JPS5983693A - Color developer for leuco dye - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel color developer for leuco dyes. More specifically, the leuco dye fluorescent compound of the present invention is composed of a polymerizable phenol compound represented by the following formula: It relates to colorants.

Conventionally, various phenolic substances have been proposed as color developers for leuco dyes (for example, Japanese Patent Publication No. 45-1
4+139), and 4,4'-isopropylidecidiphenol (bisphenol A) is generally employed. However, in the case of this bisphenol, since the reaction rate with leuco dye is slow, it is not satisfactory as a color developer in leuco-based recording materials that require a high thermal recording speed. Phenol carboxylic acid esters are known as coloring agents with high thermal recording speed (Japanese Patent Application Laid-open No. 144/1983), and parahyaloxybenzoic acid bennor ester is known to be particularly effective. 'it is, but for this one,
The storage stability of the colored area obtained by reaction with leuco dye is not sufficient, and when the recorded material is stored for a long time, K whitening development occurs in the recorded area (colored area) and the density of the image decreases. (It has eight drawbacks.

The present inventor, J-j, has discovered that the TJ Iko Dyeing Machine I Iroki d is different from the above-mentioned conventional one, and has an excellent recording speed.
．． :The storage stability of colored images has deteriorated/We are working hard to develop a 5IlrH coloring agent for IJ Ico dyeing Fl? As a result of our research, we have completed the present invention.

The color developer for leuco dyes in the present invention is composed of a polymerizable phenol compound represented by the above-mentioned general formula (1), and specific examples thereof are as follows.

The color developer of the present invention is prepared by combining P-chlorostyrene and the required phenolic carboxylic acids in a bamboo medium of trimethylformamide (in the presence of a base (organic amine) catalyst and a small amount of high-10 quinone) in a nitrogen stream. It is produced by reacting with

CH2(4J(2) (wherein, R1 and R2 are H or OH) The color developer of the present invention, like conventional phenolic compounds, has traditionally been used for pressure-sensitive paper and thermal paper. It is applied as a color developer for leuco dyes that have been used in LA, such as triphenylmethane-based, fluoran-based, phenothiazine-based, oleamine-based, and spirocopyran-based leuco dyes. It is advantageously applied as a color developer for No. 11 ico dye.

The color developer of the present invention is used in combination with a leuco dye in the fields of pressure-sensitive paper and thermal paper that utilize the color-forming reaction of both. For example, a heat-sensitive recording material can be obtained by combining the visible cutting of the present invention with leuco dyeing and supporting it on a support. This j44 case, ('f'
Auxiliary components of i river, analogy &:lr, carbonic acid,
In addition to silica, polyvinyl chloride, 4fl fat powder, etc., inorganic or organic fibers, metal soaps such as zinc stenophosphate, antioxidants, ultraviolet absorbers, binders, etc. used. The ratio of rJ ico dye and color developer supported on the support is 1-1 for all the components supported on the support. is 7 to 15% by weight, and the colorant is 10 to 50% by weight, preferably 20 to 40% by weight.

The color developer of the present invention easily reacts with leuco dyes, producing a heat-sensitive recording material suitable for high-speed recording of 4/-i. The first aspect of the coloring aspect is that it has a very short shelf life. It is something that

Next, the present invention will be explained in more detail with reference to Examples. Note that "department" and "department" shown below are based on weight.

Example A: Preparation example of color developer I) S? and 4-hi1
50 kg/benzoic acid 351. F and trimethylformamyl
-''150+++ (!Added in addition to 25.117 liters of trini-r) L amine as a catalyst, and further added a small amount of high I-quinone (11), and reacted in a nitrogen gas atmosphere at a temperature of 90°C for 3 hours. After cooling the reaction product, it was neutralized with about 300 ml of diluted hydrochloric acid. Then, it was extracted with jl--7-, 1L, and 15Q ml, and the extract was washed successively with water and aqueous sodium bicarbonate. reaction 4
-Removes hydroxybenzoic acid.

After drying the extract over anhydrous sodium sulfate, the ether was distilled off to obtain a pale brown oil, which was left to stand for crystallization.The crude product was recrystallized from a mixed solvent of petroleum ether. In this way, 4-human OX 7benzoic acid-4'~vinyl
Reester (mP 85-88℃) Lye II (yield 80
%).

Also, in the same manner as above (except that 3,4-dish-droxybenzoic acid and 3゜4.5-tIJ hydroxybenzoic acid were used instead of 4-hydroxy-7benzoic acid, 3,4-dihydroxybenzoic acid-4'-vinylbenzoyl ester (mP 105-107°C) and 3,4-dihydroxybenzoic acid, respectively.
．． 5-l.lich l-''roquinobenzoic acid-4'-vinyl norester (mP 87-89°C) obtained*.

B: A leuco dye dispersion and an egg-colored dispersion were prepared in the following examples.

Leuco dye dispersion (1) 3-N, N-noethyl r-mino-7-ordoli "1 4
0 parts Luaniline Fluoranhi+-c Mouth 7 Ethyl Cellulose-1: (10% water soluble W&
) 40 parts water
120 parts Color developer dispersion (1) 4-hydroxybenzoic acid 4+ e-benzoic acid 2
0 parts esthetics / 1 nohi 1: ``Login A Y-L Resel Rose (10 parts water-soluble 7 &) 20 parts water
60 copies+! +'4 coloring agent dispersion ([1) 3.4-1-4-vinylbenzoic acid-4'-vinylleben 20 parts;
20 parts water
60 parts developer dispersion (III
) Human'roxyethyl cellulose, I? (10φ water la liquid)
20 parts water
60 parts color developer dispersion (X) (comparative example) Parahi IF (+4 xybenzoic acid, ;), az varnish=,
rshi20 @'5 Hydroxyethylce I Rerose (IO
Water WJW) 20 Soundμ water
Part 60 Next,
Ze-? After stirring and dispersing in Remille for 2 days, 15 parts of color developer dispersion were added to 5 parts of leuco dye dispersion, and 8 parts of 20% yJ< solution of oxidized starch were added and mixed well. 1) to (m) and (X) were obtained, respectively.

These heat-sensitive coloring liquids have a standard basis weight of 52y/lri.
Dry adhesion amount on one side of double-quality paper is 4y/m% smoothness force; 13
The coating was applied for 0 to 200 seconds and dried to form thermal recording sheets (1) to (1) and (X), respectively.

In order to evaluate the degree of heat sensitivity of the heat-sensitive recording/...-t obtained in this way, 7.
Fakunomiri Simire -ter V (J: Su, Netsu\:,/
Apply F'' for +1.94 msec, apply '+11.Il:
Contact with the softness F of 2 +l V, color development at that time, r
, 1.11 degrees <,''measured with a Nick Ma/densitometer.

In addition, in order to evaluate the storage stability of thermal recording notebooks, a thermal head was brought into contact with the notebook at 120°C for 1 second. Record notebook, Fuku, degree 40℃, temperature 90
The density of the image area and the degree of change in the valve area 1 quadrant 4 degrees when left in an atmosphere of %RH (7) for 24 hours were investigated.

The following table shows the evaluation results.

Table 1 From the results shown above, it can be seen that when using the color developer of the present invention (thermal recording sheets (f) to (III)), when using the conventional color developer (thermal recording sheets (f) to (III)), Recording note (X))
It can be seen that, although the color density is the same, the color image stability is improved compared to 1 to 1.

Patent applicant Rico Co., Ltd. Agent Patent Attorney Toshiaki Ikeura

Claims (1)

[Scope of Claims] A color developer for a 1-ico dye consisting of a polymerizable phenol compound represented by the following formula: (wherein R1 and R2 represent a hydrogen atom or a human group).