JPS6148432B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a recording material that uses a color developer sheet in which a color developer component is present on the base material surface and a colorless or light-colored ink, and forms a strong and stable print record with high contrast by bringing the two into contact with each other. . Color developing sheets of conventionally known recording materials are stored and used for long periods of time, so they are exposed to high temperatures and
Due to the effects of high humidity and sunlight, the color developer component of the color developer sheet deteriorates and the color developer sheet becomes naturally colored, despite the addition of various stabilizers such as antioxidants and ultraviolet absorbers. There is a drawback that it does.
When such a color developing sheet is used in combination with color developing ink, the printed records developed on the color developing sheet will have a low density and be unclear, and it will take several tens of seconds for the printed records to develop color, and furthermore, the printed records after color development will There is a problem that the color fades, and a solution to this problem is currently desired. The present inventor completed the present invention as a result of research to solve this problem. That is, the present invention provides (A) general formula (wherein R is hydrogen, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, an alkanol group having 1 to 12 carbon atoms) present at least on the substrate surface. (B) a color-developing ink containing a vanadium compound and/or a leuco dye; The present inventor has discovered that although the compound represented by the general formula () is itself a colorless solid, it develops a high contrast color when it comes into contact with a vanadium compound and/or a leuco dye, and the color development is robust. It was discovered for the first time that it is stable in water and does not wash out in water. Therefore, the compound represented by the general formula () can be effectively used as a color developer for recording materials by taking advantage of this property. This compound has extremely superior characteristics compared to color developers conventionally used for these purposes. That is, in conventional color developers for recording materials, the developer itself has coordination ability and chemically active coordination groups, so the ligand component itself is extremely susceptible to oxidation. Decomposition and discoloration due to heat, light, and oxygen,
It is colored, has strong sublimation properties, and has a very limited usable pH range. Moreover, even if a coloring inhibitor is added, sunlight resistance and oxidation resistance are not satisfied. For this reason, there is a serious drawback in that even if there is no contact with a color-forming material, the material naturally colors over time due to heat, light, and oxygen, and if it is brought into contact with a color-forming material in this state, its color-forming performance is reduced by more than half. Conventional color developers for recording materials have such problems, but the compound represented by the general formula () used in the present invention has no such defects and has a color development speed and color density that are higher than those of conventional color developers. It has various excellent properties such as being equivalent to or better than other agents and having no sublimation property. Such excellent properties are limited to compounds in which the group represented by R in the general formula () is hydrogen, hydroxyl group, alkyl group, or alkanol group; other than these, there is a decrease in color density and color development rate, and there is a problem with solvents. This leads to a decrease in solubility in In addition, in the case of alkyl groups, those having 13 or more carbon atoms, and in the case of alkanol groups, those having 13 or more carbon atoms are unsuitable for practical use because they lead to a decrease in color density. must be alkyl and alkanol groups with carbon atoms. Examples of the trimming material represented by the general formula () are as follows.

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[Formula] Preferred groups represented by R in the general formula () are hydrogen and hydroxyl. A compound having this structural formula has a high solubility in a solvent, so that the color density and speed of color development are high. Next, the reason why the compound represented by the general formula () is present on the base material surface of the color developing sheet will be explained. The vanadium compound that reacts with the compound represented by the general formula () has the disadvantage that it can be washed away with water or the colored symbol display can be washed away with water, and it is also easily decomposed by heat, light, and oxygen and becomes colored naturally. There are drawbacks. Leuco dyes also have the disadvantage that they are easily decomposed by heat, light, and oxygen and naturally become colored. For this reason, a vanadium compound and a leuco dye are used in the color-developing ink, and the compound represented by the general formula () is present on the base material surface of the color-developing sheet. The preparation of the color developer sheet is not particularly limited as in the preparation of known color developer sheets. For example, the compound is dissolved in a solvent such as alcohol, ester, or ether to form a solution with a concentration of 1 to 20% by weight, and the color developer sheet is It is present on the base material surface of the sheet. As the solvent to be used, a low boiling point solvent is preferable than a high boiling point solvent because it has better drying properties. In addition, as a base material for the color developer sheet, paper, synthetic paper,
Cloth, porous plastic film, ceramic paper, etc. can be used, and the material is present on the substrate surface by either coating or impregnation. When applying or impregnating a color developer ink onto a base material, acid clay, acid clay, or
Finely powdered white pigments such as activated clay, alumina, and silicon dioxide may be added, and to further increase the color development speed, organic or Adding inorganic acids, adding additives such as fluorescent brighteners to increase whiteness, and adding binders made of natural or synthetic polymer substances to provide binding properties to the substrate. You can also do it. Various coaters such as roll coaters and knife coaters can be used to apply the developer ink to the base material, and methods for impregnating the base material include dipping the base material in the developer ink or spraying the developer ink onto the base material. or
It is done by letting it flow down. When a color developer sheet is formed by applying the color developer ink to a base material, it is particularly preferable to add a finely powdered white pigment to the color developer ink. Therefore, the color developing sheet of the present invention is prepared by dissolving the compound represented by the general formula () in a solvent, and adding finely powdered white pigments, a color development speed enhancer, a fluorescent whitening agent, and a binder as necessary. It is obtained by coating or impregnating a base material with this. Next, the coloring material will be explained. There are many vanadium compounds and leuco dyes used in the present invention, examples of which are as follows. (1) _VOX3
(X is an anion of an organic acid or an inorganic acid.) (2)

[Formula] (R ₁ to _{R 4} are hydrogen atoms, alkyl groups, and aryl groups.) (3) Vanadium siloxane compound

[Formula] (R ₁ to _{R 3} are an alkyl group or an aryl group.) (4) Polymethylphenylvanadosiloxane (5) Triallylmethane compounds (6) Diphenylmethane compounds (7) Xanthene compounds (8) Thiadiane compounds (9) Spiropyran compounds Vanadium compounds and leuco dyes can be used alone or in combination, and are colorless. Alternatively, the lighter the color, the more suitable it is. The coloring ink of the present invention is made by dissolving a vanadium compound and/or a leuco dye in a solvent, but any solvent that dissolves a vanadium compound or a leuco dye may be used, such as water, alcohol, glycol, ester, ketone, or ether. , hydrocarbons, acids, amines, and aldehydes can be used alone or in combination. In addition, various additives such as viscosity modifiers, color inhibitors, antioxidants, ultraviolet absorbers, surfactants, polymeric substances, and finely powdered white pigments are added to color-forming inks in order to increase their use and stability. It can also be used in addition to. Furthermore, depending on the properties of the coloring material, it is not always necessary to dissolve the coloring material as described above; for example, the coloring material can be emulsified and combined with the color developing sheet. Therefore, the color forming material used in the present invention is prepared by dissolving or emulsifying a vanadium compound and/or a leuco dye in a solvent, and optionally containing a viscosity modifier, a color preventive agent, and a leuco dye.
Antioxidants, ultraviolet absorbers, surfactants, polymeric substances, and finely powdered white pigments are added to form solution-type inks or emulsion-type inks. Furthermore, the present invention provides (A) (a) general formula (In the formula, R is hydrogen, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, an alkanol group having 1 to 12 carbon atoms) and (b) polyhydric phenol. It also relates to a recording material comprising a color-developing sheet in which one or more selected from the following are present at least on the base material surface, and (B) a color-developing ink containing a vanadium compound and/or a leuco dye. The chelate type or leuco type recording material of the present invention is not normally used in places exposed to a lot of heat or light, but may be required to be exposed to such heat or light for special purposes. The present inventor has discovered that the combined use of polyhydric phenols is extremely effective in such uses, and has completed the present invention. Of course, it is also effective to use polyhydric phenol in combination under normal circumstances. There are many types of polyhydric phenols, and any of them can be used in the present invention, but it is best to use one or more of the compounds selected from the following groups (a) and (b) to improve the color development rate. This is preferable because it improves. (stomach) (Here, R ₂ and R ₃ are hydrogen, a hydroxyl group, an alkyl group having 1 to 18 carbon atoms, an acyl group having 1 to 4 carbon atoms, and an aryl group having 6 to 12 carbon atoms. , R ₄ is -, n is 1~
16 (-CH ₂ -) _o , n is 6 to 10 -CO(-
CH ₂ -) _o CO-, phenylene group, benzal group, n
is 1 to 18

【formula】 n is 1-10.

[Formula] (R ₅ and R ₆ are the same as R ₂ and R ₃ above.)) (b) (Here, R ₇ is a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 5 carbon atoms, an acyl group having 1 to 4 carbon atoms, and R ₈ is a hydrogen atom, 1 to 5 carbon atoms.
(alkyl group having 18 carbon atoms, aryl group having 6 to 12 carbon atoms) Examples of the compounds represented by the general formula () are as follows. Examples of the compounds represented by the general formula () are as follows. Next, examples of the present invention will be described. Parts are parts by weight. Example 1 (A) Color developer sheet

Each component in [Table] was mixed and dissolved, impregnated into paper, and dried with ethanol to make a color developing sheet. (B) Coloring ink Sodium metavanadate 9 parts Glycerin 25 parts Diethylene glycol 125 parts Water 140 parts Each component was mixed and dissolved to prepare a colorless color ink. When this color-forming ink and color-developing sheet are brought into contact,
The recording surface of the developer sheet developed a deep blue color with high contrast. Examples that were carried out in the same manner by changing each component are summarized in the table below.

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[Table] The meanings of abbreviations used in the examples are as follows. *D: Means "impregnation". *: Means “coating”. SAS―295;
Alkylene bisphenyl SAS-296 manufactured by Nippon Oil Co., Ltd.; 〃 PSD-G; Leuco dye PSD-O manufactured by Nisso Kako Co., Ltd.; 〃 PSD-P; 〃 PSD-R; 〃 Next, Example 1 to Examples Showing the results of 21 tests. The test was conducted as follows to check the performance under normal environment. First, the color developer sheet was left indoors in a bright place for 30 days, and the natural coloring state of the color developer sheet was observed. Subsequently, a color developing ink was brought into contact with this color developing sheet to print and record, and the color density and speed of color development were observed. Furthermore, in order to check the fastness of the printed records, the sheet was exposed to direct sunlight for 5 days and the state of discoloration of the printed records was observed.

[Table] Next, comparative examples to be compared with Examples 22 to 50 are summarized in a table.

[Table] The meanings of the abbreviations used in the comparative examples are as follows. -1, -3, -2; Same as abbreviations in table. Tinuvin 327; Ultraviolet absorber S-FW manufactured by Ciba Geigy; Fluorescent brightener *C, *D manufactured by Shinro Kaisha; Same as the abbreviations in the table. Next, test results of the above comparative example and Examples 22 to 50 of the present invention will be shown. Tests were conducted as follows to check performance under harsh environments. First, the color developer sheet was irradiated with a xenon lamp for 72 hours, and the state of natural coloring of the color developer sheet due to light, heat, and oxygen was observed. continue,
A color developing ink was brought into contact with this color developing sheet to perform printing and recording, and the color density and speed of color development were observed. Furthermore, in order to check the fastness of the recording, the color developing sheet on which the printed records were exposed was exposed to direct sunlight for 5 days and the state of discoloration of the printed records was observed.

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[Table] As is clear from the above results, the recording material of the present invention exhibited excellent performance in all test items and was extremely useful. Therefore, the recording material of the present invention can be used to create records on recording paper in writing sets that combine writing paper, typewriters, registers, ticket vending machines, etc.

Claims (1)

[Claims] 1 (A) General formula (wherein R is hydrogen, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, an alkanol group having 1 to 12 carbon atoms) present at least on the substrate surface. A recording material comprising a combination of a color-developing sheet and (B) a color-developing ink containing a vanadium compound and/or a leuco dye. 2. The recording material according to claim 1, which uses a color developing sheet using a compound in which the group represented by R in the general formula () is hydrogen. 3. The recording material according to claim 1, which uses a compound in which the group represented by R in the general formula () is a hydroxyl group. 4 (A) (A) General formula (In the formula, R is hydrogen, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, an alkanol group having 1 to 12 carbon atoms) and (b) polyvalent A recording material comprising a color-developing sheet in which one or more selected from phenols are present at least on the base material surface, and (B) a color-developing ink containing a vanadium compound and/or a leuco dye.