JPS5824494A - Color-developing material - Google Patents

Abstract

PURPOSE:To provide a color-developing material which produces a color with high color density irrespectively of its not so high acidity, imparts a lubricating property to the surface of a heat-sensitive paper, is free from unpleasant odor and low in toxity, by incorporating a specified fluoro-alcohol and a colorless dye. CONSTITUTION:The color-developing material comprises (A) a fluoro alcohol having a 1-3C alkylene group between a fluoroakyl group or a fluoroalkylene group and hydroxyl group preferably, an alcohol represented by the formula RfAOH or the formula HOARf'AOH (wherein Rf is 1-20C fluoroalkyl; Rf' is 1-20C fluoroalkylene; A is 1-3C alkylene), e.g., HCF2CF2CH2OH and HOCH2CF2CF2CH2OH are particularly pereferable and (B) a colorless dye (e.g., crystal violet lactone), preferably in the ratio of 0.1-1mol of component A to 1mol of component B. EFFECT:A thermal head can be prevented from wearing.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color-forming material, and more particularly to a color-forming material containing a fluoroalcohol and a colorless dye.

Coloring materials such as thermal paper or pressure-sensitive copying paper utilize the coloring phenomenon caused by contact between a colorless dye such as a colorless basic leuco dye and a coloring agent, and in recent years their use as various information recording materials has been remarkable. I'm worried.

Conventionally, acidic substances such as phenols and organic acids are well known as color formers used in combination with colorless basic leuco dyes.

The present inventor has discovered that a specific fluoroalcohol, which is different from such conventional color formers, has a fluoroalkyl group and/or a fluoroalkylene group having 1 to 8 carbon atoms between a fluoroalkylene group and a hydroxyl group. We have discovered a new fact that it exhibits excellent performance as a color former, and have completed the present invention.

That is, one gist of the present invention is that carbon a is present between a fluoroalkyl group and/or a fluoroalkylene group and a water group.
The invention consists in a color-forming material comprising a fluoroalkofur having 1 to - fulkylene groups and a colorless dye.

Although the fluoroalcohol according to the present invention is not as sensitive as the conventional color formers, it has a surprisingly high degree of color development, and in particular, the polymer-sensitive ones have sharp melting points. Since 7Jh also has low water solubility, it exhibits excellent performance such as good printing resolution and less concern about background coloring. The fluoroalcohol of the present invention provides lubricity to the surface of thermal paper due to its low surface energy, can prevent wear of the thermal head during printing, and has less unpleasant odor and chronicity against humans and animals. Excellent as a coloring agent for thermal paper.

It is important that the fluoroalcohol used in the present invention has an alkylene group having 1 to 3 carbon atoms between the fluoroalkyl group and/or the fluoroalkylene group, and the fluoroalcohol used in the present invention must have an alkylene group having 1 to 3 carbon atoms between the fluoroalkyl group and/or the fluoroalkylene group. The alcohol having an alkylene group does not include a color former and a prime number.

Preferred fluoroalcohols include -1fflE
:R(AOH or t:l OA R(A Otl[
In the formula, R [represents a fluoroalkyl group having 1 to 20 carbon atoms;
Rf' is a fluoroalkylene group having 1 to 20 carbon atoms; A
Among them, alcohols represented by #1 and 3 alkylene brackets] are mentioned, among others.

tiOF20F2C1120)1. )1(OF20F
2) 2C1-120i1゜ti (OF20F2) 30L
120ft, H (OF20F2) 4C! fi2O
f-1゜ti(OFCI(3F2)2CE120tl,
l-1(OF(31(3F2)3CL-1201-1,
HOCEI20F20F2C)120H1H00H2(
CF20F2)3C1(201(,)100t120f
-I2(CF2CF2)〆■2C1120H1HO(A
l, CF20FM (OF2F20F, 20FHOF20
H20H, or HOCH2CF2CH2 (CF, CF
2) 2CH2CF2CH20H is particularly preferred.

The colorless dye used in the present invention is not particularly limited as long as it is commonly used, but colorless basic leuco dyes are preferred, such as crystal violet lactone and 4-hydroxy-4'-dimethylaminotriphenylmethane lactone. , 3-diethylamino-6-methy/
L/-7-phenylaminofluorane, 3.7-bisdiethylaminofluorane, 1.3-dimethyl-6-diethylaminofluorane, 2-dibenzylamino-6-diethylaminofluorane, 2-anilino-3-methyl −
6-(N-cyclohexyl-N-methylamino)fluoran, 4,4'-bisdimethylamino-3,4-chlorophenylleukoolamine, paramethoxybenzoylleucomethylene blue, 6-nitro-8-methoxybenzospiropyran , spiro[isoindoline-1,9'-zanthene]-3-6hubis(diethylamino)-2-
Examples include phenyl-3-one.

The ratio of fluoroalcohol to these colorless dyes is 1 mol of the former to 1 mol of the latter or less, usually 0.1 to 1 mol. As described above, there is an advantage that the amount of fluoroalcohol used in the present invention is smaller than when using the conventional coloring agent.

The color-forming material of the present invention is advantageously used for thermal paper as described above, and is also preferably used for pressure-sensitive copying paper as in the case of thermal paper.

When manufacturing thermal paper, first obtain an aqueous solution of a water-soluble polymer as a binder, then add a colorless dye and a color former fluoroalcohol to this aqueous solution to prepare two types of aqueous dispersions, and then add the dye and the color former. The respective aqueous dispersions are mixed in a predetermined ratio, and the resulting mixture is applied to the surface of the base paper to a thickness of several micrometers.

In addition, thermal paper consists of a capsule layer in which a colorless dye is dissolved in an organic solvent and contained in capsules (usually made of gelatin) with a diameter of 2 to 5 μm and coated on raw paper, and a fluoroalcohol coloring agent. It is created by laminating a coloring agent layer distributed on a base paper so that they are in contact with each other.

Next, the present invention will be explained in more detail by showing Examples and Comparative Examples.

Examples 1 to 12 and Comparative Examples 1 to 2 Crystal violet lactone was used as a dye, and fluoroalcohol or bisphenol A shown in Table 1 was mixed therewith as a coloring agent, and the temperature was raised as necessary to develop color. I conducted a test.

Except for Comparative Example 1, in all examples, beautiful dark purple-blue to purple-blue colors were observed. The color temperature of each side is shown in Table 1.

Examples 13 to 17 If (CF2CF2) 5CH20H as a coloring agent was mixed with the various dyes shown in Table 2 at an equal mo/l ratio, and a coloring test was conducted by raising the temperature. The coloring temperature and color of each example are also listed in Table 2.

Examples 18-24 Crystal violet lactone with H(CF2CF2
)F;-G (A color development test was conducted by mixing different amounts of 20H and raising the temperature.The color development temperature was 95°C.The color development results are shown in Table 3.

Table 3

Claims (1)

[Scope of Claims] 1. A color-forming material containing a fluoroalkyl group and/or a fluoroalkyl group having an alkylene group having 1 to 8 carbon atoms between the fluoroalkylene group and the hydroxyl group, and a colorless dye. 2,74/oroalcohol has the general formula: RfAOH or HOARE'AOH [wherein Rf is fluoroalkyl having 1 to 20 carbon atoms 1fR
f' represents a fluoroalkylene group having 1 to 20 carbon atoms; A represents an alkylene group having 1 to 8 carbon atoms. ] The color-forming material according to claim 11, which is an alcohol represented by the following. 8. No colorless dye! The color-forming material according to claim 1, which is a subbase leuco dye. The color forming material according to claim 1, which contains fluoroalcohol in a proportion not exceeding 1 mole per mole of the 4J monochromatic dye.