JP4281818B2 - Optical information recording medium - Google Patents

Description

  The present invention relates to an optical information recording medium, and more particularly to an optical information recording medium that can be printed on a surface (opposite side to a light incident surface) with a thermal printer.

  Reproduction-only optical recording media such as compact discs (CDs) and laser discs (LDs), which are widely used nowadays, manufacture substrates with information by injection molding methods based on masters usually called stampers. . This method makes it possible to manufacture a large amount of media having the same information at low cost, but is not suitable for producing a small amount of media because the stamper is very expensive. In addition, with the progress of the information society in recent years, higher density recording has been eagerly desired than magnetic recording media. Therefore, an optical recording medium has been developed for producing a small amount of medium or allowing a user to freely record and store data.

  Optical recording media are classified into two types: a write-once type capable of recording and reproducing information, and a rewritable type capable of erasing data after recording. Among them, the recordable compact disc having a single-plate structure is called a CD-R, and the number of users is increasing explosively because it is compatible with a normal read-only CD. Recently, since the DVD-R that can record at higher density is compatible with the CD-R, the demand is expected to increase greatly. In this CD-R and DVD-R, after purchasing a medium that does not contain data, each user writes and uses various information and data unique to the user. For this reason, it is preferable to know at a glance what kind of information is recorded on the medium by some method.

  In general, as a method for displaying a title of written information or the like, direct printing on a disk surface by an ink jet printer or a thermal transfer printer is currently performed. Recently, many printers dedicated to CD-R and DVD-R having high-definition printing performance have appeared.

  As for attempts to apply a coating layer (dye receiving layer) that can be printed by an ink jet printer or a thermal transfer printer on the opposite side of the light incident surface of the optical information recording medium, a number of applications such as Patent Document 1 or Patent Document 2 have been published so far. Has been made.

  On the other hand, recently, instead of ink jet printers and thermal transfer printers, etc., there is a new type of printing on the surface of printing layers with a thermal printer that can print on the surface of recording media without ink cartridges, or without film, and maintenance-free. Attempts have begun. Patent Documents 3 and 4 describe a thermal transfer recording medium that can be printed by such an ink cartridge-less, film-less, and maintenance-free thermal printer. In addition to the above points, Patent Document 5 further describes prevention of fading of an optical information recording medium or a thermal transfer sheet. This is a natural flow in order to avoid the cost problem of an ink cartridge or print film that is frequently used and consumed.

Therefore, it is conceivable to combine a thermal transfer recording medium printable by such an ink cartridge-less or film-less, maintenance-free thermal printer with an optical information recording medium. However, the biggest problem when trying to print on the surface of an optical information recording medium with a thermal printer is that the organic dye in the recording layer is damaged and destroyed by the heat and pressure at the time of printing, and recording / reproduction is not possible. It was an impossible point. Regarding this problem, Patent Document 6 describes an attempt to avoid this problem by providing a heat insulating layer or an elastic layer between the print layer and the recording layer. However, as a result of various studies by the present inventors to newly provide a heat insulating layer and an elastic layer, optical information recording has sufficient characteristics because it has a great influence on the warpage, surface vibration, tilt, etc. of the disc itself. The medium could not be produced. In addition, the provision of the heat insulating layer and the elastic layer more than anything has a great influence on the manufacturing cost, and it is impossible to provide an optical information recording medium that can be printed with an inexpensive and high-quality thermal printer. It was.

JP-A-6-60432 JP 7-169100 A JP 2000-85249 A JP 2000-345067 A JP 2001-158879 A JP 2000-155989 A

  In view of the above problems, the present inventors have intensively studied an optical information recording medium that can be printed by a thermal printer that can be manufactured at low cost without impairing recording characteristics and / or the system.

  As a result of intensive studies to solve the above problems, the present inventors have found that the protective layer is an optical information recording medium having a heat-sensitive color-developing layer that can be printed by a heat-sensitive printer, and the light is affected by the heat of the thermal head. The present inventors have found that this problem can be solved by using a phthalocyanine dye and / or an azo dye having heat resistance and light resistance that are not easily damaged by the recording layer of the information recording medium. Furthermore, the present inventors have also found an optical information recording medium using a color developer having sufficient heat resistance and light resistance, because simply laminating a thermosensitive coloring layer will cause peeling or fading over time. It was.

That is, the present invention relates to an optical recording medium having a transparent substrate, a recording layer, a metal reflective layer, and a protective layer. The protective layer is a thermosensitive coloring layer that can be printed by at least one thermal printer, and the thermal coloring layer. The overcoat layer contains calcium carbonate having an average particle size of 2.0 μm or less, and the recording layer is selected from phthalocyanine dyes and azo dyes having a heat resistant temperature of 260 ° C. or more. The present invention relates to an optical information recording medium formed of at least one dye.

  As described above, according to the present invention, a phthalocyanine dye and / or an azo dye having a heat-resistant temperature of 260 ° C. or higher is used as an organic dye used in the recording layer as a protective layer having a heat-sensitive color-developing layer that can be printed by a heat-sensitive printer. By producing an optical information recording medium having each layer in a sufficiently bound state, heat resistance and light resistance are ensured so as not to damage the recording layer of the optical information recording medium due to the heat effect of the thermal head. It is possible to provide an optical information recording medium that can be printed with a thermal printer that can be manufactured at low cost.

“Printable” in the present invention means that printing with a thermal printer is possible.
As shown in FIG. 1, the optical recording medium of the present invention comprises a transparent substrate 1, a recording layer 2, a metal reflective layer 3, a protective layer (underlayer) 4, a thermosensitive coloring layer 5, and an overcoat layer 6. Moreover, you may take the structure which abbreviate | omitted the overcoat layer 6 as needed. In the optical recording medium of the present invention, as shown in FIG. 2, a dummy substrate 7 made of polycarbonate is bonded to the substrate formed up to the reflective layer 3 through an adhesive layer 8 to form a protective layer (underlayer). Thereafter, the thermosensitive coloring layer 5 and the overcoat layer 6 may be provided thereon.

  The substrate used in the present invention can be made of any material as long as it is transparent because it performs recording and reproduction by light. For example, a polymer material such as polycarbonate resin, acrylic resin, polystyrene resin, vinyl chloride resin, epoxy resin, polyester resin, amorphous polyolefin, or inorganic material such as glass can be used. In particular, a polycarbonate resin is more preferable because it is desirable to have a high light transmittance and a small optical anisotropy. Alternatively, a two-layer bonded substrate such as a DVD, DVD-R, DVD-RW, or DVD-RAM may be used.

  These substrate surfaces may have guide grooves and pits representing recording positions, and pits for information for reproduction only partially. These grooves, pits, and the like are usually applied when a substrate is formed by injection molding or casting, but may be formed by a laser cutting method or a 2P method (Photo-Polymer method).

  The recording layer used in the present invention must be recordable by irradiating with laser light.

  In the case of a recording layer made of an organic material, an organic dye is mainly used. The dye used may be a mixture of a plurality of dyes. Further, materials other than the light absorbing material, for example, a quencher or a metal compound may be added.

  Specific examples of the dye used in the recording layer include macrocyclic azaannulene dyes (phthalocyanine dyes, naphthalocyanine dyes, porphyrin dyes, etc.), polymethine dyes (cyanine dyes, merocyanine dyes, squarylium dyes, etc.), anthraquinone dyes, In the present invention, an azo dye such as a phthalocyanine dye, a naphthalocyanine dye, or an azaporphyrin dye must be used. In particular, phthalocyanine dyes and azo dyes have a symmetric structure and have very excellent moisture and light resistance and are suitable for the present invention. The present inventors have found that the dye group is extremely effective in terms of recording characteristics for thermal printers or thermal transfer printers.

  In general, the heat-resistant temperature of the recording layer dye is considered to be substantially equal to the decomposition start temperature of the dye. In the present invention, the temperature at the time of 5% by mass reduction with respect to the initial mass of the dye is defined as the decomposition start temperature, and is used as an index of heat resistance of the recording layer dye.

  As a result of comparing the recording characteristics and surface printing characteristics of various dyes with respect to thermal printers or thermal transfer printers, the present inventors have found that phthalocyanine dyes and azo dyes have extremely high resistance to moisture and light. It has been found that it has excellent characteristics. As a result of measuring the heat resistance temperature of phthalocyanine dyes and azo dyes in particular, good surface printing characteristics can be obtained without damaging the recording layer when a dye decomposition start temperature of 260 ° C. or higher is used. I found.

The measurement of the dye decomposition start temperature is generally TGA measurement using a thermobalance. TGA measurement is useful as a simple method because the decomposition temperature can be specified even with a very small amount of dye. In the present invention, in order to avoid the influence of oxygen, the weight loss temperature (decomposition temperature) in a nitrogen atmosphere was measured.

  The recording layer containing the dye can be usually formed by a coating method such as spin coating, spray coating, dip coating or roll coating. At this time, it is common to dissolve the dye and other substances forming the recording layer in a solvent that does not damage the substrate, and then dry after coating. Solvents used include aliphatic and alicyclic hydrocarbons such as hexane, heptane, octane, decane and cyclohexane, aromatic hydrocarbons such as toluene and xylene, ethers such as diethyl ether and dibutyl ether, methanol, Polar solvents such as alcohols such as ethanol, isopropyl alcohol, and methyl cellosolve, ketones such as dimethylheptanone, and halogenated hydrocarbons such as 1,2-dichloroethane and chloroform can be used. These solvents may be used alone or in combination.

  Note that a vacuum deposition method may be used as a method for forming the recording layer. This method is effective when the recording layer substance is difficult to dissolve in the solvent or when a solvent that does not damage the substrate cannot be selected.

Various underlayers may be provided between the recording layer and the substrate. For example, a layer made of an organic substance such as polystyrene or polymethyl methacrylate, or an inorganic substance such as SiO ₂ can be used. These may be used alone or in combination. Two or more types may be laminated and used.

  A metal reflective layer is formed on the recording layer using a metal such as Au, Al, Pt, Ag, Ni, or an alloy thereof. It is particularly desirable to use gold that is stable against oxygen and moisture. The reflective layer is formed by vapor deposition, sputtering, or ion plating.

  An intermediate layer may be provided between the metal reflective layer and the recording layer for the purpose of improving the adhesion between the layers or increasing the reflectance.

  A protective layer (underlying layer) is usually provided on the reflective layer for the purpose of improving recording characteristics, particularly high-speed recording characteristics.

  Examples of the resin for forming the protective layer (underlayer) include those that polymerize by a general radical reaction of acrylate or methacrylate, and those that undergo cationic polymerization with light, such as an epoxy. These resins may be polymerized alone, or may be mixed with monomers and oligomers. It is also possible to apply after diluting with a solvent. The protective layer is formed by a method such as spin coating, dip coating, bar coating, or screen printing. In view of workability, the protective layer is often subjected to a spin coating method. These film thicknesses are 1 μm to 100 μm, and preferably 1 to 20 μm. In the case of bonding two sheets such as DVD, DVD-R, DVD-RW, and DVD-RAM, the polycarbonate substrate on the reflective layer is considered as the protective layer (underlayer).

  An intermediate protective layer may be further provided on the protective layer (underlayer). By providing the intermediate protective layer in the present invention, the color development sensitivity can be further increased and the dot reproducibility during printing can be enhanced. In general, the intermediate protective layer contains a pigment or a synthetic resin.

Examples of the pigment used for the intermediate protective layer include calcined kaolin, aluminum hydroxide, calcium carbonate, barium sulfate, zinc oxide, lithopone, wax, kaolin, silica, amorphous silica, and the like. Is calcined kaolin.

  Examples of the synthetic resin used for the intermediate protective layer include styrene-acrylic resin, polystyrene resin, acrylic resin, polyethylene resin, polypropylene resin, polyacetal resin, and the like, and more preferably plastics made of these synthetic resins. Spherical particles or plastic spherical hollow particles, preferably plastic spherical particles or plastic spherical hollow particles having an average particle size of 0.5 to 3 μm, more preferably an average particle size made of styrene-acrylic resin Are plastic spherical particles of 0.5 to 3 μm, or plastic spherical hollow particles.

  The pigment and the synthetic resin may be used alone or in combination. In general, the coating liquid for the intermediate protective layer is prepared as an aqueous dispersion by mixing a binder in addition to a pigment or a synthetic resin. As the binder, a binder used for forming the recording layer can be used. Further, if desired, in the coating solution for the intermediate protective layer, a release agent, a water-proofing agent, a sizing agent (for example, alkenyl succinate, alkyl ketene dimer, rosin compound), wax (for example, paraffin wax) , Microcrystalline wax, carboxy-modified paraffin wax, carnauba wax, polyethylene wax, polystyrene wax, canderia wax, montan wax, higher fatty acid ester) and the like.

The coating solution for the intermediate protective layer is formed on the base protective layer by using an appropriate knife such as an air knife coater, blade coater, bar coater, short dwell coater, gravure coater, curtain coater, roll coater, wire bar, spin coater or screen printing. An undercoat layer can be formed by coating and drying with a coating apparatus. With respect to the coating amount of the intermediate protective layer is not particularly limited, in general, on a dry weight, 0.5 to 20 g / m ^2, more preferably about, is adjusted to about 1 to 15 g / m ² . Moreover, when a base protective layer has a synthetic resin as a main component, it can also adjust to an appropriate film thickness (for example, 2-50 micrometers). The intermediate protective layer may be a single layer or two or more layers. Conversely, the protective layer (underlying layer) can also function as an intermediate protective layer.

  On the protective layer (underlying layer) or the intermediate protective layer, a heat-sensitive color forming layer capable of coloring with a heat-sensitive printer is formed. The heat-sensitive coloring layer contains a heat-sensitive recording material comprising an electron-donating color-forming compound and an electron-accepting compound on a protective layer (underlayer). Further, as the electron-accepting compound, the general formula (1) A developer composition containing at least one compound selected from the compounds represented by the formula and at least one compound selected from the compounds represented by formulas (2) and (3) is used.

(In the formula, X ₁ , X ₂ and X ₃ represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group or a hydroxyl group, Z ₁ , Z ₂ and Z ₃ represent a hydrogen atom or an alkyl group, R ₁ ~R ₅
, R _{11 to} R ₁₅ , R _{21 to} R ₂₅ and R _{31 to} R ₃₅ represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or an aryl group, and R ₁ and R ₂ , R ₂ and R ₃ R ₁₁ and R ₁₂ , R ₁₂ and R ₁₃ , R ₂₁ and R ₂₂ , R ₂₂ and R ₂₃ , R ₃₁ and R ₃₂ , or R ₃₂ and R ₃₃ are adjacent to each other. A carbocyclic aromatic ring may be formed together with the substituted carbon atom)

  The thermosensitive coloring layer preferably contains a heat-fusible compound, an ultraviolet absorber, a hindered phenol compound, a binder, or a pigment.

In the compounds represented by general formula (1), general formula (2), and general formula (3), X ₁ , X _2, and X ₃ represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or a hydroxyl group, Preferably, a hydrogen atom, a halogen atom (for example, fluorine atom, chlorine atom, bromine atom), an alkyl group having 1 to 6 carbon atoms (for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group) , Isobutyl group, tert-butyl group, n-pentyl group, n-hexyl group, cyclopentyl group, cyclohexyl group), C 1-6 alkoxy group (for example, methoxy group, ethoxy group, n-propoxy group, n- Butoxy group, isobutoxy group, n-pentyloxy group, n-hexyloxy group, cyclohexyloxy group) and hydroxyl group, more preferably hydrogen atom, halogen An atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or a halogen atom.

In the compounds represented by general formula (1), general formula (2), and general formula (3), Z ₁ , Z _2, and Z ₃ represent a hydrogen atom or an alkyl group, preferably a hydrogen atom or carbon number 1 to 6 alkyl groups (for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group, n-hexyl group, cyclopentyl group, cyclohexyl group) Group), more preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

In the compounds represented by general formula (1), general formula (2), and general formula (3), R _{1 to} R ₅ , R _{11 to} R ₁₅ , R _{21 to} R _25, and R _{31 to} R ₃₅ are hydrogen atoms. Represents a halogen atom, an alkyl group, an alkoxy group, or an aryl group, preferably a hydrogen atom, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom), an alkyl group having 1 to 6 carbon atoms (for example, a methyl group) , Ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group, n-hexyl group, cyclopentyl group, cyclohexyl group), alkoxy group having 1 to 6 carbon atoms (For example, methoxy group, ethoxy group, n-propoxy group, n-butoxy group, isobutoxy group, n-pentyloxy group, n-hexyloxy group, cyclohexyloxy group), carbon number 6 to 10 aryl groups (for example, phenyl group, 4-methylphenyl group, 3-methylphenyl group, 2-methylphenyl group, 4-ethylphenyl group, 3-ethylphenyl group, 4-n-propylphenyl group, 4- Isopropylphenyl group, 4-n-butylphenyl group, 4-sec-butylphenyl group, 4-tert-butylphenyl group, 4-methoxyphenyl group, 3-methoxyphenyl group, 2-methoxyphenyl group, 4-ethoxyphenyl Group, 4-isopropoxyphenyl group, 4-n-butoxyphenyl group, 4-fluorophenyl group, 3-fluorophenyl group, 4-chlorophenyl group, 3-chlorophenyl group, 2-chlorophenyl group, 4-chloro-2- Methylphenyl group, 4-chloro-3-methylphenyl group, 2,4-dimethylphenyl group, 2,5-di Tylphenyl group, 3,4-dimethylphenyl group, 2,4-dichlorophenyl group, 2,5-dichlorophenyl group, 2-methoxy-4-methylphenyl group, 2-methyl-4-methoxyphenyl group, 2,4-dimethoxy Phenyl group, 3,4-dimethoxyphenyl group, 3,5-diethoxyphenyl group, 1-naphthyl group, 2-naphthyl group), more preferably a hydrogen atom, a halogen atom, or an alkyl having 1 to 4 carbon atoms. Group or an alkoxy group having 1 to 4 carbon atoms, and more preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

Furthermore, in the compounds represented by the general formula (1), the general formula (2), and the general formula (3), R ₁
And R ₂ , R ₂ and R ₃ , R ₁₁ and R ₁₂ , R ₁₂ and R ₁₃ , R ₂₁ and R ₂₂ , R ₂₂ and R ₂₃ , R ₃₁ and R ₃₂ , or R ₃₂ and R ₃₃ Adjacent groups may be bonded to each other to form a carbocyclic aromatic ring together with the substituted carbon atom, preferably a benzene ring.

  The compound represented by the general formula (1) is a sulfonamide derivative having a phenolic hydroxyl group, and the substitution position of the hydroxyl group is 4-position, 3-position or 2-position with respect to the sulfonamide group, more preferably. Is the 4th or 3rd position. That is, the compound represented by general formula (1-a) or general formula (1-b) is more preferable.

〔式中、Ｘ₁、Ｚ₁およびＲ₁〜Ｒ₅は一般式（１）と同じ意味を表す〕

[Wherein X ₁ , Z ₁ and R _{1 to} R ₅ represent the same meaning as in general formula (1)]

  Specific examples of the compound represented by the general formula (1) include, for example, the following compounds, but the present invention is not limited thereto.

  The compound represented by the general formula (2) is a sulfonic acid ester derivative having an amino group, and the substitution position of the sulfonic acid ester is the 4-position, the 3-position, or the 2-position with respect to the amino group. Preferably, it is the 4th or 3rd position. That is, the compound represented by general formula (2-a) or general formula (2-b) is more preferable.

〔式中、Ｘ₂、Ｚ₂およびＲ₁₁〜Ｒ₁₅は一般式（２）と同じ意味を表す〕

[Wherein X ₂ , Z ₂ and R _{11 to} R ₁₅ represent the same meaning as in general formula (2)]

  Specific examples of the compound represented by the general formula (2) include, for example, the following compounds, but the present invention is not limited thereto.

  The compound represented by the general formula (3) is a sulfonamide derivative having a sulfonic acid ester group, and the substitution position of the sulfonic acid ester group is the 4-position, the 3-position or the 2-position with respect to the sulfonamide group. Yes, more preferably 4th or 3rd. That is, a compound represented by the general formula (3-a) or the general formula (3-b) is more preferable.

〔式中、Ｘ₃、Ｚ₃、Ｒ₂₁〜Ｒ₂₅およびＲ₃₁〜Ｒ₃₅は一般式（３）と同じ意味を表す〕

[Wherein X ₃ , Z ₃ , R _{21 to} R ₂₅ and R _{31 to} R ₃₅ represent the same meaning as in general formula (3)]

  Specific examples of the compound represented by the general formula (3) include, for example, the following compounds, but the present invention is not limited thereto.

  The thermosensitive coloring layer of the present invention is at least one selected from the compounds represented by the general formula (1) and the compounds represented by the general formula (2) and the general formula (3) as the electron-accepting compound. A developer composition containing one compound (hereinafter abbreviated as developer composition A) is used.

  In the developer composition A, the compounds represented by the general formula (1), the general formula (2) and the general formula (3) may be used alone or in combination. Good.

The method for mixing the compound represented by the general formula (1) and the compound represented by the general formula (2) or / and the general formula (3) is not particularly limited. For example, a compound represented by the general formula (1), a compound represented by the general formula (2) or / and the general formula (3), and a heat-fusible compound as required are mixed in a solid state. Method, or in the presence of water, a compound represented by general formula (1), a compound represented by general formula (2) or / and general formula (3), and a thermofusible compound as desired The method of mixing can be applied. In addition, when mixing in presence of water, it can implement in presence of a binder and surfactant, for example.

  Further, in order to improve the final state of the base protective layer and the thermosensitive coloring layer, an appropriate amount of styrene-acrylic resin, polystyrene resin, acrylic resin, polyethylene resin, polypropylene resin, polyacetal resin, etc. may be mixed in the thermosensitive coloring layer. .

  The temperature of the mixing treatment is not particularly limited, but is preferably a temperature not lower than the melting point of the compound represented by the general formula (1), the general formula (2) and the general formula (3). However, it can also be carried out at a temperature equal to or higher than the melting point of the compound represented by the general formula (1), the general formula (2) or / and the general formula (3).

  In addition, in mixing, suitable stirring and mixing apparatus [eg, mortar, propeller-type stirrer, turbine-type stirrer, paddle-type stirrer, homogenizer, homomixer, line mixer, line homomixer, etc. without using media Or media such as an agitator-type mill such as an attritor or a sentry mill, a flow-through mill such as a sand mill, a grain mill, a pearl mill, a matter mill, or a dyno mill, or an annular continuous wet-stir mill such as a conical ball mill or an annular mill (for example, It is preferable to use a stirring and mixing apparatus filled with glass beads, ceramic balls, steel balls, etc.).

  The developer composition A produced and prepared as described above sometimes forms a solvate such as a hydrate, and the solvate is also included in the developer composition A. It can be used as an electron-accepting compound for the thermosensitive coloring layer of the present invention. Of course, the developer composition A obtained by removing a solvent such as water from the solvate can also be used in the heat-sensitive color developing layer of the present invention.

  In the heat-sensitive coloring layer of the present invention, the amount of the developer composition A of the present invention is not particularly limited as the electron-accepting compound, but in general, the amount is 100 parts by weight of the electron-donating coloring compound. On the other hand, it is desirable to use about 50 to 700 parts by mass, preferably about 100 to 500 parts by mass.

  The electron-accepting compound (developer) is a compound that acts upon heating with an electron-donating color-forming compound and has a function of coloring the electron-donating color-forming compound.

  The electron-donating color-forming compound used in the heat-sensitive color developing layer of the present invention is not particularly limited, but is a triarylmethane compound, a vinyl phthalide compound, a diarylmethane compound, a rhodamine-lactam compound, a thiazine compound. , Fluorane compounds, pyridine compounds, spiro compounds, fluorene compounds, and other known electron-donating chromophoric compounds, more preferably fluorane compounds, and more particularly represented by the general formula (A) A fluoran compound is preferred.

(In the formula, A and B are an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, an alkoxyalkyl group having 3 to 8 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a tetrahydrofurfuryl group. In addition, A and B may form a heterocyclic ring with the nitrogen atom to which Z is bonded, and Z ₁₁ is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or A halogen atom, Z ₁₂ and Z ₁₃ represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a halogen atom or a trifluoromethyl group)

  Specific examples of the electron donating chromogenic compound include triarylmethane compounds such as 3,3-bis (4-dimethylaminophenyl) -6-dimethylaminophthalide ["crystal violet lactone"], 3 , 3-bis (4-dimethylaminophenyl) phthalide, 3- (4-dimethylaminophenyl) -3- (4-diethylamino-2-methylphenyl) -6-dimethylaminophthalide, 3- (4-dimethylamino) Phenyl) -3- (1,2-dimethylindol-3-yl) phthalide, 3- (4-dimethylaminophenyl) -3- (2-methylindol-3-yl) phthalide, 3,3-bis (1 , 2-Dimethylindol-3-yl) -5-dimethylaminophthalide, 3,3-bis (1,2-dimethylindol-3-yl) 6-dimethylaminophthalide, 3,3-bis (9-ethylcarbazol-3-yl) -6-dimethylaminophthalide, 3,3-bis (2-phenylindol-3-yl) -6-dimethylamino Phthalides, 3- (4-dimethylaminophenyl) -3- (1-methylpyrrol-3-yl) -6-dimethylaminophthalide, and the like.

  Examples of the vinyl phthalide compound include 3,3-bis [1,1-bis (4-dimethylaminophenyl) ethylene-2-yl] -4,5,6,7-tetrachlorophthalide, 3,3- Bis [1,1-bis (4-pyrrolidinophenyl) ethylene-2-yl] -4,5,6,7-tetrabromophthalide, 3,3-bis [1- (4-dimethylaminophenyl)- 1- (4-Methoxyphenyl) ethylene-2-yl] -4,5,6,7-tetrachlorophthalide, 3,3-bis [1- (4-pyrrolidinophenyl) -1- (4-methoxy Phenyl) ethylene-2-yl] -4,5,6,7-tetrachlorophthalide, 3- [1,1-di (1-ethyl-2-methylindol-3-yl) ethylene-2-yl] -3- (4-Diethylaminophenyl) phthalide 3- [1,1-di (1-ethyl-2-methylindole-3-yl) ethylene-2-yl] -3, etc. (4-N-ethyl -N- phenylamino phenyl) phthalide.

  Examples of diarylmethane compounds include 4,4-bis-dimethylaminobenzhydrin benzyl ether, N-halophenyl-leucooramine, N-2,4,5-trichlorophenylleucooramine, and the like.

Examples of the rhodamine-lactam compound include rhodamine-B-anilinolactam, rhodamine- (4-nitroanilino) lactam, and rhodamine-B- (4-chloroanilino) lactam.

  Examples of thiazine compounds include 3,7-bis (diethylamino) -10-benzoylphenoxazine, benzoylleucomethylene blue, and 4-nitrobenzoylmethylene blue.

  Examples of the fluorane compound include 3,6-dimethoxyfluorane, 3-dimethylamino-7-methoxyfluorane, 3-diethylamino-6-methoxyfluorane, 3-diethylamino-7-methoxyfluorane, and 3-diethylamino. -7-chlorofluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3-diethylamino-6,7-dimethylfluorane, 3-N-cyclohexyl-Nn-butylamino-7-methylfluor Oran, 3-diethylamino-7-dibenzylaminofluorane, 3-diethylamino-7-octylaminofluorane, 3-diethylamino-7-di-n-hexylaminofluorane, 3-diethylamino-7-anilinofluorane 3-diethylamino-7- (2′-fluorophenylamino ) Fluorane, 3-diethylamino-7- (2′-chlorophenylamino) fluorane, 3-diethylamino-7- (3′-chlorophenylamino) fluorane, 3-diethylamino-7- (2 ′, 3′-dichlorophenylamino) fluorane 3-diethylamino-7- (3′-trifluoromethylphenylamino) fluorane, 3-di-n-butylamino-7- (2′-fluorophenylamino) fluorane, 3-di-n-butylamino-7 -(2'-chlorophenylamino) fluorane, 3-N-isopentyl-N-ethylamino-7- (2'-chlorophenylamino) fluorane, 3-Nn-hexyl-N-ethylamino-7- (2 ' -Chlorophenylamino) fluorane, 3-diethylamino-6-chloro-7-anilinofur Lan, 3-di-n-butylamino-6-chloro-7-anilinofluorane, 3-diethylamino-6-methoxy-7-anilinofluorane, 3-di-n-butylamino-6-ethoxy- 7-anilinofluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 3-piperidino-6-methyl-7-anilinofluorane, 3-morpholino-6-methyl-7-anilinofluor Oran, 3-dimethylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-di-n-butylamino-6-methyl-7-anilino Fluorane, 3-di-n-pentylamino-6-methyl-7-anilinofluorane, 3-N-ethyl-N-methylamino-6-methyl-7-anilinofluorane, 3-N-n − Propyl-N-methylamino-6-methyl-7-anilinofluorane, 3-Nn-propyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-Nn-butyl- N-methylamino-6-methyl-7-anilinofluorane, 3-Nn-butyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-N-isobutyl-N-methylamino -6-methyl-7-anilinofluorane, 3-N-isobutyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-N-isopentyl-N-ethylamino-6-methyl-7 -Anilinofluorane, 3-Nn-hexyl-N-methylamino-6-methyl-7-anilinofluorane, 3-N-cyclohexyl-N-ethylamino-6-methyl-7-anilinofluor Oran, -N-cyclohexyl-Nn-propylamino-6-methyl-7-anilinofluorane, 3-N-cyclohexyl-Nn-butylamino-6-methyl-7-anilinofluorane, 3-N -Cyclohexyl-Nn-hexylamino-6-methyl-7-anilinofluorane, 3-N-cyclohexyl-Nn-octylamino-6-methyl-7-anilinofluorane, 3-N- ( 2'-methoxyethyl) -N-methylamino-6-methyl-7-anilinofluorane, 3-N- (2'-methoxyethyl) -N-ethylamino-6-methyl-7-anilinofluorane 3-N- (2′-methoxyethyl) -N-isobutylamino-6-methyl-7-anilinofluorane, 3-N- (2′-ethoxyethyl) -N-methylamino-6-methyl- -Anilinofluorane, 3-N- (2'-ethoxyethyl) -N-ethylamino-6-methyl-7-anilinofluorane, 3-N- (3'-methoxypropyl) -N-methylamino -6-methyl-7-anilinofluorane, 3-N- (3'-methoxypropyl) -N-ethylamino-6-methyl-7-anilinofluorane, 3-N- (3'-ethoxypropyl) ) -N-methylamino-6-methyl-7-anilinofluorane, 3-N- (3'-ethoxypropyl) -N-ethylamino-6-methyl-7-anilinofluorane, 3-N- 2'-tetrahydrofurfuryl-N-ethylamino-6-methyl-7-anilinofluorane, 3-N- (4'-methylphenyl) -N-ethylamino-6-methyl-7-anilinofluorane , 3-diethylami No-6-ethyl-7-anilinofluorane, 3-diethylamino-6-methyl-7- (3'-methylphenylamino) fluorane, 3-diethylamino-6-methyl-7- (2 ', 6'- Dimethylphenylamino) fluorane, 3-di-n-butylamino-6-methyl-7- (2 ′, 6′-dimethylphenylamino) fluorane, 3-di-n-butylamino-7- (2 ′, 6 '-Dimethylphenylamino) fluorane, 2,2-bis [4'-(3-N-cyclohexyl-N-methylamino-6-methylfluorane) -7-ylaminophenyl] propane, 3- [4'- (4-Phenylaminophenyl) aminophenyl] amino-6-methyl-7-chlorofluorane, 3- [4 '-(dimethylaminophenyl)] amino-5,7-dimethylfluor Run, and the like.

  Examples of the pyridine compound include 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-octyl-2-methylindol-3-yl) -4 or 7-azaphthalide, 3- (2-ethoxy -4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4 or 7-azaphthalide, 3- (2-hexyloxy-4-diethylaminophenyl) -3- (1-ethyl) -2-methylindol-3-yl) -4 or 7-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-ethyl-2-phenylindol-3-yl) -4 or 7 -Azaphthalide, 3- (2-butoxy-4-diethylaminophenyl) -3- (1-ethyl-2-phenylindol-3-yl) -4 or 7-azaphthalide, and the like.

  Examples of spiro compounds include 3-methyl-spiro-dinaphthopyran, 3-ethyl-spiro-dinaphthopyran, 3-phenyl-spiro-dinaphthopyran, 3-benzyl-spiro-dinaphthopyran, 3-methyl-naphtho (3-methoxy Benzo) spiropyran, 3-propyl-spiro-dibenzopyran and the like.

  Examples of the fluorene compound include 3,6-bis (dimethylamino) fluorene-9-spiro-3 ′-(6′-dimethylamino) phthalide and 3,6-bis (diethylamino) fluorene-9-spiro-3. '-(6'-dimethylamino) phthalide and the like. Of course, it is not limited to these electron-donating color-forming compounds, and these electron-donating color-forming compounds may be used alone or in combination.

  The thermosensitive coloring layer of the present invention is characterized in that it contains the developer composition A of the present invention as an electron-accepting compound, but other electrons can be used as long as the desired effects of the present invention are not impaired. It is also possible to use a receptive compound in combination. In this case, the ratio of the developer composition A in the total electron-accepting compound is usually adjusted to 20% by mass or more, preferably 50% by mass or more, and more preferably 60% by mass or more. .

  The electron accepting compound other than the developer composition A of the present invention is not particularly limited, but organic electron accepting such as phenol derivatives or metal salts thereof, organic acid derivatives or metal salts, complexes, urea derivatives thereof. And various known electron-accepting compounds such as inorganic compounds and inorganic electron-accepting compounds.

Specific examples of the electron accepting compound other than the developer composition A of the present invention include, for example, 4-te
rt-butylphenol, 4-tert-octylphenol, 4-phenylphenol, 1-naphthol, 2-naphthol, hydroquinone, resorcinol, 4-tert-octylcatechol, 2,2′-dihydroxybiphenyl, 4,4′-dihydroxydiphenyl ether, 2,2-bis (4′-hydroxyphenyl) propane [“bisphenol A”], 1,1-bis (4′-hydroxyphenyl) cyclohexane, 2,2-bis (4′-hydroxy-3′-methylphenyl) ) Propane, 1,3-bis (4′-hydroxycumyl) benzene, 1,4-bis (4′-hydroxycumyl) benzene, 1,3,5-tris (4′-hydroxycumyl) benzene, Bis (4-hydroxyphenyl) acetic acid-n-butyl ester, 2,2-bis (4′-hydride) Roxyphenyl) acetic acid ethyl ester, 4,4- (4′-hydroxyphenyl) pentanoic acid-n-butyl ester, 4-hydroxybenzoic acid benzyl ester, 4-hydroxybenzoic acid phenethyl ester, 2,4-dihydroxybenzoic acid phenoxy Ethyl ester, 4-hydroxyphthalic acid dimethyl ester, gallic acid-n-propyl ester, gallic acid-n-octyl ester, gallic acid-n-dodecyl ester, gallic acid-n-octadecyl ester, hydroquinone monobenzyl ether, bis ( 3-methyl-4-hydroxyphenyl) sulfide, bis (2-methyl-4-hydroxyphenyl) sulfide, bis (3-phenyl-4-hydroxyphenyl) sulfide, bis (3-cyclohexyl-4-hydroxyphenyl) sulfur Bis (4-hydroxyphenyl) sulfoxide, bis (4-hydroxyphenyl) sulfone, bis (3-allyl-4-hydroxyphenyl) sulfone, bis (3-phenyl-4-hydroxyphenyl) sulfone, 4-hydroxy -4'-methyldiphenylsulfone, 4-hydroxy-4'-tert-butyldiphenylsulfone, 4-hydroxy-4'-chlorodiphenylsulfone, 4-hydroxy-4'-methoxydiphenylsulfone, 4-hydroxy-4'- n-propoxydiphenylsulfone, 4-hydroxy-4'-isopropoxydiphenylsulfone, 4-hydroxy-4'-n-butoxydiphenylsulfone, 4-hydroxy-4'-chlorodiphenylsulfone, 4-hydroxy-4'-benzyl Oxydiphenyl sulfone, 3,4- Hydroxy-4'-methyldiphenylsulfone, 2,4'-dihydroxydiphenylsulfone, 2-methoxy-4'-hydroxydiphenylsulfone, 2-ethoxy-2'-hydroxydiphenylsulfone, 4-hydroxy-3-methyl-4 ' -N-propoxydiphenylsulfone, bis (2-hydroxy-5-tert-butylphenyl) sulfone, bis (2-hydroxy-5-chlorophenyl) sulfone, bis [4- (3'-hydroxyphenyloxy) phenyl] sulfone, 4-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 2,4′-dihydroxybenzophenone, 4,4′-dihydroxybenzophenone, 1,7-di (4′-hydroxyphenylthio) -3,5-dioxaheptane, 1,5-di (4′-hydroxypheny Thio) -3-oxapentane, phenol derivatives such as 2,4-dihydroxy-2′-methoxybenzanilide, or metal salts of these phenol derivatives (for example, metal salts of nickel, zinc, aluminum, calcium, etc.), for example 5- [4 '-(2- [4-methoxyphenoxy] ethoxy) cumyl] salicylic acid, 4- [3'-(4-methylphenylsulfone) propoxy] salicylic acid, 4- [2 '-(4-methoxyphenoxy) ) Ethoxy] salicylic acid, 4-n-butyloxycarbonylaminosalicylic acid, 4-n-octyloxycarbonylaminosalicylic acid, 4-n-nonyloxycarbonylaminosalicylic acid, 4-n-decyloxycarbonylaminosalicylic acid, 5-cyclohexyloxycarbonyl Aminosalicylic acid, 1-naphtho Acid, 2-naphthoic acid, 1-hydroxy-2-naphthoic acid, 2-hydroxy-3-naphthoic acid, 2-hydroxy-6-naphthoic acid, 1-acetyloxy-2-naphthoic acid, 2-acetyloxy-1 -Naphthoic acid, 2-acetyloxy-3-naphthoic acid, phthalic acid monobenzyl ester, phthalic acid monophenyl ester, isophthalic acid, terephthalic acid, 4-methylbenzoic acid, 4-tert-butylbenzoic acid, 2-benzoylbenzoic acid Acids, 2- (4′-chlorobenzoyl) benzoic acid, 4-nitrobenzoic acid, 4-chlorobenzoic acid, 4-trifluoromethylbenzoic acid, 4-formylbenzoic acid, 4-cyanobenzoic acid, stearic acid, etc. Organic acid derivatives or metal salts of these organic acid derivatives (for example, metals such as nickel, zinc, aluminum, calcium, etc.) ), For example, complexes such as zinc thiocyanate antipyrine complex, molybdate acetylacetone complex, for example, N, N′-diphenylthiourea, N, N′-di (3-trifluoromethylphenyl) thiourea, N, N ′ -Di (3-chlorophenyl) thiourea, 1,4-di (3'-chlorophenyl) -3-thiosemicarbazide, N-phenyl-N '-(4-methylphenylsulfone) urea, 4,4'-bis ( Organic electron accepting compounds such as urea derivatives such as 4 "-methylphenylsulfonaminocarbonylamino) diphenylmethane, for example, inorganic electron accepting compounds such as acid clay, attapulgite, activated clay, aluminum chloride, zinc chloride, zinc bromide Although it can mention, it is not limited to these compounds. A plurality of these electron-accepting compounds can be used in combination.

  Furthermore, adding a heat-fusible compound (melting point: about 70 to 150 ° C., more preferably, a melting point: about 80 to 130 ° C.) as a sensitizer to the heat-sensitive color developing layer is a heat sensitive material corresponding to high speed recording. This is preferable for obtaining a coloring layer. In this case, the amount of the heat fusible compound used is not particularly limited, but is generally 10 to 700 parts by weight, preferably 20 to 500 parts by weight with respect to 100 parts by weight of the electron donating color forming compound. It is desirable to do.

  Specific examples of the heat-fusible compound include, for example, caproic acid amide, capric acid amide, palmitic acid amide, stearic acid amide, oleic acid amide, erucic acid amide, linoleic acid amide, linolenic acid amide, and N-ethylcapric acid. Amide, N-butyl lauric acid amide, N-methyl stearic acid amide, N-methyl oleic acid amide, N-stearyl cyclohexyl amide, N-octadecyl acetamide, N-oleyl acetamide, stearyl urea, stearic acid anilide, linoleic acid anilide, N-ethylcarbazole, 4-methoxydiphenylamine, N-hydroxymethyl stearamide, methylene bis stearamide, ethylene bis stearamide, acetanilide, 2-benzoylacetanilide, acetoacetate Nilide, 2'-methylacetoacetanilide, 4'-methylacetoacetanilide, 2 ', 4'-dimethylacetoacetanilide, 2'-methoxyacetoacetanilide, 4'-methoxyacetoacetanilide, 2'-chloroacetoacetanilide, Nitrogen-containing compounds such as 4′-chloroacetoacetic acid anilide, 4′-chloro-2 ′, 5′-dimethoxyacetoacetic acid anilide, such as 4-benzyloxybenzoic acid benzyl ester, 2-naphthoic acid phenyl ester, 1-hydroxy- 2-naphthoic acid phenyl ester, oxalic acid dibenzyl ester, oxalic acid di (4-methylbenzyl) ester, oxalic acid di (4-chlorobenzyl) ester, adipic acid diphenyl ester, glutaric acid diphenacyl ester, di (4 -Methylphenyl) carbonate, te Ester compounds such as phthalic acid dimethyl ester, terephthalic acid dibenzyl ester, 4-benzoyloxybenzoic acid methyl ester, for example, 4-benzylbiphenyl, m-terphenyl, 1,2-bis (3 ′, 4′-dimethylphenyl) ) Hydrocarbon compounds such as ethane, fluorene, fluoranthene, 2,6-diisopropylnaphthalene, 3-benzylacenaphthene, such as 2-benzyloxynaphthalene, 2- (4′-methylbenzyloxy) naphthalene, 1,4-di Ethoxynaphthalene, 1,2-diphenoxyethane, 1,2-bis (3′-methylphenoxy) ethane, 1-phenoxy-2- (4′-methylphenoxy) ethane, 1-phenoxy-2- (4′- Ethylphenoxy) ethane, 1- (4′-methoxyphenoxy) -2- Phenoxyethane, 1- (4′-methoxyphenoxy) -2- (3′-methylphenoxy) ethane, 1- (4′-methoxyphenoxy) -2- (2′-methylphenoxy) ethane, 1,2-bis (4′-methoxyphenylthio) ethane, 1,5-bis (4′-methoxyphenoxy) -3-oxapentane, 1,4-bis (2′-vinyloxyethoxy) benzene, 4- (4′-methyl) Phenoxy) biphenyl, 1,4-dibenzyloxybenzene, 1,4-bis (2′-chlorobenzyloxy) benzene, 4,4′-di-n-butoxydiphenylsulfone, 4,4′-diallyloxydiphenylsulfone 1,2-bis (phenoxymethyl) benzene, 1,2-diphenoxybenzene, 1,4-bis (2′-chlorophenoxy) benzene, 4-bis (4′-methylphenoxy) benzene, 1,4-bis (3′-methylphenoxymethyl) benzene, 4-chlorobenzyloxy- (4′-ethoxybenzene), 4,4′-bis (phenoxy) Ether compounds such as diphenyl ether, 4,4′-bis (phenoxy) diphenyl thioether, 1,4-bis (4′-benzylphenoxy) benzene, 1,4-bis [(4′-methylphenyloxy) methoxymethyl] benzene For example, 1,4-diglycidyloxybenzene, 4-benzyloxy-4 ′-(2-methylglycidyloxy) diphenylsulfone, 4- (4-methylbenzyloxy) -4′-glycidyloxydiphenylsulfone, N— Examples include epoxy compounds such as glycidyl phthalimide. The present invention is not limited to, et al. These thermofusible compounds may be used alone or in combination.

  In the coating liquid for the thermosensitive coloring layer, a binder and a pigment are usually blended. Although it does not specifically limit regarding the usage-amount of a binder, Generally, about 5-50 mass% of total solid content is mix | blended.

  As the binder, a water-soluble binder or a water-insoluble binder is generally used, and more preferably a water-soluble binder is used.

  Examples of the water-soluble binder include polyvinyl alcohol derivatives such as polyvinyl alcohol, carboxy-modified polyvinyl alcohol, sulfonate-modified polyvinyl alcohol, and alkyl-modified polyvinyl alcohol, cellulose derivatives such as methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose, and epichlorohydrin-modified. Polyamide, ethylene-maleic anhydride copolymer, styrene-maleic anhydride copolymer, isobutylene-maleic anhydride copolymer, polyacrylic acid, polyacrylamide, methylol-modified polyacrylamide, starch, starch derivative (oxidized starch, ether And starch), casein, gelatin, gum arabic and the like.

  Synthetic rubber latex or synthetic resin emulsion is generally used as the water-insoluble binder, and examples thereof include styrene-butadiene rubber latex, acrylonitrile-butadiene latex, methyl acrylate-butadiene rubber latex, and vinyl acetate emulsion. These binders may be used alone or in combination. Of course, a water-soluble binder and a water-insoluble binder can be used in combination.

  Although the amount of the pigment used is not particularly limited, it is generally desirable to use about 50 to 700 parts by weight, preferably about 100 to 500 parts by weight with respect to 100 parts by weight of the electron donating color forming compound. .

  Examples of the pigment include calcium carbonate, amorphous silica, amorphous calcium silicate, barium carbonate, magnesium carbonate, zinc carbonate, zinc oxide, aluminum oxide, titanium oxide, aluminum hydroxide, magnesium hydroxide, barium sulfate, Inorganic pigments such as talc, wax, kaolin, clay, diatomaceous earth, silica, styrene microballs, polyamide resin (nylon) particles, urea-formalin filler, polyethylene particles, cellulose filler, starch particles, silicon resin particles, etc. However, it is not limited to these.

  These pigments may be used alone or in combination. In consideration of various characteristics of the thermosensitive coloring layer (for example, compatibility with the thermal head), the pigment is preferably a pigment having an oil absorption amount of 50 ml / 100 g or more according to the JISK-5101 method, more preferably the oil absorption amount. Is an inorganic pigment of 50 ml / 100 g or more, more preferably calcium carbonate, amorphous silica or amorphous calcium silicate having an oil absorption of 50 ml / 100 g or more.

  Furthermore, if necessary, in the coating solution for the thermosensitive coloring layer, metal soap, wax, surfactant, UV absorber, UV stabilizer, crosslinking agent, hindered phenol compound, phosphorus compound, antifoaming agent Etc. can be added. For example, when a heat-sensitive color developing layer contains a UV absorber (UV light stabilizer) or a hindered phenol compound, the characteristics of the heat-sensitive color developing layer (for example, storage stability of a color image) can be further improved. There is.

  Examples of the metal soap include metal salts of higher fatty acids such as zinc stearate, calcium stearate, aluminum stearate, and zinc oleate.

  Examples of the wax include paraffin wax, microcrystalline wax, carboxy-modified paraffin wax, carnauba wax, polyethylene wax, polystyrene wax, canderia wax, montan wax, and higher fatty acid ester.

  Examples of the surfactant (dispersant) include sulfosuccinic acid-based alkali metal salts [for example, sodium salts such as di (n-hexyl) sulfosuccinic acid and di (2-ethylhexyl) sulfosuccinic acid], and dodecylbenzenesulfonic acid. Examples thereof include sodium salts, sodium salts of lauryl alcohol sulfate, fatty acid metal salts, and fluorine-containing surfactants.

  The ultraviolet absorber (ultraviolet stabilizer) may be a compound that absorbs at least part of ultraviolet rays of about 300 to about 400 nm. Examples of the ultraviolet absorber include cinnamic acid derivatives, benzophenone derivatives, triazole derivatives, salicylic acid derivatives, cyanoacrylate derivatives, hindered amine derivatives, and the like. In particular, a triazole derivative is preferable as an ultraviolet absorber.

  Examples of the triazole derivative include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-5′-tert-butylphenyl) benzotriazole, and 2- (2′-hydroxy). -3 ′, 5′-di-tert-butylphenyl) benzotriazole, 2- (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) -5-chlorobenzotriazole, 2- (2 ′ -Hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3', 5'-di-tert-amylphenyl) benzotriazole, 2- ( 2′-hydroxy-5′-tert-octylphenyl) benzotriazole, and the like. Not intended to be. These triazole derivatives may be used alone or in combination.

  The amount of the ultraviolet absorber and the ultraviolet stabilizer used is not particularly limited, but is generally about 10 to 400 parts by mass, preferably 20 to 300 parts by mass with respect to 100 parts by mass of the electron donating color forming compound. It is desirable to use about 1 part.

  Examples of the crosslinking agent include aldehyde derivatives such as glyoxal, epoxy compounds, polyamide resins, diglycidyl compounds, aziridine compounds, magnesium chloride, and ferric chloride.

The hindered phenol compound is preferably a phenol derivative in which at least one of the ortho positions of the phenolic hydroxyl group is substituted with a branched alkyl group. For example, 2,6-diisopropyl-4-methylphenol, 2,6-di-tert- Butyl-4-methylphenol, 2-tert-butyl-4-methoxyphenol, 2,5-di-tert-octyl-4-methoxyphenol, 2,5-di-tert-butylhydroquinone, 2,5-di- tert-octylhydroquinone, 1,1,3-tris (2′-methyl-4′-hydroxy-5′-tert-butylphenyl) butane, 1,1,3-tris (2′-methyl-4′-hydroxy) -5′-cyclohexylphenyl) butane, 1,1,3-tris (2′-ethyl-4′-hydroxy-5′-te) t-butylphenyl) butane, 1,1,3-tris (3 ′, 5′-di-tert-butyl-4-hydroxyphenyl) butane, 1,1,3-tris (2′-methyl-4′-) Hydroxy-5'-tert-butylphenyl) propane, 1,1-bis (2'-methyl-5'-tert-butyl-4'-hydroxyphenyl) butane, tetrakis [methylene-3- (3 ', 5'-Di-tert-butyl-4'-hydroxyphenyl) propionate] methane, bis (3-tert-butyl-5-methyl-2-hydroxyphenyl) methane, bis (3-tert-butyl-5-ethyl-2-) Hydroxyphenyl) methane, 1,3,5-trimethyl-2,4,6-tris (3 ′, 5′-di-tert-butyl-4-hydroxybenzyl) benzene, 1,3,5-tris ( '-Tert-butyl-3'-hydroxy-2', 6'-dimethylbenzyl) isocyanuric acid, 1,3,5-tris (4'-tert-butyl-3'-hydroxy-2'-methyl-6 ') -Ethylbenzyl) isocyanuric acid, bis (2-methyl-4-hydroxy-5-tert-butylphenyl) sulfide and the like can be mentioned, but are not limited thereto. These hindered phenol compounds may be used alone or in combination.

  Although it does not specifically limit regarding the usage-amount of a hindered phenol compound, Generally, about 10-400 mass parts with respect to 100 mass parts of electron-donating color-forming compounds, Preferably, about 20-300 mass parts is used. It is desirable to do.

  As a phosphorus compound, a phosphite compound is preferable, for example, 2,2′-methylenebis (4 ″ -methyl-6 ″ -tert-butylphenyl) phosphate, 2,2′-methylenebis (4 ″ -ethyl-6 ″). -Tert-butylphenyl) phosphate, 2,2'-methylenebis (4 ", 6" -di-tert-butylphenyl) phosphate, diphenylphosphate, bis (4-tert-butylphenyl) phosphate, bis (2,4 -Di-tert-butylphenyl) phosphate, bis (4-chlorophenyl) phosphate, bis (2-phenylphenyl) phosphate, bis (4-phenylphenyl) phosphate, etc., or these metals (for example, potassium, sodium, zinc, Calcium, magnesium, aluminum) It can be mentioned.

In the optical information recording medium of the present invention, the method for forming the thermosensitive coloring layer is not particularly limited, and can be formed according to a conventionally known technique. For example, the coating solution for the thermosensitive coloring layer is coated on the protective layer (underlayer) with an air knife coater, blade coater, bar coater, short dwell coater, gravure coater, curtain coater, roll coater, wire bar, spin coater, The thermosensitive coloring layer can be formed by coating and drying with a suitable coating apparatus such as screen printing. The coating amount of the thermosensitive coloring layer is not particularly limited, but is generally about 1.5 to 12 g / m ² in terms of dry mass, preferably
It is adjusted to about ² to 10 g / m2.

  In the present invention, an overcoat layer is provided on the heat-sensitive color forming layer thus obtained. First, an overcoat layer mainly composed of a water-soluble resin or a water-dispersible resin will be described.

Examples of the water-soluble resin or water-dispersible resin include polyvinyl alcohol, acetoacetyl group-modified polyvinyl alcohol, carboxy-modified polyvinyl alcohol, sulfonated-modified polyvinyl alcohol, alkyl-modified polyvinyl alcohol, olefin-modified polyvinyl alcohol, nitrile-modified polyvinyl alcohol, and amide. Modified polyvinyl alcohol, polyvinyl alcohol derivatives such as pyrrolidone modified polyvinyl alcohol, cellulose derivatives such as methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, casein, gum arabic, starch, starch derivatives (oxidized starch, etherified starch, etc.), styrene-butadiene Copolymer, vinyl acetate-vinyl chloride-ethylene copolymer, meta Acrylate - Although butadiene copolymers, not limited thereto. A polyvinyl alcohol derivative is preferable, and in particular, when a medium surface having a touch feeling close to that of plain paper is produced, the tear strength of the film formed is 9.8 N / mm to 58.8 N / mm (1 kg). Polyvinyl alcohol derivatives that are / mm to 6 kg / mm) are preferred.

  This overcoat layer further contains a pigment. Examples of such pigments include the inorganic pigments and organic pigments described above, and these may be used alone or in combination. Particularly preferable pigments are calcium carbonate, silica, and starch particles. Among them, when preparing a medium surface having a touch feeling close to that of plain paper, calcium carbonate having an average particle diameter of 0.5 to 2.0 μm, average Silica having a particle size of 2.0 to 5.0 μm is preferable. Although the usage-amount of a pigment is not specifically limited, Usually, it is 10-500 mass parts with respect to 100 mass parts of resin components, More preferably, it is 40-400 mass parts.

  Next, an overcoat layer containing an ultraviolet absorber will be described. In this case, the overcoat layer is obtained by further adding a UV absorber to an overcoat layer mainly composed of a water-soluble resin or a water-dispersible resin. In addition, it is preferable that the ultraviolet absorber is encapsulated in the microcapsule.

The ultraviolet absorber is not particularly limited as long as it is a compound that absorbs at least part of ultraviolet rays of about 300 to about 400 nm. Specific examples of the ultraviolet absorber include, for example, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-5′-tert-butylphenyl) benzotriazole, 2- ( 2'-hydroxy-3 ', 5'-di-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2 -(2'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3', 5'-di-tert-amylphenyl) benzotriazole 2- [2′-hydroxy-3 ′-(3 ″, 4 ″, 5 ″, 6 ″ -tetrahydrophthalimidomethyl) -5-methylphenyl] benzotriazole, 2- (2 ′ -Hydroxy-5'-tert-octylphenyl) benzotriazole, 2- (2'-hydroxy-3'-decyl-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3'-undecyl-5) '-Methylphenyl) benzotriazole, 2- (2'-hydroxy-3'-dodecyl-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3'-tetradecyl-5'-methylphenyl) benzo Triazole, 2- (2′-hydroxy-3′-pentadecyl-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-3′-hexadecyl-5′-methylphenyl) benzotriazole, 2- [2 '-Hydroxy-4'-(2 "-ethylhexyloxy) phenyl] benzotriazole, 2- [2'-hydroxy-4 '-(2 -Ethylheptyloxy) phenyl] benzotriazole, 2- [2'-hydroxy-4 '-(2 "-ethyloctyloxy) phenyl] benzotriazole, 2- [2'-hydroxy-4'-(2" -propyl) Octyloxy) phenyl] benzotriazole, 2- [2′-hydroxy-4 ′-(2 ″ -propylheptyloxy) phenyl] benzotriazole, 2- [2′-hydroxy-4 ′-(2 ″ -propylhexyloxy) ) Phenyl] benzotriazole, 2- [2′-hydroxy-4 ′-(1 ″ -ethylhexyloxy) phenyl] benzotriazole, 2,2-methylenebis [4 ′-(1,1,3,3-tetrabutyl)- 6 '-(2H-benzotriazol-2'-yl] phenol, polyethylene glycol (molecular weight about 300) and methyl-3 [3-tert-butyl-5- (2H-benzotriazol-2-yl) -4-hydroxyphenyl] benzoic acid UV absorbers such as condensates with propionate, phenyl salicylate, p-tert-butylphenyl Salicylic acid UV absorbers such as salicylate and p-octylphenyl salicylate, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, 2-hydroxy-4 -Octyloxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-methoxy- 5-sulfove Benzophenone ultraviolet absorbers such as nzophenone and bis (2-methoxy-4-hydroxy-5-benzoylphenyl) methane, 2-ethylhexyl-2-cyano-3,3′-diphenyl acrylate, ethyl-2-cyano-3, Cyanoacrylate ultraviolet absorbers such as 3′-diphenyl acrylate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (2,2,6,6-tetramethyl-4-succinate) Examples include, but are not limited to, hindered amine ultraviolet absorbers such as piperidyl) ester and malonic acid (1,2,2,6,6-pentamethyl-4-piperidyl) ester. These ultraviolet absorbers may be used alone or in combination. In particular, benzotriazole ultraviolet absorbers are preferred.

  The ultraviolet absorber may be contained not in the overcoat layer but in the heat-sensitive color developing layer, but in order to further enhance the effects of the present invention, it is preferable to contain the ultraviolet absorber in the overcoat layer. .

The amount of the ultraviolet absorber used is not particularly limited, but is usually 0.05 to 2.0 g / m ² , more preferably 0.1 to 0.1 g in the heat-sensitive color developing layer or the overcoat layer. Adjust to about 1.0 g / m ² . The ultraviolet absorbent may be encapsulated in microcapsules, and the microcapsules can be prepared by various known methods. For example, it is prepared by a method in which a core material obtained by dissolving an ultraviolet absorber in an organic solvent is emulsified and dispersed in an aqueous medium as necessary to form a wall film made of a polymer material around an oily liquid. The

  There are no particular limitations on the polymer material that forms the wall of the microcapsule, but examples include polyurethane / polyurea resin, polyamide resin, polyester resin, polycarbonate resin, aminoaldehyde resin, melamine resin, polystyrene resin, and styrene-acrylate. Examples thereof include copolymer resins, styrene-methacrylate copolymer resins, gelatin, and polyvinyl alcohol. Particularly preferred are polyurethane / polyurea resins and aminoaldehyde resins.

  A microcapsule having a wall film made of polyurethane / polyurea resin is contained in a core material that encapsulates a capsule wall film material such as a polyisocyanate and a polyol that reacts therewith, or an adduct of a polyvalent isocyanate compound and a polyol compound. It is produced by mixing, emulsifying and dispersing in an aqueous medium in which a protective colloid material such as polyvinyl alcohol is dissolved, heating, and polymerizing at the oil droplet interface.

  Examples of the polyvalent isocyanate compound used for producing the microcapsule include m-phenylene diisocyanate, p-phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,4-diisocyanate, Diphenylmethane-4,4′-diisocyanate, 3,3′-dimethyldiphenylmethane-4,4′-diisocyanate, xylylene-1,4-diisocyanate, 4,4′-diphenylpropane diisocyanate, trimethylene diisocyanate, hexamethylene diisocyanate, propylene -1,2-diisocyanate, butylene-1,2-diisocyanate, cyclohexane-1,2-diisocyanate, cyclohexane-1,4-diisocyanate, etc. Cyanate compounds, triisocyanate compounds such as 4,4 ′, 4 ″ -triphenylmethane triisocyanate, toluene-2,4,6-triisocyanate, 4,4′-dimethyldiphenylmethane-2,2 ′, 5,5 ′ -Tetraisocyanate compounds such as tetraisocyanate, adducts of hexamethylene diisocyanate and trimethylolpropane, adducts of 2,4-tolylene diisocyanate and trimethylolpropane, and xylylene-1,4-diisocyanate and trimethylolpropane Examples thereof include isocyanate prepolymers such as adducts.

  Examples of the polyol compound include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8. -Octanediol, propylene glycol, 1,2-dihydroxybutane, 2,3-dihydroxybutane, 2,2-dimethyl-1,3-propanediol, 2,4-pentanediol, 2,5-hexanediol, 3- Methyl-1,5-pentanediol, 1,4-cyclohexanedimethanol, dihydroxycyclohexane, diethylene glycol, 1,2,6-trihydroxyhexane, phenylethylene glycol, 1,1,1-trimethylolpropane, hexanetriol, penta Erythritol, glycerin, , 3-Di (2′-hydroxyethoxy) benzene, 1,4-di (2′-hydroxyethoxy) benzene, m-xylylene glycol, p-xylylene glycol, α, α′-dihydroxy-p-diisopropylbenzene 4,4′-dihydroxydiphenylmethane, 2,2-bis (4′-hydroxyphenyl) propane, 4,4′-dihydroxydiphenyl sulfide, 4,4′-dihydroxydiphenylsulfone, and the like. A plurality of polyisocyanate compounds and polyol compounds can be used in combination as desired.

  Microcapsules with a wall membrane made of aminoaldehyde resin are manufactured by adding a wall membrane material after emulsification of the core material, so the thickness of the wall membrane is adjusted regardless of the particle size of the emulsion. There is also an advantage that can be done. A microcapsule having a wall film made of an aminoaldehyde resin usually contains at least one amine compound such as urea, thiourea, alkylurea, ethylene urea, acetoguanamine, benzoguanamine, melamine, guanidine, biuret, cyanamide, formaldehyde, At least one aldehyde compound such as acetaldehyde, paraformaldehyde, hexamethylenetetramine, glutaraldehyde, glyoxal, furfural, or an initial reactive condensate obtained by condensing them is produced by an in-situ method.

  As an emulsifier (protective colloid agent) used for microencapsulation, various anions, nonions, cations, or amphoteric water-soluble polymer compounds are used. The amount of emulsifier used is not particularly limited. For example, when a polyurethane / polyurea resin is used as a wall film material, it is usually used with respect to the total of the wall film material, the ultraviolet absorber and the organic solvent. 1 to 50% by mass, preferably 3 to 30% by mass. Moreover, when using aminoaldehyde resin as a wall membrane material, the usage-amount of an emulsifier is 1-20 mass% normally with respect to a core substance, Preferably, it is 3-10 mass%.

Although it does not specifically limit as an organic solvent, For example, the organic solvent of various high boiling points currently used for the pressure sensitive recording material etc. can be used. Specific examples of the organic solvent include ester organic solvents such as tricresyl phosphate, trioctyl phosphate, dibutyl phthalate, dioctyl phthalate, butyl oleate, and diethylene glycol dibenzoate, isopropyl naphthalene, diisopropyl naphthalene, 1-methyl- Aromatic organic solvents such as 1-phenyl-1-tolylmethane, 1-methyl-1-phenyl-1-xylylmethane, 1-phenyl-1-tolylmethane, isopropylbiphenyl, and cottonseed oil, castor oil, kerosene, paraffin, Examples thereof include chlorinated paraffin and naphthenic oil. These may be used alone or in combination.

  The amount of the organic solvent used is not particularly limited, but an amount sufficient to sufficiently dissolve the ultraviolet absorber in the microcapsule is used. For example, when a polyurethane / polyurea resin is used as the wall film material, the organic solvent is usually 10 to 60% by mass, preferably 20 to 20%, based on the total of the organic solvent, the ultraviolet absorber and the microcapsule wall film material. 60% by mass. Moreover, when using aminoaldehyde resin as a wall membrane material, the usage-amount of an organic solvent is 50-2000 mass% normally with respect to a ultraviolet absorber, Preferably, it is 100-1000 mass%. Moreover, when using a liquid ultraviolet absorber at room temperature, the organic solvent may not be used.

  The amount of the microcapsule wall membrane material used is not particularly limited. For example, when a polyurethane / polyurea resin is used as the wall membrane material, the total amount of the organic solvent, the ultraviolet absorber, and the microcapsule wall membrane material is used. In contrast, it is usually 37 to 75% by mass, preferably 35 to 60% by mass, and when an aminoaldehyde resin is used as a wall film material, an ultraviolet absorber, an organic used as necessary. It is 30-300 mass% normally with respect to the sum total of a solvent, Preferably, it is 35-200 mass%.

  The amount of the ultraviolet absorber used is not particularly limited. For example, when a polyurethane / polyurea resin is used as the wall membrane material, the total amount of the organic solvent, the ultraviolet absorber and the microcapsule wall membrane material is used. In general, it is 3 to 50% by mass, preferably 3 to 20% by mass, and when an aminoaldehyde resin is used as a wall film material, an ultraviolet absorber, a microcapsule wall film material, if necessary It is 3 to 75 mass% normally with respect to the sum total of the organic solvent used, Preferably, it is 3 to 50 mass%. In addition to the ultraviolet absorber, various additives such as an antioxidant and a mold release agent can be added to the microcapsules as desired. In microencapsulation, a reaction accelerator such as a tin compound, a polyamide compound, an epoxy compound, or a polyamine compound may be used in combination.

  Although the average particle diameter of a microcapsule is not specifically limited, Usually, 0.1-5 micrometers, Preferably it is 0.3-3 micrometers. The amount of the microcapsules in the heat-sensitive recording layer or the overcoat layer is not particularly limited, but is usually 5 to 80% by mass, preferably 15 to 70% with respect to the total solid content of each layer. % By mass.

The coating liquid for forming the overcoat layer of the present invention is prepared by mixing and dispersing with a stirrer such as a ball mill, an attritor or a homogenizer, and prepared as an aqueous coating liquid. Applied to form an overcoat layer. Furthermore, various additives that may be added to the thermosensitive coloring layer, such as metal soaps, waxes, surfactants, crosslinking agents, antifoaming agents, etc., are added to the coating liquid for forming the overcoat layer. Also good. For the coating amount of the coating liquid for forming an overcoat layer is not particularly limited, in general, on a dry weight, 0.1 to 20 g / m ^2, preferably about, 0.5 to 10 g / m ² approximately It is adjusted to the range.

An intermediate layer mainly composed of a water-soluble resin or a water-dispersible resin and an overcoat layer mainly composed of an ionizing radiation curable resin may be provided. In this case, an intermediate layer mainly comprising a water-soluble resin or a water-dispersible resin is first provided on the thermosensitive coloring layer, and then an overcoat layer mainly comprising an ionizing radiation curable resin is provided on the intermediate layer. Provide. In forming the intermediate layer, the water-soluble resin or water-dispersible resin used in forming the overcoat layer is used, and a polyvinyl alcohol derivative is particularly preferable. In the intermediate layer, the above-mentioned various inorganic pigments and organic pigments can be added, and the amount used is usually 10 to 500 parts by mass, more preferably 80 to 100 parts by mass with respect to 100 parts of the resin component. 350 parts by mass. Further, in the coating liquid for forming the intermediate layer, various additives that may be added to the thermosensitive coloring layer, such as metal soap, wax, surfactant, UV absorber, UV stabilizer, crosslinking agent, quenching agent, etc. A foaming agent or the like may be added.

  The coating solution for forming the intermediate layer is usually prepared as an aqueous coating solution, and if necessary, mixed and dispersed by a mixing and stirring device such as a ball mill or an attritor, and then by various known coating devices, a thermosensitive coloring layer. Applied on top to form an intermediate layer. After application, it can be cured and dried by irradiation with ultraviolet rays or electron beams.

For the coating amount of the coating liquid forming the intermediate layer is not particularly limited, in general, on a dry weight, 0.1 to 20 g / m ^2, preferably about, 0.5 to 10 g / m ² of about Adjusted in range.

  For the purpose of increasing the smoothness of the surface of the intermediate layer, it is preferable to perform a smoothing process with a super calender or the like. In this case, the Beck smoothness of the surface of the intermediate layer is 50 seconds or more, more preferably 300 seconds or more, Particularly preferably, it is adjusted to 3000 seconds or more.

  On the intermediate layer thus obtained, an overcoat layer containing an ionizing radiation curable resin is provided. As the ionizing radiation curable resin for forming the overcoat layer, for example, various prepolymers or monomers are used.

  Examples of the prepolymer include poly (meth) acrylates of aliphatic or aromatic substituted aliphatic 2-6 valent polyhydric alcohols and polyalkylene glycols, aliphatic or aromatic substituted aliphatic 2-6 valent polyvalents. Polyhydric alcohol poly (meth) acrylate, poly (meth) acryloyloxyalkyl phosphate ester, polyester poly (meth) acrylate, epoxy poly (meth) acrylate, polyurethane poly (meth) ) Acrylates, polyamide poly (meth) acrylates, polysiloxane poly (meth) acrylates, vinyl or diene low molecular weight polymers having (meth) acrylate groups in the side chain and / or terminal, the above oligoester (meth) acrylates Prepo such as modified products Mer, and the like.

  Examples of the monomer include carboxyl group-containing monomers such as ethylenically unsaturated mono- or polycarboxylic acids and carboxylic acid group-containing monomers such as alkali metal salts, ammonium salts and amine salts thereof, ethylenically unsaturated (meth). Amide group-containing monomers such as acrylamide or alkyl-substituted (meth) acrylamide and N-vinylpyrrolidone, sulfone group-containing monomers such as aliphatic or aromatic vinyl sulfone, and sulfonate groups such as alkali metal salts, ammonium salts, and amine salts thereof -Containing monomers, hydroxyl-containing monomers such as ethylenically unsaturated ethers, amino-group-containing monomers such as dimethylaminoethyl (meth) acrylate-2-vinylpyridine, quaternary ammonium base-containing monomers, and ethylenically unsaturated carboxylic acids Alkyl esters, nitrile group-containing monomers such as (meth) acrylonitrile, esters of ethylenically unsaturated alcohols such as vinyl acetate and (meth) allyl acetate, mono (meth) acrylates of alkylene oxide addition polymers of compounds having active hydrogen , Diesters with polycarboxylic acids or unsaturated alcohols, or polyfunctional monomers containing ester groups such as polyesters, diesters of alkylene oxide addition polymers of compounds having active hydrogen and mono (meth) acrylic acid, or polyesters Such as polyfunctional monomer, bisacrylamide such as N, N-methylenebisacrylamide, styrene, divinylbenzene, divinylethylene glycol, divinylsulfene, divinyl ether, divinyl ketone, trivinylbenzene. Such monofunctional or polyfunctional monomer may be mentioned. These prepolymers and monomers may be used alone or in combination.

  Particularly preferred is an ionizing radiation curable resin having a glass transition point (Tg) after curing of 150 ° C. or higher. Specific examples include, for example, pentaerythritol triacrylate, trimethylolpropane triacrylate, dipentaerythritol hexa Examples thereof include polyfunctional monomers such as acrylate and tris (acryloxyethyl) isocyanurate, polysiloxane polyacrylate, and tetrafunctional or higher oligoester acrylate.

  If desired, the ionizing radiation curable resin layer may contain the various inorganic pigments and organic pigments described above. In general, it is desirable to use a pigment having an average particle diameter of 15 μm or less, preferably 5 μm or less.

  In the ionizing radiation curable resin, a non-ionizing radiation curable resin (for example, acrylic resin, alkyd resin, silicon resin, fluororesin, butyral resin, etc.), wax, surfactant, ultraviolet absorber, if desired Various additives such as may be added.

The ionizing radiation curable resin component is mixed by an appropriate mixing and stirring device such as a mixer, and then coated on the intermediate layer by various known methods. Although it does not specifically limit regarding an application quantity, Usually, about 0.1-20 g / m < ² >, More preferably, it adjusts to about 0.3-10 g / m < ² >.

  Examples of the ionizing radiation for curing the ionizing radiation curable resin include electron beam, ultraviolet ray, α ray, β ray, γ ray, X ray and the like. Is more preferable. Regarding the use amount of ionizing radiation, for example, when an electron beam is used, it is usually about 0.1 to 15 Mrad, more preferably about 0.5 to 10 Mrad.

  In the case of the electron beam radiation method, for example, a scanning method, a curtain beam method, a broad beam method, or the like is used, and irradiation is usually performed with an acceleration voltage of about 100 to 300 KV.

  In the case of the ultraviolet radiation method, the ionizing radiation curable resin components include thioxanthone, benzoin, dimethylxanthone, benzophenone, anthracene, benzyldimethyl ketal, anthraquinone, 1-chloroanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, etc. Add photosensitizer.

  The addition amount of the photosensitizer is usually about 0.1 to 10% by mass, more preferably about 0.3 to 5% by mass with respect to the ionizing radiation curable resin.

  For the purpose of accelerating curing, in addition to the photosensitizer, for example, 3 such as triethanolamine, 2-dimethylaminoethanol, dimethylaminobenzoic acid, dimethylaminobenzoic acid amyl ester, dimethylaminobenzoic acid lauryl ester, etc. About 0.05-5 mass% can also be added to a class of amines with respect to the ionizing radiation curable resin.

  In the case of the ultraviolet radiation method, ultraviolet rays having an intensity of about 500 to 8000 μW / cm are usually irradiated. As the light source, for example, an ultraviolet lamp (for example, a low pressure, medium pressure or high pressure mercury lamp), a xenon lamp, a tungsten lamp, or the like can be used.

  In the present invention, if necessary, an intermediate layer composed of a pigment, a binder, or the like is provided between the thermosensitive coloring layer and the protective layer (underlayer) or between the thermosensitive coloring layer and the overcoat layer (intermediate layer). It may be provided. In addition, it is preferable to increase the smoothness by, for example, performing a super calender treatment after the formation of the protective layer (underlying layer), the thermosensitive coloring layer, and / or the overcoat layer.

  In the present invention, the protective layer (underlying layer), the thermosensitive coloring layer, and the overcoat layer need to be in a sufficiently bound state in order not to cause peeling or the like over time. Therefore, in order to measure the binding strength of each layer, a scratch test was adopted here.

  A commercially available device is used for the scratch tester, and a diamond needle is used for the pressure needle. The load weight is sequentially pressurized at intervals of 5 g, and tracing is performed with a pressure needle from the outer peripheral radius r = 59 mm of the disk surface to the inner peripheral radius r = 11 mm. The binding strength of each layer was measured by defining the weight of load until the protective layer (underlying layer) was rubbed by scratch and exposed to the surface. In general, if the binding strength of each layer is 50 g or more, scratch peeling with a nail (hereinafter referred to as “nail peeling”) does not occur and there is no problem. It was an indicator of whether or not.

  In order to confirm the structure of each layer in the optical information recording medium on which a coat layer printable by a thermal printer is formed, it is effective to observe the layer shape of each layer of the protective layer by cross-sectional SEM or FIB. In addition, measurement by FT-IR, GC-MC, HPLC, UV spectrum, TOF, NMR, or the like is effective for the composition analysis of the protective layer (underlayer), the thermosensitive coloring layer, or the overcoat layer.

  The protective layer (underlying layer), the thermosensitive coloring layer, and the overcoat layer configured as described above are printed, and a predetermined writing is made on the entire surface of the printing layer by scanning the thermal head of the thermal printer on the protective layer portion. Can be done.

  Examples of the present invention will be described below. However, the present invention is not limited to these. In addition, unless otherwise indicated,% represents mass%.

Example 1
3-Di-n-butylamino-6-methyl-7-anilinofluorane is used as the electron-donating chromogenic compound, 2-benzyloxynaphthalene is used as the thermofusible compound, and the electron-accepting compound As a thermosensitive coloring material, N- (4-hydroxyphenyl)-(4′-methylbenzene) sulfonamide (developer composition of Exemplified Compound No. 1-4) was prepared by the following method.

(1) Preparation of thermosensitive coloring material

  The above A liquid and B liquid were each dispersed with a sand mill so that the average particle diameter was 1.5 μm, to prepare dispersion liquids. Next, 100 g of solution A, 100 g of solution B, 10 g of 30% paraffin wax, 10 g of calcium carbonate (trade name “CALLITE KT” manufactured by Shiraishi Kogyo Co., Ltd.) with an oil absorption of 138 ml / 100 g, 75 g of 20% aqueous starch starch solution, 20% A 75% aqueous solution of polyvinyl alcohol (trade name, “PVA-105” manufactured by Kuraray Co., Ltd.) was mixed and stirred to prepare a coating solution for the thermosensitive coloring layer.

(2) Preparation of overcoat material An overcoat material comprising a coating liquid (C solution) having the following composition was prepared. Note that in C solution, polyvinyl alcohol, Kuraray trade name "PVA-117" (tear strength ^{39.2N / m 2 (4.0kg / m} 2), 20 ℃, 60% RH) was used. As the calcium carbonate, light calcium carbonate PC manufactured by Shiroishi Kogyo Co., Ltd., ground to an average particle size of 1.5 μm was used. As the silica, a product name “Nip Seal E-150J” (average particle diameter 4 μm) manufactured by Nippon Silica was used.

(3) Production of optical information recording medium A coating solution was prepared by dissolving 0.5 g of a phthalocyanine dye represented by the following formula (B) synthesized according to JP-A No. 03-62878 as a recording dye in 20 ml of dimethylcyclohexane. . This solution is spin-coated at a rotation speed of 1500 rpm on a polycarbonate injection molded substrate (outer diameter 120 mm, thickness 1.2 mm) having a spiral groove with a track pitch of 1.6 μm, a groove width of 0.6 μm, and a groove depth of 0.17 μm. A recording layer was formed.

  For measurement of the thermal decomposition start temperature of the phthalocyanine dye (formula (B)) used for the recording layer dye, about 3.5 mg was collected using a Shimadzu Corporation thermobalance (Shimadzu TA-50WS). Later, it was measured under a nitrogen atmosphere. As a result of TGA measurement, the decomposition start temperature at the time of 5% by mass reduction with respect to the initial dye weight was 330 ° C.

  Next, silver was deposited on the recording layer to a thickness of 60 nm by sputtering. Further, an ultraviolet curable resin “SD-1700” (trade name, manufactured by Dainippon Ink & Chemicals, Inc.) was spin-coated on the reflective layer, and then cured by irradiating with ultraviolet rays to form a 3 μm-base protective layer.

(4) Production of optical information recording medium having thermosensitive color developing layer The dry coating amount of the thermosensitive color developing material on the protective layer (underlayer) of the optical information recording medium produced in (3) was 5.5 g / After coating and drying so as to be m ² , super calender treatment was performed. Next, the overcoat material was applied on the formed thermosensitive coloring layer so that the coating amount after drying was 2.0 g / m ² , dried, and then subjected to supercalendering to form an overcoat layer. .

  When characters were scanned on the thermal coloring layer and the overcoat layer with a commercially available thermal type thermal head on this printing surface, it was possible to color and print cleanly. Further, as a result of performing a scratch test to measure the adhesion strength of the printed portion, it was found that the stylus reaching strength to the underlying protective layer was 65 g, which was sufficient. Moreover, no obstacles such as nail peeling were confirmed.

  Further, the optical information recording medium having the thermosensitive coloring layer thus prepared was subjected to a 12 × speed compatible optical disc recording apparatus (laser wavelength 780 nm, NA = 0.5) manufactured by Sanyo Co., Ltd., and a linear velocity of 14.4 m / s Recording was performed with a recording laser power of 16.5 mW (EFM recording), and then the thermal coloring layer was printed with a thermal printer. When this printed optical information recording medium was reproduced using an optical disk evaluation apparatus DDU-1000 (Pulstec Industrial Co., Ltd., laser wavelength 781 nm, NA = 0.45; using an optical head equipped with a commercially available CD player). Jitter and block error rate were measured using an LJM-1851 jitter meter (manufactured by Reader Electronics Co., Ltd.), a CD-decoder manufactured by Kenwood: DR3552, and a TIA-175 timing interval analyzer manufactured by ADC.

  Evaluation of recording characteristics after printing with a thermal printer showed good 12-times high-speed recording characteristics results with pit jitter = 30 ns, land jitter = 28 ns, and block error rate = 5 ns or less. The compatibility with each CD player was very good.

Example 2
As a recording dye, 0.015 g of an azo dye of the following formula (C) synthesized according to Japanese Patent Application Laid-Open No. 08-332772 was dissolved in 3 g of tetrafluoropropanol to prepare a coating solution. This solution is spin-coated at a rotation speed of 800 rpm on a polycarbonate injection-molded substrate (outer diameter 120 mm, thickness 1.2 mm) having a spiral groove with a track pitch of 1.6 μm, a groove width of 0.55 μm, and a groove depth of 0.18 μm. A recording layer was formed.

  With respect to the azo dye (C) used for the recording layer dye, the thermal decomposition initiation temperature was measured in the same manner as in Example 1. As a result, it was 320 ° C.

  Next, silver was deposited on the recording layer to a thickness of 60 nm by sputtering. Further, an ultraviolet curable resin “SD-1700” (manufactured by Dainippon Ink & Chemicals, Inc.) was spin-coated on the reflective layer, and then cured by irradiating with ultraviolet rays to form a 3 μm-base protective layer.

Next, using the same heat-sensitive color former and overcoat material as in Example 1, a dry application amount of the heat-sensitive color former is 5.5 g / m ² on the protective layer (underlayer) of the optical information recording medium described above. After coating and drying so as to be, a super calender treatment was performed. Next, the overcoat material was applied on the formed thermosensitive coloring layer so that the coating amount after drying was 2.0 g / m ² , dried, and then subjected to supercalendering to form an overcoat layer. .

  When characters were scanned on the thermal coloring layer and the overcoat layer with a commercially available thermal type thermal head on this printing surface, it was possible to color and print cleanly. Further, as a result of conducting a scratch test to measure the adhesion strength of the printed portion, it was found that the stylus reaching strength to the underlying protective layer was 65 g as in Example 1 and had sufficient strength. . Moreover, no obstacles such as nail peeling were confirmed.

  Further, the optical information recording medium having the thermosensitive coloring layer thus produced was recorded at a linear velocity of 14.4 m / s / recording laser power using the same 12 × speed optical disc recording apparatus manufactured by Sanyo as in Example 1. After recording at 19.5 mW (EFM recording), the thermal coloring layer was printed with a thermal printer. When the printed optical information recording medium was reproduced using the same optical disk evaluation apparatus as in Example 1, the recording characteristics were evaluated as follows: pit jitter = 31 ns, land jitter = 30.5 ns, block error rate = 5 ns or less. Good 12 × speed high speed recording characteristics were obtained. The compatibility with each CD player was very good.

Example 3
0.015 g of the same azo dye as in Example 2 was dissolved in 3 g of octafluoropropanol to prepare a coating solution. This solution is spin-coated at a rotation speed of 800 rpm on a polycarbonate injection molded substrate (outer diameter 120 mm, thickness 0.6 mm) having a spiral groove with a track pitch of 0.8 μm, a groove width of 0.25 μm, and a groove depth of 0.6 μm. A recording layer was formed.

  Next, silver was deposited on the recording layer to a thickness of 60 nm by sputtering. Further, a polycarbonate dummy substrate having a thickness of 0.6 mm was laminated on the reflective layer through an adhesive layer made of an ultraviolet curable resin, and then cured by irradiation with ultraviolet rays to form a protective layer.

Next, using the same heat-sensitive color former and overcoat material as in Example 1, the dry amount of the heat-sensitive color former is 5.5 g / m ² on the protective layer (polycarbonate layer) of the optical information recording medium described above.
After coating and drying so as to be, a super calender treatment was performed. Next, the overcoat material was applied on the formed thermosensitive coloring layer so that the coating amount after drying was 2.0 g / m ² , dried, and then subjected to supercalendering to form an overcoat layer. .

  When characters were scanned on the thermal coloring layer and the overcoat layer with a commercially available thermal type thermal head on this printing surface, it was possible to color and print cleanly. Further, as a result of a scratch test for measuring the adhesion strength of the printed portion, it was found that the stylus reaching strength to the underlying polycarbonate protective layer was 65 g as in Example 1 and had sufficient strength. It was. Moreover, no obstacles such as nail peeling were confirmed.

  Further, the optical information recording medium having the thermosensitive coloring layer thus prepared was used as an optical disk recording device “DDU-1000” (DVD-R compatible; laser wavelength 650 nm, NA = 0.60) manufactured by Pulstec. Then, after recording (EFM recording) at a linear velocity of 2.8 m / s and a recording laser power of 10.0 mW, printing was performed on the thermosensitive coloring layer with a thermosensitive printer. This printed optical information recording medium was reproduced using an optical disk evaluation apparatus “DDU-1000” (Pulstec Industrial Co., Ltd., laser wavelength 650 nm, NA = 0.60; using an optical head mounted on a commercially available DVD player). The time jitter and the block error rate were measured in the same manner as in Example 1.

Evaluation of recording characteristics after printing with a thermal printer showed that pit jitter = 7 ns, land jitter = 8 ns, error rate = 4 × 10 ⁻⁴ or less, and good results were obtained with double speed high speed recording characteristics. Also, compatibility with each DVD player was very good.

Comparative Example 1
As a recording dye, 0.4 g of a cyanine dye of the following formula (D) synthesized according to Japanese Patent Laid-Open No. 03-52142 was dissolved in 20 ml of 2,2,3,3-tetrafluoro-1-propanol to prepare a coating solution. . This solution is spin-coated at a rotation speed of 600 rpm on a polycarbonate injection-molded substrate (outer diameter 120 mm, thickness 1.2 mm) having a spiral groove with a track pitch of 1.6 μm, a groove width of 0.55 μm, and a groove depth of 0.12 μm. A recording layer was formed.

  With respect to the cyanine dye (D) used for the recording layer dye, the thermal decomposition temperature was measured in the same manner as in Example 1. As a result, it was 259 ° C.

  Next, silver was deposited on the recording layer to a thickness of 60 nm by sputtering. Further, an ultraviolet curable resin “SD-1700” (manufactured by Dainippon Ink & Chemicals, Inc.) was spin-coated on the reflective layer, and then cured by irradiating with ultraviolet rays to form a 3 μm-base protective layer.

Next, using the same heat-sensitive color former and overcoat material as in Example 1, a dry application amount of the heat-sensitive color former is 5.5 g / m ² on the protective layer (underlayer) of the optical information recording medium described above. After coating and drying so as to be, a super calender treatment was performed. Next, the overcoat material was applied on the formed thermosensitive coloring layer so that the coating amount after drying was 2.0 g / m ² , dried, and then subjected to supercalendering to form an overcoat layer. .

  When characters were scanned on the thermal coloring layer and the overcoat layer with a commercially available thermal type thermal head on this printing surface, it was possible to color and print cleanly.

  On the other hand, the optical information recording medium having the thermosensitive coloring layer thus produced was recorded using a 12 × speed compatible optical disc recording apparatus manufactured by Sanyo Corporation as in Example 1, with a linear velocity of 14.4 m / s / recording laser power. After recording at 22.5 mW (EFM recording), the thermal coloring layer was printed with a thermal printer. When the printed optical information recording medium was reproduced using the same optical disk evaluation apparatus as in Example 1, the recording characteristic evaluation was as follows: pit jitter = 41 ns, land jitter = 42.5 ns, block error rate = 200 ns or more. There was a sufficient result as a 12 × high speed recording characteristic. There was also a problem in compatibility with some CD players.

Comparative Example 2
As a recording dye, pentamethine cyanine dye “NK2627” (3,3′-diethyl-2,2 ′-(6,7,6 ′, 7′-dibenzo) thiadicarbocyanine iodide) (manufactured by Nippon Photosensitivity Laboratories) 0.4 g was dissolved in 20 ml of 2,2,3,3-tetrafluoro-1-propanol to prepare a coating solution. This solution is spin-coated at a rotation speed of 800 rpm on a polycarbonate injection molded substrate (outer diameter 120 mm, thickness 0.6 mm) having a spiral groove with a track pitch of 0.8 μm, a groove width of 0.25 μm, and a groove depth of 0.6 μm. A recording layer was formed.

  When the thermal decomposition temperature of the pentamethine cyanine dye used for the recording layer dye was measured in the same manner as in Example 1, it was 250 ° C.

Next, silver was deposited on the recording layer to a thickness of 60 nm by sputtering. Further, a polycarbonate dummy substrate having a thickness of 0.6 mm was laminated on the reflective layer through an adhesive layer made of an ultraviolet curable resin, and then cured by irradiation with ultraviolet rays to form a protective layer.

Next, using the same heat-sensitive color former and overcoat material as in Example 1, the dry amount of the heat-sensitive color former is 5.5 g / m ² on the protective layer (polycarbonate layer) of the optical information recording medium described above.
After coating and drying so as to be, a super calender treatment was performed. Next, the overcoat material was applied on the formed thermosensitive coloring layer so that the coating amount after drying was 2.0 g / m ² , dried, and then subjected to supercalendering to form an overcoat layer. .

  When characters were scanned on the thermal coloring layer and the overcoat layer with a commercially available thermal type thermal head on this printing surface, it was possible to color and print cleanly.

On the other hand, the optical information recording medium having the thermosensitive coloring layer thus prepared was used in the same manner as in Example 3 for the optical disc recording apparatus “DDU-1000” (DVD-R compatible; laser wavelength 650 nm, NA = NA = 0.60) was used (EFM recording) at a linear velocity of 2.8 m / s and a recording laser power of 10.0 mW, and then the thermal coloring layer was printed with a thermal printer. The optical information recording medium subjected to this printing was used in the same manner as in Example 3 for the optical disk evaluation apparatus “DDU-1000” (manufactured by Pulstec Industrial Co., Ltd., laser wavelength 650 nm, NA = 0.60; using an optical head mounted on a commercially available DVD player) ), The recording characteristics were as follows: pit jitter = 14 ns, land jitter = 16 ns, error rate = 9 × 10 ⁻² , and sufficient results for 12 × speed high-speed recording characteristics were not obtained. There was also a problem in compatibility with some CD players.

It is sectional drawing which shows one Embodiment of the optical recording medium of this invention. It is sectional drawing which shows other embodiment of the optical recording medium of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transparent substrate 2 Recording layer 3 Metal reflective layer 4 Protective layer (underlayer)
5 Thermosensitive coloring layer 6 Overcoat layer 7 Dummy substrate 8 Adhesive layer

Claims (5)

In an optical recording medium having a transparent substrate, a recording layer, a metal reflective layer, and a protective layer, the protective layer has a heat-sensitive color layer that can be printed by at least one heat-sensitive printer, and an overcoat layer on the heat-sensitive color layer. The overcoat layer contains calcium carbonate having an average particle size of 2.0 μm or less , and the recording layer is made of at least one dye selected from a phthalocyanine dye and an azo dye having a heat resistant temperature of 260 ° C. or more. An optical information recording medium characterized by being formed. The optical information recording medium according to claim 1, wherein the overcoat layer contains calcium carbonate having an average particle diameter of 0.5 μm to 2.0 μm. The optical information recording medium according to claim 1, wherein the thermosensitive coloring layer contains at least an electron donating coloring compound and an electron accepting compound.   The optical information recording medium according to claim 3, wherein the electron-donating color-forming compound is a fluoran compound. The optical information recording medium according to any one of claims 1 to 4, wherein the protective layer has the thermosensitive coloring layer at least on a base protective layer.

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