JPS5971891A - Thermosensitive recording material - Google Patents

Abstract

PURPOSE:To obtain a thermosensitive recording material useful for a thermosensitive graphic type label sheet and a thermographic magnetic ticket having an excellent color-formed image stability utilizing a color forming reaction between a fluorane compound and a phenolic compound respectively as specified. CONSTITUTION:A binder (e.g. PVA) is added to a fluorane compound (e.g. 3- diethylamino-6-methyl-7-anilinofluorane) as represented by the formula I (R1 and R2 are each C1-6 alkyl or cyclohexyl, R3 is C1-2 alkyl, n is 0 or 1) and a phenol compound as represented by the formula II (X is lower alkyl or halogen, n is 0-3) and an auxiliary adhesive, a hot melting material and the like as required. A liquid coat for forming a thermal layer thus obtained is applied on a support such as paper and dried to obtain a thermographic material.

Description

[Detailed description of the invention]

The present invention relates to a heat-sensitive recording material, and particularly to a heat-sensitive recording material with excellent image stability. Heat-sensitive recording sheets that utilize a heated color-forming reaction between normally colorless or light-colored colorless dyes (leuco dyes), phenols, and organic acids are disclosed in Japanese Patent Publication No. 43-4160 and Japanese Patent Publication No. 45.
-14039, JP-A-4G-27736, etc., and has been widely put into practical use. In general, heat-sensitive recording sheets are produced by pulverizing and dispersing a leuco dye and a color developer such as a phenolic substance into fine particles, and then mixing the two.
ζ Inner, filler, sensitivity improver, lubricant, and other auxiliary agents are added to the resulting coating liquid, which is coated on a support such as paper or film, and color recording is obtained through an instant chemical reaction upon heating. It is something. A thermal printer, a facsimile machine, etc. having a built-in thermal spatula P is used to heat the coloring reservoir of such a heat-sensitive recording sheet. Compared to other recording materials, such recording sheets can produce records in a relatively short time without complex processes such as development and fixing, and do not generate noise. It has the advantage of being inexpensive, etc.: Not only can it be used to copy documents such as Figure J1, Bunsou, etc., but also electronic R19, facsimile, telex, etc.
It is widely used as a record of various information such as medical measuring instruments and measuring instruments. However, the density of the heat-sensitive recording sheet C, which is a combination of conventional leuco dye and phenolic substance, decreases due to contact with oils and fats, polyvinyl chloride film, etc., or immersion in water, etc. It has the disadvantage that it may fade or fade. On the other hand, as an improved version of the conventional heat-sensitive recording sheet, one in which a water-soluble polymer O-ζ-coat layer is provided on the heat-sensitive coloring layer has been proposed. It hinders conduction, reduces thermal sensitivity, and
This method has disadvantages in that a coating process for the O-ζ-coat layer is required and costs are high. As a means to solve such problems, the present inventors first discovered that by using a phenolic substance represented by the general formula (1) below as a color developer, the colored portions could be removed even by oils and fats on fingers, etc. The company has successfully developed a heat-sensitive recording sheet that does not fade, and has already applied for a patent. As a result of further intensive research, the present inventors have found that the colored image obtained by the combination of a phenolic compound represented by the general formula (II) described later and a specific leuco dye represented by the general formula (1) described later is , 7j? l) It was discovered that it has an even more excellent anti-fading effect even when it comes into contact with a vinyl chloride film or when immersed in water, and the present invention was completed based on this discovery. That is, according to the present invention, general formula (1) (wherein 11,1 and R12 are each an alkyl group having 1 to 6 carbon atoms or a cyclohexyl group, and I(, 3 is a group having 1 to 2 carbon atoms) is an alkyl group, +1 represents the number 0 or 1) and a fluoran compound represented by the general formula Cl1l (wherein, X represents a lower alkyl group and/or a halogen atom, There is provided a heat-sensitive recording device characterized by utilizing a color reaction between the fluoran compound and the phenolic compound represented by the general formula. , 3-diethylamino-6-me f-
Leu7-aniritefluorane, 3-(N-ethyl-N-
inamylamino)-6-methyl-7-anilithufluorane, 3-(N-methyl-N-n-n-hexolamino)-6-, l-thyl-7-anilithufluoran, 3-(N
-cyclohexyl-N-methylamine)-6-methyl-
7-What are some of these? 11-D, applied in the form of a mixture of two or more -J2. Specific examples of the phenolic compound represented by the general formula (II) include those shown below. The phenolic compounds used in the present invention are not limited to these, but they may be used alone or in combination with Q-12 or more. The phenolic substance C1 represented by the general formula -1] has never been used as a material for heat-sensitive recording notebooks. In the present invention, as described above! The reason why the colored image obtained by the combination of a fluoran compound and a phenolic compound at certain times has excellent image stability is not yet clear, but the colored image obtained by the reaction of the two has excellent image stability. Show stability! : rIJ,
This is a surprising 4F fact. In the present invention, in order to bind and support the fluoran compound and the phenol compound on the support, various commonly used binders may be used as appropriate, such as polyvinyl alcohol, methoxy cellulose, hydroxyethyl cellulose, etc. , calxoxymethylcellulose, polyhinylpyrrolidone, polyacrylamide, polyacrylic acid, starch, gelatin, etc., or water-based emulsion types such as polystyrene, vinyl chloride-vinyl acetate copolymer, polybutyl methacrylate, etc. Can be used as a binder. However, in the present invention, if necessary, conventional auxiliary additives, such as fine powders such as cal/rum carbonate, silica, sulfuric acid/glycum, and aluminum stearate, are added to improve the clarity of the colored image. can be improved. Also,
Various conventional thermofusible substances can be used in combination to improve thermal sensitivity. Examples of the thermofusible substance include organic low-molecular compounds, oligomers, and high-molecular compounds having an appropriate melting point or softening point. Specific examples include animal waxes, vegetable waxes, mineral waxes, petroleum waxes, and other synthetic waxes such as higher fatty acids, higher fatty amines, higher fatty acid flax, phenyl benzoate derivatives, and crystalline alkylnaphthalenes. , crystalline alkyldiphenyl derivatives (L-alkylterphenyl derivatives, etc.) The thermosensitive recording material of the present invention can have various structures, and can be formed by a color-forming reaction between a leuco dye and a color developer. use]
All conventionally known structures are included. For example, the heat-sensitive recording device A1 of the present invention has a structure in which a leuco dye and a color developer are supported on a support as the same coated layer or separate coated layers, and a leuco dye is transferred. A ζ transfer note formed by being supported on a support as a layer,
It can be used as a thermal transfer type thermosensitive recording monthly sheet consisting of a receptor sheet supported on a support with a color developer as a receptor layer. In the case of a thermal transfer type thermal recording material, by overlaying the receiving/- sheet on the transfer note 1 so that the receiving layer is in contact with the transfer layer of the transfer sheet, and thermally printing from the front or back side of the polymerized note. A desired colored image can be completely formed on the surface of the receiving layer of the receiving notebook. The heat-sensitive recording material of the present invention can be produced, for example, by applying a coating liquid for forming a heat-sensitive layer containing the above-mentioned components onto a suitable support such as paper, synthetic paper, or plastic film, and drying it. It is used in the field of recording, especially for monthly heat-sensitive recording for high-speed recording. The heat-sensitive recording material of the present invention is used in various fields, but in particular, it takes advantage of the above-mentioned excellent color image stability,
It can be advantageously used as a heat-sensitive recording label or a heat-sensitive recording magnetic ticket. In the case of a heat-sensitive recording type label sheet, a heat-sensitive coloring layer containing the above-mentioned fluoran compound and phenolic compound is provided on one side of the support,
A release mount may be provided on the other side of the support via an adhesive layer, and in the case of magnetic ticket paper, instead of this release mount,
A magnetic recording layer containing a ferromagnetic material and a binder as main components may be provided. Examples of the present invention are shown below. Note that parts and parts are parts by weight, respectively. Example 1 A mixture consisting of the following compositions was separately ground and dispersed for 21 minutes using a magnetic Seel mill to obtain liquid [A], liquid [■3],
A CC''J solution was prepared. [A] Solution 3-(N-7 clohexol-N-20 parts by weight methylamino)-6-methyl-7 monoanilifluorane 10 dihydroxy/ethyl cellulose ykJfJH, 20
tr water
60 ・[13] Liquid 4-hydroxy/-47-chlorosif 20 parts by weight enyl sulpon 1()% hydroxyethyl cellulose aqueous solution 20
rr water
. . , 1 [C] Liquid calcium carbonate 20 parts by weight 5-thimethylcellulose aqueous solution 20 Water
. . [A1-[C obtained as in 9 to 1-]
] Using the solution, a heat-sensitive coloring layer solution with the following composition was prepared, and the standard basis weight was 50! il-/m" commercially available" dry coating amount 4 ~
5 f/m'' wire S-, apply and dry, then calender and book so that the surface flatness of the heat-sensitive coloring layer is 500 to 600 seconds in Bekk smoothness. A thermosensitive recording notebook (a) of the invention was prepared.Thermosensitive coloring layer liquid [A] 10 parts by weight [I
3]Liquid 3Q LL[C]Liquid
3Q/I inobutylene-maleic anhydride co-10 tr Polymer in aqueous 20 alkaline solution Example 2 All procedures were carried out in the same manner as in the example except that the following (1) 1 was used in place of the [A') solution in Example 1. Thermal recording sort (
b) was made. [D] Solution 3-) Ethylamino-6-methyl 20 parts by weight-7-
Anilinofluoran 10% hydroxy 7 ethyl cellulose water soluble/I1.20
Water 60 parts by weight Example 3 Thermal Recording 7-1.(
(,)made. CL;:]Liquid 3-(N-Ethyl-N-isoamide 20 parts by weight Ruamino)-6-methyl-7-anilite fluorane 1()% human 80 kg/ethyl cellulose water mH20rr
water
60 ・Example 4 Thermal recording /-1・((1
)made. [1i'] Liquid 3-(N-methyl-N-normal 20 parts by weight to parts by weight Aquino)-6-methyl-7-anilite fluorane 10% hydro/ethyl cellulose water tF4 20
LL water 60 parts by weight Comparative Example 1 A thermosensitive recording sheet (c) was prepared in the same manner as in the example except that the following liquid [0] was used instead of the CAI liquid in the example.

[0]Liquid 3-Dinormaldithylamino-7-20 parts by weight (o-chloroanilino)fluoran 10% H-V loxoethylcellulose aqueous solution Wl 2
0 n water
60 u Comparative Example 2 Thermal recording sheet (f) was prepared in the same manner as in the example except that the following liquid [1■] was used instead of the liquid [A] in the example.
made. [11] Liquid 3-(N-ethyl-1'1-P-toluy 2Q parts by weight dino)-6-methyl-7-anilite fluorane 10 parts Hydroxy-engineered methyl cellulose water M liquid 2 On water
60
〃Thermal recording sheet obtained as above) Li
1 to (') at a pressure of 2 on a thermal gradient test rock (Toyo Seiki Membrane)
Printing was carried out at 150° C. with a contact time of 1 second. (,1~(``
) Press your finger against the colored part and ground colored part of the thermal recording notebook,
The samples were stored in a 60" dry storage test room for 24 hours, and the changes in the colored areas and background areas were observed. As a result, the colored areas of both Examples and Comparative Examples disappeared. There was still no color development in the ground color part. Next, thermal records of (j to (f)) were printed in the same way,
Cut out 4 square pieces with the printed area in the center, immerse each piece separately in a 100 mt beaker filled with tap water for 24 hours, take it out, dry it, and measure the density of the colored area with a Macbeth densitometer (old) - 514) and compared with the concentration before the test, and the results are listed in Table 1. In addition, heat-sensitive recording sheet I of (,) to (r) was printed in the same way, cut out into a 4 cm square with the printed part in the center, and covered with polyvinyl chloride film (Polyratsuzo V manufactured by Shin-Etsu Polymer ■).
-3(]O) was stacked, and after applying a load of soo 7-/cl for 5 hours, it was taken out and the density of the colored part was measured at the Macbeth density i1 (11, 11-' 514), and the density before the test was The results are listed in Table 1. Table 1 From Table 1, the heat-sensitive recording sheet of the present invention not only does not lose its color due to oils and fats on fingers, etc., but also resists water immersion. It can be seen that the colored image does not fade even when it comes into contact with a vinyl chloride film, and has an extremely excellent anti-fading effect. Patent applicant: Ricoh Co., Ltd. Patent attorney Toshiaki Ikeura

Claims (1)

[Claims] (1) General formula (1) (wherein, R5l and 几 are each an alkyl group or a cyclohexyl group having 1 to 6 carbon atoms, and R3 is a carbon number 1 to 2
is an alkyl group of A heat-sensitive recording material characterized by utilizing a color-forming reaction between a phenolic compound represented by the number 3).