JPH084305Y2 - Thermal recording material - Google Patents

Description

TECHNICAL FIELD The present invention relates to a thermosensitive recording material having a thermosensitive coloring layer containing an organic fluorescent pigment.

[Prior art]

The thermosensitive recording material is a recording material having a structure in which a so-called thermosensitive coloring layer that develops color by heating is formed on a support such as paper, synthetic paper or resin film, and a thermal head is built in for heating for coloring. A thermal printer or the like is used. Such a recording material is relatively inexpensive as compared with other recording materials in that recording can be obtained in a relatively short time without complicated processing such as development and fixing, no noise is generated, and the like. Due to the advantages such as not only copying books and documents, various information such as electronic calculators, facsimiles, telex, medical measuring instruments and recording materials of measuring instruments, and
It is also widely used as a ticket for train affairs systems and as a label for POS systems such as department stores and markets.

Such a label is used by color-printing characters and bar codes such as product names and prices with a printer having a thermal head, peeling off the release paper and sticking to the product. In addition to providing information such as price, price, etc., at the time of sale of the product, the barcode recorded on the label is read by an automatic reading device, and the information recorded in the barcode is processed by a computer to sell the product. It is used to manage inventory, ordering, etc.

In addition to the above-mentioned use, this label can also be used as a means for transmitting other information intended by the seller to the purchaser of the product.

For example, when performing a discount sale or performing a special sale, the purchaser can transmit information for identifying the target product from other products by using the label.

Conventionally, for such identification, (1) a method of printing a graphic or a character on a white thermosensitive coloring label with a colored printing ink, (2) a fluorescent pigment or a pigment-containing fluorescent ink is applied on a support. A method of printing a barcode or the like on a label is used, but in the case of (1), it takes a lot of time to print, and a pattern formed by printing ink contacts the thermal head when recording with the thermal head. Therefore, the head is liable to be soiled, and therefore, there is a drawback that dust is attached to the head and the thermal printing portion is soiled.

Further, in the case of (2), it is necessary to stock a label printed on a barcode or the like for each product, which is inconvenient in use.

Furthermore, when such a thermosensitive coloring label is used by being attached to a product such as food, when it comes into contact with a plastic film containing a food containing oils or a plasticizer packaging the food, It is required that the colored image does not bleed or disappear.

〔Purpose〕

An object of the present invention is to provide a heat-sensitive recording material that can be easily manufactured, is convenient in use, and has a remarkable identification effect.

〔Constitution〕

According to the present invention, an organic fluorescent pigment powder (hereinafter, referred to as a solid solution of an organic fluorescent dye in a synthetic resin on a support)
Provided is a heat-sensitive recording material characterized in that a heat-sensitive coloring layer containing an organic fluorescent pigment) is provided, a protective layer is provided on the heat-sensitive coloring layer if necessary, and an adhesive layer is provided on the back surface of the support if necessary. To be done.

Next, an example of the heat-sensitive recording material according to the present invention will be described with reference to the accompanying drawings. In FIG. 1, reference numeral 1 is a conventional support such as paper or film, on the upper surface of which a thermosensitive coloring layer 2 containing an organic fluorescent pigment and a protective layer 3 are sequentially provided, and on the back surface thereof an adhesive layer 4 is provided. Has been.

FIG. 2 shows another embodiment of the present invention, in which a release liner 5 is provided on the lower surface of the adhesive layer 4 in FIG. FIG. 3 shows still another embodiment of the present invention. In FIG. 1, a release layer 6 such as a silicone resin is provided on the protective layer 3 in FIG.

An under layer containing a filler and a binder as a main component may be provided between the support 1 and the thermosensitive color developing layer for the purpose of improving color developability.

The heat-sensitive recording material of the present invention has the above-mentioned constitution, and in particular, since the heat-sensitive coloring layer containing an organic fluorescent pigment as a main component is provided on the support, it has a remarkable discriminating effect and has a very high practical value. It is a thing. In the present invention, the organic fluorescent pigment powder contained in the thermosensitive coloring layer 2 means a powder of organic fluorescent dye in a solid solution in a synthetic resin. This organic fluorescent pigment can be easily produced by a method in which a fluorescent dye is dyed or dissolved after the synthetic resin production process or after the production, and the resulting colored bulk resin is powdered, an emulsion polymerization method, or a resin precipitation method. it can.

The fluorescent dyes used in the present invention include the following. The value in parentheses is the value of the color index.

Brilliansulfoflavine FF (CI56205) Basic yellow HG (CI46040) Eosine (CI45380) Rhodamine 6G (CI45160) Rhodamine B (CI45170) Thioflavine (CI49005) Fluoresein (CI35350) Also, synthetic resin to be dyed is acrylic resin,
A vinyl chloride resin, an alkyd resin, an aromatic sulfonamide resin, a urea resin, a melamine resin, a benzoguanamine resin, and a copolycondensate thereof are used. The amount of the organic fluorescent pigment added is 15% to 60% by weight, preferably 35 to 55% by weight of the thermosensitive coloring layer.

Further, the thermosensitive coloring layer 2 in the present invention contains, for example, the following thermochromic materials together with the above organic fluorescent pigment.

(1) A thermochromic system comprising a combination of a long-chain aliphatic iron salt such as ferric stearate and ferric myristate and phenols such as tannic acid, gallic acid and ammonium salicylate.

(2) A thermochromic system comprising a combination of a heavy metal sulfate such as silver, lead, mercury or thorium sulfate and a sulfur compound such as Na-tetrathionate, sodium thiosulfate or thiourea.

(3) A thermochromic system comprising a combination of a noble metal salt of an organic acid such as silver behenate and silver stearate and an aromatic organic reducing agent such as protocatechuic acid, spiroindane and hydroquinone.

(4) A thermochromic system comprising a combination of an organic acid lead salt such as lead caproate, lead beargonate or lead behenate and a thiourea derivative such as ethylene thiourea or N-dodecyl thiourea.

(5) A thermocoloring system composed of a combination of a leuco dye and a color developer is mentioned, but from the viewpoint of color development sensitivity and clear color development (5)
It is desirable to use the leuco dye of.

Specific examples of the color-forming substance used in the present invention include 3- {N- (p-tolylamino)}-7-anilinofluorane and 3- {N- (p-tolyl) -N-methylamino}. -7-anilinofluorane, 3- {N- (p-tolyl) -N-ethylamino} -7-anilinofluorane, 3- {N- (p-tolyl) -N-propylamino}
-7-anilinofluorane, 3- {N- (p-tolyl)
-N-butylamino} -7-anilinofluorane, 3-
Dimethylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-dipropylamino-6-methyl-7-anilinofluorane, 3-dibutyll Amino-6-methyl-7-anilinofluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 3-piperidino-6-methyl-7-anilinofluorane, 3-piperazino-6-
Methyl-7-anilinofluorane, 3-N- (N'-methylpiperazino) -6-methyl-7-anilinofluorane, 3-morpholino-6-methyl-7-anilinofluorane, 3-dibenzyl Amino-6-methyl-7-anilinofluorane, 3- (N-methyl-N-cyclohexyl) -6-methyl-7-anilinofluorane, 3- (N
-Cyclohexylamino) -6-methyl-7-anilinofluorane and the like.

As a developer that makes a color-forming substance develop color when heated, 2,
2'-methylenebis (4-ethyl-6-t-butylphenol), 2,2'-methylenebis (4-methyl-6-t)
-Butylphenol), 4,4'-isopropylidene diphenol, 4,4'-isopropylidene bis (2-chlorophenol), 4,4'-isopropylidene bis (2,6-dibromophenol), 4,4 ' -Isopropylidene bis (2,6-dichlorophenol), 4,4'-isopropylidene bis (2-methylphenol), 4,4'-isopropylidene bis (2,6-dimethylphenol), 4,4'- Isopropylidene bis (2-t-butylphenol), 4,
4'-sec-butylidene diphenol, 4,4'-sec-butylidene bis (2-methylphenol), 4,4'-cyclohexyl dendiphenol, 4,4'-cyclohexylidene bis (2-methylphenol), 2 , 2'-thiobis (4,6-dichlorophenol), P, P '-(1-methyl-
Examples thereof include, but are not limited to, n-hexylidene) diphenol.

A binder is usually used for the thermosensitive coloring layer 2. Examples of such a binder include gelatin, starch, hydroxyethyl cellulose, polyacrylic acid, carboxyethyl cellulose, methoxycellulose, polyvinyl alcohol, polyvinylpyrrolidone and the like.

Further, an inorganic or organic filler or sensitizer may be added to the thermosensitive coloring layer 2 in order to improve the head matching property.

Further, in the present invention, it is preferable to provide a protective layer 3 on the thermosensitive coloring layer 2 in order to impart oil resistance and plasticizer resistance.

The protective layer 3 may be formed of polyvinyl alcohol, carboxymethyl cellulose, methyl cellulose, ethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, polyacrylamide, starch, gelatin, casein, polyvinylpyrrolidone, or other water-soluble polymer, or polystyrene emulsion. Water dispersible resins such as Further, in order to make the water-soluble polymer water resistant, a water resistant agent such as formaldehyde, glyoxal, chromium alum, melamine, melamine-formaldehyde resin, polyamide resin, polyamide-epichlorohydrin resin can be added. Further, organic or inorganic fillers or fillers may be added to the protective layer 3 in order to improve head matching.

Further, conventionally known coloring pigments and coloring dyes may be added to the thermosensitive coloring layer 2 for the purpose of improving coloring density and color matching.

When the adhesive layer 4 on the back surface of the support is provided in the present invention, an acrylic adhesive, a starch adhesive, styrene / butadiene latex, or a microcapsule of these is used.

Further, a release liner 5 can be provided on the lower surface of the adhesive layer 4 if necessary. As such a release liner 5, for example, paper having a coating film of silicone resin or the like on one surface is preferably used. To be done.

Further, in the present invention, a release layer 6 made of, for example, a silicone resin may be provided on the upper surface of the thermosensitive coloring layer 2 or the protective layer 3.

〔effect〕

The heat-sensitive recording material of the present invention, which has the above-mentioned constitution, has a remarkable identifying effect and is extremely highly practical with excellent plasticizer resistance, oil resistance, water resistance and light resistance, and is widely used as a heat-sensitive color label. It is used.

〔Example〕

Next, the present invention will be described with reference to examples. Parts indicate parts by weight.

Example 1 A color former (liquid A) was prepared by pulverizing and dispersing a mixture having the following formulation for 24 hours with a magnetic ball mill.

Liquid A formulation 3- (N-ethyl-N-p-tolyl) 6-methyl-7-
Anilino fluoran 150 parts 5% aqueous solution of polyvinyl alcohol 150 parts water 200 parts Next, a mixture consisting of the following formulations was pulverized and dispersed for 24 hours by a magnetic ball mill to prepare a developer (liquid B).

Liquid B formulation Bisphenol A 120 parts Stearic acid amide 120 parts 5% aqueous solution of polyvinyl alcohol 120 parts Water 200 parts Next, a mixture composed of the following formulations is dispersed with a magnetic ball mill so as to have an average particle diameter of 2 μ, and a fluorescent pigment dispersion liquid ( C
Liquid) was prepared.

Liquid C formulation Fluorescent pigment (Rhodamine B (CI4517 in the condensate of melamine resin)
0) as a solid solution powder) 100 parts polyvinyl alcohol 10% aqueous solution 100 parts dispersant (dialkyl zodium sulfosuccinate) 1 part water 199 parts solution A 100 parts, solution B 400 parts, solution C 150 parts And were mixed to prepare a thermosensitive coloring layer forming liquid.

Next, this solution was applied on a wood free paper support having a basis weight of 52 g / m ^{2 so} that the dry weight was 10 g / m ² , and dried to form a thermosensitive color forming layer containing a fluorescent pigment.

Next, the following liquid D was applied onto the thermosensitive coloring layer so that the dry weight was 3 g / m ² , dried, and surface-treated with a calender to form a protective layer.

Liquid D formulation Carboxy group-modified polyvinyl alcohol 50 parts Urea-formalin resin filler 10 parts Polyamide epichlorohydrin resin 5 parts Water 500 parts Next, an adhesive made of an acrylic resin is applied to the lower surface of the support to form an adhesive layer. Then, a release liner having a silicone resin coating was temporarily attached to this adhesive layer surface to obtain a heat-sensitive recording type adhesive label of the present invention. This label had a red-orange fluorescent color and had a remarkable discriminating effect. Further, when printed with a thermal head, a clear black image was obtained.

Example 2 Except that 300 parts (50% aqueous dispersion, average particle size 1.8 μ) of a fluorescent pigment obtained by solidifying rhodamine B (CI45170) in an acrylic resin were used instead of the liquid C of Example 1. A thermal recording type adhesive label was obtained in the same manner as in Example 1.

This label had a red-orange fluorescent color and had a remarkable discriminating effect. Further, when printed with a thermal head, a clear black image was obtained.

Comparative Example 1 A thermosensitive recording adhesive label was obtained in the same manner as in Example 1 except that Rhodamine B (CI45170) was used in place of the fluorescent pigment of the liquid C formulation in Example 1.

This label shows a purple fluorescent color, but the discrimination effect was lower than that of the labels of Examples 1-2. When printing was performed with a thermal head, a black and slightly unclear image was obtained.

Next, the heat-sensitive recording type adhesive labels of Example 1 and Comparative Example 1 were each subjected to 110 using a thermal gradient tester manufactured by Toyo Seiki Co., Ltd.
An image was obtained by printing under conditions of ² kg / cm ² and 1 second at temperatures of 120 ° C., 120 ° C., and 130 ° C. The color density of the image portion and the background portion of this sample was measured with a Macbeth densitometer RD-914. Using this sample, tests for plasticizer resistance, oil resistance, water resistance and light resistance were conducted by the following measuring methods. The results are shown in Table 1.

[Plasticizer resistance] Food wrap (polyvinyl chloride wrap) as a sample
Is contacted at a pressure of 0.2 kg / cm ² and 22 ° C. and stored for 12 hours.
The densities of the image area and the background area were measured.

[Oil resistance] Cottonseed oil was applied to the sample with absorbent cotton, and the densities of the image area and the background area after 16 hours of storage at 22 ° C were measured.

[Water resistance] The sample was immersed in water at 22 ° C., and the densities of the image area and the background area after storage for 12 hours were measured.

[Light resistance] The densities of the image area and the background area were measured after the sample was exposed to direct sunlight for 6 hours.

[Brief description of drawings]

1 to 3 are sectional views of the heat-sensitive recording type adhesive sheet of the present invention. 1 ... Support, 2 ... Thermosensitive coloring layer, 3 ... Protective layer, 4 ...
... Adhesive layer, 5 ... Release mount, 6 ... Release layer.

 ─────────────────────────────────────────────────── --- Continuation of the front page (56) Reference JP 54-128349 (JP, A) JP 55-86789 (JP, A) JP 53-86229 (JP, A) JP 50- 134799 (JP, A) JP-B 58-35874 (JP, B1) "Chemical Dictionary" Volume 3 Kyoritsu Shuppan Sho 51-9-10.298

Claims (4)

[Scope of utility model registration request] 1. A thermosensitive recording material comprising a support and a thermosensitive coloring layer containing an organic fluorescent pigment powder obtained by solid-solving an organic fluorescent dye in a synthetic resin. 2. A utility model registration in which a thermosensitive coloring layer containing an organic fluorescent pigment powder obtained by solid solution of an organic fluorescent dye in a synthetic resin is provided on a support, and an adhesive layer is provided on the back surface of the support. The heat-sensitive recording material according to claim 1. 3. A heat-sensitive recording material according to claim 2, wherein a release mount is provided on the adhesive layer. 4. A heat-sensitive recording material according to claims 1 to 3, wherein a protective layer is provided on the heat-sensitive color developing layer.