are more effective, and that by using a specific resin component, it is possible to prevent not only the contamination of the thermal head but also blocking during storage, leading to the completion of the present invention. .

[Structure of the invention] The present invention will be explained in more detail below.

The basic structure of the thermal transfer recording medium of the present invention is that it has at least a coloring material layer on the upper surface of a film support and at least a backing layer on its lower surface.

The backing layer in the present invention contains at least one curable resin and a thermofusible substance.

The curable resin used in the present invention is an lT!# thermal resin that does not have a melting point (41! measured value with this NPJ-2 type) at a temperature of 200°C or lower, preferably 250°C or lower. It is a resin cured by light or electron beam irradiation.Specific examples of these include urea resin, melamine resin, polyamide resin, alkyd resin, epoxy resin, furan resin, silicone resin, phenol resin, and resorcinol resin. A typical example is at least one type of heat-resistant resin selected from resins.

The curing method for these resins differs depending on the type of resin.
Add 0% (wt%, the same applies hereafter) (to epoxy varnish) and leave it at 20°C for 30 minutes. ■ Silicone resin (for example, X-41-1007-A).

Shin-Etsu Chemical Co., Ltd.) is 07100? -A (manufactured by Shin-Etsu Chemical Co., Ltd.) 2 to 20% (vs. Add zinc chloride and heat at 1OOoC for 5 hours; ■ For melamine resin, heat at 200°C for 2 hours; ■ For polyamide resin, add 2-20% of triisocyanate to the polyamide resin and heat at 100°C. Heating for 5 hours, ■In the case of alkyd resin, leaving it at room temperature for one week, ■In the case of furan resin, leaving it for one week at room temperature,■
For phenolic resin.

It can be cured by heating at 120° C. for 5 hours, (2) In the case of resorcinol resin, heating at 120° C. for 5 hours, etc.

The thermofusible substance preferably used in the present invention has a softening point (
The melting point (measured by the ring and ball method) or the melting point (measured by Yanagimoto NPJ-2 type) is 120°C or lower, and particularly preferably the melting point is 50 to 120°C. If the temperature is lower than 50° C., a blocking phenomenon occurs in which a part of the backing layer adheres to the coloring material layer when heat-sensitive transfer recording media are stacked on top of each other. On the other hand, 1
When the temperature exceeds 20°C, it does not melt easily, resulting in poor lubricity and a sticking phenomenon.

Specific examples of heat-melting substances preferably used in the present invention include paraffin waxes such as paraffin wax and microwax, natural waxes such as beeswax, carnauba wax, and wood wax, and ester waxes such as Hoechst wax. , stearic acid, palmitic acid,
Higher fatty acids such as behenic acid, myristic acid, l,20-eicosanniic acid, higher alcohols such as stearyl alcohol and palmityl alcohol, higher amides such as stearamide, oleoamide, palmityloamide V, butyl stearate, ethyl palmitate, The composition ratio of the backing layer of the present invention, which can include esters such as myristyl stearate, is such that the resin component is 50 to 88%.
．． 8% (wt%, same hereinafter), heat melting substance 0.1~
50%, preferably the resin component is 70-911.11%,
If the content of the heat-melting substance is 0.1 to 30% and the content of the resin component is less than 50%, the backing layer will have poor film adhesion, causing contamination of the thermal head; %
If the temperature exceeds 0.050, the lubricity between the heating head and the film support decreases, causing wear of the heating head. On the other hand, if the content of the heat-fusible substance is less than 0.1%, the lubricity of the backing layer with respect to the heating head will decrease, causing wear of the heating head, and conversely, if the content exceeds 50%. However, the backing layer of the present invention may contain components other than the resin component and the heat-fusible substance of the present invention.

The film support used in the present invention may be any resin film that has excellent surface smoothness and dimensional stability, and may be a resin film (polymer, copolymer, or (including the original polymer) can be cited as a specific example. The thickness of these film supports is not limited, but is preferably about 2 to 15 IL. These supports may be used to provide corona discharge, glow discharge, or other electronic It may be subjected to treatments such as impact treatment, flame treatment, ultraviolet irradiation, oxidation treatment, saponification treatment, surface roughening, etc., or it may be subjected to undercoat treatment.

The backing layer of the present invention may be coated on the film support by any method, such as hot melt coating or solvent coating with a coating solution in which the backing layer composition is dispersed in an appropriate solvent. The solvent used at this time may be any solvent as long as it can dissolve or disperse each component of the present invention to form a coating liquid. For example, n-
Paraffin solvents such as hexane, ligroin, isoparaffin, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, alcohol solvents such as methanol, ethanol, propatool, methanol, ester solvents such as ethyl acetate, DMF, DMSO For coating, any coating technique such as reverse roll coater method, extrusion coater method, gravure coater method or wire bar coating method can be used. Can be adopted.

After the backing layer is applied in this manner, it is hardened by the method described above.

The color material layer of the present invention will be explained below.

The colorant to be contained in the color material layer of the present invention may be appropriately selected from conventionally known dyes, and may be selected from direct dyes, acid dyes, basic dyes, disperse dyes, oil-soluble dyes, etc. The pigment used in the color material layer of the present invention may be any pigment that can be transferred (transferred) together with a heat-fusible substance. Can be mentioned. N. As the yellow pigment, Kayalon Polyester Light Yellow 5G-3 (Nippon Kayaku) was used.

Oil Yellow 5-7 (white clay), Eisenspiron GR
H Special (Hodogaya), Sumiplast Yellow FG
(Sumitomo), Eisensviron Yellow GRH (Hodogaya), etc. are preferably used. Red pigments include Diaceritone Fast Red R (Mitsubishi Kasei), Dianix Brilliant Red BS-E (Mitsubishi Kasei), Sumipura Tread FB (Sumitomo), Sumipura Tread HFG
(Sumitomo), Kayalon Polyester Pink RCL-E (
Nippon Kayaku), Eisen Subiron Red OEM Special (Hodogaya), etc. are preferably used. As a blue pigment,
Diaceritone Fast Brilliant Blue R (Mitsubishi Kasei), Diaanifukus Blue EB-E (Mitsubishi Kasei),
Kayalon Polyester Blue B-3F Conch (Nippon Kayaku), Sumiplast Blue 3R (Sumitomo), Sumiplast Blue G (Sumitomo), etc. are preferably used. In addition, as noble pigments, Hansa Yellow 3G, Tarte Radin Lake, etc. are used, and as red pigments, brilliant carmine FB-Pure (deuteron pigment), brilliant carmine 6
8 (deuterochrome), alizarin lake, etc. are used, and the blue pigments include cerulean blue, Sumikablintocyanine blue GN-0 (Sumitomo), phthalocyanine blue, etc., and the black pigments include carbon black,
Oil black or the like is used.

A heat-fusible substance is used in the coloring material layer of the present invention. The thermofusible substance has a melting point (value measured by Yanagiki MPJ-2yJ) of 4.
Preferably, it is a solid or semi-solid substance with a temperature of θ to 120°C. Specific examples include vegetable waxes such as carnauba wax, wood wax, auriculie wax, and nispar wax;
In addition to waxes such as animal waxes such as beeswax, insect wax, shellac wax, and spermaceti wax, paraffin wax, petroleum waxes such as microcrystalline wax, ester wax, and acid wax, and mineral waxes such as montan wax, oshikerite, and ceresin]・Higher fatty acids such as valmitic acid, stearic acid, margarine, and behenic acid; higher alcohols such as palmityl alcohol, stearyl alcohol, behenyl alcohol, marganyl alcohol, myricyl alcohol, and eicosanol; cetyl palmitate, myricyl valmitate , higher fatty acid esters such as cetyl stearate and myricyl stearate; amides such as 7cetamide, propionic acid 7mide, valmitic acid amide, stearic acid amide, and amide wax; ester gum, rosin maleic acid resin, rosin phenol resin, water Rosin derivatives such as added rosin; phenolic resin, terpene resin,
Softening point of cyclopentadiene resin, aromatic resin, etc. 50
-120°C polymer compounds: stearylamine, behenylamine.

Higher amines such as palmitinamine; polyethylene glycol 4000. Polyethylene oxide such as polyethylene glycol 6000, etc., and silicone wax that is solid or completely solid at room temperature (Japanese Patent Application No. 58-204709
), and these may be used alone or in combination.

The composition ratio of the coloring material layer of the present invention is not limited, but 50 to 90 parts of the heat-melting substance 1 5 to 20 parts of the coloring material per 100 parts (parts by weight, same hereinafter) of the total coloring material layer parts, and 0 to 30 parts (preferably 5 to 30 parts) of resin.

In addition to the above-mentioned components, the coloring material layer of the present invention may contain various additives. For example, as a softening agent, castor oil,
Vegetable oils such as linseed oil, olive oil, animal oils such as whale oil and mineral oils may be suitably used.

Note that the coloring material layer has a thickness of 15 #Lm or less, preferably 2 to 8 #Lm.
It is better to be considered as

[Effects of the Invention] According to the present invention, in a thermal transfer recording medium having a coloring material layer containing a heat-melting substance on one side of a film support and a backing layer on the other side, the backing layer is made of a curable resin. Since it contains a heat-fusible substance that is solid or semi-solid at room temperature, it is possible to achieve the above-mentioned object of the present invention, and in particular, it has the effect of realizing so-called maintenance-free property.

[Example] Examples are given below, but the embodiments of the present invention are not limited thereto.

Example 1 A backing wear coating solution having the following composition was applied to the lower surface of an 81L polyethylene terephthalate film support using a wire bar, heated at 120°C for 30 minutes, and then cooled to a thickness of 0.5IL after drying. ■A backing layer was applied.

[Coating solution for backing wear]

Beeswax: 45 parts by weight Diethylene triamine: 25 parts by weight Methyl ethyl ketone: 30 parts by weight Next, a heat-sensitive transferable colorant layer composition having the following composition was coated on two sides of the polyethylene terephthalate film support using a wire bar, and dried to a thickness of 3. 4 #1. A thermal transfer recording medium sample (2) having a coloring material layer of 1 was obtained.

[Coloring material layer composition]

Carnauba wax 40 parts by weight Wax (0 stones Microwax 155) 40 parts by weight Olive oil 5 parts by weight Carbon black 15 parts by weight Example 2 Apply a backing wear coating liquid having the following composition to the lower surface of the polyethylene terephthalate film support in Step 1. After coating with a wire bar, it was heated at 120℃ for 5 hours after drying, and the thickness was reduced to 0.
．． 5 A backing layer of #L Peng was applied.

[Coating solution for backing wear]

Phenolic resin (Tespol PRG).

(manufactured by Tokushima Seyu Co., Ltd.) 240 heavy weight parts Beeswax 80 parts by weight Methyl ethyl ketone 20 parts by weight A thermal transfer recording medium sample (2) of the present invention was obtained.

Comparative Example 1 A comparative sample 1 was prepared based on Example 1 described in JP-A-58-171992. That is, the following coating solution was applied to the lower surface of the same support as in Example 1 using the same method as in Example 1 to provide a backing layer with a dry film thickness of 0.5 mm.

Further, in the same manner as in Example 1, a coloring material layer having a dry film thickness of L4 gvr was coated on the upper surface of the support to obtain a comparative thermal transfer recording medium sample (2). .

[Coating solution for backing wear]

Cellulose acetate propionate 10 weight parts Lecithin 4 weight parts These thermal transfer recording medium samples were printed on plain paper using a thermal printer (prototype machine equipped with a thin-film line thermal head with a heating element density of 8 dots/plate). printed on.

To determine whether or not the sticking phenomenon occurred, recording was performed under the conditions that the applied power per heating element was 0.7 W and the application time was 2.3 milliseconds, and it was observed whether the thermal transfer recording medium was driven smoothly. For stains on the heating head, check 20 sheets of A4 plain paper (Beck smoothness 200 seconds) and 10 sheets.
After printing a solid image on 0 sheets.

I observed the dirt on the thermal head using a looper.

The blocking phenomenon can be detected by overlapping two samples with the backing layer and coloring material layer facing each other, and heating the sample to 1001 at a temperature of 50°C.
/crn'' pressure was applied, and after being left for 24 hours, it was peeled off and the presence or absence of transfer of the colorant layer composition to the backing layer was observed.

These results are shown in Table 1.

Book 1: There is no dirt on the 0 mark head. There is some dirt on the 0 mark head. There is some dirt on the Δ mark head. There is a lot of dirt on the X mark head. As is clear from Table 1, according to the present invention, 4F is being stored. For I/X applications, it is important to be able to prevent the sticking phenomenon from occurring without contaminating or abrading the thermal head.

Claims (2)

[Claims] (1) In a thermal transfer recording medium having a coloring material layer containing a heat-melting substance on one side of a film support and a backing layer on the other side, the backing layer is made of a curable resin and a solid or semi-solid material at room temperature. A heat-sensitive transfer recording medium characterized by containing a heat-melting substance. (2) The curable resin is at least one type of heat-resistant resin selected from urea resin, melamine resin, polyamide resin, alkyd resin, epoxy resin, furan resin, silicone resin, phenol resin, and resorcinol resin. A thermal transfer recording medium according to claim 1.