JPH0796528B2 - Novel vinyl ether compound and heat-sensitive recording material using the compound - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel vinyl ether compound and a heat-sensitive recording material using the compound as a sensitivity improver.

[Prior art]

A general heat-sensitive recording material is a colorless or light-coloring coloring dye such as leuco dye as a coloring agent on a support such as paper or film, and a phenolic compound (especially bisphenol A) as a color developing agent for coloring the same when heated. A thermosensitive coloring layer in which a binder, a filler, a sensitivity improver, a lubricant, and other auxiliaries are dispersed in a coloring system made of an acidic substance such as an organic acid.For example, JP-B-43-4160, Kosho 45-14039,
It was introduced in Japanese Patent Laid-Open No. 48-27736 and is widely put to practical use. This type of heat-sensitive recording sheet obtains a color-developed image by an instantaneous chemical reaction between a color-developing agent and a color-developing agent during heating (a thermal printer or a facsimile having a thermal head is used for heating). Therefore, compared to other recording materials, it is possible to obtain recording in a short time with a relatively simple device without performing complicated processing such as development and fixing, low noise and environmental pollution, and low cost. Because of its advantages, it is useful not only for copying books and documents, but also as a recording material for various information such as electronic calculators, facsimile machines, telex machines, medical measuring machines, and measuring instruments.

On the other hand, in recent years, along with the development of society, there has been an increasing demand for high speed recording and high density recording. For this reason, it is strongly desired to develop a recording material capable of coping with the speedup of the recording apparatus itself. The first method is to lower the melting point of the electron-accepting compound as a color developer to a practically acceptable level such as storage stability (for example, 80 to 120 ° C.), and set the melting start temperature with the leuco dye. It is to lower the speed and increase the speed. However, it is difficult to control the melting point of a phenolic compound, which is a color developing agent that is widely used in the field of thermal recording materials, and the phenolic compound itself is expensive and is not practical. The second method is, for example, JP-A-53-39139 and JP-A-53-26139.
JP-A-53-5636, JP-A-53-11036, and JP-A-58
As described in JP-A-57989, JP-A-58-87088, JP-A-59-155096, etc., various waxes, fatty acid amides, alkylated biphenyls, substituted biphenylalkanes, coumarins are used in the thermosensitive color developing layer. , Diphenylamines, biphenyl alkyl ethers, naphthalene alkyl ethers, and other low-melting-point heat-melting substances can be added as sensitizers (or melting point depressants). However, it is hard to say that the heat-sensitive recording materials produced by these methods are still sufficient in terms of color density, color sensitivity, background whiteness, image stability and the like.

〔Purpose〕

The object of the present invention is to provide a novel vinyl ether compound useful as a sensitivity improver for a heat-sensitive recording material and a compound using the compound as a sensitivity improver, which has a sufficient color density and color sensitivity, is suitable for high-speed recording, and has a background whiteness. The object is to provide a heat-sensitive recording material having high thermal stability and high image stability, which is extremely practical.

〔Constitution〕

According to the present invention, as a first invention, the formula A p- (2-vinyloxyethoxy) benzoic acid benzyl ester represented by the following is provided, and as a second invention, a sensitivity improver in a heat-sensitive recording material utilizing a color-forming reaction between a leuco dye and a developer thereof. A p- (2-vinyloxyethoxy) benzoic acid benzyl ester represented by the above formula is used as a heat-sensitive recording material.

The p- (2-vinyloxyethoxy) benzoic acid benzyl ester of the present invention is a novel substance, which is a white solid having a melting point of 82 to 85 ° C., and utilizes the coloring reaction between the leuco dye and the color developer. It is useful as a sensitivity improver for heat-sensitive recording materials. The compound is synthesized, for example, from p-hydroxybenzoic acid benzyl ester by the reaction shown below.

The heat-sensitive recording material obtained by using the p- (2-vinyloxyethoxy) benzoic acid benzyl ester of the present invention is excellent in color density and color sensitivity as compared with the conventional heat-sensitive recording materials, and thus is suitable for high-speed recording. At the same time, the background whiteness is high and the image stability is also excellent. Therefore, various waxes, fatty acid amides, alkylated biphenyls, substituted biphenyl alkanes, coumarins, diphenylamines, biphenyl alkyl ethers, naphthalene alkyl ethers, and other low-melting substances conventionally known as sensitizers (or melting point depressants) are used. Although it cannot be said that the heat-sensitive recording material used is sufficient in terms of color density, color sensitivity, background whiteness, etc., the compound of the present invention does not have such drawbacks and is very excellent. It can be said that it is a sensitivity improver.

When a heat-sensitive recording material is produced using the compound of the present invention as a sensitivity improver, the compound of the present invention may be used in combination with a color-forming system comprising a leuco dye and a color developer.

The leuco dyes used in the present invention may be used alone or as a mixture of two or more kinds. As such leuco dyes, those applied to this type of heat-sensitive material are arbitrarily applied, for example, triphenyl Leuco compounds of dyes such as methane-based, fluoran-based, phenothiazine-based, auramine-based, spiropyran-based and indolinophtalide-based dyes are preferably used. Specific examples of such leuco dyes include those shown below.

3,3-bis (p-dimethylaminophenyl) -phthalide, 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (also known as crystal violet red lactone), 3,3-bis (p- Dimethylaminophenyl) -6-diethylaminophthalide, 3,3-bis (p-dimethylaminophenyl) -6-chlorophthalide, 3,3-bis (p-dibutylaminophenyl) phthalide, 3-cyclohexylamino-6-chloro Fluoran, 3-dimethylamino-5,7-dimethylfluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-7-methylfluorane, 3-diethylamino-7,8-benzfluorane, 3- Diethylamino-6-methyl-7-chlorofluorane, 3- (Np-tolyl-N-ethylamino) -6-methyl- -Anilinofluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 2- {N- (3'-trifluoromethylphenyl) amino} -6-diethylaminofluorane, 2- {3,6 -Bis (diethylamino) -9- (o-chloroanilino) xanthylbenzoic acid lactam}, 3-diethylamino-6-methyl-7- (m-trichloromethylanilino) fluorane, 3-diethylamino-7- (o-chloroanilino) Fluorane, 3-dibutylamino-7- (o-chloroanilino) fluorane, 3-N-methyl-N-isoamylamino-6-methyl-
7-anilinofluorane, 3-N-methyl-N-cyclohexylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3- (N, N -Diethylamino) -5-methyl-7- (N, N
-Dibenzylamino) fluorane, benzoyl leuco methylene blue, 6'-chloro-8'-methoxy-benzoindolino-pyrrolispirane, 6'-bromo-3'-methoxy-benzoindolino-pyrrolispirane, 3- (2'-hydroxy) -4'-Dimethylaminophenyl) -3- (2'-methoxy-5'-chlorophenyl)
Phthalide, 3- (2'-hydroxy-4'-dimethylaminophenyl) -3- (2'-methoxy-5'-nitrophenyl)
Phthalide, 3- (2'-hydroxy-4'-diethylaminophenyl) -3- (2'-methoxy-5'-methylphenyl)
Phthalide, 3- (2'-methoxy-4'-dimethylaminophenyl) -3- (2'-hydroxy-4'-chloro-5'-
Methylphenyl) phthalide, 3,6-bis (dimethylamino) fluorene spiro (9,
3 ')-6'-Dimethylaminophthalide, 3- (N-ethyl-N-isoamyl) amino-6-methyl-7-anilinofluorane, 3- (N-methyl-N-isopropyl) amino-6 -Methyl-7-anilinofluorane, 3-dibutylamino-6-methyl-7-anilinofluorane, 3-morpholino-7- (N-propyl-trifluoromethylanilino) fluorane, 3-pyrrolidino-7 -Trifluoromethylanilinofluorane, 3-diethylamino-5-chloro-7- (N-benzyl-trifluoromethylanilino) fluorane, 3-pyrrolidino-7- (di-p-chlorophenyl) methylaminofluorane , 3-diethylamino-5-chloro-7- (α-phenylethylamino) fluorane, 3- (N-ethyl-p-toluidino) -7 (Α-Phenylethylamino) fluorane, 3-diethylamino-7- (o-methoxycarbonylphenylamino) fluorane, 3-diethylamino-5-methyl-7- (α-phenylethylamino) fluorane, 3-diethylamino-7- Piperidinofluoran, 2-chloro-3- (N-methyltoluidino) -7- (p
-N-butylanilino) fluorane, 3- (N-benzyl-N-cyclohexylamino)-
5,6-benzo-7-α-naphthylamino-4′-bromofluorane, 3-diethylamino-6-chloro-7-anilinofluorane, 3-N-ethyl-N- (2-ethoxypropyl) amino -6-Methyl-7-anilinofluorane, 3-N-ethyl-N-tetrahydrofurfurylamino-
6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-mesitidino-
4 ', 5'-benzofluorane and the like.

As the developer used in the present invention, various electron-accepting compounds such as phenolic compounds, thiophenolic compounds, thiourea derivatives, organic acids and metal salts thereof are preferably applied, and specific examples thereof The following may be mentioned as examples.

4,4'-isopropylidene bisphenol, 4,4'-isopropylidene bis (o-methylphenol).

4,4'-Secondary butylidene bisferrol 4,4'-isopropylidene bis (2-tert-butylphenol), 4,4'-cyclohexylidene diphenol, 4,4'-isopropylidene bis (2-chlorophenol) 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 2,2'-methylenebis (4-ethyl-6-tert-butylphenol), 4,4'-butylidenebis (6-tertbutyl-2) Methyl)
Phenol, 4,4'-thiobis (6-tertbutyl-2-methyl) phenol, 4,4'-diphenol sulfone, 4-isopropoxy-4'-hydroxydiphenyl sulfone, 4-benzyloxy-4'-hydroxydiphenyl Sulfone, 4,4′-diphenol sulfoxide, isopropyl P-hydroxybenzoate, benzyl P-hydroxybenzoate, benzyl protocatechuate, stearyl gallate, lauryl gallate, octyl gallate, 1,7-bis (4-hydroxy) Phenylthio) -3,5-dioxaheptane, 1,5-bis (4-hydroxyphenylthio) -3-oxapentane, 1,3-bis (4-hydroxyphenylthio) -propane, 1,3-bis (4-Hydroxyphenylthio) -2-hydroxypropane, N, N'-diphenylthiourea, N, N'- (M-chlorophenyl) thiourea, salicylanilide, 5-chloro-salicylanilide, salicyl-o-chloroanilide, 2-hydroxy-3-naphthoic acid, 2-hydroxy-1-naphthoic acid, 1-hydroxy-2-naphthoic acid. Acids, metal salts of hydroxynaphthoic acid such as zinc, aluminum and calcium.

To produce a heat-sensitive recording material using the p- (2-vinyloxyethoxy) benzoic acid benzyl ester of the present invention,
The compound, leuco dye and developer may be bound and supported on a support. As the binder in this case, various conventional binders can be appropriately used, and examples thereof include polyvinyl alcohol, starch and derivatives thereof, methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose, cellulose derivatives such as ethylcellulose, and polyacrylic. Acid soda, polyvinylpyrrolidone, acrylamide / acrylic acid ester copolymer, acrylamide / acrylic acid ester / methacrylic acid terpolymer, styrene / maleic anhydride copolymer alkali salt, isobutylene / maleic anhydride copolymer alkali salt , Water-soluble polymers such as polyacrylamide, sodium alginate, gelatin, and casein, polyvinyl acetate, polyurethane, polyacrylic acid, polyacrylic ester, vinyl chloride / vinyl acetate Polymers, polybutyl methacrylate, ethylene / vinyl acetate copolymer emulsion and styrene / butadiene copolymer, latexes such as styrene / butadiene / acrylic copolymer.

Further, in the present invention, together with the compound of the present invention, the leuco dye and the color developer, if necessary, further, auxiliary additives commonly used in this type of heat-sensitive recording material, for example, a filler, a surfactant, and a thermosetting agent. A fusible substance (or a lubricant) or the like can be used in combination. In this case, as the filler, for example, calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, talc, inorganic fine powder such as surface-treated calcium or silica, etc. , Urea-formalin resin, styrene / methacrylic acid copolymer, polystyrene resin, and other organic fine powders, and examples of the heat-fusible substance include higher fatty acids or their esters, amides, or metal salts. Other
Various waxes, condensates of aromatic carboxylic acids and amines, benzoic acid phenyl esters, higher linear glycols,
50-200 ℃ for 3,4-epoxy-dialkyl hexahydrophthalate, higher ketones and other heat-fusible organic compounds
Those having a melting point of about

In the present invention, between the support and the thermosensitive coloring layer,
If necessary, a layer containing a filler, a binder, a heat-fusible substance, etc. can be provided as an undercoat layer. In this case, specific examples of the filler, the binder and the heat-fusible substance are:
The same thing as what was illustrated in the said thermosensitive coloring layer is mentioned.

Further, in the heat-sensitive recording material of the present invention, a protective layer may be provided on the heat-sensitive color developing layer for the purpose of improving the matching property with a thermal head or the like and further improving the storability of recorded images. In this case, the above-mentioned filler, binder, surfactant and heat-fusible substance can also be used as the component constituting the protective layer.

The heat-sensitive recording material of the present invention is produced, for example, by applying a heat-sensitive color forming layer-forming coating liquid containing each of the above-mentioned components onto a suitable support such as paper, synthetic paper, or a plastic film, and drying it. . In this case, leuco dye, developer,
The amount of the sensitivity improver used is 5 to 40% by weight and 20 to 60%, respectively.
%, 20-60% by weight are suitable.

〔effect〕

The heat-sensitive recording material using the compound of the present invention as a sensitivity improver has improved sensitivity, is suitable for high-speed recording, has high background whiteness, is excellent in image stability, and has extremely high practicality. is there.

〔Example〕

Next, the present invention will be described in more detail with reference to examples. The parts and% shown below are based on weight.

Example 1 10 g of p-hydroxybenzoic acid benzyl ester was dissolved in 30 ml of dimethyl sulfoxide, and sodium hydroxide was added thereto.
An aqueous solution prepared by dissolving 2.0 g in 5 ml of water is added. Then 5.2 g of 2-chloroethyl vinyl ether are added dropwise to this mixture. After completion of dropping, the mixture was heated and reacted for 1 hour. After cooling to room temperature, the reaction solution was poured into water 1, the precipitated crystals were collected by filtration, and sufficiently washed with water. Then, the crystals were recrystallized with a water / ethanol mixed solvent to obtain 9.2 g of white crystals of p- (2-vinyloxyethoxy) benzoic acid benzyl ester. The melting point of the obtained compound was 82 to 85 ° C., and the result of elemental analysis was as shown in Table 1.

Example 2 The following mixtures were ground in a magnetic ball mill for 2 hours to prepare [solution A], [solution B], [solution C] and [solution D].

[Liquid A]

3- (N-methyl-N-cyclohexylamino) -6-
Methyl-7-anilinofluoran 20 parts 10% aqueous solution of polyvinyl alcohol 20 parts water 60 parts [B solution] Bisphenol A 20 parts 10% aqueous solution of polyvinyl alcohol 20 parts water 60 parts [C solution] p- (2- Vinyloxyethoxy) benzoic acid benzyl ester 20 parts 10% aqueous solution of polyvinyl alcohol 20 parts water 60 parts [solution D] calcium carbonate 20 parts 5% aqueous solution of methylcellulose 20 parts water 60 parts [solution A] 10 parts [B Liquid] 30 parts, [C liquid] 30 parts, [D
Liquid] 20 parts of isobutylene / maleic anhydride copolymer
A thermosensitive coloring layer forming liquid was prepared by mixing 10 parts of a 20% aqueous alkaline solution, and this was applied to a high quality paper having a basis weight of 50 g / m ^{2 in} a dry amount of 4 to
A thermosensitive coloring layer was provided by coating and drying so as to be 5 g / m ^2, and then the surface of the layer was calendered so that the surface smoothness was 500 to 600 seconds to prepare a thermosensitive recording material (a).

Example 3 A thermosensitive recording material (b) was prepared in the same manner as in Example 2 except that the following [Solution E] was used instead of [Solution B] in Example 2.
It was created.

[Liquid E]

p-Hydroxybenzoic acid benzyl ester 20 parts 10% aqueous solution of polyvinyl alcohol 20 parts water 60 parts Comparative Example 1 Thermal recording was carried out in the same manner as in Example 2 except that water was used instead of [solution C] in Example 2. Material (c) was made.

Comparative Example 2 A thermosensitive recording material (d) was prepared in the same manner as in Example 2 except that the following [F liquid] was used instead of the [C liquid] of Example 2.

[F liquid]

Stearic acid amide 20 parts 5% aqueous solution of methylcellulose 20 parts water 60 parts Comparative Example 3 A thermosensitive recording material (e) was prepared in the same manner as in Example 3 except that water was used instead of [solution C] in Example 3. Created.

Comparative Example 4 A thermosensitive recording material (f) was prepared in the same manner as in Example 3 except that the [F liquid] was used in place of the [C liquid] in Example 3.

The thermal recording materials (a) to (f) obtained as described above are
Head thermal power 0.45W / dot, 1 line recording time 20 in a thermal printing experimental device with a thin film head manufactured by Matsushita Electronic Components Co., Ltd.
Printing was performed with a pulse width of 1.6, 2.0 and 2.4 msec under the condition of msec /, scanning line density 8 × 3.85 dots / mm, and the printing density was measured by Macbeth densitometer RD-514 (filter W-106). The results are shown in Table-2.

From the above, the heat-sensitive recording material of the present invention has high coloring sensitivity,
It can be seen that it is a heat-sensitive recording material which is suitable for high-speed recording and also has a high degree of background whiteness and is extremely highly practical.

Claims (2)

[Claims] 1. A formula P- (2-vinyloxyethoxy) benzoic acid benzyl ester represented by: 2. A heat-sensitive recording material utilizing a color-forming reaction between a leuco dye and a color-developing agent thereof, wherein the formula is used as a sensitivity improver. A heat-sensitive recording material characterized by using p- (2-vinyloxyethoxy) benzoic acid benzyl ester represented by: