JPH0625148A - Production of new diphenylsulfone compound - Google Patents

Abstract

PURPOSE:To provide the subject new compound useful as a developer for heat- sensitive recording paper. CONSTITUTION:A compound of formula I (R is 3C alkyl), i.e., 4-propoxy-4'- hydroxydiphenylsulfone or 4-isopropoxy-4'-hydroxydiphenylsulfone. The compound of the formula I can be obtained by alkylating 4,4'-bisphenolsulfone with a 3C alkylating agent. Heat-sensitive recording paper containing this compound can further be incorporated with a compound of formula II (R' is 1-5C alkyl, benzyl or phenethyl), e.g. 4,4'-dimethoxidophenylsulfone, for the purpose of improving color-developing sensitivity, weatherability and preservability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a novel diphenyl sulfone compound for thermal recording paper. More specifically, it relates to a method for producing a diphenyl sulfone compound which is useful as a developer for heat-sensitive recording paper.

[0002]

BACKGROUND OF THE INVENTION It has long been known that a colorless or light-colored coloring substance such as crystal violet lactone reacts with a phenol compound to form a color, and a heat-sensitive paper of this reaction is used. Application to is known, for example, in US Pat. No. 3,539,375.

However, there are many drawbacks to be dealt with, such as the recent progress of recording apparatuses, the diversification of uses, high-speed reactivity, and high sensitivity. For example, in a thermal printer, thermal facsimile, etc., when the color-developing sensitivity of the thermal recording paper is insufficient, the power consumption increases,
Since the printing speed decreases, it is necessary to increase the color development sensitivity.

As a method for improving the color-developing sensitivity of such a thermal recording paper, an example of using waxes in combination with a color-forming substance is disclosed in JP-A-48-19231.
JP-A-49-34842 and examples of using a sensitivity improver such as a nitrogen-containing compound.

In a thermal recording paper, a color-forming substance and a phenol compound are dispersed in the form of fine particles or separately and stably exist in different layers during thermal coating. One component of both is melted or sublimated by heating. Alternatively, it is considered that both components melt or sublimate and come into intimate contact with each other, and are mixed to generate a thermal color. Therefore, it is necessary that each component of the reaction color developing agent is a colorless or light-colored crystal or solid at room temperature, and the one having a melting point of 70 ° C. or higher and completely liquefying and / or vaporizing at 150 to 200 ° C. is preferable. .

In US Pat. No. 3,539,375, 4,4'-isopropylidenediphenol is described as an example of a suitable phenol compound used for such a purpose, and the compound is widely used today. Is.

[0007]

The present inventors have completed the present invention as a result of earnest research on a thermosensitive recording paper having improved color development sensitivity, weather resistance and storability. That is, the present invention has the general formula

[0008]

[Chemical 2]

The present invention relates to a process for producing a novel diphenyl sulfone compound represented by the formula (wherein R represents alkyl having 3 carbon atoms).

The compound of the general formula (I) is produced by alkylating 4,4'-bisphenol sulfone with an alkylating agent having 3 carbon atoms.

The novel diphenyl sulfone compounds represented by the general formula (I) are 4-propoxy-4'-hydroxydiphenyl sulfone and 4-isopropoxy-4'-.
It is hydroxydiphenyl sulfone.

[0012]

The novel diphenyl sulfone compound of the general formula (I) obtained by the present invention is used as a color developer for heat-sensitive recording paper.
It is used in combination with a color forming substance as described above.

The color-forming substance may be any substance as long as it can react with a phenol compound to form a color, for example, crystal violet lactone, malachite green lactone, 3,3-bis (paradimethylaminophenyl). ) -4,5,6,7-Tetrachlorophthalide, benzo-β-naphthospiropyran, 3-methyl-di-β-naphthospiropyran, 1,3,3-trimethyl-6′-chloro-8′-methoxy Indolinobenzospiropyran, N-phenylrhodamine lactam, 3-ethylamino-6-chlorofluorane, 3-morpholino-
5,6-benzofluorane, 3-dimethylamino-6-
Methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3-diethylamino-6,7-dimethylfluorane, 3-diethylamino-7,8-benzofluorane, 3-diethylamino −
6-methoxyfluorane, 3-diethylamino-7-dibenzylaminofluorane, 3-diethylamino-7-
Anilinofluorane, 3-diethylamino-5,6-benzo-7-benzylaminofluorane, 3-piperidino-6-methyl-7-anilinofluorane, 3-pyrrolidino-6-methyl-7-anilinoflu Oran, 3-N-ethyl tolylamino-6-methyl-7-anilinofluorane, and 3-diethylamino-7- (N-3-trifluoromethylphenyl) aminofluorane can be mentioned.
It is not limited to this.

The novel diphenyl sulfone compound of the present invention is generally another phenol compound having a property of liquefying or vaporizing at 70 ° C. or higher and reacting with the color forming substance to form a color, for example, 4-phenylphenol, 4-phenylphenol. Methyl-2,6-di-tert-butylphenol, 4,4'-dihydroxydiphenol, 4,4'-isopropylidene diphenol, 4,4'-isopropylidenebis (2-
Chlorphenol), 4,4'-isopropylidene bis (2-methylphenol), 4,4'-isopropylidene bis (2-tert-butylphenol), 4,4'-isopropylidene bis (2,6-dimethyl) Phenol),
4,4'-Secondary-butylidene diphenol, 4,4'-
Dichlorohexylidene diphenol, 4,4'-cyclohexylidene bis (2-methylphenol), 4,4'-
Cyclohexylidene bis (2-isopropylphenol), 2,2'-methylenebis (4-chlorophenol), 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 2,2'-bis ( 4-hydroxyphenyl) hexane, 2,2'-bis (4-hydroxysphenyl) heptane, 2,2'-bis (4-hydroxyphenyl) octane, 4,4'-thiodiphenol, 4,4'- Thiobis (3-methyl-6-tert-butylphenol), methyl p-hydroxybenzoate, p-
Ethyl hydroxybenzoate, benzyl p-hydroxybenzoate, trimethyl p-hydroxybenzoate, phenethyl p-hydroxybenzoate, p-hydroxybenzoic acid 3
-Phenylpropyl, phenyl p-hydroxybenzoate, 4-hydroxyacetophenone, 4-hydroxybenzophenone, anilide salicylate, novolac type phenol resin, halogenated novolac type phenol resin,
α-naphthol, β-naphthol, 2,2′-bis (4
It can also be used in combination with -hydroxyphenyl) -n-heptane.

The heat-sensitive recording paper of the present invention further comprises
General formula for improving color development sensitivity, weather resistance and storage stability

[0016]

[Chemical 3]

(In the formula, R'is alkyl having 1 to 5 carbon atoms,
Indicates benzyl or phenethyl. ) Can be included.

As the compound of the general formula (II), 4,4'-
Dimethoxydiphenyl sulfone, 4,4'-diethoxydiphenyl sulfone, 4,4'-dipropoxydiphenyl sulfone, 4,4'-dibutoxydiphenyl sulfone, 4,4'-diisobutoxydiphenyl sulfone,
4,4'-di-tert-butoxydiphenyl sulfone, 4,
4'-diamyloxydiphenyl sulfone, 4,4'-
Examples thereof include diisoamyloxydiphenyl sulfone, 4,4′-ditertiary amyloxydiphenyl sulfone, 4,4′-dibenzyloxydiphenyl sulfone and 4,4′-diphenethyloxydiphenyl sulfone.

The thermal recording paper itself is manufactured by a known method. For example, the color-forming substance and the novel diphenylsulfone compound (I) are separately separated in water or in an organic solvent, if necessary, together with a surfactant, a binder and a dispersant,
It is crushed with a crusher such as a ball mill or a sand grinder, and both dispersions are applied to a support and dried.

[0020]

【Example】

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Example 1 4 g of 4,4′-bisphenol sulfone, 40 ml of dimethyl sulfoxide, 1 g of sodium hydroxide and 2.7 g of propyl bromide were stirred at room temperature for 5 hours. Then, the reaction solution is acidified with hydrochloric acid and then extracted with ethyl acetate. After washing the extract with hydrochloric acid, an aqueous sodium hydroxide solution is added to bring the pH of the aqueous layer to 10, and unreacted raw materials are removed. The organic layer is washed with hydrochloric acid and concentrated. Crystallization of the residue with toluene gives 4-propoxy-4′-hydroxydiphenyl sulfone with a melting point of 138-140.5 ° C. Further, when recrystallized with toluene, the melting point is 152.5 to 1
This shows 54.0 ° C.

Similarly, 4-isopropoxy-4'-
Hydroxydiphenyl sulfone is obtained.

[0024]

【The invention's effect】

The following experimental examples and comparative examples (“parts” are
The effect of the present invention will be specifically described with reference to "parts by weight".

Comparative Example 1 Dispersion A: Crystal Violet Lactone 1 part 5% Polyvinyl alcohol 5 parts Water 40 parts Dispersion B: 4,4'-isopropylidenediphenol 5 parts 5% Polyvinyl alcohol 25 parts Water 20 parts

Comparative Example 2 Dispersion A: Same as Dispersion A of Comparative Example 1 46 parts Dispersion B: 4,4'-butylidene bis (6-tert-butyl-m-cresol) 5 parts 5% Polyvinyl Alcohol 25 parts Water 20 parts

Experimental Example 1 Dispersion A: Same as Dispersion A of Comparative Example 1 46 parts Dispersion B: 4-propoxy-4'-hydroxyphenylsulfone 5 parts 5% polyvinyl alcohol 25 parts Water 20 parts

Experimental Example 2 Dispersion A: Same as Dispersion A of Comparative Example 1 46 parts Dispersion B: 4-propoxy-4'-hydroxydiphenylsulfone 4.75 parts 4,4'-Diamyloxydiphenylsulfone 0 2 parts 5% polyvinyl alcohol 25 parts water 20 parts

In each of the above Comparative Examples and Examples,
Dispersion A and Dispersion B were separately prepared by pulverizing and dispersing the solid components in a ball mill for 2 days, that is, Dispersions A and B were not mixed, and then Dispersions A and B were mixed, Use as a coating liquid for thermal recording paper. The coating solution was applied on the surface of a high-quality paper having a basis weight of 50 g / m ^{2 so} that the dry application amount was 4 g / m ^2, and the temperature was 50 ° C. in a dryer.
To dry. The heat-sensitive recording paper thus obtained is used for 80 to 15
A hot plate heated to 0 ° C. is pressed at a pressure of 1.5 kg / cm ² (gauge) for 5 seconds.

The recording sensitivities and the storage states of the recorded images of the thermal recording papers of Experimental Example 1 and Comparative Examples 1 and 2 are as shown in Table 1, and the color densities of the thermal recording papers of Experimental Example 2 and Comparative Example 1 are shown in Table 1. The result measured by the photoelectric densitometer is as shown in FIG.

[0032]

[Table 1] Table 1 ────────────────────────────── Recording sensitivity Decolored state of recorded image ^* ──── ────────────────────────── Experimental Example 1 ++ ++ Comparative Example 1 ++ Comparative Example 2 ＋ − ───────── ───────────────────── * Judged after 24 hours at room temperature Recording sensitivity: ++: Very good +: Normal −: Bad Decolored state of recorded image: ++ : Do not erase +: Normal −: Almost erase

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between temperature and color density measured with an optical densitometer.

Claims (1)

[Claims] 1. A general formula characterized in that 4,4′-bisphenol sulfone is alkylated with an alkylating agent having 3 carbon atoms. (In the formula, R represents alkyl having 3 carbon atoms.) A method for producing a novel diphenyl sulfone compound.