JPS6256195A - Recording method - Google Patents

Abstract

PURPOSE:To permit the recording of pictures with high coloring sensitivity and high energy utilizing efficiency by a method in which a light absorbing layer composed of a light absorber is provided on the surface of a transparent or semi-transparent supporter, a thermal color-forming layer composed of a thermal color-forming agent is provided on the light absorbing layer, and laser beam is irradiated onto the back side of them. CONSTITUTION:A light absorbing layer composed of a light absorber is provided on the surface of a transparent or semi-transparent supporter, and a thermal color-forminglayer composed of a thermal color-forming agent is provided on the light absorbing layer to form a recording medium. As the supporter used, polyester film, polymide film, thin papers, papers impregnated with resin or wax, etc., may be cited, which refuges to absorb laser beam wavelength. When laser beam is irradiated onto the back side of the recording medium, the light absorbing layer is heated up, and the thermal color-forming layer on the light absorbing layer is allowed to color thermally for desired recording. Since a laser beam passes through the supporter and is irradiated to the light absorbing layer directly, high light absorbing efficiency can be obtained, permitting high- speed printing to be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a recording method using a laser beam.

[Prior art]

Conventionally, a thermosensitive recording method is widely known in which a support with a thermosensitive coloring layer provided on the surface is used as a recording medium, and a colored image is recorded by closely scanning the thermosensitive coloring layer on the surface with a thermal head having a heating element. It is being However, in such a thermal recording method, since the thermal head is scanned in close contact with the thermosensitive coloring layer, wear of the thermal head and debris adhesion to the surface of the thermal head occur, resulting in abnormal images and damage to the thermal head. In addition to problems such as a shortened lifespan, there is also the major problem that the recording speed, that is, the heating rate, is not sufficient and it is difficult to increase the recording speed.In addition, the density of the heating elements of the thermal head is low, so the images obtained have low resolution. There is also the problem that it is inferior to

On the other hand, in order to avoid the above-mentioned problems encountered in thermal recording using a thermal head, it is possible to perform thermal recording on the thermosensitive coloring layer in a non-contact manner at high density and high speed using a laser beam. is proposed. (for example,
JP-A-59-42994, JP-A-59-891
Publication No. 92, etc.). However, in such a heating method using a laser beam, the heat-sensitive color forming layer generally has a weak property of absorbing light in the visible and near-infrared regions, so the laser beam must be of considerably high energy. Color development is difficult to occur. Therefore, 5 conventional laser beams 11
In the recording method using the laser beam, it is common practice to add a light absorbing material suitable for the wavelength of the laser beam to the thermosensitive coloring layer. In this case, it is sufficient if the light-absorbing material to be added is white, but if it is colored, it is not preferable because it lowers the background whiteness of the recording medium. In addition, in general, many white light absorbing materials are inorganic compounds.

Since the degree of light absorption of these materials is considerably lower than that of organic compounds, it is necessary to develop light-absorbing materials of non-colored organic compounds in order to create highly sensitive recording media. However, it is difficult to obtain non-colored and inexpensive organic light-absorbing materials.

〔the purpose〕

An object of the present invention is to solve the above-mentioned problems seen in the prior art, and to make it possible to use a recording medium with high background whiteness, a laser with high energy utilization efficiency, and capable of recording images with high color development sensitivity. The goal is to provide beam recording power.

〔composition〕

According to the present invention, a translucent support is provided with a light-absorbing layer made of a light-absorbing material on the surface thereof, and a heat-sensitive color-forming layer made of a heat-sensitive color-forming material is provided on the surface of the translucent support, which is used as a recording medium. A recording method is provided which is characterized in that desired recording is performed on the thermosensitive coloring layer by irradiating a norther beam from the back surface thereof.

In the present invention, the recording medium used is one in which a light absorption layer made of a light absorption material is provided on the surface of a transparent or translucent support, and a heat-sensitive coloring layer made of a heat-sensitive coloring material is provided on one of the surfaces of the support. Examples of transparent or translucent supports include various resin films such as polyester, polyimide, polyvinyl chloride, polyvinylidene chloride, cellulose acetate, and polyacrylate, as well as thin paper such as tracing paper, impregnated with resin or wax. Examples include paper.

It is important to use a support used in the present invention that is highly transparent and does not exhibit absorption at the wavelength of the irradiated laser beam, and if necessary, an antireflection layer such as a metal layer is provided on the back side of the support. can be provided by a coating method, a vapor deposition method, or the like.

The light-absorbing material may be any material as long as it exhibits absorption properties for the laser beam used, and various conventionally known materials can be used, such as metal oxides, hydroxides, etc. In addition to various inorganic compounds such as silicates, sulfates, carbonates, nitrates, and complex compounds, cyanine,
Examples include various light-absorbing organic compounds such as polyenes. Specific examples of these light-absorbing materials include copper sulfate, barium sulfate, zinc silicate, zinc carbonate, feldspar group minerals,
Ovallitic group minerals, pomegranate group minerals, mica group minerals, carbon, triphenyl phosphate, bis(1-thio-2-ferulate) nickel tetrabutylammon, 1,1-
Bis-diethyl-6,6'-dichloro-4,4'-
Kitlicarposianine iodide, 1,5-di(P
-dimethylaminophenyl)-1゜4-pentadiene perchlorate, etc. 6. The thermosensitive coloring materials include:
Any material that exhibits thermochromic properties may be used, and any conventionally known material may be used. Examples of such thermosensitive coloring materials include the following.

(a) Silk combination of leuco dye and color developer.

(b) Combinations of long-chain aliphatic iron salts such as ferric stearate and ferric myristate with phenols such as gallic acid and ammonium salicylate.

(c) Organic acid heavy metal salts such as nickel, cobalt, lead, copper, iron, mercury, and silver salts such as acetic acid, stearic acid, and palmitic acid, and alkaline earth metals such as calcium sulfide, strontium sulfide, and potassium sulfide. A combination with a sulfide or a combination of the organic acid heavy metal salt with an organic chelating agent such as S-diphenylcarbazide or diphenylcarbazone.

(d) Heavy metal sulfates such as silver, button, mercury, thorium sulfates, Na-tetrathionate, sodium thiosulfate6
combination with sulfur compounds such as thiourectal (e) fatty acid ferric salts such as ferric stearate;
3. Combination with aromatic polyhydroxy compounds such as 4-dihydroxytetraphenylmethane.

(f) A combination of an organic noble metal salt such as silver oxalate or mercury oxalate and an organic polyhydroxy compound such as polyhydroxy alcohol, glycerin, or glycol.

(g) A combination of an organic metal salt such as silver behenate or silver stearate and an aromatic organic reducing agent such as protocatechuic acid, spiroindane or hydroquinone.

(H) A combination of an aliphatic ferric salt such as ferric pelargonic acid or ferric laurate and a thiocetyl ferric salt or an isothioceyl ferric rubamide derivative.

(S) Combinations of organic acid lead salts such as lead caproate, lead pelargonate, and lead behenate and thiourea derivatives such as ethylenethiourea and N-dodecylthiourea.

(n) A combination of a higher fatty acid heavy metal salt such as ferric stearate or copper stearate and zinc dialkyldithiocarbamate.

(l) Those that form oxazine dyes, such as the combination of resorcinol and nitroso compounds.

(w) Combination of aromatic diazo compound and coupler.

(iv) A combination of a formazan compound and a reducing agent and/or a metal salt.

In the heat-sensitive color forming material consisting of a leuco dye and a color developer shown in (a) above, the leuco dye may be one that is applied to this type of heat-sensitive material, such as triphenylmethane type, fluoran type, or phenothiazine type. Leuco compounds of basic dyes such as auramine-based dyes, auramine-based dyes, and spiropyran-based dyes are preferably used. Specific examples of such basic leuco dyes include those shown below.

3.3-Bis(P-dimethylaminophenyl)-phthalide.

3.3-His(p-dimethylaminophenyl)-6-dimethylaminophthalide (also known as crystal violet lactone), 3.3-bis(p-dimethylaminophenyl)-6-dibutylaminophenyl, 3.3- Bis(P-dimethylaminophenyl)-6-chlorophthalide, 3.3-bis(P-dibutylaminophenyl)phthalide, 3-cyclohexylamino-6-chlorofluoran, 3-diethylamino-6-chloro-7-methyl Fluoran, 3-dimethylamino-5,7-dimethylfluoran, 3
-diethylamino-7-chlorofluorane, 3-diethylamino-7-methylfluorane, 3-diethylamino-7,8-benzfluorane, 3-diethylamino-6
-Methyl-7-chlorofluorane, 3-(N-p-tolyl-N-ethylamino)-6-methyl-7-anilinofluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane.

2- (N-(3'-trifluoromethylphenyl)
amino)-6-dinithylaminofluorane.

2-(3,6-bis(diethylamino)-9-(o-
chloranilino)xantylbenzoic acid lactam), 3-
Diethylamino-6-methyl-7-(m-trichloromethylanilino)fluoran, 3-diethylamino-7-(0-chloroanilino)fluoran, 3-dibutylamino-7-(o-chloroanilino)fluoran, 3-dibutylamino- 7-(0-fluoroanilino)fluorane, 3-N-methyl-N-amylamino-6-methyl-7-
Anilinofluorane, 3-N-methyl-N-cyclohexylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-(N-isoacyl- N-ethyl)amino-7-(0
-chloroanilino)fluoran, 3-(N-hexyl-N-methyl)amino-7-(0-
chloroanilino)fluoran 3-(N,N-diethylamino)-5-methyl-7-(
~.

N-dibenzylamino)fluorane, benzoylleucomethylene blue, 6'-chloro-8'-methoxy-benzoindolino-pyrylosubiran, 6'-bromo-3'-methoxy-benzoindolino-pyrylosubiran, 3-(2'- 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-41-chloro-5'
-methylphenyl)phthalide, 3-morpholino-7-(N-propyl-trifluoromethylanilino)fluoran, 3-pyrrolidino-7-(m-trifluoromethylanilino)fluoran, 3-diethylamino-5-chloro- 7-(N-benzyl-trifluoromethylanilino)fluorane.

3-pyrrolidino-7-(di-p-chlorophenyl)methylaminofluorane, 3-diethylamino-5-chloro-7-(α-phenylethylamino)fluoran.

3-(N-Ethyl-P-F Luidino)-7-(α-phenylethylamino)fluoran, 3-diethylamino-7-(o-methyl-xycarbonylphenylamino)fluoran, 3-diethylamino-5- Methyl-7-(α-phenylethylamino)fluoran.

3-diethylamino-7-piperidinofluorane, 2-
Chloro-3-(N-methyltoluidino)-7-(p-n
-butylanilino)fluorane, 3-(N-benzyl-/N-cyclohexylamino)-
5,6-penzo 7-α-naphthylamino-4'-bromofluorane, 3-diethylamino-6-methyl-7-mesitidino 4
', 5'-benzofluorane, etc.

As the leuco dye, in addition to the above-mentioned basic leuco dye, acylated lactone type or sultone type acidic leuco dye as shown below can be used, and can be colored by reacting with the above-mentioned basic leuco dye under heat. Examples of the color developer include the following.

N,N'--diphenylthiourea, N-P-ethylphenyl-N'-phenylthiourea, N-p-butylphenyl-N'-phenylthiourea, N,N'-di-m-chlorophenylthiourea, N , N'-di-P-chlorophenylthiourea, N,N'-di-m-trifluoromethylphenylthiourea, N,N'-di1rmethylphenylthiourea, 4,4'-isopropylidenediphenol, 4 , 4'-isopropylidene bis(2-chlorophenol), 4.4'-isopropylidene bis(2-chlorophenol)
, 6-dibromophenol), 4,4'-isopropylidene bis(2,6-dichlorophenol), 4,4'-
Isopropylidene bis(2-methylphenol), 4.
4'-isopropylidene bis(2,6-dimethylphenol), 4,4'-isopropylidene bis(2-ter
t-butylphenol), 4.4'-5ee-butylidene diphenol, 4,4'-cyclohexylidene bisphenol, 4,4'-cyclohexylidene bis(2
-methylphenol), 4-tart-butylphenol, 4-phenylphenol, 4-hydroxydiphenoxide, α-naphthol, β-naphthol, 3.5-xylenol, thymol, methyl-4-hydroxybenzoate, 4-hydroxyacetophenone, Novolak type phenolic resin, 2,2'-thiobis(4,6-dichlorophenol), catechol, resorcinol, hydroquinone, pyrogallol, phloroglycine, phloroglycine carboxylic acid, 4-F, ert-octyl tether,
2.2”-methylenebis(4-chlorophenol), 2
．． 2'-<tyrenebis(4-methyl-6-tert
-butylphenol), 2°2'-dihydroxydiphenyl, ethyl p-hydroxybenzoate, propyl p-hydroxybenzoate.

butyl p-hydroxybenzoate, benzyl p-hydroxybenzoate, p-chlorobenzyl p-bitroxybenzoate, 0-chlorobenzyl p-hydroxybenzoate,
P-methylbenzyl p-hydroxybenzoate, n-octyl p-hydroxybenzoate, benzoic acid, 1-hydroxy-2-naphthoic acid, 2-hydroxy-6-naphthoic acid, 4-hydroxydiphenylsulfone, 4- Hydroxy-4'-chlorodiphenyl sulfone, bis(4-hydroxyphenyl) sulfide, etc.

Furthermore, examples of color developers that can develop color by reacting with the acidic leuco dye described above under heat include the following.

N,N'-dicyclohexyl-N-phenylguanidine, N,N'-diphenylacetylpiperazine, isophthaloylbis(N-methyl-cyclohexylamine), terephthaloylbis(N-ethyl-cyclohexylamine).

Terephthaloyl bis (N-isopropyl-cyclohexylamine, etc.).

The laser beam used in the present invention is one for generating heat, and preferably has a wavelength range of 0.8 μm to 20 μm. As the laser beam light source, for example, a variable wavelength carbon dioxide laser, a YAG laser, a semiconductor laser, etc. are used.

In the recording medium used in the present invention, the amount of the light absorbing material attached to the support is 0.5 to 10 g/rr! It is preferable that the amount of heat-sensitive coloring material adhered is within a range of 2 to 2.
The amount is preferably in the range of 10 g/-. When applying the light-absorbing material to the surface of the support, it may be applied in the form of a fine powder pulverized with a sand glider or ball mill, or it may be applied as an organic solvent solution. The heat-sensitive color forming material is preferably contained in the heat-sensitive color forming layer in the form of solid fine particles, and for this purpose, the heat-sensitive color forming material is preferably applied in the form of a dispersion.

〔effect〕

To carry out the recording method of the present invention, a laser beam is irradiated from the back side of the recording medium, that is, from the side that does not have a thermosensitive coloring layer. As a result, the light absorption layer generates heat, and due to the heat generation, the thermosensitive coloring layer above it is thermally colored, and desired recording can be performed on the thermosensitive coloring layer. In this recording method, the laser beam passes through the support and is directly irradiated onto the light absorption layer, resulting in significantly increased light absorption compared to when the laser beam is irradiated onto the light absorption layer through the thermosensitive coloring layer. Efficiency is achieved and high-speed printing is possible.

Further, in the recording medium used in the present invention, the light-absorbing material is not added to the thermosensitive coloring layer, but is coated as a lower layer of the thermosensitive coloring layer, so that the recording medium can have a high background whiteness. In particular, when the thermosensitive coloring layer is formed using a thermosensitive coloring material in the form of solid fine particles and the thermosensitive coloring layer is made opaque, the recording medium has a high background whiteness even if a colored light absorbing material is used. Can be done. Therefore, in the present invention, the material of the light absorbing material is not particularly limited, and colored organic materials with high light absorption efficiency can be used.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples. Note that all parts and percentages shown below are based on weight.

Example [Dispersion A] Zinc silicate 30 parts Polyvinyl alcohol 10% aqueous solution 30 parts Surfactant 0.2 part Water
40 parts of the above composition was dispersed in a ball mill to obtain a dispersion A having an average particle size of 2 μm.

[Dispersion B]

3-Dibutylamino-7-(o-chloroanilino)fluoran 20 parts Polyvinyl alcohol 10% aqueous solution 20 parts Surfactant
0.1 part water
60 parts [Dispersion C] N,N-bis(Il+-talolophenyl)urea 2
0 parts titanium oxide 10 parts α
- Methyl cyanocinnamate 20 parts High density polyethylene wax 2 parts Surfactant
0.5 parts polyvinyl alcohol 1
0% aqueous solution 50 parts water
78 parts of the dispersion A was applied onto a polyester film having a thickness of 30 μm at a dry adhesion amount of 3.
g/rrf with a lab wire rod and 1 at 50°C.
After drying for a while, a light absorbing layer was formed.

Next, a mixture of the dispersion B and the dispersion C in a ratio of 1=3 was placed on the light absorption layer with a dry adhesion amount of 4,
It was coated at 0 g/rrf and dried to form a heat-sensitive coloring layer.

Next, a wavelength tunable carbon dioxide laser (output 0.8 W, wavelength 10.8
p m, beam diameter 100 p m, linear density 12 n
p/mm, scanning speed 1 m/s) to obtain a black colored image.

The density of this colored image was measured using a microdensitometer and found to be 0.9. The density of the non-image area (background) was 0.10 as a result of the measurement, indicating a high degree of whiteness.

Comparative Example When the recording medium shown in Example 1 was similarly irradiated with a laser beam from the front side, the obtained black image density was 0.5.

From the results of the Examples and Comparative Examples, it can be seen that the recording method of the present invention provides high color image density and can print at higher speeds.

Claims (2)

[Claims] (1) A recording medium is used in which a light-absorbing layer made of a light-absorbing material is provided on the surface of a transparent or semi-transparent support, and a heat-sensitive coloring layer made of a heat-sensitive coloring material is provided on the light-absorbing layer, and the back side of the recording medium is A recording method characterized by irradiating a laser beam with a laser beam to perform desired recording on the thermosensitive coloring layer. (2) The method according to claim 1, wherein the thermosensitive coloring material is present in the form of solid fine particles in the thermosensitive coloring layer.