JPH02577A - Heat-sensitive recording material - 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] [Industrial application field] The present invention relates to a novel thermosensitive recording material.

[Prior Art] Various methods have been proposed for heat-sensitive recording, but the main one is a method using leuco dye, which is an electron-donating colorless dye, as a heat-sensitive dye. The principle of this thermosensitive recording is that during thermal melting, an electron-accepting developer removes electrons from the electron-donating leuco dye, turning the dye into a colored substance. This action is performed by the acidic group of the color developer, and generally a phenolic hydroxyl group is used as the acidic group. Therefore, the use of various phenolic compounds as color developers, that is, electron-accepting compounds in heat-sensitive recording materials is proposed in Japanese Patent Publication Nos. 40-9309 and 45.
-14039, Japanese Patent Publication No. 51-29830, and many others.

Typical thermal paper is manufactured by applying a dispersed mixture of a leuco dye and a phenolic developer as fine particles to paper and drying the mixture.

The applied material melts by heating, and the melted area develops color. For this reason, there is a drawback that the white background gradually discolors during manufacturing or when left under high temperature conditions for a long period of time.

JP-A No. 62-59080 describes a heat-sensitive recording material that utilizes a color-forming reaction between a leuco dye and its color developer.
A heat-sensitive recording material is disclosed which contains, in its heat-sensitive coloring layer, a compound having as part of its molecular structure a structure in which the hydrogen atom of phenolic OH is replaced with an allyl group or an acyl group. However, according to the results of studies conducted by the present inventors, it has been found that all of the exemplified compounds have the drawbacks of slow rearrangement speed and the need for high temperature and long time for color development.

[Problems to be Solved by the Invention] Therefore, the object of the present invention is to develop a color by heating at a relatively low temperature for a short time, but not to develop color under normal temperature conditions.
That is, the object is to provide a heat-sensitive recording material that has a good shelf life and can be coated as a solution type without requiring a dispersion type during coating.

[Means for Solving the Problems 1 The above object of the present invention is achieved by the following heat-sensitive recording material.

In a heat-sensitive recording material in which an electron-donating colorless dye that can develop a color by reacting with a phenolic hydroxyl group and an aromatic alkenyl ether compound that can generate a phenolic hydroxyl group through a Claisen rearrangement reaction coexist, the aromatic alkenyl ether compound has the formula ( 1) % formula % () [wherein R is a substituent that does not cause the electron-donating colorless dye to develop color or does not have a desensitizing effect on color development, Y is an alkenyl group, and n is a group of 2 or more is an integer. 1 A compound represented by formula (II) [wherein R1 and R2 and Y have the same meanings as R and Y in formula (I), m and n are O or an integer of 1 or more, and m+n≧1. ], or a compound represented by R6 [wherein Ar does not cause the electron-donating colorless dye to develop color, or
or a phenyl group or naphthyl group which may be substituted with a substituent that does not have a desensitizing effect on color development, and R3
, R4, R6, R6 and R7 are H or preferably C
3 to CIO alkyl group, R1, R4, R5, R
At least one of 6 and R7 is an alkyl group, and at least one of the 0-position and p-position with respect to the alkenyloxy group is a hydrogen atom. ] A heat-sensitive recording material characterized by being a compound represented by the following.

In the present invention, the Claisen rearrangement reaction that can produce a phenolic hydroxyl group is defined as "Ganic Reaction, Vol. 22, p. 1-252 (1905)""The C1
aisen and Cope Rearrangeme
For example, it means a reaction represented by the following formula, as described in detail in ``nts''.

Alternatively, in the heat-sensitive recording material of the present invention, the aromatic alkenyl ether undergoes a Claisen rearrangement reaction upon heating to become a compound having a phenolic hydroxyl group, which causes the electron-donating colorless dye to develop color.

In formulas (1), (II), and (III), the substituent that does not cause the electron-donating colorless dye to develop color is COOH.

Substituents other than OH, SO, 1 (1), such as alkyl groups, alkenyl groups, aryl groups, halogeno groups.

Such as an alkoxy group. Also, what are the substituents that do not have a desensitizing effect on the color development of electron-donating colorless dyes?

A substituent other than an amino group, a monoalkylamino group, a dialkylamino group, etc., such as an alkyl group, an alkenyl group, an allyl group, a halogeno group, an alkoxy group, etc.

Examples of the polyfunctional alkenyl ether compound of formula (1) are as follows.

o-, m-, p-diallyloxybenzene, 1,2-diallyloxy 4-ethylcarbethoxybenzene, 2,4-
Diallyloxyphenylbenzophene, 1,3-diallyloxy 4-chlorobenzene, 1,4-diallyloxy 2
-chlorobenzene, 1,2-diallyloxy-4-ritetralobenzene, 1,2-diallyloxy-3-methoxybenzene, 1,4-diallyloxy-2-methoxybenzene, 1
．． 2-diallyloxy 4-methylbenzene, 1,2-diallyloxy 4-t-butylbenzene, 1,3-diallyloxy 5-methylbenzene, 1,3-diallyloxy 2
-Methylbenzene, 1.2-diallyloxy3-methylbenzene, 1.2.3-triaryloxybenzene, 1.
2.4-Triaryloxybenzene, 1.3.5-trialyloxybenzene, 3.4.5-1-realyloxybenzophenone, 3.4° methyl 5-trialyloxybenzoate. In addition, among these compounds, instead of the allyl (2-propenyl) group of the allyloxy group, for example, meta-allyl (2-methyl-2-propenyl), crotyl (3-methyl-2-propenyl), l-methyl-2 -propenyl,
]-Ethyl-2-propenyl, 1,1-dimethyl-2-
propenyl, 1,3-dimethyl-2-propenyl, l-
Chloromethyl-2-propenyl, 2-chloro-2-furobenyl, cinnamyl (3-phenyl-2-propenyl)
Aromatic alkenyl ether compounds substituted with etc.

Examples of naphthyl alkenyl ether compounds of formula (If) are as follows.

l-allyloxinaphthalene, 2-allyloxinaphthalene, 1.4-diallyloxinaphthaline, 1.5-diallyloxinaphthaline, 1.6-diallyloxinaphthaline, 1
．． 7-diallyloxinaphthaline, 2.3-diallyloxinaphthaline, 2.7-diallyloxinaphthaline.

In addition, among these compounds, 1, for example, metaallyl (2-propenyl group) in place of the allyl group (2-propenyl group) of the allyloxy group,
-methyl-2-propenyl), crotyl (3-methyl-
2-propenyl), l-methyl-2-propenyl, l-
Ethyl-2-propenyl, 1,1-dimethyl-2-propenyl, 1,3-dimethyl-2-propenyl, l-chloromethyl-2-propenyl, 2-chloro-2-flobenyl, cinnamyl (3-phenyl-2-propenyl) -propenyl), etc.

Specific examples of the alkenyl ether compound of formula (Ill) are as follows.

■-Methyl-2-propenoxybenzene, 1.1-dimethylpropenoxybenzene, 1-methyl-2-butenoxybenzene, 1.1-dimethylpropenoxy-p-phenylbenzene, 1f1-methyl-2 -propenoxy)naphthalene, 2-(l-methyl-2-propenoxy)naphthalene, 1-(1,1-dimethyl-2-propenoxy)
Naphthalene, 2,3-di(1-methyl-2-probenoxy)naphthalene.

The compounds of formulas (r), (II) and (ITI) can also be used as a mixture of the compounds of each formula or with each other.

The above aromatic alkenyl ether compound is usually a metal salt (IV) of the corresponding phenolic compound as shown in the following formula.
and the corresponding alkenyl compound (V).

Ar0M + XY-4ArOY (+v) (v) (III) (wherein, Ar is an aryl group, M is Na, K, Li, M
g is an alkali or earth metal, and X is a halogen, an alkylsulfonic acid group, a p-toluenesulfonic acid group, a benzenesulfonic acid group, etc. ) Electron-donating colorless dyes used in the present invention include triphenylmethane phthalide compounds, fluoran compounds, phenothiazine compounds, indolyl phthalide compounds, leuco auramine compounds, triphenylmethane compounds, and triazenes. There are various compounds such as type compounds and spiropyran type compounds, and if we disclose examples of these,
As a trianormethane compound, 3,3-bis(p-
dimethylaminophenyl)-4-dimethylaminotuclide (crystal violet lactone), 3.3-
Bis(p-dimethylaminophenyl)phthalide, 3-
(p-dimethylaminophenyl) to 3-fl, 3-dimethylindol-3-yl)phthalide, 3-(p-dimethylaminophenyl)-3-f2-methylindol-3-yl)phthalide, and the like.

Examples of diphenylmethane compounds include 4,4-bis-dimethylaminobenzhydrin benzyl ether, N-herophenyl leuco auramine, and N-2,4°5-trichlorophenyl leuco auramine.

Examples of xanthine compounds include rhodamine-8-anilinolactam, rhodamine (p-nitroanilino)lactam, rhodamine B (p-chloroanilino)lactam, and 2-
Dibenzylamino-6-diethylaminofluorane, 2
-anilino-6-diethylaminofluorane, 2-anilino-3-methyl-6-diethylaminofluorane, 2
-anilino-3-methyl-6-N-cyclohexyl-N
-methylaminofluorane, 2-anilino-3-methyl-6-N-ethyl-N-isoamylaminofluorane,
2-0-chloroanilino-6-diethylaminofluorane, 2-(3,4-dichloroanilino)-6-diethylaminofluorane, 2-year-old cutylamino-6-diethylaminofluorane, 2-anilino-3-methyl-6 -siphenylaminofluorane, 2-anilino-3-methyl-5-chloro-6-diethylaminofluorane, 2-anilino-3-methyl-6-dinithylamino-7-methylfluorane, 2-butylamino-3-chloro -6-diethylaminofluorane, 2-ethoxyethylamino-3
-Chloro-6-diethylaminofluorane, 2-anilino-3-chloro-6-diethylaminofluorane, 2-
Anilino-3-methyl-6-cyoctylaminofluorane, 2-dimethylaminocarbonylethylamino-6-
Diethylaminofluorane, 2-0-chloroanilino-
6-Sibutylaminofluorane, 2-anilino-3-pentadecyl-6-diethylaminofluorane, 2-anilino-3-ethyl-6-sibutylaminofluorane, 2
-anilino-3-ethyl-6-N-ethyl-N-isoamylaminofluorane, 2-anilino-3-methyl-6-N-ethyl-N-γ-methoxypropylaminofluorane, 2-p-chloroanilino- 3-phenyl-6-
Examples include diethylaminofluoran, 2-phenyl-6-diethylaminofluoran, and the like.

Thiazine compounds include benzoylleucomethylene blue and p-nitrobenzylleucomethylene blue, and spiro compounds include 3-methyl-spiro-dinaphthopyran, 3-ethyl-spiro-dinaphthopyran,
3-benzyl-spiro-dinaphthopyran, 3-methyl-
naphtho-(3-methoxy-benzo)-spiropyran, 3
-propyl-spiro-benzylbilane and the like. These may be used alone or in combination.

The weight ratio of the electron-donating colorless dye used to the aromatic alkenyl ether compound is preferably between 1:50 and 1.l, particularly preferably between 1:10 and 2.3.

The heat-sensitive recording material according to the present invention contains an electron-donating colorless dye, a binder in addition to the aromatic alkenyl ether compound according to the present invention, and, if necessary, a thermofusible substance, in addition to kaolin, calcined kaolin, talc, diatomaceous, synthetic It is prepared by adding oil-absorbing pigments such as calcium carbonate, aluminum hydroxide, acid clay, barium sulfate, urea-formalin filler, and cellulose filler. A paraffin wax emulsion, a latex binder, a sensitivity improver, a metal soap, an antioxidant, an ultraviolet absorber, an inorganic pigment, etc. can be added to this as necessary.

Examples of the binder include styrene-butadiene copolymer, modified acrylamide copolymer, carboxy-modified polyvinyl alcohol, acrylic latex, vinyl acetate copolymer, styrene-maleic anhydride copolymer, hydroxyethyl cellulose, alkyd resin,
Examples include polyvinyl butyral. As the thermofusible substance, if necessary, erucic acid amide, stearic acid amide, behenic acid amide, stearic acid anilide, N-milstoyl-p-anisidine, l-methoxycarbonyl-4-N-stearylcarbamoylbenzene,
N-octadecyurea, N,N-didodecylurea,
Phenylcarbamoyloxydodecane, pt-butylphenolphenoxyacetate, 4,4-isopropylidene bismethoxybenzene, 2-p-chloropenzyloxynafculene, l-penzyloxynafculene, 1
．． 4-Diphenoxybutane.

2-phenoxyacetyloxynaphthalene, phthalic acid diphenyl ester, 2-benzoyloxynaphthalene,
Hydroquinone diacetate, p-methoxycarbonylbenzoic acid butyramide, etc. are used.

Waxes include paraffin wax, polyethylene wax, and higher fatty acid amides such as stearic acid amide, ethylene bisstearamide, and higher fatty acid esters. Six metal soaps include higher fatty acid polyvalent metal salts such as stearic acid. Examples include zinc, aluminum stearate, calcium stearate, zinc oleate, and the like.

The composition of the heat-sensitive recording material according to the present invention is 1 to 2 parts by weight of an electron-donating colorless dye and 1-1 parts by weight of an aromatic alkenyl ether compound.
0 parts by weight, thermofusible substance 0-30 parts by weight, pigment 1-15
parts by weight, 1-15 parts by weight of binder and antioxidant,
It generally consists of small amounts of fluorescent brighteners, dispersants, etc.

[Examples] The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

Example 1 Catechol 22. Dissolve Og (0.2 mol) in 80.0 g of dimethyl sulfoxide (DMSO), add 26.9 g (0.48 mol) of caustic potash, stir, and dissolve the acrylic while maintaining the temperature at 50-60°C. 37.6 g (0.48 mol) of chloride was added dropwise over 1 hour, and stirring was continued for an additional 2 hours after the addition. Water 300II1
12 was added and extracted with 200ml of toluene. After separating the toluene layer, add 5% aqueous potash solution (100+nl2
) and then washed twice with water. After toluene was distilled off using an evaporator, the residue was further dried under high vacuum to obtain 34.3 g (yield: 90.3%) of diaryloxybenzene.

3.3-bis(p-dimethylaminophenyl)-4-dimethylaminophthalide (hereinafter abbreviated as CVL) 0.5
g and diaryloxybenzene (1.0 g) were mixed to obtain a coloring material. Put some of this into a test tube.

When it was immersed in a constant temperature bath at 200°C for 5 minutes, it developed a deep blue color. On the other hand, even after being left at room temperature for one month, no color developed and no change was observed.

On the other hand, when diaryloxybenzene was heated at 200'C for 5 minutes and analyzed by TCL, the peak of the raw material had disappeared. The product was separated by liquid chromatography (column: silica gel - Wakogel G-100, eluent: toluene) to obtain two types of compounds. IR.

As a result of confirming these structures by NMR, 3.6-diallyl-1,2-dihydroxybenzene (IV), 3.
It was confirmed to be 4-cyano-1,2-dihydroxybenzene (V). These are all Cs of diaryloxybenzene.
H□CH=CH2 It is produced by Claisen rearrangement reaction.

Both (IV) and (V) developed a strong color when mixed with crystal violet lactone (CVL).

From the above results, it was determined that diaryloxybenzene is useful as a latent color developer.

Example 2 31.3 g (0.33 mol) of phenol was added to DMSO6
Dissolve in 7.8g and add 16g (0.4g) of caustic soda to this.
mol) was added to synthesize the phenol salt. 3-chloro-1-butene (36.2 g) was added dropwise to this over 3 hours while keeping the temperature below 50°C, and then stirred for 2 hours. Water was added and extracted with toluene, and after washing with water, the toluene was distilled off using an evaporator. Dry under high vacuum, 1-methyl-
2-propenoxybenzene 43.2g (88.6%)
I got it.

A coloring material was obtained by mixing 0.5 g of LV and 1.0 g of 1-methyl-2-propenoxybenzene. When a portion of this was placed in a test tube and placed in a constant temperature bath at 200℃ for 5 minutes,
A dark blue colored body was obtained. The material left at room temperature did not develop any color.

Example 3 Pyrogallol, caustic soda and allyl chloride were reacted in DMSO in the same manner as in Example 1.2, and 1,
2.3-Triaryloxybenzene (yield 82%) was obtained.

In the same way, a coloring material with CVL was prepared and heated at 200℃5.
A deep blue color product was obtained in minutes. The material left at room temperature did not develop any color.

Example 4 Catechol 11. Og (0,1 mol) D&4S04
Dissolve in 7.8g and add 9.5g of caustic soda (0
, 24 moles) generates heat and forms a salt. 36.6 g (0.24 mol) of cinnamyl chloride was added dropwise to this salt solution while keeping the temperature at 50-55°C.
The mixture was stirred at 50°C for 6 hours. 200 al of water was added and extracted with toluene, washed twice with water, and the toluene was distilled off using an evaporator to obtain crystals. Recrystallize three times with chloroform-〇-hexane to obtain 1,2-dicinnamyloxybenzene 19
．． 0 g (yield 55.3%) was obtained. Structure is IR, NMR
Confirmed by.

VL 0.5g1. : 2.0 g of 1,2-dicinnamyloxyhenzene was mixed to obtain a coloring material. When a portion of this was placed in a test tube and placed in a constant temperature bath at 200°C for 5 minutes, a deep blue coloring material was obtained. The material left at room temperature did not develop any color.

Example 5 Phloroglycitur dihydrate #40.5g (0,25
mol) in 109.4 g of DMSO and 36 g (0.9 mol) of caustic soda are added thereto to form a salt. 68.9 g (0.9 mol) of allyl chloride was added dropwise to this solution over 3 hours while maintaining the temperature at 50-55°C.
After the dropwise addition, the mixture was stirred at 50°C for 5 hours. 500 trDL of water was added, extracted with benzene-ether (1:1), washed with water, and the batter layer was dried over anhydrous sodium sulfate. The solvent was distilled off using an evaporator, and the residue was dried under reduced pressure to obtain 3Ig of 1,3.5-triaryloxybenzene (yield: 55.3%). The structure was confirmed by IR and NMH.

GVL O, 5g di-1,3.5-triaryloxybenze: / 1. Og was mixed to obtain a coloring material. When a portion of this was placed in a test tube and placed in a constant temperature bath at 200°C for 5 minutes, a deep blue coloring material was obtained. The material left at room temperature did not develop any color.

Examples 6 to 15 Color development tests were conducted on the compounds shown in Table 1 in the same manner as in Example 1. The results are shown in Table 1.

Table 1 Note 1: A represents an allyl group.

Note 2: lj! The sample was left at room temperature for a period of time until it developed an i color, and no color development was observed at all.

Example 16 48 g (0,:I:] mol) of 2-naphthol was added to DNS
o Dissolve in 94g and add 16g of caustic soda (0
, 4 mol) was added and stirred, and 30.6 g (0.4 mol) of allyl chloride was added dropwise over 1.5 hours while maintaining the temperature at 50 to 60°C, and after the dropwise addition, the mixture was stirred at 50°C for 5 hours. Add 300ml of water, extract with toluene, and wash with water 2.
After that, it was distilled off using an evaporator, and the residue was dried under reduced pressure.
58 g (yield 94.5%) of 2-aryloxinaphthalin was obtained. The structure was confirmed by rR, NMH. Example 1
A color-forming material was obtained in the same manner as above, and a color-forming test was conducted at 200°C, and it turned dark blue in 3 minutes. The material left at room temperature did not develop any color.

Examples 17 to 19 Alkenyl ether compounds of the naphthalene compounds shown in Table 2 were synthesized in the same manner as in Example 16, and a color development test was conducted. Table 2 shows the results.

Notes 1 and 2: The materials shown in Table 1 left at the same room temperature did not develop color at all, and the color development speed was extremely fast, with the compounds of Examples I8 and I9 exhibiting 15
Color develops easily and quickly even at 0°C.

Example 20 25 g (0.15 mol) of 2.3-dihydroxynaphthalene was dissolved in 50 g of DMSo, 13.8 g (0.345 mol) of caustic soda was added thereto, and 5 mj of water was added.
When 2 is added and stirred, the temperature rises. The mixture was added dropwise while maintaining the temperature at 50 to 70°C, and after the dropwise addition, the mixture was stirred at 50 to 60°C for 1 hour.

Diluted with water, extracted with toluene, washed with caustic soda water,
After washing twice with water, toluene was distilled off. Dissolve the residue in toluene and add 100 g of silica gel (Wakogel 300).
) to remove color, and the solvent was distilled off. 33.4 g (yield: 81.0%) of crude 2,3-diallyloxinaphthalene was obtained. A pure product was obtained by recrystallization from ethanol-acetone (9:1). The structure was confirmed by IR and NMR.

A coloring material was obtained in the same manner as in Example 1, and a coloring test was conducted. As a result, the coloring time was 1 minute at 200°C and 5 minutes at 150°C.

The material left at room temperature did not develop any color. The color development rate was extremely fast even at 150°C.

Examples 21 to 26 Bifunctional alkenyl ether compounds of naphthalene were synthesized in the same manner as in Example 21, and a color development test was conducted at 200°C. The results are shown in Table 3.

Table 3 Notes 1 and 2: Same as Table 1 Example 27 10.0 g (0,059 mol) of p-phenylphenol, 5.0 g of potassium carbonate, and 1.2 g of potassium iodide were added to 100 ml of 2% aqueous acetone. 3-Methyl-3-chloro-1-butene lO,og (0,098 mol) was added to the mixture, and the mixture was heated to reflux. After 8 hours, 5.0 g of potassium carbonate, 3
-Methyl-3-chloro-1-butene lo, add Og 2
The mixture was heated under reflux for 4 hours. Acetone was distilled off, and the mixture was extracted with ethyl acetate.

After evaporation of the solvent, chromatography was carried out using silica gel, and ρ-
3.6 g (yield 25.9%) of α,α-dimethylpropargyl ether of phenylphenol was obtained. The structure is IR
, confirmed by NMR.

Add 2.6g (0,011 mol) of propargyl ether to methanol 20011IJ! Pd-B
100 mg of a504 (manufactured by AIdrich) was added and hydrogenated at room temperature and pressure. The reaction was terminated when 1 molar equivalent of hydrogen was absorbed, and the catalyst was removed by filtration, then methanol was distilled off, extracted with rhohexane, and washed with water. n-
Hexane was distilled off using an evaporator, and the residue was chromatographed on silica gel. α, α-dimethyl p-
Phenyl phenyl ether 1.97g (yield 75.2
%) was obtained. A coloring material was obtained in the same manner as in Example 1, and a coloring test was performed.
A dark blue color product was obtained in ~4 minutes.

The material left at room temperature did not develop any color. The color development speed was fast even at 150°C.

Example 28 1.1-Dimethyl-2-propenoxybenzene is Che
m, Ind, (London) 1969.178
Synthesized according to 0.

A color-forming material was obtained in the same manner as in Example 2, and a color-forming test was conducted. A dark blue color-forming material was obtained at 200° C. for 15 seconds.

Comparative Example 1 4.4°-Diallyloxydiphenylsulfone (1 platinum loop) and 3.3-bis(p-dimethylaminophenyl)-
4-dimethylaminophthalide (1 platinum loop) was mixed to obtain a coloring material. This was placed in a test tube and placed in a constant temperature bath at 200°C, and it took 1 hour for it to develop a deep blue color. Analysis by TLC showed that the time required for the raw materials to disappear was 4 hours.

Comparative Example 2 25g of 1-hydroxy-3-methoxybenzene was added to DMS
After dissolving in O and adding caustic potash to make a salt, acrylic chloride was added dropwise to react, yielding 24.3 g of 1-allyloxy-3-methoxybenzene (yield 73.0%).
) was obtained. CVL O, 5g and 1-7 Riloxy 3-
A color-forming material was obtained from 1.0 g of methoxypentene and treated in the same manner at 200°C for 1 hour to obtain a dark blue color-forming body.

Comparative Example 3 26.3 g of 1-allyloxy-2-cyclohexylbenzene (yield: 83.0%) was obtained in the same manner as in Comparative Example 2 from 25 g of 0-cyclohexylphenol.

When a color development test was conducted in the same manner as in Comparative Example 2, 20
A deep blue colored body was obtained at 0°C for 3 hours.

Comparative Example 4 Commercially available allyl phenyl ether 1.0g and GVL O,5
Tororo, which obtained the coloring material from g and conducted the coloring test in the same way,
A dark blue colored body was obtained at 200° C. for 6.0 hours.

Comparative Example 5 From 25 g of p-methoxyphenol, 25.4 g of 1-allyloxy-4-methoxybenzene (
A yield of 76.3% was obtained.

When a color development test was conducted in the same manner as in Comparative Example 2, 20
A deep blue colored body was obtained at 0° C. for 1.0 hour.

Comparative Example 6 0-phenylphenol (25g
) to 1-allyloxy-2-phenylbenzene 26.9
g (yield 88.2%) was obtained.

When a color development test was conducted in the same manner as in Comparative Example 2, 20
A deep blue colored product was obtained at 0° C. for 1 hour.

〔Effect of the invention〕

Since the aromatic alkenyl ether compound according to the present invention is not an electron-accepting compound, it does not react with an electron-donating colorless dye at all and does not develop color. Therefore, heat-sensitive recording materials using this compound are extremely stable, and even when left in a solvent solution at room temperature, they do not become colored at all, making them suitable for long-term storage and ease of application. Particularly advantageous.

Claims (1)

[Scope of Claims] 1. A heat-sensitive recording material in which an electron-donating colorless dye that can develop a color by reacting with a phenolic hydroxyl group and an aromatic alkenyl ether compound that can generate a phenolic hydroxyl group through a Claisen rearrangement reaction coexist, An aromatic alkenyl ether compound has the formula (I) ▲Mathematical formulas, chemical formulas, tables, etc.▼(I) [In the formula, R does not cause the electron-donating colorless dye to develop color or does not have a desensitizing effect on color development. is a substituent, and Y
is an alkenyl group, and n is an integer of 2 or more. ] A compound represented by the formula (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) [In the formula, R_1 and R_2 and Y are R of formula (I)
and Y, m and n are integers of 0 or 1 or more, and m+n≧1. ] or formula (III) ▲Mathematical formulas, chemical formulas, tables, etc.▼(III)
or a phenyl group or naphthyl group that may be substituted with a substituent that does not have a desensitizing effect on color development, and R_3
, R_4, R_5, R_6 and R_7 are H or preferably an alkyl group of C_1 to C_1_0, R_3
, R_4, R_5, R_6 and R_7 is an alkyl group, and at least one of the o-position and p-position with respect to the alkenyloxy group is a hydrogen atom. ] A heat-sensitive recording material characterized by being a compound represented by the following.