JP2003182238A - Heat sensitive recording material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To develop a heat sensitive recording material having small ground fogging and being excellent in color-developability and preservability. <P>SOLUTION: In the heat sensitive recording material providing a heat sensitive color forming layer including a normally colorless or light-colored color forming compound, a color developing compound developing color under heat in the color forming compound on a support, a bis(4-hydroxyphenyl) acetate is included as the color developing compound and a dibenzoyl methane is included as a sensitizer. <P>COPYRIGHT: (C)2003,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] The present invention relates to a thermosensitive recording material.
You. More specifically, it has high sensitivity and low background fog,
The present invention relates to a heat-sensitive recording material having excellent image storability. [0002] 2. Description of the Related Art A thermosensitive recording material generally comprises a leuco dye and a fluorocarbon dye.
Developing agents such as phenolic substances separately into fine particles
After dispersing, mix both, then add binder, sensitizer, filling
Additives such as lubricants and lubricants to make a coating liquid, paper,
Coated on paper, synthetic paper, etc.
Chemical reaction that occurs when one or both of
In this way, a color recording is obtained. This thermal recording sheet
In order to develop colors, a thermal head
Printer or the like is used. This thermal recording method is
(1) No noise during recording, (2) Current
No need for image, fixation, etc. (3) Maintenance-free
(4) Machines are relatively inexpensive.
Facsimile field, computer output, power
Printers such as desks, recorders for medical measurement,
Widely used in the field of automatic ticket vending machines, thermal recording labels, etc.
Have been. In recent years, retail stores, supermarkets, etc.
POS system for transportation, automated system for transportation
As a result, the use of labels, tickets, coupons, etc. has increased
I have. In these applications, thermal recording materials are even more
It has been desired to improve the storage stability of the product. Also for high-speed recording
Requirements are further increased, and it is possible to sufficiently cope with high-speed recording.
There is a strong demand for the development of heat-sensitive recording materials.
Improving the sensitivity of the recording material and improving the thermal responsiveness
Is more likely to occur. Conventionally,
Good response, and to improve the storage stability
A method has been proposed, but nothing is still satisfactory.
No. [0004] The object of the present invention is as described above.
It is to solve the disadvantages of the prior art. That is, with high sensitivity
Feel less background fogging and excellent image storage stability
It is to provide a thermal recording material. [0005] The present inventor has achieved the above object.
As a result of various studies to achieve this, the present invention was completed.
Things. That is, the present invention provides (1) a method in which a support is usually colorless.
Or light-colored coloring compound and the coloring compound when heated
Heat-sensitive with color-developing compounds and sensitizers as main components
In a thermosensitive recording material provided with a color-forming layer,
And the following equation (1) [0006] Embedded image (In the formula (1), R is an alkenyl having 1 to 4 carbon atoms.
Represents a alkyl group or a benzyl group. A) a sensitizer
Containing dibenzoylmethane as
A thermosensitive recording material. [0008] BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, ordinary paper, plastic
It is usually colorless on a support such as a sticky sheet or synthetic paper.
A light-coloring compound and a developing compound represented by the formula (1)
The compound shown is dibenzoylmethane as a sensitizer.
As the main components, binders and other necessary
The heat-sensitive coloring layer can be formed with fillers and other additives as necessary.
Be prepared. In forming the thermosensitive coloring layer in the present invention,
The color-forming compound is usually 1 to 50% by weight, preferably
5 to 30% by weight, the compound represented by the formula (1) is usually 1 to
80% by weight, preferably 5 to 40% by weight, dibenzoyl
Methane is usually 0.5 to 80% by weight, preferably 5 to 40%.
% By weight, binder 1-90% by weight, filler 0-80 weight
%, Other lubricants, surfactants, defoamers, UV absorption
The agents and the like are each in an arbitrary ratio, for example, each is 0 to 30% by weight,
Used (weight% is the weight of each component in the thermosensitive coloring layer)
Quantitative ratio). Further, in the heat-sensitive recording material of the present invention,
Known color developing compounds or sensitizers other than the main components of
(Fusible compound). The color-forming compound used in the present invention
Is generally used for pressure-sensitive recording paper and thermal recording paper.
Is not particularly limited. Available color development
Examples of compounds include, for example, fluoran compounds, tria
Reel Methane compounds, spiro compounds, diphenylmeth
Tan compounds, thiazine compounds, lactam compounds,
Fluorene-based compounds and the like. Specific examples of fluoran compounds that can be used include
For example, 3-diethylamino-6-methyl-7-a
Nilinofluoran, 3-dibutylamino-6-methyl-
7-anilinofluoran, 3- (N-methyl-N-cyclic)
Rohexylamino) -6-methyl-7-anilinofluor
Orchid, 3- (N-ethyl-N-isopentylamino)-
6-methyl-7-anilinofluoran, 3- (N-ethyl
Ru-N-isobutylamino) -6-methyl-7-anili
Nofluoran, 3- [N-ethyl-N- (3-ethoxy
Propyl) amino] -6-methyl-7-anilinofluor
Run, 3- (N-ethyl-N-hexylamino) -6
Methyl-7-anilinofluoran, 3-dipentylami
No-6-methyl-7-anilinofluoran, 3- (N-
Methyl-N-propylamino) -6-methyl-7-ani
Linofluoran, 3- (N-ethyl-N-tetrahydro
Furylamino) -6-methyl-7-anilinofluora
, 3-diethylamino-6-methyl-7- (p-chloro
Roanilino) fluoran, 3-diethylamino-6-meth
Tyl-7- (p-fluoroanilino) fluoran, 3-
[N-ethyl-N- (p-tolyl) amino] -6-methyl
Ru-7-anilinofluoran, 3-diethylamino-6
-Methyl-7- (p-toluidino) fluoran, 3-di
Ethylamino-7- (o-chloroanilino) fluora
, 3-dibutylamino-7- (o-chloroanilino)
Fluoran, 3-diethylamino-7- (o-fluoro
Anilino) fluorane, 3-dibutylamino-7- (o
-Fluoroanilino) fluoran, 3-diethylamino
-7- (m-trifluoromethylanilino) fluora
, 3-diethylamino-7- (3,4-dichloroani
Rino) Fluorane, 3-pyrrolidino-6-methyl-7-
Anilinofluoran, 3-diethylamino-6-chloro
-7-ethoxyethylaminofluoran, 3-diethyl
Amino-6-chloro-7-anilinofluoran, 3-di
Ethylamino-7-chlorofluoran, 3-diethyla
Mino-7-methylfluoran, 3-diethylamino-7
-Octylfluoran, 3- [N-ethyl-N- (p-
Tolyl) amino] -6-methyl-7-phenethylfluor
And the like. Also, a triarylmethane compound which can be used
As a specific example of, for example, 3,3-bis (p-dimethyl
Aminophenyl) -6-dimethylaminophthalide (separate
Name: crystal violet lactone or CVL),
3,3-bis (p-dimethylaminophenyl) phthaly
, 3- (p-dimethylaminophenyl) -3- (1,
2-dimethylaminoindol-3-yl) phthalide,
3- (p-dimethylaminophenyl) -3- (2-methyl
Ruindol-3-yl) phthalide, 3- (p-dimethyl)
Ruaminophenyl) -3- (2-phenylindole-
3-yl) phthalide, 3,3-bis (1,2-dimethyl
Indole-3-yl) -5-dimethylaminophthaly
, 3,3-bis (1,2-dimethylindole-3-
Yl) -6-dimethylaminophthalide, 3,3-bis
(9-ethylcarbazol-3-yl) -5-dimethyl
Aminophthalide, 3,3- (2-phenylindole-
3-yl) -5-dimethylaminophthalide, 3-p-di
Methylaminophenyl-3- (1-methylpyrrole-2
-Yl) -6-dimethylaminophthalide and the like.
You. Further, specific examples of spiro compounds that can be used include
For example, 3-methylspirodinaphthopyran,
Ethylspirodinaphthopyran, 3,3'-dichlorospir
Rosinaphthopyran, 3-benzylspirodinaphthopyra
, 3-propylspirobenzopyran, 3-methylnaph
To- (3-methoxybenzo) spiropyran, 1,3,3
-Trimethyl-6-nitro-8'-methoxyspiro (a
Ndrin-2,2'-benzopyran) and the like
Examples of the methane compound include N-halophenyl-II
Ico auramine, 4,4-bis-dimethylaminopheni
Rubens hydryl benzyl ether, N-2,4,5-
Trichlorophenyl leuco auramine, etc.
As the compound, for example, benzoyl leucomethylene ble
-, P-nitrobenzoyl leucomethylene blue and the like,
Lactam compounds include, for example, rhodamine B
Nolactam, Rhodamine B-p-chloroanilinolacta
Are fluorene-based compounds such as 3,6-
Bis (dimethylamino) fluorenespiro (9,3 ')
-6'-dimethylaminophthalide, 3,6-bis (dim
Tylamino) fluorenespiro (9,3 ')-6'-pi
Loridinophthalide, 3-dimethylamino-6-diethyl
Aminofluorene spiro (9,3 ')-6'-pyrrolid
Nophthalide and the like can be mentioned. These color-forming compounds are simply
Used alone or as a mixture. In the present invention, the formula (1)
Color developing compounds other than the above compounds can be used in combination.
Examples of color-developing compounds such as
Or any material used for thermal recording paper
Can also be used, and there is no particular limitation. As a specific example,
For example, α-naphthol, β-naphthol, p-octylph
Enol, 4-tert-octylphenol, pt-butyl
Phenol, p-phenylphenol, 1,1-bis
(P-hydroxyphenyl) propane, 2,2-bis-
(P-hydroxyphenyl) propane (alias: bisphe
Nord A or BPA), 2,2-bis- (p-hydroxy
Cyphenyl) butane, 1,1-bis- (p-hydroxy
Phenyl) cyclohexane, 4,4'-thiobispheno
4,4'-cyclo-hexylidenediphenol,
2,2'-bis- (2,5-dibromo-4-hydroxy
Phenyl) propane, 4,4'-isopropylidenebis
(2-t-butylphenol), 2,2'-methylenebi
(4-chlorophenol), 4,4'-dihydroxy
Diphenylphone, 2,4'-dihydroxydiphenyls
Rufone, bis (3-allyl-4-hydroxyphenyl)
Sulfone, 4-hydroxy-4'-isopropoxydif
Phenylsulfone, 4-hydroxy-4'-benzyloxy
Phenolic compounds such as sidiphenyl sulfone;
Benzyl droxybenzoate, p-hydroxybenzoic acid
Tyl, dibenzyl 4-hydroxyphthalate, 4-hydro
Dimethyl xyphthalate, 5-hydroxyisophthalic acid
Tyl, 3,5-di-t-butylsalicylic acid, 3.5-di
-Aromatic carboxylic acids such as α-methylbenzylsalicylic acid
Derivatives, aromatic carboxylic acids or polyvalent metal salts thereof, and the like.
But not limited to these. These colors
Compounds are used alone or in combination as necessary.
You. In the present invention, dibenzoyl meth
Sensitizers (thermally fusible compounds) other than
Examples of such sensitizers (thermally fusible compounds)
Waxes such as animal and vegetable waxes and synthetic waxes
And higher fatty acids, higher fatty acid amides, higher fatty acid anilis
De, naphthalene derivative, aromatic ether, aromatic carbo
Acid derivatives, aromatic sulfonic acid ester derivatives, carbonic acid
Are oxalic acid diester derivatives, biphenyl derivatives,
Solid at room temperature, such as phenyl derivatives and sulfone derivatives
Can have a melting point of about 70 ° C or higher.
Wear. Examples of waxes that can be used in combination include, for example, wood
Wax, carnauba wax, shellac, paraffin, mon
Tan wax, oxidized paraffin, polyethylene wax, acid
Polyethylene, etc., as higher fatty acids, for example,
Aric acid, behenic acid and the like, as higher fatty acid amide,
For example, stearic acid amide, oleic acid amide, N-meth
Tilstearic acid amide, erucic acid amide, methylol
Behenamide, methylenebisstearic acid amide, d
Tylene bis-stearic acid amide etc.
For example, stearic acid anilide, linoleic acid
Anilides and the like, as naphthalene derivatives, for example, 1-
Benzyloxynaphthalene, 2-benzyloxynaphthalene
Len, 1-hydroxynaphthoic acid phenyl ester, etc.
However, examples of aromatic ethers include 1,2-dipheno
Xiethane, 1,4-diphenoxybutane, 1,2-bi
(3-methylphenoxy) ethane, 1,2-bis (4
-Methoxyphenoxy) ethane, 1,2-bis (3,4
-Dimethylphenyl) ethane, 1-phenoxy-2-
(4-chlorophenoxy) ethane, 1-phenoxy-2
-(4-methoxyphenoxy) ethane and the like
As the boronic acid derivative, for example, p-hydroxybenzoic acid
Benzyl ester, p-benzyloxybenzoic acid benzyl
Esters, dibenzyl terephthalate, etc.
As aromatic sulfonic acid ester derivatives, for example, p-to
Ruenesulfonic acid phenyl ester, phenyl mesitile
Sulfonate, 4-methylphenyl mesitylene sulfo
Nart and the like, as a carbonic acid or oxalic acid diester derivative
Is, for example, diphenyl carbonate, dibenzyl oxalate
Oxalic acid di (4-chlorobenzyl) ester, oxalic acid
Di (4-methylbenzyl) ester of uric acid
The derivatives include, for example, p-benzylbiphenyl, p
-Allyloxybiphenyl and the like are terphenyl derivatives
For example, m-terphenyl or the like is a sulfone derivative
Examples include, for example, diphenyl sulfone, etc.
Shown. These sensitizers (thermoplastic compounds) are needed
It is used alone or as a mixture. The above-mentioned color-developing compound which can be used in combination and sensitization
The amount of the agent used is within a range that does not impair the effects of the present invention, for example, the formula
Use of the compound represented by (1) and dibenzoylmethane
A proportion in the range not exceeding the amount is preferred. In the present invention, examples of binders that can be used
For example, methylcellulose, methoxycellulose,
Hydroxyethyl cellulose, carboxymethyl cellulose
Glucose, sodium carboxymethylcellulose, cellulose
Ose, polyvinyl alcohol (PVA), carboxyl
Group-modified polyvinyl alcohol, sulfonic acid group-modified polyvinyl
Nyl alcohol, polyvinylpyrrolidone, polyacryl
Amide, polyacrylic acid, starch and its derivatives,
Zein, gelatin, water-soluble isoprene rubber, styrene /
Alkaline salt of maleic anhydride copolymer, iso (or di
So) Alkaline salts of butylene / maleic anhydride copolymer
Water-soluble or polyvinyl acetate, vinyl chloride / vinegar
Acid vinyl copolymer, polystyrene, polyacrylic acid ester
Ter, polyurethane, styrene / butadiene (SB)
Polymer, carboxylated styrene / butadiene (SB)
Copolymer, styrene / acrylate copolymer,
Tylene / butadiene / acrylic acid copolymer, colloida
Hydrophobic polymers such as composite particles of silica and acrylic resin
Emulsions and the like. These binders alone
Or mixed. Examples of fillers that can be used include, for example,
Calcium carbonate, magnesium carbonate, magnesium oxide
, Silica, white carbon, talc, clay, aluminum
Mina, bentonite, magnesium hydroxide, aluminum hydroxide
Minium, aluminum oxide, barium sulfate, polystyrene
Len resin, urea-formalin resin and the like. this
These fillers may be used alone or as a mixture if necessary.
It is. Further, other additives such as thermal
To prevent head wear and sticking.
Higher fatty acids such as zinc arate and calcium stearate
Metal salts, phenol to provide antioxidant or antiaging effects
Derivatives, benzophenones, benzotriazoles, etc.
Need UV absorbers, various surfactants, defoamers, etc.
Will be added accordingly. Using the above materials, for example, the following method
Therefore, the heat-sensitive recording material of the present invention is prepared. That is,
First, a color-forming compound, a compound represented by the formula (1),
Dibenzoylmethane can be used separately as binder or
Ball mill, attra with other additives if necessary
It was pulverized and dispersed with a disperser such as
After (When grinding and dispersion are performed by wet method, usually water is used as a medium.
Mix) to prepare a coating solution for the thermosensitive coloring layer.
Usually dry weight on a support such as a sticky sheet or synthetic paper
1-20 g / m^TwoBar coater and blade to become
Coated by a coater or the like, and dried, the heat-sensitive recording material of the present invention
Get. In the heat-sensitive recording material of the present invention, if necessary,
By providing an intermediate layer between the heat-sensitive coloring layer and the support,
An overcoat layer (protective layer) may be provided on the color layer.
The intermediate layer and the overcoat layer (protective layer) are as described above.
Binder or heat fusibility as described above if necessary
Heat-sensitive coloring layer coating solution with compounds, fillers and other additives
Pulverize and disperse in the same manner as in the preparation, for the intermediate layer, or
Is the coating liquid for overcoat layer (protective layer)
Usually 0.1 to 10 g / m by weight^TwoAbout
It is applied as follows. Usually, a colorless or pale-colored color-forming compound of the formula
The compound represented by (1), dibenzoylmethane, is heat-sensitive
The heat-sensitive recording material of the present invention contained in the color-forming layer has high sensitivity and
Less fogging and excellent image storability. [0024] EXAMPLES The present invention will be described more specifically with reference to examples.
However, the present invention is not limited to these. Implementation
In the examples, "parts" indicates parts by weight, and "%" in the description of the solution.
Is% by weight, indicating that the medium is water. Embodiment 1 (Formation of thermosensitive coloring layer) A mixture of the following composition
Powder so that the average particle size is 1 μm or less.
Crushed and dispersed to obtain solution [A], solution [B], solution [C]
Is prepared.   [A] liquid: 3-dibutylamino-6-methyl-7-anilinofluoran                                                                   25 parts             20% 25% PVA aqueous solution             55 parts of water   [B] Liquid: benzyl bis (4-hydroxyphenyl) acetate (CAS No.             114851-44-4) 25 parts             20% 25% PVA aqueous solution             55 parts of water   [C] solution: 25 parts of dibenzoylmethane (CAS No. 120-46-7)             20% 25% PVA aqueous solution             55 parts of water Next, the mixture is mixed in the following ratio to form a heat-sensitive coloring layer.
Prepare a coating solution for use, and weigh 50 g / m ^TwoDry on high quality paper
Weight at the time of 8g / m^TwoApply and dry so that it becomes heat-sensitive
A coloring layer is obtained.   [A] 8 parts of liquid   [B] 16 parts of liquid   [C] 24 parts of liquid   12 parts of 50% calcium carbonate dispersion   7 parts of 50% carboxylated styrene / butadiene copolymer latex (Formation of protective layer) Further, a coating for a protective layer having the following ratio
The dry weight of the cloth solution is 2 g / m2 on the thermosensitive coloring layer.^Two
Coated and dried so that it becomes heat-sensitive of the present invention with a protective layer
Obtain the recording material.   20% 40% styrene acrylate copolymer emulsion   40 parts of 5% bentonite dispersion   3 parts of 30% zinc stearate dispersion Embodiment 2 Bis (4-hydroxyphenyl) acetic acid benzyl of Example 1
Bis (4-hydroxyphenyl) acetate
(CAS No. 7100-33-3)
Heat-sensitive recording material of the present invention having a protective layer in the same manner as in Example 1
Get. Embodiment 3 Bis (4-hydroxyphenyl) acetic acid benzyl of Example 1
Methyl bis (4-hydroxyphenyl) acetate
(CAS No. 5129-00-0)
Heat-sensitive recording material of the present invention having a protective layer in the same manner as in Example 1
Get. Embodiment 4 3-Dibutylamino-6-methyl-7-ani of Example 1
3- (N-ethyl-N-iso) instead of linofluoran
(Pentylamino) -6-methyl-7-anilinofluora
Using a protective layer in the same manner as in Example 1.
Obtain a light thermosensitive recording material. Embodiment 5 3-Dibutylamino-6-methyl-7-ani of Example 1
3- (N-methyl-N-cyclyl) instead of linofluoran
Rohexylamino) -6-methyl-7-anilinofluor
Using a run, a book with a protective layer in the same manner as in Example 1
The thermosensitive recording material of the invention is obtained. The heat-sensitive recording of the present invention obtained as described above
Table 1 shows the quality performance table of the materials. [0032]                             Table 1 Quality performance test               Scalp¹⁾    Color density²⁾  Moisture resistance³⁾    water resistant^Four)    Plasticizer resistance^Five) Example 1 0.04 1.62 1.54 1.47 1.54 Example 2 0.05 1.60 1.51 1.46 1.53 Example 3 0.05 1.60 1.57 1.46 1.54 Example 4 0.05 1.65 1.58 1.52 1.60 Example 5 0.04 1.63 1.56 1.50 1.56 1) Background: The uncolored part of the sample is reflected at a high density.
Meter (measured with Macbeth (Germany) RD-914 type)
Value (Macbeth reflection density value and the same hereinafter). 2) Color density: Thermal printer (manufactured by Ishida Corporation)
  D-805P) Macbeth reflection density of image part printed
Degree value. 3) Moisture resistance: 4 samples of the color developed by the above printer
Left for 24 hours in a humidity chamber at 0 ° C. and 90% relative humidity
Macbeth reflection density of the subsequent image part. 4) Water resistance: The sample developed with the above printer
Macbeth reflection of image after 24 hours immersion in tap water at high temperature
concentration. 5) Plasticizer resistance: Positive
Double-sided wrap film made of polyvinyl chloride (PVC)
Of the image after leaving for 15 hours at room temperature
Reflection density. As is clear from the table, the heat-sensitive recording material of the present invention
The material is excellent in whiteness and color density of the background, and the color image
In the image, moisture resistance, water resistance and plasticizer resistance etc. are immediately
Have been. [0035] According to the present invention, an image having high sensitivity and little background fog is obtained.
A heat-sensitive recording material having excellent storage properties was obtained.

Claims (1)

Claims: 1. A heat-sensitive color-forming layer comprising a colorless or light-colored color-forming compound, a color-developing compound capable of forming the color-forming compound upon heating, and a sensitizer as main components on a support. In the heat-sensitive recording material provided with, the heat-sensitive coloring layer is represented by the following formula (1) as a color-developing compound. A thermosensitive recording material comprising a compound of the formula (1) wherein R represents an alkyl group having 1 to 4 carbon atoms or a benzyl group, and dibenzoylmethane as a sensitizer.