JPH03153644A - Aromatic ether compound and coloring promoter - Google Patents

Abstract

NEW MATERIAL:A p-xylene glycol diaryloxymethyl ether shown by formula I [Ar is phenyl which may contain substituent group (lower alkyl or lower alkoxy)]. EXAMPLE:p-Xylene glycol di-p-tolyloxymethyl ether. USE:A coloring promoter for heat-sensitive recording material having excellent thermal response and heat resistance. PREPARATION:p-Xylene glycol is reacted with formaldehyde shown by formula III and an anhydrous hydrogen halide shown by formula IV (X is Cl, Br or I) to give a p-xylene glycol dihalomethyl ether, which is reacted with a phenol shown by formula VI in the presence of sodium hydroxide to give a compound shown by formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a novel compound and a color development accelerator for heat-sensitive recording materials comprising this compound.

[Conventional technology]

In recent years, the amount of information has increased with the diversification of information, and various recording methods and recording materials have been researched and put into practical use in the field of information recording for recording this information.

Among them, the thermal recording method is: 1. A recorded image can be obtained by simply heating the thermal recording material, and no complicated development process is required. 2. The manufacturing and storage management of the thermal recording material is similar to that of other recording materials. It is easy and inexpensive compared to others. In many cases, inexpensive paper is used as a support for heat-sensitive recording materials, but in this case, the resulting recording material has advantages such as a feel similar to that of ordinary paper. It is used in many fields such as computer output, printers such as calculators, recorders and facsimiles for various measuring instruments, automatic ticket issuing machines, and thermal copying machines.

Heat-sensitive recording materials used for these purposes have conventionally contained leuco dyes that are colorless or light-colored at room temperature and organic acidic substances such as phenolic compounds that react with the leuco dyes to develop color when heated. It is known that a heat-sensitive coloring layer is provided on a support such as paper, synthetic paper, synthetic resin film, etc.
0 and Special Publication No. 45-14,039).

However, these conventional heat-sensitive recording materials have a problem in that their thermal responsiveness is insufficient and sufficient color density cannot be obtained when used for high-speed recording. In the field of information recording as well, we are trying to improve the recording speed by making it possible to heat the thermal head for a short time and to produce sufficient density with a low voltage. is marked blue.

Therefore, in an attempt to solve these problems with conventional heat-sensitive recording materials, it has been proposed to add a thermofusible substance to the heat-sensitive coloring layer to improve the thermal responsiveness (Unexamined Japanese Patent Publication No. Publication No. 51-27.599 and Japanese Unexamined Patent Publication No. 48-488
9.231).

However, even with this technique, since the demand for high-speed recording has become even higher in recent years, a sufficiently satisfactory result regarding the thermal response has not yet been obtained.

[Problem to be solved by the invention]

Therefore, the present inventors have discovered that they can be added to the heat-sensitive coloring layer of a heat-sensitive recording material to promote color development by the leuco dye and organic acidic substance in the heat-sensitive coloring layer, and thereby have excellent heat responsiveness. As a result of extensive research into color accelerators that can provide heat-sensitive recording materials, we found that paraxylene glycol diaryloxymethyl ether, a new compound obtained by reacting paraxylene glycol dihalomethyl ether with phenols, is excellent. The present invention has been achieved based on the discovery that it has a color development promoting effect.

Therefore, it is an object of the present invention to provide a new compound of paraxylene glycol diaryl oxymethyl diaryl.

Another object of the present invention is to provide a color development accelerator that can be added to a heat-sensitive coloring layer in order to obtain a heat-sensitive recording material having excellent thermal responsiveness.

[Means to solve the problem]

That is, the present invention is a paraxylene glycol diaryloxymethyl ether represented by the following formula (1) (wherein Ar represents a phenyl group or a phenyl group having a lower alkyl group or a lower alkoxy group).

Further, the present invention is a color development accelerator for heat-sensitive recording materials comprising paraxylene glycol diaryloxymethyl ether represented by the above general formula (1).

This paraxylene glycol diaryl oxydimethyl ether is produced by reacting paraxylene glycol with formaldehyde and anhydrous hydrogen halide to form paraxylene glycol dihalomethyl ether, as shown in the reaction formula below, and then adding sodium hydroxide in an appropriate solvent. It can be obtained by reacting with phenols in the presence of.

HOCH, be()ΣCHxOH+ HCHO+
HX-→XCH20CH2-QC)IfOCH3XXC
H,0CH2◇CH20CH2X + Ar-0H (wherein, X represents a halogen atom such as CI, 8r or I, and Ar represents a phenyl group or a lower alkyl group, particularly a phenyl group having a lower alkoxy group) Here, examples of the phenols represented by Ar-OH include phenol, 0-lm- or p-cresol, xylenols, and methoxyphenols.

Among the paraxylene glycol diaryloxymethyl ethers produced in this way, particularly preferred are:
Barraxylene glycol dichloro, methyl ether is reacted with baraxylene glycol diparatriloxymethyl ether, which is obtained by reacting baraxylene glycol diparatriloxymethyl ether, which has a melting point (mp) of 98°C and is suitable for heat-sensitive recording materials. It is most suitable as a color development accelerator added to the color development layer.

In addition, in the present invention, the leuco dye used as a coloring agent is a substance that is colorless or light-colored at room temperature and develops color by reacting with an acidic substance under heating.
triallylmethane dyes such as p-dimethylaminophenyl)-6-dimethylaminophthalide, and 4,4-bis-
Diphenylmethane dyes such as dimethylaminobenzhydridobenzyl ether, thiazine dyes such as benzoylleucomethylene blue, spiro dyes such as 3-methyl-spiro-dinaphthopyran, and other fluoran dyes.
Examples include leucoauramine dyes, indoline dyes, and indigo dyes.

The organic acidic substance used together with the leuco dye is a substance that becomes a color developer when it comes into contact with the leuco dye when heated, and includes various phenolic compounds and organic acids.

The organic acidic substance used for this purpose is preferably one that is solid at room temperature and liquefies or vaporizes at 50°C or higher. Specific examples of such substances include, for example, phthalic anhydride, gallic acid, salicylic acid, 4.4'-isopropylidene (2-t-butylphenol), 4.4''-5
ec-butylidenephenol, 4,4'-(1-methyl-n-hexylidene)diphenonope 4-phenylphenol, 4-hydroxydiphenoxide methyl-4-hydroxybenzoate, 4-hydroxyacetophenone salicylic acid anilide, 4,4' -cyclohexylidenephenol, 4,4'-cyclohexylidenebis(2-methylphenol), 4,4'-benzylidenephenol, 4,4''-thiobis(6-butyl-3-methylphenol), novolac type phenolic resin, halogenated novolak type phenolic resin, α-teftol, β-
Naphthol etc. can be mentioned.

The paraxylene glycol diaryl oxydimethyl ether of the present invention has a melting point lower than both the leuco dye and/or the organic acidic substance, has solubility in the leuco dye and/or the organic acidic substance, and has a solubility in the leuco dye and/or the organic acidic substance. It dissolves both and promotes the reaction between them, that is, it functions as a color development accelerator. The amount of paraxylene glycol diaryloxymethyl ether to be used as a color accelerator varies depending on the leuco dye, organic acid substance, or type of paraxylene glycol diaryloxymethyl ether used, but it is based on 1 part by weight of the leuco dye. Usually 0.5-3
0ffiffi parts, preferably 1 to 10 parts by weight.

Furthermore, various additives can be added to the heat-sensitive recording material of the present invention depending on its use.

Examples of such additives include polyvinyl alcohol (PVA), methylcellulose, carboxymethylcellulose, polyacrylic acid, which isolates and fixes the leuco dye and organic acidic substance dispersed in fine particles from each other.
binders such as casein, gelatin, starch, or their derivatives, the whiteness of the heat-sensitive coloring layer, the slipperiness of writing instruments,
White pigments such as calcium carbonate, kaolin, clay, talc, titanium oxide, and aliphatic metal salts are added to prevent sticking. These additives are mixed or applied separately to a support such as paper or film to form a heat-sensitive coloring layer.

[For production]

When the paraxylene glycol diaryloxymethyl ether of the present invention is used as a color development accelerator in the thermosensitive coloring layer of a heat-sensitive recording material, the paraxylene glycol diaryloxymethyl ether is used as a leuco dye and a leuco dye constituting the thermosensitive coloring layer. It has a lower melting point than both or either of the organic acidic substances, and also exhibits excellent solubility for both the leuco dye and/or the organic acidic substance, thereby making it possible to dissolve the leuco dye and the organic acidic substance. It is thought to promote reactions with substances.

〔Example〕

The present invention will be specifically described below based on Examples and Comparative Examples.

Example 1 Add 9.6 g of paraformaldehyde to 20 g of paraxylene glycol and add 50 TI of benzene! Dispersed within, 0~
While maintaining the temperature at 5°C, anhydrous hydrogen chloride gas was blown into the reactor for about 1 hour to cause a slow reaction. After the reaction is complete,
The reaction mixture was allowed to stand still to separate into two layers, and the upper layer was separated.

Next, 33.4g of para-cresol and 25g of sodium hydroxide
．． 5g and 57' of tetrahydrofuran (THF) and 1 part of water.
The above-mentioned upper layer was added dropwise to this solution, and after the completion of the dropwise addition, the reaction was allowed to proceed at room temperature for about 1 to 2 hours.

After the reaction, the reaction mixture was allowed to stand, the organic layer and the aqueous layer were separated, the solvent in the organic layer was distilled off under reduced pressure, the resulting residue was recrystallized with ethanol, and dipara Triloxymethyl ether 27.2g (melting point 98°C
) was obtained.

The results of NMR analysis performed on the obtained valaxylene glycol divalatryloxymethyl ether are shown below.

H-NMR (CDCh): δ (ppm) near, 30 (
4H, s), 7.09 (4H, d, J=8.54Hz
), 6.97<4H,d, J=8.54)1z), 5
．． 24 (4H, s), 4.70 (4H, S), 2.29
(6H,s) Also, infrared absorption spectrum analysis (KBr)
The results are shown in Figure 1.

Example 2 Using the paraxylene glycol divaratryloxymethyl ether synthesized in Example 1 above, a thermosensitive recording paper was prepared in the following manner, and its performance was measured.

[1] Preparation of Solution A 3-dibutylamino-6-methyl-7-anilinofluorane (ODB-2) 1 50 parts by weight of ONN Koribe calcium carbonate, 100 parts by weight of 5wtX-P'/A aqueous solution,
and 140 parts by weight of water were pulverized and mixed using a sand mill to prepare liquid A having two average particle diameters.

[Preparation of liquid 21B 10 parts by weight of bisphenol A, 10 parts by weight of paraxylene glycol divalatryloxymethyl ether, 5 w
5 parts of tX-P VA aqueous solution were pulverized and mixed using a sand mill to prepare liquid B having an average particle size of 31Jrn.

[31 Preparation of thermal recording paper A coating liquid was prepared by mixing 30 parts by weight of liquid A, 20 parts by weight of liquid B, and 5 parts by weight of paraffin wax emulsion (Chukyo Oil IW (FJ) %, Hydrin P-7), This coating liquid was applied onto the base paper and dried, and the coating amount after drying was 6g/
A heat-sensitive recording paper of 500 m was obtained.

The thermosensitive recording paper thus obtained was subjected to a dynamic color development test and a static color development test at 70°C. The results are shown in Table 1.

The dynamic color test uses a printing tester (made by Daikane Electric Co., Ltd.), and the static color test uses a stamp-type color tester (manufactured by Kiki).
Daiei Kagaku Seiki (manufactured by Kiki) is used to measure color density using a reflection densitometer (Konishi Roku Photo Industries (manufactured by Kiki): Sakura Digital Reflection Densitometer P
DA-45).

Comparative Example I A thermosensitive recording paper was prepared in the same manner as in Example 2 above, except that stearic acid amide was used in place of the paraxylene glycol divaratryloxymethyl ether in the preparation of Solution B. A color development test was conducted in the same manner as in Example 2. The results are shown in Table 1.

Comparative Example 2 A thermosensitive recording paper was prepared in exactly the same manner as in Example 2, except that parabenzyl biphenyl was used in place of the paraxylene glycol dibaratryloxymethyl ether in the preparation of Liquid B. A color development test was conducted in the same manner as in Example 2. The results are shown in Table 1.

No. 1 often

[Brief explanation of the drawing]

FIG. 1 is a graph showing an infrared absorption spectrum.

Claims (2)

[Claims] (1) The following general formula (1) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (1) (However, in the formula, Ar represents a phenyl group, a lower alkyl group, or a phenyl group having a lower alkoxy group) Paraxylene glycol diaryloxymethyl ether. (2) The following general formula (1) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (1) (However, in the formula, Ar represents a phenyl group, a lower alkyl group, or a phenyl group having a lower alkoxy group) A color accelerator for heat-sensitive recording materials consisting of paraxylene glycol diaryloxymethyl ether.