JPS61130085A - Thermal recording paper - Google Patents

Abstract

PURPOSE:To facilitate the arrangement and classification of printed matter so as to make it possible to discriminate which recording apparatus printed out recording data at a glance when a plurality of recording apparatuses are provided, by applying coloration to the recording surface of thermal recording paper, that is, by containing a color dye or pigment in a thermal color forming layer. CONSTITUTION:The max. value of the visible light absorbancy of a coated surface is set to 0.2-1.0 when monochromatic light with a wavelength of 380-780nm is irradiated. As a color dye or pigment, ones used in a paper, fiber or paint industry can be used and, as color inorg. pigment, chromium yellow, iron oxide pigment, molybdenic acid orange, cadmium red, prussian blue are designated. As the dye, there are sufranine, rhodamine, magenta, alizarin red, rubin red or chromium blue. These dyes or pigments are used alone or in a mixed state. The use amount thereof is different according to absorbancy but pref. 10-500mg/m<2>.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application of the Invention) The present invention relates to a thermal recording paper, and more particularly to a thermal recording paper that is easy to handle.

(Prior Art) Thermosensitive recording paper is a paper that records images by utilizing physical and chemical changes in substances caused by thermal energy, and a large number of processes are being studied.

So-called wax-type thermosensitive recording paper has been known for a long time as a book that takes advantage of the physical changes in substances caused by heat, and is used for things such as electrocardiograms. In addition, various types of coloring mechanisms have been proposed that utilize chemical changes caused by heat, but a two-component coloring type thermosensitive recording paper is particularly representative.

Two-component color-forming thermosensitive recording paper is made by dispersing two types of heat-reactive compounds in the form of fine particles, mixing them with a binder, etc., so that the two types of heat-reactive compounds are separated by the binder, etc., and forming a support. One or both of them are melted and brought into contact with each other by heating, and the coloring reaction that occurs is used to obtain records. These two types of heat-reactive compounds are
Generally, they are called electron-donating compounds and electron-accepting compounds.

These two-component coloring thermosensitive recording papers are: (1) secondary coloring and does not require development; (2) paper quality is close to that of ordinary paper; and (3)
) It has many advantages as a recording sheet, such as being easy to handle. In particular, those using colorless dyes as electron-donating compounds have further advantages such as (4) high degree of color development and (5) ease of producing thermal recording paper with various color hues, so they have great utility value. . Therefore, it is most commonly used as a heat-sensitive recording material.

In recent years, with the development of electronic technology, facsimiles, measuring instruments,
Thermal recording paper is attracting attention as a means of printing out messages such as printers. Accordingly, requirements for recording paper have become more diverse, and it is no longer satisfying to simply obtain colored images on a conventional white background. That is, multiple recording devices +1
In this case, it is necessary to visually determine by which recording device the recorded data was printed out.

(Object of the present invention) An object of the present invention is to meet the various demands for heat-sensitive recording paper as described above, particularly the need to facilitate the sorting and classification of printed matter.

(Structure of the present invention) The object of the present invention is achieved by applying color to the recording surface of thermal recording paper. Specifically, this is achieved by incorporating a colored dye or pigment into the thermosensitive coloring layer 1 and setting the maximum visible spectral absorption of the thermosensitive coloring surface to 0.2 or more/0 or less. Furthermore, by providing the thermosensitive coloring layer with visible spectral absorption, it becomes possible to perform light-thermosensitive recording using a laser (for example, a Ne--He laser) having an emission wavelength in the visible range.

Next, a method for manufacturing the thermal paper of the present invention will be described.

The thermal paper of the present invention can be produced by separately adding a basic colorless dye (hereinafter referred to as a color former) and an electron-accepting compound (hereinafter referred to as a color developer) to a ball mill, a sand mill, an attritor, a three-roll mill, or the like. , dispersed in a water-soluble polymer solution to an average particle size of o, i microns to io microns. In addition, when it is necessary to improve thermal sensitivity, melting point ro
A thermofusible substance of 0c or more and 1-ro0c or less is dispersed by the same means. The thermofusible substance may be mixed and dispersed with a color forming agent or a color developer.

A color forming agent, a color developer, and a thermofusible substance if necessary are mixed after being dispersed, and a colorless or light-colored oil-absorbing pigment, a wax dispersion, a mold release agent dispersion, etc. are added as necessary.

The colored dye or pigment of the present invention may be dispersed simultaneously during the above-mentioned dispersion process, or may be added by being dispersed alone.

The preferred ratio of the color former and color developer during mixing is from /near to /:. Further, when a thermofusible substance is added, it is preferably from jO to 200% by weight based on the color developer. The amount of oil-absorbing face is JIS-! 10/
It is preferable that the oil absorption amount is 30 m1/100f or more, and the amount added is preferably IO to 200 weight percent of the total of the color former, color developer, and thermofusible substance. When adding wax and release agent, add 10% by weight of coloring agent, e-
Cents to 300 weight percent is preferred.

Examples of the coloring agent used in the present invention include triarylmethane compounds, diphenylmethane compounds, xanthine compounds, thiazine compounds, and spiropyran compounds. Some examples of these include 3.3-bis(p-dimethylaminophenyl)-1-dimethylaminophthalide (i.e. crystal violet lactone);
j,j-bis(p-dimethylaminophenyl)phthalide, l-3-(p-dimethylaminophenyl)-J-(/.

no-dimethylindol-3-yl)phthalide, 3-(
p-dimethylaminophenyl)-j-(,2-methylindol-3-yl)phthalide, 3-(p-dimethylaminophenyl)-! -(,2-phenylindole-3
-Il) Lid IJ)", J, J-Bis-(/, 2
-dimethylindol-3-yl)-1-dimethylaminophthalide, 3.3-bis(/, 2-dimethylindol-3-yl)-t-dimethylaminophthalide, 3,
3-bis(terethylcarbazol-3-yl)-j-
Dimethylaminophthalide, 3,3-bis-(2-phenylindol-3-yl)-! -dimethylaminophthalide, 3-p-dimethylaminophenyl-3-(/-) tilvirol-choyl)-bu-dimethyl-aminophthalide 3-diethylamino-7-medoxyfluoran, 3-
Diethylamino-t-methoxyfluorane, 3-diethylamine-7-sibenzylaminofluorane, 3-diethylamino-4-methyl-7-anilite fluorane, 3
-N-ethyl-N-)dylamino-2-methyl-fuanilifluorane, 3-N-methyl-N-1lylamino-t-methyl-7-anilinofluorane, 3-piperidino-6-methyl-7 -anilinofluorane, 3-diethylamino-+-chloro-7-anilinofluorane, 3-
N-cyclohexyl-N-methylamino-t-methyl-
7-anilinofluorane, 3-piperazino-t-methyl-7-(p-methylanilino)fluorane, 3-diethylamine-7-(o-chloroanilino)fluorane, 3
-diethylamine-7-butylaminofluorane, 3-
diethylminino-7-diphenethylaminofluorane,
3.7-bis(methyltolylamino)fluorane, 3-
Examples include piperidino-7-phenethylaminofluorane, 3-diethylamino, -7-phenylfluorane, 3-diethylamino-7, and I-benzofluorane.

These may be used alone or in combination for the purpose of color tone adjustment.

The color developer used in the present invention includes a fetol compound,
Examples include hydroxybenzoic acid fat conductors and salicylic acid derivatives. Examples include 29.2-bis(4t'-hydroxyphenyl)pronoξ (bisphenol A), 2.2
-bis(l-hydroxyphenyl)pentane, λ, 2-
Bis(1,1/-hydroxy-3/,zl-dichlorophenyl)furopane, /, /-bis(Hiro'-hydroxyphenyl)cyclohexane, λ,, 2-bis(μ'-
hydroxyphenyl)hexane, /, l-bis(V'-
hydroxyphenyl)butane, /, /-bis(hiro'-hydroxyphenyl)butane, /, /-bis(
al-hydroxyphenyl)pentane, /, /-bis(hiro'-hydroxyphenyl)hexane, /, l-bis(μ'-hydroxyphenyl)hebutane, /, /-bis(li'-hydroxyphenyl)octane, /,/-his(ri'-hydroxyphenyl)-2-methyl-antane, /,/-bis(couhydroxyphenyl)-2-ethyl-hexane%/11-bis(ri'-hydroxyphenyl)dodecane p -cumylphenol, p-phenylphenol, benzyl p-hydroxybenzoate, butyl p-hydroxybenzoate, phenethyl p-hydroxybenzoate, 3. j-tertiarydutylsalicylic acid, 3.
Examples include z-di-α-methylbenzylsalicylic acid and 3-α-methylbenzylsalicylic acid. Salicylic acid derivatives can be used in the form of their metal salts such as zinc or aluminum salts.

Examples of the thermofusible substance used in the present invention include higher fatty acid amides, benzoic acid ester derivatives, naphthol derivatives, naphthoic acid derivatives, and urea derivatives. Specifically, stearic acid amide 1. e lumitic acid amide, oleic acid amide, erucic acid amide, ethylene bisstearamide, p, <benzyl p-butoxybenzoate, benzyl p-butoxybenzoate, β-naphthol benzyl ether, α-naphthol benzyl ether, α-hydroxy- β-naphthoic acid phenyl ester, β-hydroxy-
α-naphthoic acid phenyl ester, β-naphthoic acid phenyl ester, β-naphthol-(p-chloropencyl) ether.

- Specific examples of oil-absorbing pigments include calcium carbonate, aluminum hydroxide, barium carbonate, barium sulfate, talc,
Examples include waxite, kaolin, calcined kaolin, zinc oxide, diatomaceous earth, amorphous silica, lithopone, titanium oxide, urea-formalin resin filler, polyethylene filler, and the like.

Specific examples of wax include polyethylene wax, paraffin wax, microcrystalline wax, carnauba wax, and the like.

As the mold release agent, metal salts of higher fatty acids are preferred, such as zinc stearate, aluminum stearate, calcium stearate, and the like.

Water-soluble polymers are added as protective colloids when dispersing color formers and color developers, and these water-soluble polymers are preferably compounds that dissolve at least t4 in water at 2j 0C.Specifically, Methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, starches, gelatin, gum arabic, casein, styrene.
Examples include maleic anhydride copolymer salt, ethylene-maleic anhydride copolymer salt/θ- combination salt, inbutylene-maleic anhydride copolymer salt, polyvinyl alcohol, and carboxy-modified polyvinyl alcohol.

These water-soluble polymers also serve as a binder when applying the heat-sensitive leaf material onto a support.

As the colored dyes or pigments used in the present invention, those used in the paper, fiber, paint industries, etc. can be used.

Specifically, colored inorganic pigments include chrome yellow, iron oxide pigments, molybdate orange, cadmium red, Plugin blue, zinc sulfide compounds, cadmium sulfide compounds, silicate compounds, etc., and organic pigments include azo pigments such as Hansa yellow, benzidine yellow, hansa orange, dinitraniline orange, benzidine orange,
Nora Red, Toluidine Red, Pyrazolone Red,
Phthalocyanine pigments such as linolet, hon red, maroon, etc., phthalocyanine face N such as copper phthalocyanine blue, copal polybrorophthalocyanine blue, etc., and anthraquinone pigments such as industrone blue, isodibenzatron violet, anthanthrone orange, etc.

Dyes include safranin, rhodamine, magenta, alizarin red, lupine red, chrysoidine, acetamine orange, auramine, quinoline, eucrysin yellow, first light yellow, stilbene yellow, azo yellow, methanil yellow, guictolya green, and anthraquinone. Green, naphthol green, methylene blue, indigo, diazo blue, naphthol blue, fast blue, xylene blue, methylene violet, crystal violet, Bismarck brown, chrome brown, etc.

These dyes and pigments may be used alone or in combination. The amount used depends on the absorbance of the dye and pigment, but
101q! 7m2 or t 00 Ill/m
2. Preferably from 2011497m2 to 200mp
/m2, but in order to obtain the effects of the present invention, it is necessary that the maximum value of visible spectral absorption of the coated surface be 00-2 or more/and 0 or less. The maximum value of visible spectral absorption referred to here is the maximum value of absorbance when monochromatic light with a wavelength from JfOnm to 7tθnm is irradiated.

The coating liquid thus obtained is applied onto a base paper as a support by a conventional coating method such as a bar coater, blade coater, air knife coater, roll coater, gravure coater, etc., and dried. Calendar and finish as necessary.

The preferred coating amount is jr/m2 to kθ as solid content.
f/m2. More preferably ≠y/m2 to lff7
It is m2.

It is also possible to use paper-like materials such as coated paper and synthetic paper as the support.

When calendering is used, what is the smoothness of the coated surface?

, 200 seconds or more and 1000 seconds or less, and more preferably μ00 seconds or more/000 seconds or less.

(Examples of the Invention) Examples of the present invention are shown below, but the present invention is not limited thereto.

-73 Example/-j As an electron-donating dye, 2-Ayu IJ No 3-chloro t-diethylaminofluoran 20ttl-j Polyvinyl alcohol (Kuraray PVA10.r) aqueous solution/θ
oy and dispersed in a ball mill overnight to obtain liquid A.

2.2-bis(1)-hydroxyphenyl)furopanet
The mixture was dispersed overnight with Ofijq6 polyvinyl alcohol aqueous solution toot and stearic acid amide toy to obtain liquid B.

Calcined kaolin (Engelhard Ansilex Rio)
iooy sodium hexametaphosphate/thi solution 100
? Disperse with a homogenizer to obtain liquid C.

Mix liquid A, Bf & C, and add 30% of zinc stearate.
4 dispersion (Middle East Oil Hydrin Z-7) toy and the dyes and pigments shown in Table 1-1 dispersion, 20f were added to prepare a heat-sensitive coating liquid. This was applied with a Mayer parser to a dry coating amount of 19/m2 on high-quality paper having a basis weight of toy/m2, dried with IO"c for -/#- for 3 minutes, and calendered to smooth the surface. The angle was set to !Oθ seconds (Beck).

The obtained thermal paper satisfies all the performances required for thermal recording paper, such as print density, recording sensitivity, and color former storage stability, and
The background color could be colored to the desired hue.

Comparative Examples 7 to 3 As comparative examples, cases were confirmed in which the colored dye or colored pigment of the present invention was not used at all, and even if it was used, the amount used was outside the amount specified in the present invention. The implementation method is exactly the same as the example, except that the amount of dye added is different.

The printing fIk degree of the obtained thermal recording paper was measured in the copy mode using a MiniFax ■ type facsimile manufactured by Dentsu Corporation. The measurement was carried out using a Macbeth RD-Tite reflection densitometer in visual mode.

The storage stability of the colored material is as follows: print sample is θ0C20%RH
It was stored in an atmosphere for 21 hours, and the rate of decrease in concentration before and after was measured. (The lower the value, the better the storage stability), the contrast between the printed area and the background, and the vividness and chroma of the background) were visually judged.

The results are shown in Table 1.

- Dye or pigment used Amount used Hue Maximum visible color on the background Q Example 1 Fiber Stra (L-Yellow Co01
Yellow 0.761- Crystal Violet
l Purple 0. J/l 3 Naphthol Green I Green o, zλy
4t Kono R-Phthalocyanine Blue z
Il O, IfI! Hansa yellow
I yellow o, ti comparative example 1)
Ryo Stride Yellow 111 Light yellow O
Olli 12 Same as above rot @ yellow 8l! l
3 None -White o, orl 7- Distribution Print density Preservability (decrease rate) Contrast Background saturation 1.2≠ 3% Good
Good 1, Ko 3 Guchi 1, Ko r / Section 7.24 2 Section /, Coco 0% /, 244 7%

Claims (1)

[Claims] In a thermal recording paper provided on a support with a thermosensitive coloring layer containing as a main component an electron-donating colorless dye and an electron-accepting compound that reacts with the dye to form a color when heated, a colored coloring layer is provided in the thermosensitive coloring layer. 1. A thermosensitive recording paper containing a dye or a pigment and having a maximum visible spectral absorption of a thermosensitive coloring surface of 0.2 or more and 1.0 or less.