KR100214054B1 - Heat-sensitive recording material - Google Patents

Abstract

The thermal recording agent contains a support, an electron-retaining coloring compound, an electron-receiving compound, and a binder resin, a thermal recording layer formed on the support, and an ultraviolet-curable resin and a copolymer resin containing a silicone component as a copolymerization component. It has a protective layer formed on the recording layer.

Description

Thermal recording system

The present invention is light transmissive and can form colored images on thermal recording materials by coloring reaction of electron-donating and electron-accepting compounds. It relates to thermosensitive recording materials, and more particularly to block copy films, i.e. image forming films for gravure printing, offset printing and silk screen printing: sketch films for screen fabric printing: overhead projector : An image forming film for use with OHP), and a thermal recording material that can be used in an image forming film for a computer aided design (CAD) system.

A thermal effect in which a colored image can be formed on a thermal recording material by a color reaction between an electron donor compound (hereinafter referred to as a 'coloring agent') and an electron acceptor compound (hereinafter referred to as a 'color developer'). It is about a recording material.

Generally, such a thermal recording material is produced by providing a thermal recording layer containing a thermally colored composition as a main component on a support such as paper, synthetic paper or plastic film. The colored image can be formed on the thermal recording material by applying heat to the thermal recording material using a thermal head, a thermal pen or a laser beam. This type of recording material is advantageous over other recording materials as it can be recorded quickly using a relatively simple device without requiring complicated development and image fixing steps. Noise and environmental problems can be minimized, and the cost of manufacturing the recording material is low. Due to the above advantages of the thermal recording material, it is widely used in electronic computer terminal devices, facsimile and label and ticket recorders and vending machines, and the like.

The heat-sensitive coloring composition used in the heat-sensitive recording material includes a colorant and a coloring agent to form a color in the colorant when heat is applied to the heat-sensitive recording material. More specifically, colorless to pale leuco dyes having lactones or lactams or spiropyran rings: and various acidic substances such as organic acids and phenolic compounds are commonly used as colorants. The recording material used by mixing the coloring agent and the coloring agent has a clear color tone and can form a colored image such that the background is maintained at a high level of white.

Recently, a thermal recording system has been used in place of a conventional recording system. Furthermore, there has been an increasing demand for a thermal recording system, and a demand for improving the quality of the thermal recording material for use with the thermal recording system described above has been increased. For example, transparent or translucent thermal recording materials capable of forming images with excellent image contrast, which can be used as image forming films for OHP, diazo intermediate paper, schematic films and sketch films for gravure printing, offset printing and silk screen printing. Required.

A transparent thermal recording medium is shown in Japanese Laid-Open Patent Application No. 1-99879. In order to prepare such a transparent thermal recording medium, a coating liquid of an emulsion dispersion comprising a colorant in microcapsule form and a colorant insoluble in water or slightly soluble in an organic solvent is encoded on a transparent support.

Another method for producing a transparent thermal recording medium is disclosed in Japanese Laid-Open Patent Application 5-104859. In this application, first, a solvent in which the organic acid used as the coloring agent is slightly dissolved or not dissolved and the colorant and binder resin used are dissolved. The dispersion is prepared by finely dispersing an organic acid used as a coloring agent in the solvent, and the solution is prepared by dissolving the colorant and binder resin in the solvent described above and mixing and stirring to obtain a coating liquid for use in the thermal recording layer. The coating liquid obtained as described above is coated on a transparent support, and thus a thermal recording layer is obtained. Thereafter, a protective layer mainly containing resin is provided on the thermal recording layer in order to fill the fine rough surface of the thermal recording layer. By the above method, a thermally sensitive recording medium excellent in transparency can be obtained.

Moreover, a thermal recording medium which can be applied as a printing sketch film is shown as disclosed in Japanese Laid-Open Patent Application 8-118811.

However, focusing on the transparency of the recording medium, the matching porperty of the conventional transparent or translucent thermal recording medium with respect to the heat head is hardly considered. For example, the heat meltable material used in the thermal recording medium is melted during the thermal printing process and the melted dust is attached to the heat head. As a result, the image thus obtained is smeared and blurred, the thermal head is worn and a short-circuit is generated between the column head electrodes. Furthermore, the application of heat to the thermal recording medium results in a so-called sticking phenomenon in which the thermal recording medium adheres to the thermal head, resulting in abnormal images. As mentioned above, the problem of head-matching of a conventional transparent or opaque thermal recording medium is more serious than that of a general purpose thermal recording paper, and thus needs to be improved. In particular, when the thermal recording medium is used as a printing sketch film, when these sketch films having different colors are incorporated, the size of the images independently formed on the sketch film having different colors must be accurate so that the head-matchability of the thermal recording medium can be corrected. Improvement is the most important issue.

In terms of function, it is preferable that the problem related to the head-compatibility is compensated by the protective layer provided on the thermal recording layer. It is preferable to use a material having heat resistance, excellent thermal releasability and excellent adhesion as a protective layer for the purpose of improving head-matching properties. Moreover, the protective layer serves to improve the transparency of the recording medium and to impart chemical resistance, water resistance, light resistance, and wear resistance to the recording medium. Therefore, it is very important to select a material used for the protective layer in consideration of the action of the protective layer.

Moreover, the problem of fogging, one of the problems associated with thermal recording agents, still remains and needs to be improved.

Accordingly, it is a first object of the present invention to provide a thermal recording material which does not have the problem of ordinary transparent or translucent thermal recording material, that is, insufficient matching problem with respect to the heat head. That is, a first object of the present invention is to provide a thermal recording material which minimizes dust generation of a heat-meltable material adhered to a heat head and prevents adhesion occurring.

It is a second object of the present invention to provide a thermal recording material with minimal blur.

The first and second objects of the present invention described above include a heat-sensitive recording layer formed on a support, including a support, an electron-providing coloring compound, an electron-receiving compound, and a protective resin, and a silicone component as an ultraviolet-curing resin and a copolymerization component. It is achieved by a thermosensitive recording material comprising a copolymer resin containing and comprising a protective layer formed on the thermosensitive recording layer.

The resin component used for the protective layer of the thermal recording material according to the present invention requires high heat resistance. Therefore, as the protective layer, a cured resin capable of forming a three-dimensional network structure is theoretically preferable. However, it is impossible to cure the resin at a temperature of 60 ° C. or higher at which the thermal recording material is produced. Furthermore, in consideration of the productivity of the recording material, it is considered that the protective layer containing the ultraviolet-curable resin and the copolymer resin containing the silicone component as the copolymerization component is effective.

UV-curable resins can be used with any conventional monomer, oligomer or prepolymer which polymerizes by applying ultraviolet light to form a cured resin. It does not limit the monomers, oligomers or prepolymers used in the preparation of the ultraviolet-curing resin used for the protective layer.

Specific examples of such monomers or oligomers include (poly) ester acrylates, (poly) urethane acrylates, epoxy acrylates, polybutadiene acrylates, silicone acrylates and melamine acrylates.

The (poly) ester acrylates described above react polyacrylic acids such as 1,6-hexanediol, propylene glycol (propylene oxide form) or diethylene glycol and polyacids such as adipic acid, phthalic anhydride or trimellitic acid with acrylic acid. To make it.

Examples of (poly) ester acrylate structures are as follows:

(a) adipic acid / 1,6-hexanediol / acrylic acid

However, n is an integer of 1-10.

(b) phthalic anhydride / propylene oxide acrylic acid

However, 1, m and n are the integers of 1-10 each independently.

(c) trimellitic acid / diethylene glycol / acrylic acid

The (poly) urethane acrylate is prepared by reacting a compound having an isocyanate group such as tolylene diisocyanate (TD1) with an acrylate having a hydroxy group.

The structure of the (poly) urethane acrylate is as follows:

(d) HEA / T field / HDO / ADA / HDO / T field / HEA

However, HEA is 2-hydroxyethyl acrylate, TDI is tolylene diisocyanate, HDO is 1,6-hexanediol, and ADA is adipic acid.

However, n is an integer of 1-10.

Epoxy acrylates are roughly classified into bisphenol A, noblock, and aliphatic ring types. The epoxy group of the epoxy resin is esterified with acrylic acid and converted into an acryloxy group.

Examples of epoxy acrylate structures are as follows:

(e) Bisphenol A-epichlorohydrin type / acrylic acid

However, n is an integer of 1-15.

(f) Phenol Noblec-Epichlorohydrin Type / Acrylic Acid

However, n is an integer of 0-5.

(g) alicyclic / acrylic acid

Where, R is - (CH ₂₎ represents an n-, n is an integer from 1 to 10.

Polybutadiene acrylate is prepared by reacting isocyanate or 1,2-mercaptoethanol with terminal-hydroxy-group-containing 1,2-butadiene to obtain a reaction product, and then reacting the reaction product thus obtained with acrylic acid or the like. .

Examples of the polybutadiene acrylate structure are as follows.

Silicone acrylates are obtained by modifying methacryl, which is for example carried out by the condensation reaction (methanol removal reaction) of an organofunctional trimethoxy silane with a polysiloxane containing silanol-groups.

Examples of silicone acrylate structures are as follows.

However, n is an integer of 10-14.

When ultraviolet-curing resin is used as the protective layer, a solvent may be used.

Examples of such solvents are organic solvents such as tetrahydrofuran, methyl ethyl ketone, methyl isobutyl ketone, chloroform, carbon tetrachloride, ethanol, isopropyl alcohol, ethyl acetate, butyl acetate, toluene and benzene.

Instead of an organic solvent, a photopolymerizable monomer may be used as the reaction diluent to facilitate handling.

Specific examples of the additional photopolymerizable monomers include 2-ethylhexyl acrylate, cyclohexyl acrylate, butoxyethyl acrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate trimethyl Allpropane triacrylate and pentaerythritol triacrylate.

The preferred amount of ultraviolet-curable resin used in the protective layer in the present invention is in the range of 10 to 50 wt% of the total weight of all solid components of the protective layer. When the amount of ultraviolet-curable resin used for the protective layer is within the above range, the heat resistance of the protective layer is maintained, and thus, dust of the heat-meltable material is prevented from adhering to the thermal head surface. At the same time, the thermal recording material is provided with sufficient lubricity, thereby minimizing the occurrence of adhesion.

The protective layer of the thermal recording material according to the present invention contains a copolymer resin containing the above-described ultraviolet-curable resin and a silicone component as the resin component.

Copolymer resins containing silicone segments can be used, but silicone-graft-copolymers or silicone-block-copolymers are advantageous because of their excellent heat resistance.

Specific examples of copolymer resins comprising silicone fractions include silicone-modified polyvinyl butyral, silicone-modified polyvinyl acetal, silicone-modified polyacrylate, silicone-modified polymethacrylate, silicone-modified Polyvinyl acetoacetal, silicone-modified cellulose acetate propionate, silicone-modified cellulose acetate, silicone-modified cellulose acetate butyrate, silicone-modified ethyl cellulose, silicone-modified polyurethane and silicone-modified polyester It includes.

Among the silicone-modified resins, silicone-modified polyvinyl butyral and silicone-modified polyvinyl acetals are very effective in heat resistance.

The preferred weight ratio of copolymer resin to ultraviolet-curable resin comprising the silicone fraction used in the protective layer is in the range of (1: 9) to (7: 3). When the weight ratio is within the above range, the adhesiveness is prevented from occurring because the lubricity of the obtained thermal recording material is sufficient. At the same time, the heat resistance of the protective layer is sufficient so that dust of heat-meltable material can be prevented from adhering to the heat head.

As described above, when a protective layer comprising an ultraviolet-curable resin and a copolymer resin comprising a silicone fraction is provided on the thermal recording layer, the compatibility of the thermal recording material with respect to the thermal head is improved, and thus heat-meltable to the thermal head. Dust from the material is prevented from adhering, and the occurrence of adhesion is minimized.

Furthermore, when the protective layer includes a cross-linking agent capable of reacting with the above-described copolymer resin containing a silicone fraction, the heat resistance of the protective layer is further improved, and even if the thermal printing is applied with high thermal energy to the thermal recording material The occurrence of adhesion can be minimized.

In this case, any cross-linking agent that can react with the copolymer resin containing the silicon fraction to form a three-dimensional structure can be used. For example, an isocyanate compound and a compound having an epoxy group or an amino group can be used as the crosslinking agent.

In particular, the isocyanate compound is most preferable for use as a crosslinking agent because of excellent reactivity with the copolymer including the silicone fraction and excellent stability after the reaction.

Specific examples of isocyanate compounds used as crosslinkers include xylene diisocyanate, tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane triisocyanate, tolidine diisocyanate, xylene Diisocyanate, hexamethylene diisocyanate and modified compounds thereof, dicyclohexylmethane diisocyanate and isophorone diisocyanate.

Of the above isocyanate compounds, xylene diisocyanate is particularly effective for preventing blur of the thermal recording layer.

The preferred amount of isocyanate compound used in the protective layer is 3 to 30 wt% of the total weight of the protective layer solids content. When the isocyanate compound is contained in the protective layer in such an amount, sufficient cross-linking reaction occurs, thus minimizing dust generation of the heat-meltable material that adheres to the heat head. Moreover, since substantially no unreacted isocyanate is present, the heat-resistant build-up of the protective layer is not disturbed, thus preventing the occurrence of sticking phenomenon.

Furthermore, it is preferable that the protective layer further include a metal salt and / or an amino-modified silicone oil so that it is applicable to a thermal printing operation in which high thermal energy is applied to the thermal recording material. At this time, the head-matching property of the thermal recording material is remarkably improved.

As the metal salt used in the present invention, fatty acid metal salts having 10 or more carbon atoms such as, for example, barium stearate, calcium stearate, zinc stearate, aluminum stearate and magnesium stearate can be used.

The preferred amount of metal salt used in the protective layer is in the range of 0,5 to 10 wt% of the total weight of the protective layer solids content.

The amino-modified silicone oils used in the protective layer are silicone oils having aminopropyl groups or N- (2-aminoethyl) aminopropyl groups in the molecule. Unlike dimethyl silicone oils, the amino-modified silicone oils described above are chemically active because they have reactive amino groups.

The preferred amount of amino-modified silicone oil used in the protective layer is 0.5-10 wt% of the total weight of the protective layer solids content.

In order to effectively eliminate the fogging of the thermal recording layer, the thermal recording layer or the protective layer may further include at least one decolorant selected from the group consisting of the following compounds A to D.

[Compound A]

Where n is an integer: R ¹ is CH ₃ :

[Compound B]

[Compound C]

[Compound D]

1,3-dicyclohexyl-2- (2 ', 5'-dicyclophenyl) guanidine.

In order to further improve the heat resistance and anti-sticking property of the protective layer, the protective layer may further include a filler having a high heat resistance and capable of removing heat-meltable dust adhering to the heat head.

The fillers are largely classified into two groups, organic fillers and inorganic fillers. In the present invention, the organic and inorganic fillers may be used in the protective layer by being mixed so that the surface smoothness of the protective layer is not significantly reduced and the transparency of the thermal recording material is not impaired.

Specific examples of fillers used in the present invention include finely ground inorganic filler particles such as calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, kaolin, talc, and surface treated calcium carbonate and silica. And finely ground organic filler particles such as urea formalin resin, styrene-methacrylic acid copolymer and polystyrene resin. The organic and inorganic fillers may be used alone or in combination.

The filler used in the present invention is in the form of finely-pulverized particles having an average particle size of 3 μm or less, and it is preferable to absorb 10 ml or more of oil.

In the protective layer, the filler: UV-curable resin and the silicone fraction comprises a copolymer resin comprising a resin component: cross-linking weight ratio of (10 to 60%): (5 to 75%): (3 to 30% )to be.

The protective layer of the thermal recording material requires not only excellent head-matching properties but also high transparency, storage stability and the like. Thus, other materials may be contained in the protective layer.

For example, the copolymer resin comprising the ultraviolet-curable resin and the silicone fraction can be used with the following hydrophobic resins: ethyl cellulose, cellulose propionate acetate, cellulose butyrate acetate, polyvinyl butyral, polyvinyl acetal , Polyesters, cellulose acetates, polyurethanes, polyacrylates, vinylchloride-vinyl acetate copolymers, polyacrylic acids, polyvinyl acetates, polystyrenes and ethylene-vinyl acetate copolymers.

Furthermore, like the thermal recording layer, the protective layer may further comprise not only the above-described metal salts and amino-modified silicone oils, but also lubricants, ultraviolet absorbers, antioxidants, antifogants and dispersants.

The thickness of a preferable protective layer is 0.3-10 micrometers, More preferably, it is 0.5-5 micrometers. When the thickness of the protective layer is within the above range, the protective layer functions sufficiently without an increase in manufacturing cost, thereby improving the storage stability of the recording material, and increasing the head-coincidence without reducing the thermal sensitivity of the recording material.

The thermal recording layer will be described in detail below.

In the thermal recording material of the present invention, it is preferable that the refractive index of the protective layer and the refractive index of the thermal recording layer are substantially the same. In theory, even though the refractive indices of these layers are different, the light incident on the thermal recording layer is not scattered but only refracted when the refractive index and thickness of each layer are uniform and the interface between the protective layer and the thermal recording layer is flat. When such a thermal recording material is used as a sketch film for silk screen printing, the colored image formed on the thermal recording material is printed on the screen at high resolution using transmitted light. However, if the interface between the protective layer and the thermal recording layer is not a flat surface, the resolution is actually significantly reduced. Moreover, when the refractive index of the thermally sensitive recording layer is different from that of the protective layer, the reflectance increases at the interface between the two layers, thus reducing the transparency of the recording material. In view of this fact, it is preferable that the refractive index of the thermally sensitive recording layer is substantially the same as that of the protective layer.

The thermal recording layer contains an electron-giving compound as a colorant. Colorants used in the present invention are colorless or pale-colored dye precursors and are not particularly limited, but are not limited to triphenylmethane, phthalide leuco compounds, triallymethane leuco compounds, fluorane leuco compounds, phenothiazine leuco compounds, thio Fluoran leuco compound, santen leuco compound, indophthalyl leuco compound, spiropyran leuco compound, azaphthalite leuco compound, couromeno-pyrazole leuco compound, methine leuco compound, rhoadaminanilinolactam Leuco compounds, rhodaminelactam leuco compounds, quinazoline leuco compounds, diasanthene leuco compounds and bislactone leuco compounds are preferred for use.

Specific examples of such leuco dyes are as follows:

2-anilino-3-methyl-6-diethylaminofluorane,

2-anilino-3-methyl-6- (di-butylamino) fluorane,

2-anilino-3-methyl-6- (N-n-propyl-N-ethylamino) fluorane,

2-anilino-3-methyl-6- (N-isopropyl-N-ethylamino) fluorane,

2-anilino-3-methyl-6- (N-isobutyl-N-methylamino) fluorane,

2-anilino-3-methyl-6- (N-n-amyl-N-methylamino) fluorane,

2-anilino-3-methyl-6- (N-sec-butyl-N-ethylamino) fluorane,

2-anilino-3-methyl-6- (N-n-amyl-N-ethylamino) fluorane,

2-anilino-3-methyl-6- (N-isoamyl-N-ethylamino) fluorane,

2-anilino-3-methyl-6- (N-n-propyl-N-isopropylamino) fluorane,

2-anilino-3-methyl-6- (N-cyclohexyl-N-methylamino) fluorane,

2-anilino-3-methyl-6- (N-ethyl-p-toludino) fluorane,

2-anilino-3-methyl-6- (N-methyl-p-toludino) fluorane,

2- (m-trichloromethylanilino) -3-methyl-6-diethylamino-fluorane,

2- (m-trifluoromethylanilino) -3-methyl-6-diethylamino-fluorane,

2- (m-trifluoromethylanilino) -3-methyl-6- (N-cyclohexyl-N-methylamino) fluorane,

2- (2,4-dimethylanilino) -3-methyl-6-diethylaminofluorane,

2- (N-ethyl-p-toludino) -3-methyl-6- (N-ethylanilino) fluorane,

2- (N-methyl-p-toludino) -3-methyl-6- (N-propyl-p-tolulino) fluorane,

2-anilino-6- (N-n-hexyl-N-ethylamino) fluorane,

2- (o-chloroanilino) -6-diethylaminofluorane,

2- (o-bromoanilino) -6-diethylaminofluorane,

2- (o-chloroanilino) -6-dibutylaminofluorane,

2- (m-trifluoromethylanilino) -6-diethylaminofluorane,

2- (p-acetylanilino) -6- (N-n-amyl-N-n-butylamino) fluorane,

2-benzylamino-6- (N-ethyl-p-toludino) fluorane,

2-benzylamino-6- (N-methyl-2,4-dimethylanilino) fluorane,

2-benzylamino-6- (N-ethyl-2,4-dimethylanilino) fluorane,

2-dibenzylamino-6- (N-methyl-p-toludino) fluorane,

2-dibenzylamino-6- (N-ethyl-p-toludino) fluorane,

2- (di-p-methylbenzylamino) -6- (N-ethyl-p-toludino) fluorane,

2- (α-phenylethylamino) -6- (N-ethyl-p-toludino) fluorane,

2-methylamino-6- (N-methylanilino) fluorane,

2-methylamino-6- (N-ethylanilino) fluorane,

2-methylamino-6- (N-propylanilino) fluorane,

2-methylamino-6- (N-methyl-p-toludino) fluorane,

2-methylamino-6- (N-methyl-2,4-dimethylanilino) fluorane,

2-ethylamino-6- (N-methyl-2,4-dimethylanilino) fluorane,

2-dimethylamino-6- (N-methylanilino) fluorane,

2-dimethylamino-6- (N-ethylanilino) fluorane,

2-dimethylamino-6- (N-methyl-p-toludino) fluorane,

2-dimethylamino-6- (N-ethyl-p-toludino) fluorane,

2-dipropylamino-6- (N-methylanilino) fluorane,

2-dipropylamino-6- (N-ethylanilino) fluorane,

2-amino-6- (N-methylanilino) fluorane,

2-amino-6- (N-ethylanilino) fluorane,

2-amino-6- (N-propylanilino) fluorane,

2-amino-6- (N-methyl-p-toludino) fluorane,

2-amino-6- (N-ethyl-p-toludino) fluorane,

2-amino-6- (N-propyl-p-toludino) fluorane,

2-amino-6- (N-methyl-p-ethylanilino) fluorane,

2-amino-6- (N-ethyl-p-ethylanilino) fluorane,

2-amino-6- (N-propyl-p-ethylanilino) fluorane,

2-amino-6- (N-methyl-2,4-dimethylanilino) fluorane,

2-amino-6- (N-ethyl-2,4-dimethylanilino) fluorane,

2-amino-6- (N-propyl-2,4-dimethylanilino) fluorane,

2-amino-6- (N-methyl-p-chloroanilino) fluorane,

2-amino-6- (N-ethyl-p-chloroanilino) fluorane,

2-amino-6- (N-propyl-p-chloroanilino) fluorane,

2,3-dimethyl-6-diethylaminofluorane,

3-methyl-6- (N-ethyl-p-tolutino) fluorane,

2-chloro-6-diethylaminofluorane,

2-bromo-6-diethylaminofluorane,

2-chloro-6-dipropylaminofluorane,

3-chloro-6-cyclonucleosilaminofluorane,

3-bromo-6-cyclonucleosilaminofluorane,

2-chloro-6- (N-ethyl-N-isoamylamino) fluorane,

2-chloro-3-methyl-6-diethylaminofluorane,

2-anilino-3-chloro-6-diethylaminofluorane,

2- (o-chloroanilino) -3-chloro-6-cyclonucleosilaminofluorane,

2- (m-trifluoromethylanilino) -3-chloro-6-diethylaminofluoran,

2- (2,3-dichloroanilino) -3-chloro-6-diethylaminofluorane,

1,2-benzo-6-diethylaminofluorane,

1,2-benzo-6- (N-ethyl-N-isoamaminoamino) fluorane,

1,2-benzo-6-dibutylaminofluorane,

1,2-benzo-6- (N-ethyl-N-cyclohexylamino) fluorane and

1,2-benzo-6- (N-ethyl-toludino) fluorane,

The following colorants can preferably also be used in the present invention:

2-anilino-3-methyl-6- (N-2-ethoxypropyl-N-ethylamino) fluorane,

2- (p-chloroanilino) -6- (N-n-octylamino) fluorane,

2- (p-chloroanilino) -6- (N-n-palmitylamino) fluorane,

2- (p-chloroanilino) -6- (di-n-octylamino) fluorane,

2-benzoalamino-6- (N-ethyl-p-toludino) fluorane,

2- (o-methoxybenzoylamino) -6- (N-ethyl-p-toludino) fluorane,

2-dibenzylamino-4-methyl-6-diethylaminofluorane,

2-dibenzylamino-4-methoxy-6- (N-methyl-p-toludino) fluorane,

2-dibenzylamino-4-methyl-6- (N-ethyl-p-toludino) fluoran,

2- (α-phenylethylamino) -4-methyl-6-diethylaminofluoran,

2- (p-toludino) -3- (t-butyl) -6- (N-methyl-p-toludino) fluorane,

2- (o-methoxycarbonylanilino) -6-diethylaminofluorane,

2-acetylamino-6- (N-methyl-p-toludino) fluorane,

3-diethylamino-6- (m-trifluoromethylanilino) fluorane,

4-methoxy-6- (N-ethyl-p-toludino) fluorane,

2-ethoxyethylamino-3-chloro-6-dibutylaminofluorane,

2-dibenzylamino-4-chloro-6- (N-ethyl-p-toludino) fluorane,

2- (α-phenylethylamino) -4-chloro-6-diethylaminofluoran,

2- (N-benzyl-p-trifluoromethylanilino) -4-chloro-6-diethylaminofluoran,

2-anilino-3-methyl-6-pyrrolidinofluoran,

2-anilino-3-chloro-6-pyrrolidinofluoran,

2-anilino-3-methyl-6- (N-ethyl-N-tetrahydrofurfurylamino) fluorane,

2-mesidino-4 ', 5'-benzo-6-diethylaminofluorane,

2- (m-trifluoromethylanilino) -3-methyl-6-pyrrolidinofluorane,

2- (α-naphthylamino) -3,4-benzo-4'-bromo-6- (N-benzyl-N-cyclohexylamino) fluorane,

2-piperidino-6-diethylaminofluorane,

2- (N-n-propyl-p-trifluoromethylanilino) -6-morpholinofluoran,

2- (di-N-p-chlorophenyl-methylamino) -6-pyrrolidinofluorane,

2- (N-n-propyl-m-trifluoromethylanilino) -6-morpholinofluoran,

1,2-benzo-6- (N-ethyl-N-n-octylamino) fluorane,

1,2-benzo-6-diallylaminofluorane,

1,2-benzo-6- (N-ethoxyethyl-N-ethylamino) fluorane,

Benzoleucom methylene blue,

2- [3,6-bis (diethylamino)]-6- (o-chloroanilino) anthylbenzoic acid lactam,

2- [3,6-bis (diethylamino)]-9- (o-chloroanilino) anthylbenzoic acid lactam,

3,3-bis (p-dimethylaminophenyl) phthalide,

3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (or crystalline violet lactone),

3,3-bis (p-dimethylaminophenyl) -6-diethylaminophthalide,

3,3-bis (p-dimethylaminophenyl) -6-chlorophthalide,

3,3-bis (p-dibutylaminophenyl) phthalide,

3- (2-methoxy-4-dimethylaminophenyl) -3- (2-hydroxy-4,5-dichlorophenyl) phthalide,

3- (2-hydroxy-4-dimethylaminophenyl) -3- (2-methoxy-5-chlorophenyl) phthalide,

3- (2-hydroxy-4-dimethoxyaminophenyl) -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,

3,6-bis (dimethylamino) fluorenespiro (9,3 ')-6'-dimethylaminophthalide,

6'-Chloro-8'-methoxy-benzoindolino-spiropyran and

6'-Bromo-2'-methoxy-benzoindolino-spiropyran.

The coloring agents may be used alone or in combination.

The color developer used in the thermal recording layer is an electron-receiving compound which causes color to be formed in the colorant described above. Various conventional electron-receiving colorants can be used in the present invention. In particular, as mentioned in Japanese Patent Application No. 3-355078, it is preferable to use an electron acceptor coloring agent having a long-chain alkyl group in each molecule as the coloring agent in the present invention. For example, an organic phosphoric acid compound, an aliphatic carboxylic acid compound having an aliphatic group having 12 or more carbon atoms, and a phenol compound: a metal salt of mercaptoacetic acid having an aliphatic group having 10 to 18 carbon atoms: an alkyl group having 5 to 8 carbon atoms Alkyl esters of caffeic acid with: and acid phosphates with aliphatic groups having at least 16 carbon atoms are disclosed. The aliphatic group includes a straight chain or branched alkyl group or alkenyl group, which may have a substituent such as a halogen atom, an alkoxy group or an ester group.

Of the above-described colorants, the organic phosphoric acid compound represented by the following general formula (1) or (2) is particularly preferred:

Provided that R is a straight-chain alkyl group having from 16 to 24 carbon atoms.

However, R 'is a straight-chain alkyl group which has 13-23 carbon atoms.

The coloring agents may be used alone or in combination.

As for the ratio of a coloring agent and a coloring agent amount, the coloring agent used with 1 weight part of coloring agents becomes like this. Preferably it is 1-20 weight part, More preferably, it is 2-10 weight part.

The thermal recording layer contains a binder resin. Examples of binder resins used in the thermal recording layer include polyvinyl acetal resins such as polyvinyl butyral and polyvinyl acetoacetal: cellulose derivatives such as ethyl cellulose, cellulose acetate, cellulose acetate propionate and cellulose acetate butyrate: and epoxy resins. to be. These resins can be used alone or in combination.

In order to obtain the thermal recording layer, the coating liquid used for the thermal recording layer is prepared by uniformly dispersing or dissolving a colorant, a coloring agent and a binder resin in an organic solvent. Thereafter, the coating solution thus prepared is coated on the support and dried. The coating method is not particularly limited. The particle size of the particles dispersed in the coating liquid is 10 μm or less, more preferably 5 μm or less, and more preferably 1 μm or less.

The thickness of the thermal recording layer thus obtained is changed depending on the application of the thermal recording layer blend or the thermal recording material obtained, preferably about 1 to 50 µm, more preferably 3 to 20 µm.

In order to improve the coatability and the recordability, the coating liquid used for the thermal recording layer may further include various additives used for conventional wound recording paper.

As a transparent support used for the thermal recording agent according to the present invention, a film made of a polyester resin such as polyethylene terephthalate or polybutylene terephthalate is generally used: a film made of a cellulose derivative such as cellulose triacetate: polypropylene or polyethylene Films made of polyolefin resins such as: and polystyrene films can be used. Furthermore, the film can be laminated to produce the thermal recording material as a support.

The heating means for forming an image on the transparent thermal recording material according to the present invention may be used, for example, a hot pen, a thermal head, and a means used for laser application, but the heating means is not particularly limited.

Hereinafter, embodiments of the present invention will be described in detail.

The following examples further clarify the invention and do not limit the invention thereto.

Example 1

The mixture of the following components was sufficiently dispersed and pulverized in a ball mill so that the particle size was 0.3 μm, thereby preparing Coating Solution A for use in the thermal recording layer:

[Thermal Recording Layer Coating Liquid A]

Parts by weight

3-diethylamino-6-methyl-7-anilinofluorane 4

Octadecylphosphonic acid 12

Polyvinyl Butyral Denka Butyral # 3000-2

(Manufactured by Denki Kagaku Kogyo Kabushiki Kaisha) 6

Toluene 57

Methyl Ethyl Ketone 57

The thermal recording layer coating solution A thus prepared was applied onto a 75 μm-thick polyester film (trade name Teijin Tetoron Film HMW-75, manufactured by Teijin Limited) used as a support, and dried to have a thickness of 13 on the support. A thermally sensitive recording layer of 탆 was formed.

Protective layer coating solution B was prepared by mixing the following components:

[Protective Layer Coating Liquid B]

Parts by weight

Urethane Acrylate UV Curing Resin Unidic C7-157 (trademark)

Manufactured by Dainippon Ink Chemicals, Incorporated

(Solid content 75%) 120

Silicone-modified polyvinyl butyral

(Content of silicon fraction: 20% by weight, solid content: 12.5%) 160

Methyl Ethyl Ketone 600

The protective layer coating liquid B thus prepared was coated on the above-prepared thermal recording layer, dried, and cured using an ultraviolet lamp of 80 W / cm to form a protective layer having a thickness of 3 탆 on the thermal recording layer.

Therefore, the thermal recording agent No. 1 was obtained.

Example 2

The thermal recording material No. 1 of Example 1 was changed except that the formulation of the protective layer coating liquid B used in Example 1 was changed to the following formulation of the protective layer coating liquid C. The method of making 1 was repeated:

[Protective Layer Coating Liquid C]

Parts by weight

Urethane Acrylate UV Curing Resin Unidic C7-157 (trademark)

Manufactured by Dainippon Ink Chemicals, Incorporated

(Solid content 75%) 120

Silicone-modified polyvinyl butyral

(Content of silicon fraction: 20% by weight, solid content: 12.5%) 200

Tolylene diisocyanate compound Coronate L (trademark)

Manufactured by Nippon Polyurethane Industry Co., Ltd.

(75% solids content) 40

Methyl ethyl ketone 560

Therefore, the thermal recording material No. 2 was obtained.

Example 3

The thermal recording material No. 1 was repeated the preparation method:

[Protective Layer Coating Liquid D]

Parts by weight

Urethane Acrylate UV Curing Resin Unidic C7-157 (trademark)

Manufactured by Dainippon Ink Chemicals, Incorporated

(Solid content 75%) 120

Silicone-modified polyvinyl butyral

(Content of silicon fraction: 20% by weight, solid content: 12.5%) 160

Kaolin UC (R), manufactured by ENGELHARD Corporation 100

Methyl Ethyl Ketone 600

Tolylene diisocyanate compound Coronate L (trademark)

Manufactured by Nippon Polyurethane Industry Co., Ltd.

(75% solids content) 10

Therefore, the thermal recording material No. Got 3.

Example 4

The thermal recording material No. 1, the manufacturing process was repeated:

[Protective Layer Coating Liquid E]

Parts by weight

Urethane Acrylate UV Curing Resin Unidic C7-157 (trademark)

Manufactured by Dainippon Ink Chemicals, Incorporated

(Solid content 75%) 100

Silicone-modified polyvinyl butyral

(Content of silicon fraction: 20% by weight, solid content: 12.5%) 200

Kaolin UC (R), manufactured by ENGELHARD Corporation 100

Tolylene diisocyanate compound Coronate L (trademark)

Manufactured by Nippon Polyurethane Industry Co., Ltd.

(75% solids content) 40

Methyl ethyl ketone 560

Therefore, the thermal recording material No. Got 4.

Example 5

The thermal recording material No. 1, the manufacturing process was repeated:

[Protective Layer Coating Liquid F]

Parts by weight

Urethane Acrylate UV Curing Resin, Unidic C7-157 (trademark)

Dainippon Ink Chemicals, Incorporated

(Solid content 75%) 100

Silicone-modified polyvinyl butyral

(Content of silicon fraction: 20% by weight, solid content: 12.5%) 200

Kaolin UC (R), manufactured by ENGELHARD Corporation 100

Tolylene diisocyanate compound Coronate L (trademark)

Manufactured by Nippon Polyurethane Industry Co., Ltd.

(75% solids content) 40

Zinc Stearate (toluene dispersion with 75% solids) 10

Methyl ethyl ketone 500

Therefore, the thermal recording material No. Got 5.

Example 6

The thermal recording material No. 1, the manufacturing process was repeated:

[Protective Layer Coating Liquid G]

Parts by weight

Urethane Acrylate UV Curing Resin Unidic C7-157 (trademark)

Manufactured by Dainippon Ink Chemicals, Incorporated

(Solid content 75%) 100

Silicone-modified polyvinyl butyral

(Content of silicon fraction: 20% by weight, solid content: 12.5%) 200

Kaolin UC (R), manufactured by ENGELHARD Corporation 100

Xylene Diisocyanate Compound, Coronate L (trademark)

Manufactured by Nippon Polyurethane Industry Co., Ltd.

(75% solids content) 40

Zinc Stearate (toluene dispersion with 75% solids) 10

Methyl ethyl ketone 500

Therefore, the thermal recording material No. 6 was obtained.

Example 7

The thermal recording material No. 1, the manufacturing process was repeated:

[Protective Layer Coating Liquid H]

Parts by weight

Urethane Acrylate UV Curing Resin, Unidic C7-157 (trademark)

Manufactured by Dainippon Ink Chemicals, Incorporated

(Solid content 75%) 100

Silicone-modified polyvinyl butyral

(Content of silicon fraction: 20% by weight, solid content: 12.5%) 200

Kaolin UC (R), manufactured by ENGELHARD Corporation 100

Tolylene diisocyanate compound, Coronate L (trademark)

Manufactured by Nippon Polyurethane Industry Co., Ltd.

(75% solids content) 40

Amino-Modified Silicone Oil 5

Methyl ethyl ketone 550

Therefore, the thermal recording material No. 7 was obtained.

Example 8

The thermal recording material No. 1, the manufacturing process was repeated:

[Protective Layer Coating Liquid I]

Parts by weight

Urethane Acrylate UV Curing Resin, Unidic C7-157 (trademark)

Manufactured by Dainippon Ink Chemicals, Incorporated

(75% solids content) 10

Silicone-modified polyvinyl butyral

(Content of silicon fraction: 20% by weight, solid content: 12.5%) 400

Kaolin UC (R), manufactured by ENGELHARD Corporation 50

Tolylene diisocyanate compound, Coronate L (trademark)

Manufactured by Nippon Polyurethane Industry Co., Ltd.

(75% solids content) 40

Methyl Ethyl Ketone 600

Therefore, the thermal recording material No. 8 was obtained.

Example 9

The thermal recording material No. 1, the manufacturing process was repeated:

[Protective Layer Coating Liquid J]

Parts by weight

Urethane Acrylate UV Curing Resin, Unidic C7-157 (trademark)

Manufactured by Dainippon Ink Chemicals, Incorporated.

(75% solids content) 20

Silicone-modified polyvinyl butyral

(Content of silicon fraction: 20% by weight, solid content: 12.5%) 10

Kaolin UC (R), manufactured by ENGELHARD Corporation 5

Tolylene diisocyanate compound, Coronate L (trademark)

Manufactured by Nippon Polyurethane Industry Co., Ltd.

(75% solids content) 1

Methyl Ethyl Ketone 130

Therefore, the thermal recording material No. Got 9.

Example 10

The thermal recording material No. 1, the manufacturing process was repeated:

[Protective Layer Coating Liquid K]

Parts by weight

Urethane Acrylate UV Curing Resin, Unidic C7-157 (trademark)

Manufactured by Dainippon Ink Chemicals, Incorporated.

(Solid content 75%) 100

Silicone-modified polyvinyl butyral

(Content of silicon fraction: 20% by weight, solid content: 12.5%) 200

Kaolin UC (R), manufactured by ENGELHARD Corporation 100

Xylene Diisocyanate Compound, Takenate D11ON (TM)

Manufactured by Takeda Chemical Industries, Ltd.

(75% solids content) 40

Zinc Stearate (toluene dispersion with 75% solids) 10

Methyl ethyl ketone 500

Decolorant A (available from Asahi Denka Kogyo K.K.) 1

Therefore, the thermal recording material No. 10 was obtained.

Comparative Example 1

The thermal recording material No. 1 of Example 1 was changed except that the formulation for the protective layer coating liquid B used in Example 1 was changed to the following formulation for the protective layer coating liquid L. 1, the manufacturing process was repeated:

[Protective Layer Coating Liquid L]

Parts by weight

Urethane Acrylate UV Curing Resin, Unidic C7-157 (trademark)

Manufactured by Dainippon Ink Chemicals, Incorporated.

(75% solids content) 133

Polyether-Modified Silicone Oil 3

Kaolin UC (R), manufactured by ENGELHARD Corporation 100

Methyl ethyl ketone 264

Therefore, the thermal recording material No. 1 was obtained.

Comparative Example 2

The thermal recording material No. 1 of Example 1 was changed except that the formulation of the protective layer coating liquid B used in Example 1 was changed to the following formulation of the protective layer coating liquid M. 1, the manufacturing process was repeated:

[Protective Layer Coating Liquid M]

Parts by weight

Silicone-modified polyvinyl butyral

(Silicone fraction content: 20% by weight, solid content: 12.5%) 800

Kaolin UC (R), manufactured by ENGELHARD Corporation 100

Methyl Ethyl Ketone 1600

Therefore, the thermal recording material No. 2 was obtained.

The following evaluation tests were conducted on each of the transparent thermal recording materials No 1 to 10 and the transparent thermal recording materials No 1 and 2 of the comparative example according to the present invention:

(1) Adhesion of heat meltable dust to heat head

Each thermal recording material was thermally printed using a thermal printer manufactured by Okura Denki Co., Ltd. to form a solid image of 3 m in length under the following conditions:

Dot density of heat head: 8 dots / mm

Platen pressure: 6kg / A4 size

Applied Power: 29.9mJ / mm2 and 38.4mJ / mm2 for pulses with 0.7㎳ and 0.9㎳ width respectively

Line period: 10 Hz / line

After completion of thermal printing, the amount of heat meltable material adhered to the thermal printer, the next two points A and B of the thermal head, was observed using an optical microscope:

Point A: Thermal head heating element surface in contact with the thermal recording material during thermal printing

Point B: The portion of the heat head which is downward relative to the heating element along the direction of movement of the thermal recording material.

The amount of dust of the heat meltable material was rated on a scale of 1-5 with reference to the reference sample.

[Adhesion of Heat Meltable Dust to Heat Head Point A]

5: no dust of heat meltable material

4: some dust of heat meltable material

3: Dust of heat meltable material is recognized but has no effect on heat printing

2: A significant amount of heat meltable material is perceived, and the resulting image is somewhat smeared and blurred

1: The dust of the heat meltable material is remarkable, and consequently the image blurring is noticeable.

Adhesion of Heat Meltable Dust to Heat Head Point B

5: no dust of heat meltable material

4: some dust of heat meltable material

3: Dust of heat meltable material is recognized

2: Significantly noticeable dust of heat meltable material

1: The dust of the heat meltable material is remarkable.

(2) adhesion to heat head

Solid image samples obtained from each thermal recording material were visually inspected to evaluate the presence or absence of adhesion phenomena at a scale of 1-5.

5: No sticking phenomenon

4: slight adhesion observed

3: Adhesion is recognized

2: Significant adhesion is recognized

1: The sticking phenomenon is remarkable.

(3) background density

Background concentration of each image sample was measured at the UV position using a transmission densitometer X-Rite 309 (trademark) manufactured by XRITE Company, Ltd.,.

The evaluation results are shown in Table 1 below.

As shown in the results shown in Table 1 above, when using the thermal recording material according to the present invention, the adhesion of the heat-meltable material dust to the heat head during the heat printing operation can be minimized, the occurrence of adhesion phenomenon is prevented .

Claims (11)

The thermal recording layer comprising a support, an electron-receiving coloring compound, an electron-receiving compound, and a binder resin, and a thermal recording layer formed on the support, and a copolymer resin containing a silicone component as an ultraviolet-curing resin and a copolymerization component. A protective layer formed on the layer, the thermal recording material comprising. The heat-sensitive recording material according to claim 1, wherein the protective layer further comprises a cross-linked product which reacts with the copolymer resin containing the silicone component. 3. The thermal recording material of claim 2, wherein the cross-linking agent comprises an isocyanate compound. 4. The thermal recording material of claim 3, wherein the isocyanate compound is xylene diisocyanate. The thermally sensitive recording material of claim 1, wherein the copolymer resin including the silicone component is a silicone graft copolymer or a silicone block copolymer. The thermally sensitive recording material of claim 1, wherein the copolymer resin including the silicone component is selected from the group consisting of silicon-modified polyvinyl butyral and silicon-modified polyvinyl acetal. The thermally sensitive recording material of claim 1, wherein the protective layer further comprises at least one component selected from the group consisting of metal salts and amino-modified silicone oils. The thermally sensitive recording material of claim 1, wherein the thermally sensitive recording layer or the protective layer further comprises at least one decolorant selected from the group consisting of compounds A to D. [Compound A] Where n is an integer: R ¹ is CH ₃ :

[Compound B]

[Compound C]

[Compound D] 1,3-dicyclohexyl-2- (2 ', 5'-dicyclophenyl) guanidine. 2. The thermal recording material of claim 1, wherein the protective layer further comprises a filler. The heat-sensitive recording material according to claim 1, wherein the ultraviolet-curing resin is contained in an amount of 10 to 50% by weight of the total weight of the total solid component of the protective layer. The heat-sensitive recording material according to claim 1, wherein the weight ratio of the copolymer resin containing the silicone component to the ultraviolet-curable resin is in the range of 1: 9 to 7: 3.