JP2010083001A - Heat-sensitive transfer sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-sensitive transfer sheet which can significantly reduce the degree of soiling of a head due to running, when the sheet after the lapse of shelf life time is used. <P>SOLUTION: This heat-sensitive transfer sheet has a yellow dye layer containing a special yellow dye on one side surface of a base film, and a heat-resistant lubricative layer containing a lubricant and a resin formed on the other side surface. In addition, the heat-resistant lubricative layer contains a phosphate ester with a special OH group and/or its salt as a lubricant. Further, the characteristic X rays derived from the K rays of a phosphorus element in the heat-resistant lubricative layer, can be obtained by emitting electron radiations with a beam diameter of not more than 1 μm which are accelerated to 20 kV from the heat-resistant lubricative layer side of the heat-sensitive transfer sheet, Then the intensity of the characteristic X rays is measured using an energy dispersion-type X-ray spectroscope at each spot within the square region of 200 μm lengthwise/breadthwise. In this case, the maximum value of the intensity within the region is at least, not less than 2.5 times the minimum value, and a plurality of the maximum regions with the maximum value of the intensity of the characteristic X-rays derived from the K rays of the phosphorus element, are present within the region. Besides, the coefficient of variation sought by dividing the standard deviation of the maximum value of the characteristic X-ray intensity between the maximum regions by the mean value of the characteristic X-ray intensity, is not more than 0.25. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a heat-sensitive transfer sheet, and more particularly to a heat-sensitive transfer sheet in which head contamination due to running in the case of using a heat-sensitive transfer sheet after storage has been significantly improved.

Conventionally, various thermal transfer recording methods are known. Among them, the dye diffusion transfer recording method is attracting attention as a process capable of producing a color hard copy closest to the image quality of a silver salt photograph. In addition, it has advantages over silver halide photography, such as being dry, making visible images directly from digital data, and making replicas easier.
In this dye diffusion transfer recording system, a heat-sensitive transfer sheet (hereinafter also referred to as an ink sheet) containing a dye and a heat-sensitive transfer image-receiving sheet (hereinafter also referred to as an image-receiving sheet) are superposed, and then heat is generated by an electrical signal. The ink sheet is heated by a controlled thermal head or the like, and the dye in the ink sheet is transferred to the thermal transfer image-receiving sheet to record image information, and the three colors of cyan, magenta, and yellow are overlaid. Thus, a color image having a continuous change in color shading can be transferred and recorded.

The thermal transfer sheet on the side in contact with the thermal printer head of the printer is used to prevent the thermal printer head and thermal transfer sheet from sticking and to provide slippage between the thermal printer head and thermal transfer sheet. Is provided. In general, this thermal transfer sheet is coated with a dye layer on a substrate film, dried, wound up, temporarily stored in a roll form, subsequently pulled out from the roll, cut into a desired width, and wound again. It is stored as a product form to be set in a printer as a roll form. Therefore, in this product form, the heat-resistant slipping layer and the dye layer are brought into contact with each other over time, so that the dye of the dye layer is transferred to the heat-resistant slipping layer over time, and then the print is printed. If this is done, the heat-resistant slipping layer with dye attached during printing will be heated by the thermal head, so when printing in large quantities, the decomposition products of the dye due to heat accumulate as dirt on the thermal head, and finally, Had the problem of causing screen failure during printing.
On the other hand, research on the heat-resistant slipping layer has been conducted for a long time. For example, in Patent Document 1, it is possible to add a phosphate ester surfactant to the heat-resistant slipping layer in order to improve the slipping property. Patent Document 2 discloses that a specific phosphate zinc salt is contained in order to impart lubricity. In addition, research on pigments used in the dye layer has been conducted previously. For example, Patent Document 3 discloses research on yellow pigments having a specific structure.
However, the thermal transfer sheets described in each of these patent documents are not always satisfactory with respect to the above-described problems, and improvements have been strongly desired.

JP-A-8-90942 Japanese Patent No. 2655544 Japanese Patent Publication No. 6-19033

  An object of the present invention is to provide a heat-sensitive transfer sheet in which head contamination due to running in the case of using a heat-sensitive transfer sheet after storage has been significantly improved.

As a result of intensive studies, the present inventors have found that the above object of the present invention can be achieved by the following means.
(1) A thermal transfer sheet having a yellow dye layer containing a yellow dye on one surface of a base film and a heat-resistant slip layer containing a lubricant and a resin formed on the other surface, At least one yellow dye is a yellow dye represented by the following general formula (1), the heat resistant slipping layer contains a compound represented by the following general formula (P) as a lubricant, and the thermal transfer A characteristic X-ray intensity derived from K-rays of phosphorus elements in the heat-resistant slip layer obtained by irradiating an electron beam with a beam diameter of 1 μm or less accelerated to 20 kV from the heat-resistant slip layer side of the sheet is a 200 μm square area The maximum value of the intensity in the region is at least 2.5 times the minimum value when measured by an energy dispersive X-ray spectrometer at each point in the region, and the phosphorus element K in the region Maximum value of characteristic X-ray intensity derived from rays There are a plurality of maximum regions, and the coefficient of variation obtained by dividing the standard deviation of the maximum value of the characteristic X-ray intensity between these maximum regions by the average of the characteristic X-ray intensities is 0.25 or less. Thermal transfer sheet.

(In General Formula (1), A represents a substituted or unsubstituted arylene group, and R ¹ and R ² each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted group. R ³ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, substituted or unsubstituted Represents an aryloxy group, a substituted or unsubstituted alkoxycarbonyl group, a substituted or unsubstituted aryloxycarbonyl group, or a substituted or unsubstituted carbamoyl group, and R ⁴ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted group. Represents an aryl group.)

General formula (P)
{(R ^1a O) (R ^2a O) P (═O) O} _m M

(In General Formula (P), M represents a hydrogen atom, a metal ion, or an ammonium ion. R ^1a represents a substituted or unsubstituted aliphatic group or a substituted or unsubstituted aryl group. R ^2a represents Represents a hydrogen atom, a metal ion, an ammonium ion, a substituted or unsubstituted aliphatic group, or a substituted or unsubstituted aryl group, and m is the same as the valence of M and represents a number of 1 to 6.
(2) The thermal transfer according to (1), wherein the maximum value of the intensity is at least 3.0 times the minimum value, and the coefficient of variation of the distribution is 0.22 or less. Sheet.
(3) The at least one melting point of the compound represented by the general formula (P) contained in the heat resistant slipping layer is 40 ° C. to 100 ° C., described in (1) or (2) Thermal transfer sheet.
(4) The heat-sensitive transfer sheet according to any one of (1) to (3), wherein the heat-resistant slipping layer further contains a polyvalent metal salt of an alkyl carboxylic acid.
(5) The heat-sensitive transfer sheet according to any one of (1) to (4), wherein the heat-resistant slipping layer further contains talc particles.
(6) The relationship between the content of the talc particles and the content of the compound represented by the general formula (P) is such that the content of the compound represented by the general formula (P) is 100 parts by mass. The heat-sensitive transfer sheet according to (5), wherein the content of the talc particles is 30 parts by mass or more.
(7) The heat-sensitive transfer sheet according to any one of (1) to (6), wherein the base film has an easy-adhesion layer on at least one surface of the base film.
(8) The resin according to any one of (1) to (7), wherein the resin of the heat resistant slipping layer has two or more hydroxyl groups in a polymer chain length terminal or a polymer structure of the resin. Thermal transfer sheet.
(9) The thermal transfer sheet according to (8), wherein the resin is a polyacryl polyol resin.
(10) The heat-sensitive transfer sheet according to (8) or (9), wherein the resin of the heat-resistant slipping layer is crosslinked.
(11) The thermal transfer sheet according to claim 10, wherein the crosslinking reaction in the crosslinking is performed in a temperature range of 40 ° C to 53 ° C and in a period of 1 day to 20 days.
(12) The thermal transfer sheet is a thermal transfer sheet used in combination with a thermal transfer image-receiving sheet having a heat insulating layer containing a hollow polymer latex and a receiving layer containing a polymer latex on a support. The thermal transfer sheet according to any one of (1) to (11).
(13) A heat-sensitive transfer image-receiving sheet having a heat insulating layer containing a hollow polymer latex and a receiving layer containing a polymer latex on a support, and a dye layer containing a yellow dye on one side of the substrate film. Then, a heat-sensitive transfer sheet having a heat-resistant slip layer containing a lubricant and a resin on the other surface is overlaid so that the receiving layer of the heat-sensitive transfer image-receiving sheet and the dye layer of the heat-sensitive transfer sheet are in contact with each other to form an image signal. An image forming method for forming an image by applying a suitable thermal energy from the heat-resistant slipping layer side of the heat-sensitive transfer sheet, wherein at least one of the yellow dyes is represented by the following general formula (1) A beam diameter which is a dye, contains a compound represented by the following general formula (P) as a lubricant in the heat-resistant slip layer, and is accelerated to 20 kV from the heat-resistant slip layer side of the heat-sensitive transfer sheet. The characteristic X-ray intensity derived from the K-line of phosphorus element in the heat-resistant slip layer obtained by irradiating an electron beam of μm or less is measured with an energy dispersive X-ray spectrometer at each point in a 200 μm square area. In this case, the maximum region in which the maximum value of the intensity in the region is at least 2.5 times the minimum value and the region has the maximum value of the characteristic X-ray intensity derived from the phosphorus element K-ray. And a coefficient of variation obtained by dividing the standard deviation of the maximum value of the characteristic X-ray intensity between these maximum areas by the average of the characteristic X-ray intensity is 0.25 or less. .

(In General Formula (1), A represents a substituted or unsubstituted arylene group, and R ¹ and R ² each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted group. R ³ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, substituted or unsubstituted Represents an aryloxy group, a substituted or unsubstituted alkoxycarbonyl group, a substituted or unsubstituted aryloxycarbonyl group, or a substituted or unsubstituted carbamoyl group, and R ⁴ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted group. Represents an aryl group.)
General formula (P)
{(R ^1a O) (R ^2a O) P (═O) O} _m M
(In General Formula (P), M represents a hydrogen atom, a metal ion, or an ammonium ion. R ^1a represents a substituted or unsubstituted aliphatic group or a substituted or unsubstituted aryl group. R ^2a represents Represents a hydrogen atom, a metal ion, an ammonium ion, a substituted or unsubstituted aliphatic group, or a substituted or unsubstituted aryl group, and m is the same as the valence of M and represents a number of 1 to 6.

  According to the present invention, even when a heat-sensitive transfer sheet after storage has been used, a heat-sensitive transfer sheet can be provided that has improved head contamination due to running and is improved.

Hereinafter, the present invention will be described in detail.
1) Thermal transfer sheet (Configuration of thermal transfer sheet (ink sheet))
The ink sheet is placed on the thermal transfer image-receiving sheet during thermal transfer image formation, and the dye (pigment) is transferred from the ink sheet to the thermal transfer image-receiving sheet by heating from the ink sheet side with a thermal printer head or the like. Used. The ink sheet of the present invention has a dye layer containing a thermally transferable dye and resin (hereinafter also referred to as a thermal transfer layer or a thermal transfer layer) on one side of the base film of the ink sheet, and on the other side, It has a heat-resistant slipping layer containing a lubricant and a resin. An easy adhesion layer (primer layer) may be provided between the base film and the dye layer and / or between the base film and the heat-resistant slip layer.

(Heat resistant slipping layer)
In the present invention, the heat resistant slipping layer contains a phosphate ester having an OH group or a phosphate ester salt as a lubricant.
Although the preferable aspect is illustrated about the phosphate ester or salt of phosphate ester which has OH group of this invention below, this invention is not limited to these examples.

(Phosphate ester having OH group)
The phosphoric acid ester having an OH group used in the present invention is that one phosphoric acid group (OH) per molecule of phosphoric acid is esterified at one place (monoester) or two places (diester). OH groups (hydroxyl groups) that are not esterified remain.

(Phosphate salt)
With the salt of the phosphate ester used in the present invention, esterification is performed at one place (monoester) or two places (diester) with respect to three OH groups bonded to a phosphorus atom per phosphoric acid molecule, A compound in which one of the hydrogen atoms of an unesterified OH group is replaced with a metal ion or an ammonium ion.

  As the phosphoric acid ester having the OH group and the salt of the phosphoric acid ester, a compound represented by the following general formula (P) is preferable.

General formula (P)
{(R ^1a O) (R ^2a O) P (═O) O} _m M

In the formula, M represents a hydrogen atom, a metal ion, or an ammonium ion, R ^1a represents an aliphatic group or an aryl group, and R ^2a represents a hydrogen atom, a metal ion, an ammonium ion, an aliphatic group, or an aryl group. These aliphatic groups and aryl groups may have a substituent. m is the same as the valence of M and represents a number of 1 to 6.
Examples of the substituent that may be substituted by the aliphatic group or aryl group include an aliphatic group (alkyl group, alkenyl group, alkynyl group, cycloalkyl group, cycloalkenyl group, cycloalkynyl group, etc.), aryl group ( Phenyl group, naphthyl group, etc.), heterocyclic group, halogen atom, hydroxyl group, alkoxy group, alkenoxy group, cycloalkoxy group, cycloalkenoxy group, aryloxy group, heterocyclic oxy group, mercapto group, alkylthio group, alkenyl Thio group, arylthio group, amino group, alkylamino group, arylamino group, heterocyclic amino group, acylamino group, sulfonamide group, imide group, cyano group, nitro group, carboxyl group, sulfo group, carbamoyl group, sulfamoyl group, etc. Is mentioned.
^Examples of the aliphatic group in R ^1a and R ^2a include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, and a cycloalkenyl group. Examples of the aryl group include a phenyl group and a naphthyl group. Moreover, these substituents may be further substituted with these substituents.
R ^1a is preferably an aliphatic group, more preferably an alkyl group or an alkenyl group, and R ^2a is preferably a hydrogen atom or an aliphatic group, preferably a hydrogen atom, an alkyl group or an alkenyl group. These aliphatic groups, alkyl groups, and alkenyl groups may have the above-described substituents.
When R ^1a and / or R ^2a is an aliphatic group, the following groups are preferred.

R ^{11 to} R ¹⁴ each independently represents a hydrogen atom or a substituent. Examples of the substituent include a substituent that the aliphatic group or aryl group of R ^1a and R ^2a in the general formula (P) may have. R ^{11 to} R ¹⁴ are preferably a hydrogen atom or an alkyl group, and particularly preferably a hydrogen atom. n represents the number of 0-20, and 1-8 are still more preferable. R ¹⁵ represents an aliphatic group or an aryl group.
The aliphatic group for R ¹⁵ is preferably an alkyl group or an alkenyl group, and the number of carbon atoms is preferably 6 to 20, and more preferably 12 to 18. R ¹⁵ may have a substituent, and examples of the substituent include substituents that the aliphatic group or aryl group of R ^1a and R ^2a in the general formula (P) may have. However, an unsubstituted aliphatic group is preferred.
Examples of the aryl group for R ¹⁵ include a phenyl group and a naphthyl group. The aryl group may have a substituent, and examples thereof include an aliphatic group of R ^1a and R ^2a in the general formula (P) and a substituent that the aryl group may have. Among them, an alkyl group is preferable. . In this case, the alkyl group preferably has 6 to 20 carbon atoms, and more preferably 12 to 18 carbon atoms.
R ¹⁵ is preferably an aliphatic group, more preferably a stearyl group or an oleyl group.
Further, n is preferably 0 in the present invention.
Among the phosphate esters having an OH group, phosphate monoesters or diesters having an alkyl group having 12 to 18 carbon atoms are more preferred.

The metal ions in M and R ^2a may be monovalent metal ions or polyvalent metal ions. As monovalent metal ions, alkali metal ions are preferable, lithium ions, sodium ions and potassium ions are more preferable, and sodium ions are most preferable. The polyvalent metal ion is any polyvalent metal ion other than alkali metal ions, such as magnesium ion, calcium ion, zinc ion, copper ion, lead ion, aluminum ion, iron ion, cobalt ion, chromium ion and manganese. Examples thereof include magnesium ion, calcium ion, zinc ion and aluminum ion, and zinc ion is most preferable.
The ammonium ion is preferably an ion represented by the following general formula.
⁺ N (R ^A1 ) (R ^A2 ) (R ^A3 ) (R ^A4 )
In the above, R ^{A1 to} R ^A4 each independently represent a hydrogen atom, an alkyl group that may have a substituent, or an aryl group that may have a substituent. The substituent which the aliphatic group of R ^<1a> , R ^<2a> and an aryl group in P) may have is mentioned. Of these substituents, a hydroxyl group and a phenyl group are preferable. Further, any two to three groups of R ^{A1 to} R ^A4 are bonded to each other to form a ring (eg, pyrrolidine ring, piperidine ring, morpholine ring, piperazine ring, indoline ring, quinuclidine ring, pyridine ring). Also good.
R ^{A1 to} R ^A4 are preferably a hydrogen atom or an alkyl group which may have a substituent.
Examples of ammonium ions include NH ₄ ⁺ , NH (CH ₂ CH ₂ OH) ₃ ⁺ , NH ₃ (CH ₂ CH ₂ OH) ⁺ , morpholinium, N (CH ₂ CH ₂ OH) ₄ ⁺ , NH ₃ (C ₄ H ₉ ) ⁺ is preferable, and NH ₄ ⁺ , NH ₃ (CH ₂ CH ₂ OH) ⁺ , and morpholinium are more preferable.

  In the present invention, the phosphoric acid ester having the OH group and / or the phosphoric acid ester salt contains the compound represented by the general formula (P), but these may be used alone, Can be used in combination.

Many of these phosphoric acid esters are commercially available. -8, NIKKOL DDP-10, Daiichi Kogyo Seiyaku Co., Ltd. Prisurf AL, Prisurf A208F, Prisurf A208N, Prisurf A217E, Prisurf A219B, Toho Chemical Co., Ltd. Phosphanol RB410, Phosphor Nord RB710, Phosphanol GF199, Phosphanol LP700, Phosphanol LB400, Phoslex A-8, Phoslex A-18, Phoslex A-18D (all trade names) from Sakai Chemical Industry Co., Ltd. I can get lost.
In addition, dilauryl phosphate ester, dioleyl phosphate ester, distearyl phosphate ester, and di (polyoxyethylene dodecyl phenyl ether) phosphate are exemplified.

Many of the phosphate ester salts are commercially available. For example, Prisurf M208B and Prisurf M208F from Daiichi Kogyo Seiyaku Co., Ltd., Phosphanol RD720, Phosphanol GF185 from Toho Chemical Co., Ltd. , Phosphanol GF215, Phosphanol RS710M, Phosphanol SC6103, Sakai Chemical Industry's LBT-1830, LBT-1830 purified product, LBT-2230, LBT-1813, LBT-1820 (all trade names) Is mentioned.
Other than this, zinc salt of dilauryl phosphate ester, zinc salt of dioleyl phosphate ester, zinc salt of distearyl phosphate ester, sodium di (polyoxyethylene nonyl ether) phosphate, di (polyoxyethylene dodecyl phenyl ether) phosphate , Sodium di (polyoxyethylene decylphenyl ether) phosphate, and the like.

  The total coating amount of the phosphoric acid ester having an OH group and the salt of the phosphoric acid ester of the present invention is preferably 1% or more and 25% or less of the total coating mass of the heat resistant slipping layer, and preferably 2% or more and 15% or less. More preferably. In addition, it is also preferable to use a combination of a phosphate ester having an OH group and a phosphate ester salt of the present invention. If these OH group-containing phosphate esters and phosphate ester salts are solid and have low or no solubility in the heat resistant slipping layer coating solution, dispersion in the heat resistant slipping layer coating solution In order to speed up or stabilize the powder, it is preferable to use a powder form in advance, and the particle size is preferably 0.1 μm to 100 μm, more preferably 1 μm to 30 μm.

Next, a method for measuring the characteristic X-ray intensity derived from the K-ray of the phosphorus element of the heat resistant slipping layer defined in the present invention will be described.
(Characteristic X-ray intensity)
In principle, the characteristic X-ray intensity measurement method measures the intensity of characteristic X-rays obtained by exciting atoms in a sample by electron beam irradiation, and will be described in detail below.
(Electron beam irradiation)
The electron beam to be irradiated has an acceleration voltage of 20 kV and a beam diameter of 1 μm or less in order to ensure resolution. Even if the acceleration voltage increases or decreases, the characteristic X-ray intensity derived from the phosphorus element decreases, and at the same time, the baseline noise also increases, so that the accurate intensity cannot be measured. Since electrons are scattered in the sample by the irradiation of the beam, the spatial resolution becomes larger than the beam diameter. Although electron scattering varies depending on the type of element, in the present invention, if the acceleration voltage is 20 kV, the depth direction is about 5 μm, the width direction is about 10 μm, and the beam diameter is 1 μm or less, there is no difference in spatial resolution. In order to increase the characteristic X-ray intensity to be measured, the current amount is usually increased, but at the same time, the beam diameter is increased. A field emission electron gun is used as an electron source because a larger current can be obtained and a beam diameter increase due to an increase in current amount is small. Since the amount of current and the characteristic X-ray intensity are proportional, the amount of current is kept constant.

(Characteristic X-ray measurement)
Wavelength dispersive X-ray spectroscopy (abbreviation “WDS” or “WDX”) and energy dispersive X-ray spectroscopy (abbreviation “EDS” or “EDS”) are used as measurement methods. EDX "). Although each of the measuring methods has characteristics, energy dispersive X-ray spectroscopy is used in the present invention because it is excellent in analysis of a minute region and analysis time is short. In the present invention, the measurement time at one place can be carried out in about 1 to 10 minutes. There are three types of characteristic X-rays of phosphorus element: Kα1 line (2.014 keV), Kα2 line (2.013 keV), and Kβ1 line (2.139 keV). Since it is detected as one peak, this is called K-line. The characteristic X-ray intensity derived from the K-line of the phosphorus element of the present invention is the K-line intensity of the phosphorus element. When measuring characteristic X-ray intensity derived from phosphorus element K-rays at a plurality of locations on the same sample, it is preferable to keep the measurement time constant in addition to the current amount.

An apparatus (abbreviated as “SEM-EDX”) equipped with an energy dispersive X-ray spectrometer in a scanning electron microscope (abbreviated as “SEM”) in order to be able to use an electron beam source together and to confirm a measurement position. , “SEM-EDS”) is preferable.
Specifically, the sample is first subjected to SEM measurement to confirm that the electron beam is sufficiently focused, and the same region is scanned and measured with an EDX (energy dispersive X-ray spectrometer) to perform elemental mapping of phosphorus. carry out. Elemental mapping by EDX is a method in which characteristic X-rays are measured in a short period of time while scanning with an electron beam, and mapping is performed, and points with high and low phosphorus element content are roughly selected from the mapping image. I can do it. An accurate relative intensity at each point can be measured by fixing the electron beam without scanning at each selected point and measuring the characteristic X-ray intensity derived from the phosphorus element K-ray.
Here, the obtained intensity value is taken on a plane parallel to the support (two-dimensional distance plane, X axis and Y axis orthogonal to each other), and the vertical axis (Z axis) orthogonal to this plane is the phosphorus element K line. When a three-dimensional space with the characteristic X-ray intensity derived is plotted, there are a plurality of peaks (the peak is a maximum value) and valleys (the valley bottom is a minimum value) of the intensity value.
In the present invention, the maximum region of the characteristic X-ray intensity includes at least one maximum value of the characteristic X-ray intensity (one peak of the intensity value in the three-dimensional space plot) and is adjacent to the point of the maximum value. Characteristic X-rays with a maximum value (maximum value) of 1.5 times or more of the minimum value (minimum value) with respect to a point having a low characteristic X-ray intensity surrounding the periphery (the minimum value is the above-mentioned valley bottom) It is a local maximum region having a local maximum value (region including the lowest part (minimum value) of the valley from the peak part). Here, if it is less than 1.5 times, the same verification is performed in a wider surrounding area, the distance plane is expanded until the requirement of 1.5 or more is satisfied, and the point where the characteristic X-ray intensity is the lowest A maximum region in which the relationship between (the lowest point in the maximum region) and the point having the highest characteristic X-ray intensity (the highest point in the maximum region) satisfies the relationship of 1.5 times or more is obtained. For this reason, the maximum areas of individual characteristic X-ray intensities have different distance plane areas, and there may be a plurality of local maximum values and local minimum values (mountains and valley bottoms) in one local area of the characteristic X-ray intensity. . In this way, a region satisfying the above requirements is defined as one maximum region of characteristic X-ray intensity. In the measurement method of the present invention, as described above, since the scattering of the electron beam in the width direction is about 10 μm, the distance between the points showing the maximum value in the maximum region of the characteristic X-ray intensity is at least 4 μm or more away from the spatial resolution. Yes.
In the present invention, the maximum value of characteristic X-ray intensity (hereinafter also referred to as “maximum characteristic X-ray intensity”) is the highest characteristic X-ray intensity measured in the maximum area (one maximum area). Is a maximum value among one or a plurality of maximum values included in (i.e., an intensity value corresponding to the peak of the highest mountain).

The maximum value and the minimum value of the characteristic X-ray intensity derived from the phosphorus element K-ray in the 200 μm square area are the largest and smallest values of the characteristic X-ray intensity in the 200 μm square area. In general, the minimum value can be determined by selecting a total of 10 to 20 points having a low phosphorus element content and irradiating with an electron beam. On the other hand, the maximum value can be obtained by irradiating the center of each region having a high phosphorus element content with an electron beam.
In the present invention, since the region having a high phosphorus element content is generally raised, the region raised by the SEM measurement is specified in advance, and the region having a high phosphorus element content can be roughly determined. In the present invention, the acceleration voltage can be 2 to 5 kV for SEM measurement of the surface shape.

(Sample preparation for measurement)
When the sample is charged by irradiating the sample with the electron beam, the electron beam fluctuates due to the electric field due to the charge, and the current value of the electron beam also fluctuates, so that accurate measurement cannot be performed. In order to prevent charging, the surface of the sample is usually covered with a conductive thin film to prevent charging. The conductive thin film is generally preferably formed by coating carbon (C) with a thickness of 20 nm to 35 nm by sputtering.
For more detailed explanation, “Surface analysis technology selection electronic probe microanalyzer edition edited by Japan Surface Science Society” published by Maruzen Co., Ltd., 1998, EPMA Electron probe microanalyzer electronic probe microanalyzer Are listed.

(Characteristic X-ray intensity derived from phosphorus element K-line in heat-resistant slip layer)
In the present invention, in the characteristic X-ray intensity derived from phosphorus element K-rays at each point in the heat-resistant slipping layer measured by the above method, with respect to the minimum value of the characteristic X-ray intensity in the 200 μm square area. The maximum value of the characteristic X-ray intensity in the region is preferably 2.5 times or more (preferably 10.0 times or less), preferably 3.0 times or more (preferably 8.0 times or less). Is more preferable. The larger this value, the more non-uniform and localized the phosphate ester or phosphate ester salt having an OH group is in the heat resistant slipping layer. In the present invention, a region in which the phosphate ester or phosphate ester salt having such an OH group is localized in the heat-resistant slipping layer (the above-mentioned maximum region of the characteristic X-ray intensity, that is, the above-mentioned property There are a plurality of regions having a maximum value of 1.5 times or more the minimum value of the X-ray intensity, and the number of these regions is preferably 10 to 1000 with respect to a 200 μm square region, and 20 -500 is most preferred. It is preferable that the variation in the characteristic X-ray intensity derived from the phosphorus element K-ray corresponding to the localized region of the phosphate ester or phosphate ester salt having an OH group (the aforementioned maximum value of the characteristic X-ray intensity) is small. The coefficient of variation (calculation method will be described later) corresponding to each localized region of a phosphate ester or phosphate ester salt having an OH group present in a 200 μm square region is preferably 0.25 or less. 0.22 or less is more preferable, and 0.20 or less is most preferable. Further, the total number of localized regions of phosphate esters or phosphate ester salts having OH groups in the range of 0.7 to 1.3 times the average of the maximum value of the characteristic X-ray intensity is 80 in total. % Or more, preferably 90% or more, and most preferably 98% or more.
A variation coefficient of distribution can be obtained from the average of the maximum value of the characteristic X-ray intensity and the standard deviation. The calculation formula is as follows.
Formula (1) (Average of maximum values of characteristic X-ray intensity) = (Total of maximum values of characteristic X-ray intensity) / (Total number of measurements taken as sum)
Formula (2) (Standard deviation) = {[(Maximum value of each characteristic X-ray intensity) − (Average of maximum value of characteristic X-ray intensity)] / (Sum of squares) / (Total number of measurements taken) } To the power of 0.5 (3) (Coefficient of variation) = (Standard deviation) / (Average of local maximum value of characteristic X-ray intensity)

  In the present invention, the phosphoric acid ester having the OH group or the salt of the phosphoric acid ester is used for imparting slipperiness to the heat resistant slipping layer. According to the present invention, the characteristic X-ray intensity derived from the phosphorus element K-ray is measured according to the method described in detail in the above description, and as a result, the maximum value of the characteristic X-ray intensity within the predetermined region is reduced. The ratio value is within the predetermined range defined in the present invention, the presence of a plurality of maximum regions having the maximum value of the characteristic X-ray intensity derived from the phosphorus element K-ray, and the maximum value of the characteristic X-ray intensity The thermal transfer sheet after storage has elapsed only when all of the conditions that the coefficient of variation obtained by the formulas (1) to (3) are within the predetermined range defined in the present invention are satisfied. When used, it has an excellent effect that it can improve head contamination due to running. Here, satisfying any of the above three conditions is also referred to as “a predetermined phosphate ester having an OH group or a salt thereof satisfies a predetermined distribution state defined in the present invention”.

Next, the manufacturing method of the coating liquid for heat-resistant slip layers prescribed | regulated in this invention is described.
Since the coating liquid for the heat-resistant slipping layer is a liquid having a particulate region that is not dispersed in a molecular state in the liquid, a method for producing a pigment dispersion used in the paint industry can be used.
In general, the production process can be roughly divided into a dissolution process and a dispersion process. The dissolution step is a step of dissolving a component that dissolves in the solvent for the coating solution in the heat resistant slipping layer component to form a solution, and generally involves dissolving the resin in an organic solvent. . A dispersion | distribution process is a process which mixes and disperse | distributes the said solution and the component which does not melt | dissolve completely in the solvent for coating liquids in a heat-resistant slipping layer component. In many cases, the component that does not completely dissolve in the solvent for the coating liquid is a secondary agglomerated powder. In the dispersion step, (1) a step of wetting the powder surface with a solution, (2) agglomerated powder. A step of loosening the particles into primary particles or pulverizing the primary particles, and (3) a step of stabilizing the dispersed particles. In the step (1), it is preferable that the powder surface be easily wetted with the solution, and the air on the surface of the powder is replaced with the solution, so that high pressure or high shear force (shear stress) is preferable as the dispersion condition. . In the step (2), a high shearing force is required as a dispersion condition in order to solve the powder aggregation. In order to prevent the dispersed particles from re-aggregating in the liquid in the step (3), and also to prevent re-aggregation even when the coating liquid is dried after coating and the solvent disappears, Various additives can be added. Usually, the steps (1) to (3) proceed simultaneously in the same dispersion apparatus, but it is also preferable to provide a step (premixing) in which the step (1) is performed in advance. When the heat resistant slipping layer is formed by curing the resin with a crosslinking agent, the coating can generally be carried out by adding the crosslinking agent to the liquid after dispersion before coating.

  A well-known thing can be used as a dispersion apparatus used for the said dispersion | distribution. For example, a three-roll mill disperses using shear force and pressing pressure acting on the contact between rolls with different rotational speeds, and a sand mill and bead mill stir media such as glass beads and zirconia beads in a container. It is dispersed using the impact force and shear stress obtained by this. The impact force and shear stress are limited because the media agitation in the bead mill is due to gravity, so that a strong impact force and shear stress can be obtained by forcibly agitating with the arm that rotates the media. There is an improved attritor. In addition to the above, for small-volume dispersion, in addition to the paint shaker that shakes and mixes small containers and the impact force and shear stress of the bead mill are limited, the container is forced to rotate and revolve simultaneously to force the media. There are planetary type bead mills and the like which are improved so as to obtain a strong impact force and shear stress by stirring them. For more detailed explanations, see “Paint Flow and Pigment Dispersion” issued by Kyoritsu Publishing Co., Ltd., 1992, “Paints and Painting (Enhanced Edition)”, Power Corporation, 1994, “Emulsification / Dispersion Theory and practice Theories "published by Tokushu Kagaku Kogyo Co., Ltd., 1997, and" Introduction to Printing Ink, Revised Edition ", published by the Printing Society of Japan Press, 2002.

In the present invention, the phosphate ester or phosphate ester salt having the OH group used for imparting slipperiness to the heat-resistant slipping layer has low solubility in the solution, and therefore the heat-resistant slipping layer. It is considered that the dispersed particles are in a state of dispersed particles in the coating liquid for use, and the dispersed particles are also formed in the heat-resistant slip layer formed by drying the coating liquid after coating. Further, as described above, in the dispersion process, by applying a high shearing force, heat may be generated, and further primary particles may be pulverized. Although it is possible to control the temperature as a bulk through the heat medium in the outer wall of the container and the stirring blade against the heat generation, the heat generation at the microscopic interface between the rolls or the microscopic region of the bead interface that generates shearing force is completely achieved. It cannot be suppressed to. For this reason, it is considered that the phosphate ester or phosphate ester salt having an OH group is dissolved by heat generation in a microscopic high shear force region and then precipitated during the dispersion step. In order to control the dissolution and precipitation to facilitate the control of the dispersion state, it is preferable to use at least one OH group-containing phosphate ester or phosphate ester salt having a melting point of 40 ° C. to 100 ° C. More preferably, the melting point is 50 ° C to 90 ° C.
For the above-described reasons, the state of dispersed particles in the heat-resistant slip layer generally does not match the particle size and shape of the raw material powder. Furthermore, since the dispersion conditions vary greatly depending on the composition of the coating liquid, the production scale, and the dispersion apparatus, they are not uniformly determined. For this reason, in the present invention, the dispersion state in the heat resistant slipping layer is defined by the characteristic X-ray intensity measurement.

In the present invention, additives such as other lubricants, plasticizers, stabilizers, fillers and fillers may be used in combination with the heat resistant slipping layer.
As fillers, fluorides such as calcium fluoride, barium fluoride, and graphite fluoride, sulfides such as molybdenum disulfide, tungsten disulfide, and iron sulfide, oxides such as silica, colloidal silica, lead oxide, alumina, and molybdenum oxide , Inorganic such as graphite, mica, boron nitride, magnesium oxide (magnesia), magnesium hydroxide (brucite), magnesium carbonate (magnesite), magnesium calcium carbonate (dolomite), clays (talc, kaolin, acid clay, etc.) Fillers composed of compounds, organic resins such as fluororesins and silicone resins, silicone oils, alkylcarboxylic acid polyvalent metal salts (such as zinc stearate and lithium stearate), various waxes such as polyethylene wax and paraffin wax, anions Surfactants On surfactant, amphoteric surface active agents include nonionic surface active agents, a surfactant such as a fluorine-based surfactant. The particle size of the filler is preferably 0.1 μm to 50 μm, more preferably 0.5 μm to 10 μm, and the filler particle shape may be any shape such as indefinite shape, spherical shape, cube shape, needle shape, or flat plate shape. However, needles and flat plates are preferably used.
Among these additives that can be used in combination, magnesium oxide, magnesium hydroxide, talc, kaolin and alkylcarboxylic acid polyvalent metal salt are preferable, and magnesium oxide, talc and alkylcarboxylic acid polyvalent metal salt are more preferable. Of these, zinc stearate is more preferable as the alkylcarboxylic acid polyvalent metal salt.
Here, in order to achieve the effect of the present invention more effectively, talc (talc particles) or alkylcarboxylic acid polyvalent metal salt is preferably used, and talc (talc particles) and alkylcarboxylic acid polyvalent metal salt are used. It is particularly preferred to use both.

Talc is a hydrated silicate mineral of magnesium, and the theoretical composition is Mg ₃ Si ₄ O ₁₀ (OH) ₂ . The unit structure is a three-layer structure in which a magnesium-containing layer is sandwiched between two layers of a silicate layer structure, and has a cleavage property because the bond between the silicate layers between the unit structures is weak. (Mohs hardness 1) and slipperiness. In addition, since it does not decompose to around 900 ° C. and is inert to most chemicals, it is a thermally and chemically stable substance. There are two types of talc, monoclinic and triclinic. In the present invention, any talc can be used, and a mixture of monoclinic and triclinic is also used. be able to.
The inclusion of talc in the heat-resistant slip layer makes it difficult to damage the thermal printer head due to the softness of talc. It is useful because it is less affected by fusion and corrosion on the thermal printer head.

As the talc, commercially available powdered talc derived from natural minerals can be used. For example, the Micro Ace series, SG series manufactured by Nippon Talc Co., Ltd. ) List PS series manufactured by Fukuoka Talc Kogyo, JET series manufactured by Asada Flour Milling Co., Ltd., Hytron series manufactured by Takehara Chemical Industry Co., Ltd. I can do it. In the present invention, the average sphere equivalent particle size of the talc particles is preferably 0.5 to 10 μm, more preferably 0.8 to 5 μm, and most preferably 1 to 4 μm. The average sphere equivalent particle size of talc can be determined by a laser diffraction scattering method.
In the present invention, the relation of the content of talc in the heat-resistant slipping layer is preferably 30 parts by mass or more when the total content of the phosphate ester having the OH group and the phosphate ester salt is 100 parts by mass. 40 parts by mass or more is more preferable, and 50 parts by mass or more is more preferable. The upper limit is preferably 1000 parts by mass or less, more preferably 500 parts by mass or less, and still more preferably 400 parts by mass or less.

In the alkylcarboxylic acid polyvalent metal salt, the alkylcarboxylic acid is preferably an alkylcarboxylic acid having 8 to 25 carbon atoms, more preferably 12 to 21 carbon atoms, and more preferably 14 to 20 carbon atoms, such as octanoic acid, Examples thereof include lauric acid, myristic acid, palmitic acid, stearic acid, and behenic acid. Examples of the polyvalent metal include divalent or trivalent metals such as alkaline earth metals and transition metals, such as calcium and magnesium. , Barium, strontium, cadmium, aluminum, zinc, copper, iron and the like. Among them, zinc is preferable. Alkylcarboxylic acid polyvalent metal salts include zinc laurate, zinc myristate, zinc palmitate, zinc stearate, zinc behenate, calcium stearate, magnesium myristate, barium stearate, aluminum stearate, copper stearate, etc. Among these, zinc stearate is preferable. These are commercially available or can be easily synthesized from the corresponding carboxylic acid.
These alkylcarboxylic acid polyvalent metal salts are preferably used in an amount of 0.1 to 50 parts by mass, and 0.5 to 10 parts by mass with respect to 100 parts by mass of the resin (binder resin) of the heat-resistant slip layer. Is more preferable.

  The amount of additives other than these talc and alkylcarboxylic acid polyvalent metal salt contained in the heat-resistant slip layer varies, but is preferably 0.001 to 50% by weight based on the total amount of the heat-resistant slip layer. 0.01% by mass to 20% by mass is more preferable.

Some ester surfactants have acid radicals, and when the amount of heat from the thermal head increases, the ester decomposes, and the pH of the back layer decreases, which may cause severe corrosion wear on the thermal head. is there. For this, there are a method using a neutralized ester surfactant, a method using a neutralizing agent such as magnesium hydroxide, and the like.
Examples of other additives include higher fatty acid alcohols, organopolysiloxanes, and organic carboxylic acids.

Although the heat-resistant slipping layer contains a resin, a known resin having high heat resistance can be used. Examples include cellulose resins such as ethyl cellulose, hydroxy cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, nitrocellulose, polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, polyvinyl acetoacetal Resin, vinyl chloride-vinyl acetate copolymer, vinyl resin such as polyvinylpyrrolidone, polymethyl methacrylate, polyethyl acrylate, polyacrylamide, acrylic resin such as acrylonitrile-styrene copolymer, polyamide resin, polyimide resin, Polyamideimide resin, polyvinyltoluene resin, coumarone indene resin, polyester resin, polyurethane resin, polyether resin, polybuta Ene resin, polycarbonate resin, chlorinated polyolefin resin, fluorine resin, epoxy resin, phenol resin, silicone resin, and a single or a mixture of natural or synthetic resins such as silicone-modified or fluorine-modified urethane.
In order to enhance heat resistance, the resin can be crosslinked by irradiation with ultraviolet rays or electron beams. It is also possible to crosslink by heating using a crosslinking agent. At this time, a catalyst may be added. Examples of the crosslinking agent include isocyanate (polyisocyanate, cyclic trimer of polyisocyanate, etc.), metal (titanium tetrabutyrate, zirconium tetrabutyrate, aluminum triisopropylate, etc.) and the like. Examples of the resin to be reacted with these crosslinking agents include polyvinyl acetal, polyvinyl butyral, polyester polyol, alkyd polyol, and a silicone compound containing an amino group in the side chain.

It is known that the reaction with the crosslinking agent is promoted by placing the heat-resistant slipping layer in a high temperature and high humidity environment after coating. In this regard, in the present invention, it is preferable to select a condition in which the phosphate ester represented by the general formula (P) contained in the heat resistant slipping layer or the salt localized structure of the phosphate ester is not destroyed. Moreover, the combination of the said resin and a crosslinking agent can be selected so that a crosslinking reaction can fully be accelerated | stimulated on the conditions in which the said phosphate ester or salt localized structure in the heat-resistant slipping layer of this invention is not destroyed. A combination of a resin and a cross-linking agent that can sufficiently promote the cross-linking reaction within one day under a low humidity condition of 60 ° C. is preferable.
Such a resin is preferably one having two or more hydroxyl groups in the polymer chain length terminal or polymer structure of the resin. Here, the term “having two or more hydroxyl groups in the polymer chain length terminal or polymer structure of the resin” means that two or more hydroxyl groups are present in the polymer chain length terminal of the resin or in the structure that is not the polymer terminal. It means having. Examples of such a resin include polyacryl polyol, polyester polyol, polyether polyol, and the like. In the present invention, the polyacryl polyol includes polymethacryl polyol. In the present invention, among these, a polyacryl polyol is preferable.
As the resin having two or more hydroxyl groups in the polymer chain length terminal or polymer structure of the resin, commercially available resins can be used, for example, Takelac (registered trademark) series manufactured by Mitsui Chemicals Polyurethane Co., Ltd., Soken Chemical Thermolac series manufactured by Hitachi Chemical Co., Ltd., Hitachioid Co., Ltd., Harima Chemical Co., Ltd. Hariakuron series, Dainippon Ink Co., Ltd. Acrydic series, and Nippon Polyurethane Co., Ltd. NIPPON series Product name), but is not limited thereto.

  The hydroxyl value of a resin having two or more hydroxyl groups in the polymer chain length terminal or polymer structure of the resin is preferably 5 to 300, and most preferably 15 to 100, based on the solid content of the resin. The hydroxyl value is the number of mg of potassium hydroxide equivalent to the hydroxyl group in 1 g of a sample specified in JIS K-1557-1. The acid value of such a resin is preferably 20 or less, most preferably 0 to 10 based on the solid content of the resin. The acid value is the number of mg of potassium hydroxide required to neutralize the free acid in 1 g of a sample specified by JIS K-1557-5.

When cross-linking using an isocyanate-based cross-linking agent, the progress of the cross-linking reaction can be detected by detecting residual isocyanate groups by IR spectrum measurement. The IR spectrum peak intensity derived from the residual isocyanate group after the crosslinking reaction is 20% or less with respect to the IR spectrum peak intensity derived from the residual isocyanate group in the heat resistant slipping layer, preferably 10% or less, most preferably Is 5% or less.
In order to efficiently exhibit the effects of the present invention, the temperature for promoting the reaction between the resin and the crosslinking agent is preferably 65 ° C. or less, more preferably 55 ° C. or less, and 40 ° C. to 53 ° C. Most preferably it is. The time for promoting the reaction between the resin and the crosslinking agent is preferably 12 hours or more and 40 days or less, more preferably 18 hours or more and 30 days or less, and most preferably 1 day or more and 20 days or less. preferable.

  The heat resistant slipping layer is formed by coating the above-described coating solution by a known method such as gravure coating, roll coating, blade coating, or wire bar. The film thickness of the heat resistant slipping layer is preferably 0.1 to 3 μm, and more preferably 0.2 to 2 μm.

(Base film)
The base film of the heat-sensitive transfer sheet of the present invention is not particularly limited, and any conventionally known film can be used as long as it has required heat resistance and strength. Examples include thin papers such as glassine paper, condenser paper, puffin paper, polyesters having high heat resistance such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyphenylene sulfide, polyether ketone, polyether sulfone, polypropylene, polycarbonate, Specific examples of base film that is preferably a stretched or unstretched film of plastic such as cellulose acetate, polyethylene derivative, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyimide, polymethylpentene, ionomer, or a laminate of these materials Take as an example. Among these, the polyester film is particularly preferable, a stretched polyester film is more preferable, and a polyester film formed by stretching after forming an easy-adhesion layer on at least one surface of the base film is particularly preferable.
The thickness of the base film is appropriately selected according to the material so that the strength, heat resistance, and the like are appropriate, but those having a thickness of about 1 to 30 μm are preferably used. More preferably, it is about 1-20 micrometers, More preferably, about 3-10 micrometers is used.

(Easy adhesion treatment)
The base film may be subjected to easy adhesion treatment for the purpose of improving the wettability and adhesiveness of the coating solution. As an easy adhesion treatment method, known resins such as corona discharge treatment, flame treatment, ozone treatment, ultraviolet treatment, radiation treatment, surface roughening treatment, chemical treatment, vacuum plasma treatment, atmospheric pressure plasma treatment, primer treatment, grafting treatment, etc. Surface modification techniques can be exemplified.
Among these, an easily bonding layer can also be formed by application | coating on a base film, and it is preferable to form an easily bonding layer in this invention. Examples of the resin used for the easy-adhesion layer include polyester resins, polyacrylate resins, polyvinyl acetate resins, vinyl resins such as polyvinyl chloride resins and polyvinyl alcohol resins, and polyvinyl resins such as polyvinyl acetoacetal and polyvinyl butyral. Examples include acetal resins, polyether resins, polyurethane resins, styrene acrylate resins, polyacrylamide resins, polyamide resins, polystyrene resins, polyethylene resins, polypropylene resins, and polyvinylpyrrolidone resins. .
The base film used for the support can be formed by subjecting an unstretched film to a coating treatment and then a stretching treatment when the film is formed by melt extrusion.
In addition, two or more kinds of the above treatments can be used in combination.
Here, as described above, in the present invention, a stretched film is preferably formed after forming an easy-adhesion layer on at least one surface of the base film. In the heat-sensitive transfer sheet of the present invention, it is preferable to provide an easy adhesion layer (dye barrier layer) between the dye layer and the substrate film.

  A dye layer containing a dye for transfer (preferably a sublimation dye) can be formed by applying a dye layer coating solution.

(Dye layer)
In the dye layer of the present invention, it is preferable that a dye layer of each color of yellow, magenta, and cyan and, if necessary, a black dye layer are repeatedly coated on the same base film in the order of a plane. As an example, the yellow, magenta, and cyan hue dye layers are applied in the major axis direction on the same base film in a surface sequential manner corresponding to the recording surface area of the thermal transfer image-receiving sheet. Can be mentioned. In addition to these three layers, it is also preferable that either a black dye layer or a transferable protective layer (this may be a transferable protective layer laminate described later) or both are separately applied. It is.
When taking such an aspect, it is also a preferable aspect to provide a mark on the thermal transfer sheet for the purpose of transmitting the starting point of each color to the printer. Thus, by repeatedly painting in the surface order, it is possible to form an image by transferring a dye, and further to laminate a protective layer on the image with a single thermal transfer sheet.
However, the present invention is not limited to the method of providing the dye layer as described above. A sublimation type thermal transfer ink layer and a heat melting transfer ink layer can be provided side by side, and it is also possible to change such as providing a dye layer of a hue other than yellow, magenta, cyan and black. Moreover, the form may be long, a single-wafer thermal transfer sheet, or may be preferably used in an embodiment in which the thermal transfer sheets before use are stored in an overlapped state.

(Dye layer coating solution)
The dye layer coating solution contains at least a sublimable dye and a binder resin, and if necessary, contains organic fine powder or inorganic fine powder, waxes, silicone resin, fluorine-containing organic compound and the like. This is also a preferred embodiment of the present invention.

In the heat-sensitive transfer sheet of the present invention, each dye is preferably contained in the dye layer in an amount of 20 to 80% by mass, and more preferably 30 to 70% by mass.
The dye layer is applied by a general method such as roll coating, bar coating, gravure coating, or gravure reverse coating. The coating amount of the dye layer is preferably 0.1 to 2.0 g / m ² (in terms of solid content, hereinafter the coating amount in the present invention is a numerical value in terms of solid content unless otherwise specified), and more preferably. Is 0.2 to 1.2 g / m ² . The film thickness of the dye layer is preferably from 0.1 to 2.0 μm, more preferably from 0.2 to 1.2 μm.

  The dye layer may have a single layer structure or a multilayer structure. In the case of a multilayer structure, the composition of each layer constituting the dye layer may be the same or different.

(dye)
Below, the pigment | dye represented by General formula (1) used by this invention is demonstrated in detail.

In general formula (1), A represents a substituted or unsubstituted arylene group (the number of carbon atoms is preferably 6 to 12, more preferably a phenylene group, for example, a p-phenylene group), and R ¹ and R ² are Each independently a hydrogen atom, a substituted or unsubstituted alkyl group (preferably having a carbon number of 1 to 10, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, n-octyl group), A substituted or unsubstituted alkenyl group (the number of carbon atoms is preferably 2 to 10, for example, vinyl group, allyl group, 1-propenyl group) or a substituted or unsubstituted aryl group (the number of carbon atoms is preferably 6 to 12, for example, phenyl group, a naphthyl group), R ³ is a hydrogen atom, a substituted or unsubstituted alkyl group (carbon number 1 to 10 are preferred, for example, a methyl group, an ethyl group, n- pro Group, isopropyl group, n-butyl group, n-octyl group), substituted or unsubstituted aryl group (preferably having 6 to 12 carbon atoms, for example, phenyl group, naphthyl group), substituted or unsubstituted amino group (The number of carbon atoms is preferably 0 to 12, for example, amino group, alkylamino group, anilino group, acylamino group, sulfonamide group, ureido group, urethane group), substituted or unsubstituted alkoxy group (carbon number is 1 to 10). For example, methoxy group, ethoxy group, n-propyloxy group, isopropyloxy group, n-butoxy group, n-octyloxy group), substituted or unsubstituted aryloxy group (having 6 to 12 carbon atoms) For example, a phenoxy group), a substituted or unsubstituted alkoxycarbonyl group (having preferably 2 to 11 carbon atoms, for example, Xoxycarbonyl group, ethoxycarbonyl group, n-propoxycarbonyl group, isopropoxycarbonyl group, n-butoxycarbonyl group, n-octyloxycarbonyl group), substituted or unsubstituted aryloxycarbonyl group (the number of carbon atoms is 7 to 13). Preferably, for example, a phenoxycarbonyl group) or a substituted or unsubstituted carbamoyl group (the number of carbon atoms is preferably 1 to 13, for example, carbamoyl group, N-methylcarbamoyl group, N-ethylcarbamoyl group, N-phenylcarbamoyl group, N , N-dimethylcarbamoyl group), R ⁴ is a substituted or unsubstituted alkyl group (preferably having 1 to 10 carbon atoms, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group). , N-octyl group) or substituted or unsubstituted ant Le group (the number of carbon atoms is preferably 6 to 12, for example, phenyl group).

Here, the substituent which each group of A, R ¹ , R ² , R ³ and R ⁴ may be substituted will be described in more detail.
Hereinafter, examples of such a substituent include the following groups, and specific groups of each substituent and preferred groups among the substituents will be described.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Of these, a chlorine atom and a bromine atom are preferable, and a chlorine atom is particularly preferable.
An aliphatic group is a linear, branched or cyclic aliphatic group (a cyclic aliphatic group means a cyclic aliphatic group such as a cycloalkyl group, a cycloalkenyl group, a cycloalkynyl group, or a bicycloalkyl group. The saturated aliphatic group includes an alkyl group, a cycloalkyl group, and a bicycloalkyl group, and may have a substituent. These carbon numbers are preferably 1-30. Examples include methyl, ethyl, n-propyl, isopropyl, tert-butyl, n-octyl, eicosyl, 2-chloroethyl, 2-cyanoethyl, benzyl and 2-ethylhexyl. Here, the cycloalkyl group includes a substituted or unsubstituted cycloalkyl group. The substituted or unsubstituted cycloalkyl group is preferably a cycloalkyl group having 3 to 30 carbon atoms. Examples include cyclohexyl, cyclopentyl, and 4-n-dodecylcyclohexyl. Examples of the bicycloalkyl group include a substituted or unsubstituted bicycloalkyl group having 5 to 30 carbon atoms, that is, a monovalent group obtained by removing one hydrogen atom from a bicycloalkane having 5 to 30 carbon atoms. Examples include bicyclo [1.2.2] heptan-2-yl and bicyclo [2.2.2] octan-3-yl. Further, it includes a tricyclo structure having many ring structures.

  The unsaturated aliphatic group is a linear, branched or cyclic unsaturated aliphatic group, and includes an alkenyl group, a cycloalkenyl group, a bicycloalkenyl group, and an alkynyl group. The alkenyl group represents a linear, branched, or cyclic substituted or unsubstituted alkenyl group. As the alkenyl group, a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms is preferable. Examples include vinyl, allyl, prenyl, geranyl, oleyl. The cycloalkenyl group is preferably a substituted or unsubstituted cycloalkenyl group having 3 to 30 carbon atoms, that is, a monovalent group obtained by removing one hydrogen atom of a cycloalkene having 3 to 30 carbon atoms. Examples include 2-cyclopenten-1-yl and 2-cyclohexen-1-yl. The bicycloalkenyl group includes a substituted or unsubstituted bicycloalkenyl group. The bicycloalkenyl group is preferably a substituted or unsubstituted bicycloalkenyl group having 5 to 30 carbon atoms, that is, a monovalent group in which one hydrogen atom of a bicycloalkene having one double bond is removed. Examples include bicyclo [2.2.1] hept-2-en-1-yl, bicyclo [2.2.2] oct-2-en-4-yl. The alkynyl group is preferably a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, and examples thereof include ethynyl and propargyl.

The aryl group is preferably a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and examples thereof include phenyl, p-tolyl, naphthyl, m-chlorophenyl, and o-hexadecanoylaminophenyl. Preferred phenyl groups are preferred.
The heterocyclic group is a monovalent group obtained by removing one hydrogen atom from a substituted or unsubstituted aromatic or non-aromatic heterocyclic compound, and they may be further condensed. These heterocyclic groups are preferably 5- or 6-membered heterocyclic groups, and the hetero atoms of the ring structure are preferably oxygen atoms, sulfur atoms and nitrogen atoms. More preferably, it is a 5- or 6-membered aromatic heterocyclic group having 3 to 30 carbon atoms. Examples of the heterocyclic ring in the heterocyclic group include pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, quinazoline ring, cinnoline ring, phthalazine ring, quinoxaline ring, pyrrole ring, indole ring, Furan ring, benzofuran ring, thiophene ring, benzothiophene ring, pyrazole ring, imidazole ring, benzimidazole ring, triazole ring, oxazole ring, benzoxazole ring, thiazole ring, benzothiazole ring, isothiazole ring, benzisothiazole ring, thiadiazole Ring, isoxazole ring, benzisoxazole ring, pyrrolidine ring, piperidine ring, piperazine ring, imidazolidine ring, thiazoline ring and the like.
The aliphatic oxy group (typically an alkoxy group) includes a substituted or unsubstituted aliphatic oxy group (typically an alkoxy group), and preferably has 1 to 30 carbon atoms. Examples thereof include methoxy, ethoxy, isopropoxy, n-octyloxy, methoxyethoxy, hydroxyethoxy and 3-carboxypropoxy.
The aryloxy group is preferably a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms. Examples of the aryloxy group include phenoxy, 2-methylphenoxy, 4-tert-butylphenoxy, 3-nitrophenoxy, 2-tetradecanoylaminophenoxy and the like. Preferably, it is a phenyloxy group that may have a substituent.

  The acyloxy group is preferably a formyloxy group, a substituted or unsubstituted alkylcarbonyloxy group having 2 to 30 carbon atoms, or a substituted or unsubstituted arylcarbonyloxy group having 6 to 30 carbon atoms. Examples of the acyloxy group include formyloxy, acetyloxy, pivaloyloxy, stearoyloxy, benzoyloxy, p-methoxyphenylcarbonyloxy and the like.

The carbamoyloxy group is preferably a substituted or unsubstituted carbamoyloxy group having 1 to 30 carbon atoms. Examples of carbamoyloxy groups include N, N-dimethylcarbamoyloxy, N, N-diethylcarbamoyloxy, morpholinocarbonyloxy, N, N-di-n-octylaminocarbonyloxy, Nn-octylcarbamoyloxy and the like. Can be mentioned.
The aliphatic oxycarbonyloxy group (typically an alkoxycarbonyloxy group) preferably has 2 to 30 carbon atoms and may have a substituent. Examples thereof include methoxycarbonyloxy, ethoxycarbonyloxy, tert-butoxycarbonyloxy, n-octylcarbonyloxy and the like.

  The aryloxycarbonyloxy group is preferably a substituted or unsubstituted aryloxycarbonyloxy group having 7 to 30 carbon atoms. Examples of the aryloxycarbonyloxy group include phenoxycarbonyloxy, p-methoxyphenoxycarbonyloxy, pn-hexadecyloxyphenoxycarbonyloxy and the like. Preferable is a phenoxycarbonyloxy group which may have a substituent.

  The amino group includes an unsubstituted amino group, an aliphatic amino group (typically an alkylamino group), an arylamino group, and a heterocyclic amino group. The amino group is preferably a substituted or unsubstituted aliphatic amino group having 1 to 30 carbon atoms (typically an alkylamino group) or a substituted or unsubstituted arylamino group having 6 to 30 carbon atoms. Examples of amino groups include, for example, amino, methylamino, dimethylamino, anilino, N-methyl-anilino, diphenylamino, hydroxyethylamino, carboxyethylamino, sulfoethylamino, 3,5-dicarboxyanilino, 4-quinolylamino and the like can be mentioned.

  The acylamino group is preferably a formylamino group, a substituted or unsubstituted alkylcarbonylamino group having 1 to 30 carbon atoms, or a substituted or unsubstituted arylcarbonylamino group having 6 to 30 carbon atoms. Examples of the acylamino group include formylamino, acetylamino, pivaloylamino, lauroylamino, benzoylamino, 3,4,5-tri-n-octyloxyphenylcarbonylamino and the like.

  The aminocarbonylamino group is preferably a substituted or unsubstituted aminocarbonylamino group having 1 to 30 carbon atoms. Examples of the aminocarbonylamino group include carbamoylamino, N, N-dimethylaminocarbonylamino, N, N-diethylaminocarbonylamino, morpholinocarbonylamino and the like. “Amino” in this group means that the amino moiety in this group has the same meaning as the aforementioned amino group. The same applies to other groups.

The aliphatic oxycarbonylamino group (typically an alkoxycarbonylamino group) preferably has 2 to 30 carbon atoms and may have a substituent. For example, methoxycarbonylamino, ethoxycarbonylamino, tert-butoxycarbonylamino, n-octadecyloxycarbonylamino, N-methyl-methoxycarbonylamino and the like can be mentioned.
The aryloxycarbonylamino group is preferably a substituted or unsubstituted aryloxycarbonylamino group having 7 to 30 carbon atoms. Examples of the aryloxycarbonylamino group include phenoxycarbonylamino, p-chlorophenoxycarbonylamino, mn-octyloxyphenoxycarbonylamino and the like. The phenyloxycarbonylamino group which may have a substituent is preferable.

  The sulfamoylamino group is preferably a substituted or unsubstituted sulfamoylamino group having 0 to 30 carbon atoms. Examples of the sulfamoylamino group include sulfamoylamino, N, N-dimethylaminosulfonylamino, Nn-octylaminosulfonylamino and the like.

  An aliphatic (typically alkyl) or arylsulfonylamino group is a substituted or unsubstituted aliphatic sulfonylamino group having 1 to 30 carbon atoms (typically an alkylsulfonylamino group), a substituted or unsubstituted group having 6 to 30 carbon atoms. An arylsulfonylamino group (preferably a phenylsulfonylamino group which may have a substituent) is preferable. Examples thereof include methylsulfonylamino, butylsulfonylamino, phenylsulfonylamino, 2,3,5-trichlorophenylsulfonylamino, p-methylphenylsulfonylamino and the like.

  The aliphatic thio group (typically an alkylthio group) is preferably a substituted or unsubstituted alkylthio group having 1 to 30 carbon atoms. Examples of the alkylthio group include methylthio, ethylthio, n-hexadecylthio and the like.

  The sulfamoyl group is preferably a substituted or unsubstituted sulfamoyl group having 0 to 30 carbon atoms. Examples of sulfamoyl groups include N-ethylsulfamoyl, N- (3-dodecyloxypropyl) sulfamoyl, N, N-dimethylsulfamoyl, N-acetylsulfamoyl, N-benzoylsulfamoyl, N- (N′-phenylcarbamoyl) sulfamoyl and the like can be mentioned.

An aliphatic (typically alkyl) or arylsulfinyl group is a substituted or unsubstituted aliphatic sulfinyl group having 1 to 30 carbon atoms (typically an alkylsulfinyl group), a substituted or unsubstituted arylsulfinyl group having 6 to 30 carbon atoms. (Preferably a phenylsulfinyl group which may have a substituent) is preferable. For example, methylsulfinyl, ethylsulfinyl, phenylsulfinyl, p-methylphenylsulfinyl and the like can be mentioned.
An aliphatic (typically alkyl) or arylsulfonyl group is a substituted or unsubstituted aliphatic sulfonyl group having 1 to 30 carbon atoms (typically an alkylsulfonyl group) or a substituted or unsubstituted arylsulfonyl group having 6 to 30 carbon atoms. (Preferably a phenylsulfonyl group which may have a substituent) is preferable. For example, methylsulfonyl, ethylsulfonyl, phenylsulfonyl, p-toluenesulfonyl and the like can be mentioned.

  The acyl group is a formyl group, a substituted or unsubstituted aliphatic carbonyl group having 2 to 30 carbon atoms (typically an alkylcarbonyl group), a substituted or unsubstituted arylcarbonyl group having 7 to 30 carbon atoms (preferably a substituent). An optionally substituted phenylcarbonyl group), and a heterocyclic carbonyl group bonded to the carbonyl group at a substituted or unsubstituted carbon atom having 4 to 30 carbon atoms is preferable. Examples include acetyl, pivaloyl, 2-chloroacetyl, stearoyl, benzoyl, pn-octyloxyphenylcarbonyl, 2-pyridylcarbonyl, 2-furylcarbonyl and the like.

  The aryloxycarbonyl group is preferably a substituted or unsubstituted aryloxycarbonyl group having 7 to 30 carbon atoms. Examples of the aryloxycarbonyl group include phenoxycarbonyl, o-chlorophenoxycarbonyl, m-nitrophenoxycarbonyl, p-tert-butylphenoxycarbonyl and the like. A phenyloxycarbonyl group which may have a substituent is preferable.

The aliphatic oxycarbonyl group (typically an alkoxycarbonyl group) preferably has 2 to 30 carbon atoms and may have a substituent. For example, methoxycarbonyl, ethoxycarbonyl, tert-butoxycarbonyl, n-octadecyloxycarbonyl and the like can be mentioned.
The carbamoyl group is preferably a substituted or unsubstituted carbamoyl group having 1 to 30 carbon atoms. Examples of the carbamoyl group include carbamoyl, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N, N-di-n-octylcarbamoyl, N- (methylsulfonyl) carbamoyl and the like.

Examples of the aryl or heterocyclic azo group include phenylazo, 4-methoxyphenylazo, 4-pivaloylaminophenylazo, 2-hydroxy-4-propanoylphenylazo, and the like.
Examples of the imide group include N-succinimide and N-phthalimide.
In addition to these, there are a hydroxyl group, a cyano group, a nitro group, a sulfo group, and a carboxyl group.

Each of these groups as examples of the substituent that each of the groups A, R ¹ , R ² , R ^3, and R ⁴ may be substituted may further have a substituent. Examples of the group include the above-described substituents.

  A is a substituted or unsubstituted arylene group, preferably a substituted or unsubstituted phenylene group, more preferably a methyl group or a phenylene group substituted with a chlorine atom or an unsubstituted phenylene group, most preferably An unsubstituted phenylene group. The phenylene group in A is preferably a p-phenylene group.

R ¹ is preferably a substituted or unsubstituted alkyl group (preferably having 1 to 8 carbon atoms), an allyl group, or a substituted or unsubstituted aryl group (preferably having 6 to 10 carbon atoms), more preferably substituted or An unsubstituted alkyl group (preferably having 1 to 6 carbon atoms) and an allyl group are most preferable, and an unsubstituted alkyl group (preferably having 1 to 4 carbon atoms) is preferable, and an ethyl group is particularly preferable.

R ² is preferably a substituted or unsubstituted alkyl group (preferably having 1 to 8 carbon atoms), an allyl group, or a substituted or unsubstituted aryl group (preferably having 6 to 10 carbon atoms), more preferably substituted or An unsubstituted alkyl group (preferably having 1 to 6 carbon atoms) and an allyl group are most preferable, and an unsubstituted alkyl group (preferably having 1 to 4 carbon atoms) is preferable, and an ethyl group is particularly preferable.

R ³ is preferably a substituted or unsubstituted amino group or a substituted or unsubstituted alkoxy group, more preferably a dialkylamino group (preferably having 2 to 8 carbon atoms), an unsubstituted amino group, or an unsubstituted alkoxy group. A group (preferably 1 to 6 carbon atoms), more preferably a dialkylamino group (preferably 2 to 4 carbon atoms), an unsubstituted alkoxy group (preferably 1 to 4 carbon atoms), most preferably none. It is a substituted alkoxy group (preferably having 1 to 4 carbon atoms), and an ethoxy group is particularly preferable.

R ⁴ is preferably a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms or a substituted or unsubstituted aryl group (preferably having 6 to 10 carbon atoms), more preferably a substituted or unsubstituted carbon number of 1 -6 alkyl group, substituted or unsubstituted aryl group (preferably 6-10 carbon atoms), more preferably substituted or unsubstituted aryl group (preferably unsubstituted aryl group, more preferably 6 carbon atoms). To 10), among which a substituted or unsubstituted phenyl group is preferred, and an unsubstituted phenyl group is most preferred.

With respect to a preferable combination of substituents of the dye represented by the general formula (1) (a combination of A, R ¹ , R ² , R ³ and R ⁴ ), at least one of these substituents is the above-described preferable substituent. A certain dye is preferable, a dye in which more various substituents are the preferable substituents is more preferable, and a dye in which all the substituents are the preferable groups is most preferable.

A preferable combination of substituents of the dye represented by the general formula (1) is that A is a substituted or unsubstituted phenylene group, and R ¹ is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an allyl group, A substituted or unsubstituted aryl group having 6 to 10 carbon atoms, and R ² is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an allyl group, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms. R ³ is a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, and R ⁴ is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, a substituted or unsubstituted carbon group having 6 to 10 carbon atoms. A combination that is an aryl group.
A more preferable combination of substituents is that A is a substituted or unsubstituted phenylene group, R ¹ is a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, an allyl group, a substituted or unsubstituted phenyl group, R ² is a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, an allyl group, a substituted or unsubstituted phenyl group, and R ³ is a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group. , R ⁴ is a combination of a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms and a substituted or unsubstituted phenyl group.
The most preferred combination of substituents is that A is a methyl group, a phenylene group substituted with a chlorine atom or an unsubstituted phenylene group, and R ¹ is a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms or an allyl group. R ² is a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms or an allyl group, R ³ is a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, and R ⁴ is substituted or unsubstituted A combination that is an unsubstituted phenyl group.

Among the dyes represented by the general formula (1), those that are not commercially available can be synthesized by a dehydration condensation reaction of a pyrazolone derivative and an aminobenzaldehyde derivative that is generally performed.
Specific examples of the yellow dye represented by the general formula (1) of the present invention are shown below, but the yellow dye that can be used in the present invention is not limited to the following specific examples.

The dye used in the present invention can be used in combination with other pigments, as long as it is diffused by heat, can be incorporated into a thermal transfer sheet, and can be transferred from a thermal transfer sheet to a thermal transfer image receiving sheet by heating. The dye is not particularly limited, and a dye conventionally used as a dye for a thermal transfer sheet or a known dye can be used in combination.
Preferred dyes include, for example, methine series such as diarylmethane series, triarylmethane series, thiazole series, merocyanine, indoaniline, acetophenone azomethine, pyrazoloazomethine, imidazolazomethine, imidazoazomethine, and azomethine series represented by pyridone azomethine. Cyanomethylene, thiazine, azine, acridine, benzeneazo, pyridoneazo, thiophenazo, isothiazoleazo, pyrroleazo, pyralazo, imidazoleazo, thiadiazole, typified by xanthene, oxazine, dicyanostyrene, tricyanostyrene Azos such as azo, triazole azo, and dizazo, spiropyrans, indolinospiropyrans, fluorans, rhodamine lactams, naphthoquinones, anthrax Down system, quinophthalone, and the like.

  Specific examples of the yellow dye include Disperse Yellow 231, Disperse Yellow 201, and Solvent Yellow 93, which may be used in combination with the dye represented by the general formula (1) of the present invention. Examples of magenta dyes include disperse violet 26, disperse thread 60, solvent red 19, and the like, and examples of cyan dyes include solvent blue 63, solvent blue 36, disperse blue 354, and disperse blue 35. It is not limited to. It is also possible to arbitrarily combine the dyes of the above-mentioned hues.

(Resin for dye layer)
In the heat-sensitive transfer sheet of the present invention, the dye is usually coated on the substrate film in a state of being dispersed in a polymer compound called a resin (also called a binder or a resin binder). In this invention, a well-known thing can be used as a resin binder contained in a dye layer. Examples include acrylic resins such as polyacrylonitrile, polyacrylic acid esters and polyacrylamide, polyvinyl acetal resins such as polyvinyl acetoacetal and polyvinyl butyral, ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxy cellulose, hydroxypropyl cellulose, ethyl hydroxyethyl cellulose, methyl cellulose Cellulose acetate resins such as cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cellulose nitrate, etc. Cellulose resins such as nitrocellulose, ethylhydroxyethylcellulose and ethylcellulose, polyurethane resins, polyamide resins, polyester resins, polycarbonate resins, phenoxy resins , Phenolic resin, epoxy resin, various elastomers, etc. The recited dye layer by at least one resin selected from the group consisting of the above is configured.
In addition to using these alone, they can be mixed or copolymerized, and can be crosslinked with various crosslinking agents.
In the present invention, cellulose resins and polyvinyl acetal resins are preferable, and polyvinyl acetal resins are more preferable. Among them, polyvinyl acetoacetal resin and polyvinyl butyral resin are preferably used in the present invention.
The ratio (mass ratio) of the content of the dye in the dye layer may be any ratio, but is preferably 0.1 to 5.0, more preferably 0.5 to 3.0, and 9-2.0 is more preferable.

(Transferable protective layer laminate)
In the present invention, it is also preferable to provide the heat-sensitive transfer sheet with the transferable protective layer laminate in the surface order. The transferable protective layer laminate is for forming a protective layer made of a transparent resin on the heat-transferred image by thermal transfer to cover and protect the image, and has durability such as scratch resistance, light resistance, and weather resistance. The purpose is to improve performance. This is effective when image durability such as light resistance, scratch resistance and chemical resistance is insufficient if the transferred dye is exposed to the surface of the image receiving sheet.
The transferable protective layer laminate can be formed on the base film in the order of the release layer, the protective layer, and the adhesive layer from the base film side. It is also possible to form the protective layer with a plurality of layers. When the protective layer has the functions of other layers, the release layer and the adhesive layer can be omitted. As the base film, a film provided with an easy-adhesion layer can also be used.

(Transferable protective layer)
The resin forming the transferable protective layer of the present invention is preferably a resin excellent in scratch resistance, chemical resistance, transparency and hardness, such as polyester resin, acrylic resin, polystyrene resin, polyurethane resin, acrylic urethane resin, and these Silicone-modified resins, ultraviolet blocking resins, mixtures of these resins, ionizing radiation curable resins, ultraviolet curable resins, and the like can be used. Of these, polyester resins and acrylic resins are preferable.
It is also possible to crosslink with various crosslinking agents.

(Transferable protective layer resin)
The acrylic resin is a polymer composed of at least one monomer selected from conventionally known acrylate monomers and methacrylate monomers, and may be copolymerized with styrene, acrylonitrile or the like in addition to the acrylic monomer. As a preferred monomer, methyl methacrylate is charged and contained in an amount of 50% by mass or more.
The acrylic resin of the present invention preferably has a molecular weight of 20,000 or more and 100,000 or less.

  As the polyester resin of the present invention, conventionally known saturated polyester resins can be used. When the polyester resin is used, the glass transition temperature is preferably 50 to 120 ° C., the molecular weight is preferably in the range of 2,000 to 40,000, and further in the range of 4,000 to 20,000. Sometimes the foil breakability is improved, which is more preferable.

(UV absorber)
In the present invention, the protective layer and / or the adhesive layer preferably contains an ultraviolet absorber. As the ultraviolet absorber, conventionally known inorganic ultraviolet absorbers and organic ultraviolet absorbers can be used. Examples of organic UV absorbers include salicylate-based, benzophenone-based, benzotriazole-based, triazine-based, substituted acrylonitrile-based, hindered amine-based non-reactive UV absorbers, and non-reactive UV absorbers such as, for example, Introducing an addition polymerizable double bond such as vinyl group, acryloyl group or methacryloyl group, or alcoholic hydroxyl group, amino group, carboxyl group, epoxy group, isocyanate group, etc. A polymerized or grafted product can be used. In addition, a method is disclosed in which a UV absorber is dissolved in a resin monomer or oligomer and then the monomer or oligomer is polymerized (Japanese Patent Application Laid-Open No. 2006-21333), and thus obtained UV blocking resin is used. You can also In this case, the ultraviolet absorber may be non-reactive.
Among these ultraviolet absorbers, benzophenone, benzotriazole, and triazine are particularly preferable. These UV absorbers are preferably used in combination so as to cover the effective UV absorption wavelength range according to the characteristics of the dye used for image formation. In the case of non-reactive UV absorbers, UV absorbers are used. It is preferable to use a mixture of a plurality of different structures so that the agent does not precipitate.
Commercially available UV absorbers include Tinuvin-P (manufactured by Ciba Geigy), JF-77 (manufactured by Johoku Chemical), Sea Soap 701 (manufactured by Shiraishi Calcium), Sumisop 200 (manufactured by Sumitomo Chemical), and Biosoap 520 (manufactured by Kyodo Yakuhin). , ADK STAB LA-32 (manufactured by Asahi Denka) (all are trade names) and the like.

(Formation of transferable protective layer)
Although the formation method of a protective layer is dependent on the kind of resin used, it can form by the method similar to the formation method of the said dye layer, and the thickness of 0.5-10 micrometers is preferable.

(Release layer)
In the case where the transferable protective layer is difficult to peel from the base film during thermal transfer, a release layer can be formed between the base film and the protective layer. A release layer may be further formed between the transferable protective layer and the release layer. The release layer includes, for example, waxes, silicone wax, silicone resin, fluororesin, acrylic resin, polyvinyl alcohol resin, cellulose derivative resin, urethane resin, acetic acid vinyl resin, acrylic vinyl ether resin, maleic anhydride resin, and A coating liquid containing at least one copolymer of these resin groups can be formed by coating and drying by a conventionally known method such as gravure coating or gravure reverse coating. Among the above-mentioned resins, the acrylic resin is preferably a simple substance such as acrylic acid or methacrylic acid, or a resin copolymerized with another monomer, or a cellulose derivative resin. Excellent in releasability.
It is also possible to crosslink with various crosslinking agents, and ionizing radiation curable resins and ultraviolet curable resins can also be used.

  The release layer can be appropriately selected from those that transfer to the transfer medium during thermal transfer, those that remain on the substrate film side, or those that coagulate and break down. However, the release layer is on the substrate film side by thermal transfer. It is excellent in terms of surface glossiness, transfer stability of the protective layer, etc., so that the interface between the release layer and the transferable protective layer becomes the surface of the protective layer after thermal transfer. This is a preferred embodiment. The release layer can be formed by a conventionally known coating method, and the thickness is preferably about 0.5 to 5 μm in a dry state.

(Adhesive layer)
As the uppermost layer of the transferable protective layer laminate, an adhesive layer can be provided on the outermost surface of the protective layer. As a result, the adhesion of the protective layer to the transfer target can be improved.

2) Thermal transfer image-receiving sheet Next, a thermal transfer image-receiving sheet (hereinafter also simply referred to as an image-receiving sheet) that can be used in combination with the thermal transfer sheet of the present invention to form a thermal transfer print will be described in detail.
The heat-sensitive transfer image-receiving sheet has at least one receiving layer containing a thermoplastic receiving polymer for receiving a dye on a support. The receiving layer can contain an ultraviolet absorber, a release agent, a lubricant, an antioxidant, an antiseptic, a surfactant, and other additives. Between the support and the receiving layer, for example, an intermediate layer such as a heat insulating layer (porous layer), a gloss control layer, a white background adjustment layer, a charge control layer, an adhesive layer, a primer layer, etc. may be formed. It is preferable to have at least one heat insulating layer between the support and the receiving layer.
The receptor layer and these intermediate layers are preferably formed by simultaneous multilayer coating, and a plurality of intermediate layers can be provided as necessary.
A curl adjustment layer, a writing layer, and a charge adjustment layer may be formed on the back side of the support. In order to apply each layer on the back surface of the support, general methods such as roll coating, bar coating, gravure coating, and gravure reverse coating can be used.
In the present invention, in particular, what has a heat insulating layer containing a hollow polymer (particle) latex and a receiving layer containing a polymer (particle) latex on the support effectively exhibits the effects of the present invention. preferable.

  The heat-sensitive transfer image-receiving sheet preferably uses a polymer latex capable of being dye-dyed on the receiving layer. The polymer latex may be used alone or in combination with a plurality of polymer latexes.

The polymer latex is generally a thermoplastic resin dispersed as fine particles in a water-soluble dispersion medium. Examples of the thermoplastic resin used in the polymer latex of the present invention include polycarbonate, polyester, polyacrylate, vinyl chloride copolymer, polyurethane, styrene-acrylonitrile copolymer, polycaprolactone, and the like.
Of these, polycarbonate, polyester and vinyl chloride copolymer are preferable, and polyester and vinyl chloride copolymer are particularly preferable.

  The polyester is obtained by condensation of a dicarboxylic acid derivative and a diol compound, may contain an aromatic ring or a saturated carbon ring, and may be a water-soluble group for imparting dispersibility.

Vinyl chloride copolymer includes vinyl chloride and vinyl acetate copolymer, vinyl chloride and acrylate copolymer, vinyl chloride and methacrylate copolymer, vinyl chloride, vinyl acetate and acrylate copolymer, vinyl chloride And a copolymer of acrylate and ethylene. Thus, the copolymer may be a binary copolymer or a ternary or higher copolymer, and the monomers may be distributed irregularly or may be block copolymerized.
An auxiliary monomer component such as a vinyl alcohol derivative, a maleic acid derivative, or a vinyl ether derivative may be added to the copolymer. In the copolymer, the vinyl chloride component is preferably contained in an amount of 50% by mass or more, and auxiliary monomer components such as maleic acid derivatives and vinyl ether derivatives are preferably 10% by mass or less.
The polymer latex may be used alone or as a mixture. The polymer latex may have a uniform structure or a core / shell type, and at this time, the glass transition temperatures of resins forming the core and the shell may be different.

  The glass transition temperature (Tg) of such a polymer latex is preferably 20 ° C. or higher and 90 ° C. or lower, more preferably 25 ° C. or higher and 80 ° C. or lower.

Examples of commercially available acrylate latex include Nipol LX814 (Tg25 ° C.), NipolLX857X2 (Tg 43 ° C.), etc. (all trade names) manufactured by Nippon Zeon Co., Ltd.
Commercially available polyester latexes include Toyobo Co., Ltd., Vironal MD-1100 (Tg 40 ° C.), Vironal MD-1400 (Tg 20 ° C.), Vironal MD-1480 (Tg 20 ° C.), MD-1985 (Tg 20 ° C.), etc. (Both are product names).
Commercially available vinyl chloride copolymers include Nivin Chemical Industry Co., Ltd., Vinibrand 276 (Tg 33 ° C.), Vini Blanc 609 (Tg 48 ° C.), Sumika Chemtex Co., Ltd. Sumilite 1320 (Tg 30 ° C.), Sumi Elite 1210 (Tg 20 ° C.) and the like (both are trade names).

  The amount of the polymer latex added is preferably 50 to 98% by mass, more preferably 70 to 95% by mass, based on the total polymer content in the receptor layer. The average particle size of the polymer latex is preferably 1 to 50000 nm, more preferably 5 to 1000 nm.

The heat-sensitive transfer image-receiving sheet that can be used in the present invention preferably contains a hollow polymer in the heat insulating layer.
In the present invention, the hollow polymer is a polymer particle having voids inside the particle, preferably an aqueous dispersion. For example, 1) water or the like inside the partition formed by polystyrene, acrylic resin, styrene-acrylic resin or the like. Contains dispersion medium. After coating and drying, non-foamed hollow polymer particles in which water inside the particles evaporates outside the particles and the inside of the particles becomes hollow. 2) Low boiling liquids such as butane and pentane are polychlorinated. It is covered with a resin made of vinylidene, polyacrylonitrile, polyacrylic acid, polyacrylic acid ester, or a mixture or polymer thereof. After coating, the inside of the particles expands due to expansion of the low-boiling liquid by heating. Hollow microbubbles that become hollow 3) Microballoons obtained by heating and foaming the above 2) in advance to form hollow polymers And the like.
Among these, the non-foamed hollow polymer particles of 1) above are preferable, and two or more kinds can be mixed and used as necessary. Specific examples include Ropeke HP-1055 manufactured by Rohm and Haas, SX866 (B) manufactured by JSR, Nipol MH5055 manufactured by Nippon Zeon (all are trade names), and the like.

The average particle size of these hollow polymers is preferably 0.1 to 5.0 μm, more preferably 0.2 to 3.0 μm, and particularly preferably 0.4 to 1.4 μm.
The hollow polymer preferably has a porosity of 20 to 70%, more preferably 30 to 60%.

  The size of the hollow polymer particles is calculated by measuring the equivalent-circle diameter of the outer diameter using a transmission electron microscope. The average particle diameter is obtained by observing at least 300 hollow polymer particles using a transmission electron microscope, calculating the circle equivalent diameter of the outer shape, and averaging. The void ratio of the hollow polymer is determined from the ratio of the volume of the void portion to the particle volume.

  As the polymer characteristics of the hollow polymer, the glass transition temperature (Tg) is preferably 70 ° C. or higher and 200 ° C. or lower, more preferably 90 ° C. or higher and 180 ° C. or lower. As the hollow polymer, hollow polymer latex is particularly preferable.

  A water-soluble polymer can be contained in the receiving layer and / or the heat insulating layer of the heat-sensitive transfer image-receiving sheet. Here, the water-soluble polymer has a solubility of 0.05 g or more with respect to 100 g of water at 20 ° C., more preferably 0.1 g or more, and still more preferably 0.5 g or more.

  Examples of water-soluble polymers that can be used in the thermal transfer image-receiving sheet include carrageenans, pectin, dextrin, gelatin, casein, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, polyvinylpyrrolidone, polyvinylpyrrolidone copolymer, polyvinyl alcohol, polyethylene glycol, Examples thereof include polypropylene glycol and water-soluble polyester. Of these, gelatin and polyvinyl alcohol are preferred.

Gelatin having a molecular weight of 10,000 to 1,000,000 can be used, and gelatin may contain anions such as Cl ⁻ and SO ₄ ²⁻ , Fe ²⁺ , Ca ²⁺ , Mg ^It may contain cations such as ²⁺ , Sn ²⁺ and Zn ²⁺ . It is preferable to add gelatin dissolved in water.
Moreover, well-known crosslinking agents, such as an aldehyde type crosslinking agent, an N-methylol type crosslinking agent, a vinyl sulfone type crosslinking agent, a chlorotriazine type crosslinking agent, can be added to gelatin. Of these, vinyl sulfone type crosslinking agents and chlorotriazine type crosslinking agents are preferred. Specific examples include bisvinylsulfonylmethyl ether, N, N′-ethylene-bis (vinylsulfonylacetamide) ethane, and 4,6-dichloro. -2-Hydroxy-1,3,5-triazine or its sodium salt.

  As the polyvinyl alcohol, various polyvinyl alcohols such as a completely saponified product, a partially saponified product, and a modified polyvinyl alcohol can be used. As for these polyvinyl alcohols, those described in Koichi Nagano et al., “Poval” (published by Kobunshi Shuppankai) are used. Polyvinyl alcohol can be adjusted in viscosity or stabilized by a trace amount of solvent or inorganic salt added to the aqueous solution. Specifically, the polyvinyl alcohol described in pages 144 to 154 can be used. it can. As a typical example, it is possible to improve the coating surface quality by containing boric acid, which is preferable. The amount of boric acid added is preferably 0.01 to 40% by mass relative to polyvinyl alcohol.

  Specific examples of polyvinyl alcohol include PVA-105, PVA-110, PVA-117, and PVA-117H as fully saponified products, and PVA-203, PVA-205, PVA-210, and PVA-220 as partially saponified products. Examples of the modified polyvinyl alcohol include C-118, HL-12E, KL-118, and MP-203. (All are trade names, manufactured by Kuraray Co., Ltd.)

  The receiving layer of the heat-sensitive transfer image-receiving sheet can contain a polymer compound having an aliphatic group substituted with a fluorine atom in the side chain. In this case, the thermal transfer sheet may contain the same polymer compound as the polymer compound having an aliphatic group substituted in the side chain with a fluorine atom substituted, or may contain a different polymer compound in the same category, This is a preferred embodiment. Moreover, you may contain solid waxes, such as well-known polyethylene wax and amide wax, silicone oil, a phosphoric ester compound, a fluorine-type surfactant, and a silicone-type surfactant as a mold release agent.

  The content of the polymer compound having an aliphatic group substituted with a fluorine atom in the side chain is 0.01% to 20%, preferably 0.1% to the total solid content (mass) of the receiving layer. 10%, more preferably 1% to 5%.

3) Image Forming Method Next, an image forming method that can be performed using the heat-sensitive transfer sheet of the present invention will be described.
In the image forming method, the receiving layer of the thermal transfer image-receiving sheet and the dye layer of the thermal transfer sheet are overlapped so that the thermal energy corresponding to the image signal from the thermal head is applied from the heat-resistant slipping layer side of the thermal transfer sheet. By doing so, an image is formed.
Specific image formation can be performed in the same manner as described in, for example, JP-A-2005-88545. In the present invention, the printing time is preferably less than 15 seconds, more preferably 3 to 12 seconds, and even more preferably 3 to 7 seconds from the viewpoint of shortening the time until the printed matter is provided to the consumer.

  In order to satisfy the printing time, the line speed during printing is preferably 0.73 msec / line or less, more preferably 0.65 msec / line or less. Further, from the viewpoint of improving transfer efficiency under high speed conditions, the maximum temperature reached by the thermal head during printing is preferably 180 ° C. or higher and 450 ° C. or lower, more preferably 200 ° C. or higher and 450 ° C. or lower. Furthermore, 350 degreeC or more and 450 degrees C or less are preferable.

The present invention can be used in printers, copiers and the like using a thermal transfer recording system. As the means for applying thermal energy at the time of thermal transfer, any conventionally known means for applying can be used. For example, recording is performed by a recording device such as a thermal printer (for example, product name, video printer VY-100, manufactured by Hitachi, Ltd.). By controlling the time, the intended purpose can be sufficiently achieved by applying thermal energy of about 5 to 100 mJ / mm ² . The thermal transfer image-receiving sheet used in combination with the thermal transfer sheet of the present invention is a sheet- or roll-shaped thermal transfer image-receiving sheet capable of thermal transfer recording, cards, and transmission-type manuscript preparation by appropriately selecting a support. It can also be applied to various uses such as a sheet for use.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to these. In Examples, “part” or “%” is based on mass unless otherwise specified.

Example 1
(Preparation of thermal transfer sheet)
The solid coating amount after drying is 1 g / m ² on the surface opposite to the easy-adhesion layer of a 4.5 μm thick polyester film produced by stretching after an easy-adhesion layer is formed on one side as a base film. Then, a heat resistant slipping layer coating solution described later was applied. The ratio of reactive groups (-NCO / OH) between the polyisocyanate and the resin in the heat resistant slipping layer coating solution described later was 1.1. Immediately after the coating, it was dried in an oven at 100 ° C. for 1 minute and subsequently subjected to a heat treatment (60 ° C., 20 hours) to carry out a crosslinking reaction between the isocyanate and the polyol to be cured. After the heat treatment, unreacted isocyanate groups were confirmed by IR measurement to confirm that they were sufficiently reacted.
The yellow, magenta, and cyan dye layers and the transferable protective layer laminate are arranged in a plane order on the easy-adhesion layer coating side of the heat-resistant slip layer-formed polyester film produced in this manner, using a coating liquid described later. An applied thermal transfer sheet was prepared. The solid content coating amount of each dye layer was 0.8 g / m ² . Immediately after applying these, they were dried in a 100 ° C. oven for 1 minute.
In addition, the transferable protective layer laminate is formed by applying a release layer coating solution, applying a protective layer coating solution thereon, drying, and further applying an adhesive layer coating solution thereon. Applied.

Dispersion for heat-resistant slipping layer Polyacryl polyol resin (50% solution) 51.0 parts by mass (hydroxyl value is 61, acid value is 5 with respect to resin solids)
Tris (m-cresyl) phosphate (melting point: 26 ° C.) 3.6 parts by mass Zinc stearate (zinc salt of carboxylic acid having 18 carbon atoms) 0.5 parts by mass Talc 2.0 parts by mass Magnesium oxide 0.5 parts by mass Methyl ethyl ketone / toluene mixed solvent 43.5 parts by mass

The resin and solvent of the dispersion for the heat-resistant slipping layer were dissolved in advance, and other additives were added to the solution for premixing, followed by dispersion. The dispersion condition was carried out under one of the following three conditions.
(Condition 1) Disperse for 185 minutes using a paint shaker. (Heat resistant slip layer 101)
(Condition 2) Dispersion at 500 rpm for 45 minutes using a planetary ball mill type P-7 (trade name) manufactured by Fritsch, Germany (heat-resistant slip layer 102)
(Condition 3) Dispersion at 500 rpm for 25 minutes using a planetary ball mill P-7 manufactured by Fritsch, Germany, followed by dispersion at 100 rpm for 20 minutes (heat resistant slipping layer 103)

Heat resistant slipping layer coating solution Heat resistant slipping layer dispersion 68.0 parts by weight Polyisocyanate (75% solution) 11.2 parts by weight (Bernock D-750, trade name, manufactured by Dainippon Ink & Chemicals, Inc.)
Methyl ethyl ketone / toluene mixed solvent 21.0 parts by mass

Yellow dye layer coating solution Yellow pigment listed in Table 3 5.0 parts by weight Dye Y 1.5 parts by weight Polyvinyl acetal resin 6.9 parts by weight (Denka Butyral # 5000-D, trade name, Electrochemical Industry Co., Ltd.) Made)
0.1 parts by mass of fluorine-containing polymer compound (Megafac F-472SF, trade name, manufactured by Dainippon Ink & Chemicals, Inc.)
Matting agent (Flusen UF, trade name, Sumitomo Seiko Co., Ltd. 0.12 parts by mass Methyl ethyl ketone / toluene mixed solvent 85 parts by mass

Magenta dye layer coating solution Dye compound (M-1) 0.8 part by weight Dye compound (M-2) 1.0 part by weight Dye compound (M-3) 6.8 parts by weight Polyvinyl acetal resin 6.2 parts by weight (ESREC KS-1, trade name, manufactured by Sekisui Chemical Co., Ltd.)
Release agent 0.05 parts by mass (X-22-3000T, trade name, manufactured by Shin-Etsu Chemical Co., Ltd.)
Release agent 0.03 parts by mass (TSF4701, trade name, Momentive Performance
(Materials Japan GK)
Matting agent 0.15 parts by mass (Flosen UF, trade name, manufactured by Sumitomo Seiko Co., Ltd.)
85 parts by mass of methyl ethyl ketone / toluene mixed solvent

Cyan dye layer coating solution Dye compound (C-1) 0.4 parts by weight Dye compound (C-2) 8.9 parts by weight Dye compound (C-3) 0.5 parts by weight Polyvinyl acetal resin 5.0 parts by weight (Denka Butyral # 5000-D, trade name, manufactured by Denki Kagaku Kogyo Co., Ltd.)
0.1 parts by mass of fluorine-containing polymer compound (Megafac F-472SF, trade name, manufactured by Dainippon Ink & Chemicals, Inc.)
Matting agent (Flusen UF, trade name, manufactured by Sumitomo Seiko Co., Ltd.) 0.12 parts by mass Methyl ethyl ketone / toluene mixed solvent 85 parts by mass

(Transferable protective layer laminate)
A release layer, a protective layer, and an adhesive layer coating solution having the following composition were applied to the same polyester film as that used for the preparation of the dye layer to form a transferable protective layer laminate. The coating amount of the releasing layer 0.2 g / ^{m 2} when dry film, the protective layer 0.4 g / ^{m 2,} and an adhesive layer 2.0 g / ^{m 2.}

Release layer coating solution Modified cellulose resin 5.0 parts by mass (L-30, trade name, Daicel Chemical)
Methyl ethyl ketone / toluene mixed solvent 95.0 parts by mass Protective layer coating solution Acrylic resin solution (solid content 40%) 90 parts by mass (UNO-1, trade name, manufactured by Gifu Ceramics Co., Ltd.)
Methanol / isopropanol mixed solvent 10 parts by mass Adhesive layer coating solution Acrylic resin 25 parts by mass (Dianaal BR-77, trade name, manufactured by Mitsubishi Rayon Co., Ltd.)
The following ultraviolet absorbent UV-1 0.5 part by mass The following ultraviolet absorbent UV-2 2 part by mass The following ultraviolet absorbent UV-3 0.5 part by mass The following ultraviolet absorbent UV-4 0.5 part by mass PMMA fine particles (poly Methyl methacrylate fine particles) 0.4 parts by mass Methyl ethyl ketone / toluene mixed solvent 70 parts by mass

(Preparation of thermal transfer image-receiving sheet (Z-1))
Synthetic paper (YUPO FPG200, thickness 200 μm, trade name, manufactured by YUPO CORPORATION) was used as a support, and a white intermediate layer having the following composition and a receiving layer were coated on this surface by a bar coater in this order. . The coating amount at the time of drying is such that the white intermediate layer is 1.0 g / m ² and the receiving layer is 4.0 g / m ^2. After coating, the coating is dried and processed into a shape that matches the printer settings. Thus, a thermal transfer image-receiving sheet (Z-1) was produced.

White intermediate layer Polyester resin 10 parts by mass (Byron 200, trade name, manufactured by Toyobo Co., Ltd.)
1 part by weight of optical brightener (Uvitex OB, trade name, manufactured by Ciba Specialty Chemicals)
Titanium oxide 30 parts by weight Methyl ethyl ketone / toluene (mass ratio 1/1) 90 parts by weight

Receiving layer 100 parts by mass of vinyl chloride-vinyl acetate resin (Solvine A, trade name, manufactured by Nissin Chemical Industry Co., Ltd.)
Amino-modified silicone 5 parts by mass (manufactured by Shin-Etsu Chemical Co., Ltd., trade name, X22-3050C)
Epoxy-modified silicone 5 parts by mass (manufactured by Shin-Etsu Chemical Co., Ltd., trade name, X22-3000E)
Methyl ethyl ketone / toluene (mass ratio 1/1) 400 parts by mass

Preparation of heat-sensitive transfer image-receiving sheet (Z-2) The surface of a paper support laminated on both sides with polyethylene was subjected to corona discharge treatment, and then a gelatin subbing layer containing sodium dodecylbenzenesulfonate was provided. On this, an undercoat layer, a heat insulating layer, a receiving layer lower layer, and a receiving layer upper layer having the following composition are laminated in this order from the support side in FIG. 9 in US Pat. No. 2,761,791. The simultaneous multilayer coating was carried out by the method exemplified in 1. The coating amount at the time of drying is undercoat layer: 6.0 g / m ² , heat insulating layer: 8.5 g / m ² , receiving layer lower layer: 2.4 g / m ² , receiving layer upper layer: 3.0 g / m ² After coating and drying, heat treatment is performed at 30 ° C. for 5 days to carry out a crosslinking reaction between the crosslinking agent and gelatin. Produced. Moreover, the following composition represents the mass part as solid content.

Receiving layer upper layer 21.0 parts by mass of vinyl chloride latex (Viniblanc 900, trade name, manufactured by Nissin Chemical Industry Co., Ltd.)
1.6 parts by weight of vinyl chloride latex (Viniblanc 276, trade name, manufactured by Nissin Chemical Industry Co., Ltd.)
Gelatin (10% aqueous solution) 2.5 parts by mass The following ester wax EW-1 1.8 parts by mass The following surfactant F-1 0.1 parts by mass The following surfactant F-2 0.4 parts by mass Receiving layer lower layer 18.0 parts by mass of vinyl chloride latex (Tg 46 ° C.) (Viniblanc 690, trade name, manufactured by Nissin Chemical Industry Co., Ltd.)
Vinyl chloride latex (Tg 73 ° C) 8.0 parts by mass (Viniblanc 900, trade name, manufactured by Nissin Chemical Industry Co., Ltd.)
Gelatin (10% aqueous solution) 8.0 parts by mass The following surfactant F-1 0.03 parts by mass Thermal insulation layer Acrylic styrene-based hollow polymer 66.0 parts by mass (average particle size 0.5 μm) (MH5055, trade name, Japan) (Zeon Co., Ltd.)
Gelatin (10% aqueous solution) 24.0 parts by mass 2,4-dichloro-6-hydroxy-s-triazine Na salt (crosslinking agent)
0.1 parts by mass undercoat layer 7.0 parts by mass of polyvinyl alcohol (Poval PVA205, trade name, manufactured by Kuraray Co., Ltd.)
Styrene butadiene rubber latex 55.0 parts by mass (SN-307, trade name, manufactured by Nippon A & L Co., Ltd.)
0.02 part by mass of the following surfactant F-1

Other than changing the kind of the phosphate ester in the heat resistant slipping layer to the compound represented by the general formula (P) defined in the present invention with respect to the heat resistant slipping layer (101) to (103) as follows: In the same manner, heat resistant slip layers (104) to (109) were produced.
For the heat-resistant slip layers (104) to (106), Foslex A-18 manufactured by Sakai Chemical Industry Co., Ltd. (mono- and di-stearyl phosphate ester mixture, melting point 62 ° C.) was used as the phosphate ester.
Heat-resistant slip layers (107) to (109) use Prisurf A208N manufactured by Daiichi Kogyo Seiyaku Co., Ltd. (melting point: -2 ° C. with mono- and di-polyoxyalkylene alkyl ether phosphate ester mixture) as the phosphate ester. It was. In addition, melting | fusing point of these phosphate ester is the value calculated | required by the differential scanning calorimeter (DSC) measurement.

Preparation of heat-resistant slip layer (110) As the heat-resistant slip layer not containing a phosphate ester compound, such as the slip layer described in Example 3 of JP-B-6-19033, a heat-resistant slip layer (105 The heat-resistant slipping layer (110) was prepared in the same manner as the heat-resistant slipping layer (105) except that only the mono- and di-stearyl phosphate ester mixture was removed.

Preparation of heat-resistant slip layer (201) For the heat-resistant slip layer (106), the use of zinc stearate contained in the dispersion for the heat-resistant slip layer and the distribution of phosphate esters in the heat-resistant slip layer A heat resistant slipping layer (201) was produced in the same manner except that the dispersion conditions were changed in order to change.

Preparation of heat resistant slipping layer (202) 3.5 parts by weight of mono- and distearyl phosphate ester mixture (melting point 62 ° C) of heat-resistant slipping layer dispersion mono-and heat-resistant slipping layer (201) A heat-resistant slipping layer (202) was prepared in the same manner except that the zinc salt of diethyl stearyl phosphate (melting point: 190 ° C.) was changed to 3.5 parts by mass and 0.5 parts by mass of zinc stearate was used.

Preparation of heat resistant slipping layer (203) 3.6 parts by mass of mono- and distearyl phosphate ester mixture (melting point 62 ° C.) of dispersion for heat resistant slipping layer is changed to 0.6 parts by mass with respect to (201) In the same manner, except that 2.9 parts by mass of mono- and diastearyl phosphate ester zinc salt (melting point 190 ° C.) and 0.5 parts by mass of zinc stearate are further used, ) Was produced.

(Characteristic X-ray intensity measurement and calculation)
An electron beam was irradiated from the heat-resistant slipping layer side of the heat-sensitive transfer sheet (101), and the characteristic X-ray intensity derived from the K-line of the phosphorus element in the heat-resistant slipping layer was measured. Specifically, using a high resolution field emission scanning electron microscope S-4700 (trade name) manufactured by Hitachi, Ltd., measurement was performed using an energy dispersive X-ray spectrometer equipped in the apparatus. . The acceleration voltage of the electron beam was 20 kV, and the electron beam beam diameter was 1 μm or less. In accordance with the description in this document, a region having a high phosphorus element content and a point having a low phosphorus element content were selected, and the characteristic X-ray intensity derived from the phosphorus element K-ray was measured at each point in a 200 μm square region. The ratio (maximum value / minimum value) was determined from the maximum value (the maximum value of the phosphorus element-containing characteristic X-ray intensity) and the minimum value (minimum value of the phosphorus element-containing characteristic X-ray intensity) of each measured value. . Hereinafter, this ratio is also simply referred to as “maximum value / minimum value”. The larger this value, the more localized the phosphate ester in the heat resistant slipping layer. Further, by the method described in detail in the above [Best Mode for Carrying Out the Invention], the localized region of the phosphorus element X-ray intensity (maximum region of characteristic X-ray derived from the K-line of the phosphorus element) and the corresponding region. The maximum value (maximum maximum value) of the X-ray intensity was determined, and the coefficient of variation (hereinafter also simply referred to as “variation coefficient”) of those maximum values was determined according to the above formulas (1) to (3). These values are used as a scale indicating a distribution state of a localized portion of a predetermined phosphate ester having an OH group or a salt thereof (hereinafter, these are collectively abbreviated as “phosphate ester localized portion”). . Here, the smaller the value of the coefficient of variation, the more uniform the distribution of the phosphate ester localized portion in the heat resistant slipping layer.
The above values were obtained for each sample in the same manner except that the heat-resistant slip layer (101) was changed from (102) to (109) and (201) to (203).
Table 2 shows the constitution and dispersion conditions of these heat-resistant slip layers and the above values.

From Table 2, in the heat-resistant slip layers (101) to (103) using only the phosphate ester having no OH group outside the scope of the present invention, phosphorus in the heat-resistant slip layer is changed even if the dispersion conditions are changed. The distribution state of the acid ester cannot be within the scope of the present invention. By examining the dispersion conditions in the heat-resistant slip layers (104) to (109) using a compound having a phosphate ester having an OH group within the scope of the present invention, the heat-resistant slip layers (105), ( 106), (108) and (109), the distribution state of the phosphate ester in the heat-resistant slipping layer can be within the scope of the present invention. It can also be seen that the dispersion conditions for making the distribution state of the phosphate ester in the heat resistant slipping layer more preferable range differ depending on the type of phosphate ester used, and the dispersion condition cannot be defined unconditionally.
These heat resistant slipping layers were combined with the yellow dye coating liquid described above, which was changed to the following various yellow pigments, to prepare samples of various thermal transfer sheets shown in Table 2 below.

(Evaluation conditions and image formation, measurement)
Each sample of the heat-sensitive transfer sheet was processed into a roll shape so that the heat-resistant slipping layer and the dye layer were in contact with each other, and was aged for 30 days in an environment of 30 ° C. and a relative humidity of 80%.
Thereafter, in combination with the thermal transfer image-receiving sheet Z-1, in a 25 ° C. and 50% relative humidity environment, Fuji Film Thermal Photo Printer ASK-2000 (trade name) is used. Printing was performed continuously for 4800 sheets. Remove the thermal head after printing and measure the height of the thermal head shape profile using a color 3D laser microscope VK-9500GII (trade name, manufactured by Keyence Co., Ltd.) to obtain the height μm of the adhered dirt. Was used as a guide for head contamination due to running of the heat-sensitive transfer sheet after aging, and the smaller the value, the better. Specifically, if the head dirt height is 4 μm or less, it is good, and if it is larger than 4.0 and less than 7.0 μm, there is almost no effect on the screen. Then, scratches began to appear on the screen, so it was judged that it was not acceptable.
The results are summarized in Table 3 below.

  From Table 3 above, it can be seen that in all the samples of the present invention, the head contamination is remarkably reduced with respect to the running of the thermal transfer sheet after aging.

Example 2
Except that the heat-sensitive transfer image-receiving sheet (Z-1) of Example 1 was changed to (Z-2), all the same experiments and evaluations as in Example 1 were performed. As a result, a result exceeding Example 1 was obtained.

Example 3
Preparation of heat-resistant slipping layers (301) to (308) For the heat-resistant slipping layer (203) of Example 1, zinc salts of mono- and di-stearyl phosphate esters of the heat-resistant slipping layer dispersion (melting point) (190 ° C) 2.9 parts by mass was changed to 0.6 parts by mass, and 2.4 parts by mass of a mono- and di-polyoxyalkylene alkyl ether phosphate ester mixture (melting point -2 ° C) was used. The composition of the layer dispersion was changed, and the heat-resistant slipping layer (301) was changed to 6 days at 51 ° C. in the same manner except that the heat treatment conditions for carrying out the crosslinking reaction between the isocyanate and the polyol were changed to 56 ° C. for 2 days. The heat resistant slipping layer (302) was changed in the same manner except that, and the heat resistant slipping layer was changed in the same manner except changing to the heat resistant slipping layer (303) and 35 ° C in 30 days. A layer (304) was prepared. Further, the polyacrylic polyol resin of the dispersion for the heat resistant slipping layer is replaced with polyvinyl butyral resin in the same amount as the solid content for the heat resistant slipping layers (301) to (304), and the heat resistant slipping layer coating solution poly The heat-resistant slip layers (305) to (308) were similarly formed except that the amount of the polyisocyanate was changed so that the ratio of the reactive group between the isocyanate and the resin (-NCO / OH) was 1.1. Produced. After the heat treatment, unreacted isocyanate groups were confirmed by IR measurement, and it was confirmed that they were sufficiently reacted under any heat treatment conditions.

  The produced heat resistant slip layers (301) to (308) were measured and calculated for characteristic X-ray intensity in the same manner as in Example 1. Table 4 shows values obtained from the measurement and calculation of the resin, heat treatment conditions and characteristic X-ray intensity of the heat-resistant slip layer of these heat-sensitive transfer sheets.

The following thermal transfer sheet was prepared in the same manner as the thermal transfer sheet sample 36 except that the heat resistant slipping layer and the yellow dye were changed to the combinations shown in Table 5 below. Each of these thermal transfer sheets was evaluated in the same experiment as in Example 1.
The results are shown in Table 5.

  From Table 5 above, samples 50 to 65 are all within the scope of the present invention, but the polyacryl polyol is used as the heat resistant slipping layer resin by setting the heat treatment conditions within the range of 40 ° C. to 53 ° C. and 1 day to 20 days. It can be seen that the effect of the present invention is more greatly manifested by using the combination with the dye of the present invention.

Claims (13)

A heat-sensitive transfer sheet having a yellow dye layer containing a yellow dye on one side of a substrate film and a heat-resistant slipping layer containing a lubricant and a resin formed on the other side, At least one kind is a yellow dye represented by the following general formula (1), the heat resistant slipping layer contains a compound represented by the following general formula (P) as a lubricant, and the heat resistance of the thermal transfer sheet The characteristic X-ray intensity derived from the K-line of phosphorus element in the heat-resistant slip layer obtained by irradiating an electron beam with a beam diameter of 1 μm or less accelerated to 20 kV from the slip layer side in various regions within a 200 μm square When measured with an energy dispersive X-ray spectrometer at a point, the maximum value of the intensity in the region is at least 2.5 times the minimum value, and the region is derived from phosphorus element K-rays. Has the maximum value of characteristic X-ray intensity There are a plurality of maximum regions, and the coefficient of variation obtained by dividing the standard deviation of the maximum value of the characteristic X-ray intensity between these maximum regions by the average of the characteristic X-ray intensities is 0.25 or less. Thermal transfer sheet.

(In General Formula (1), A represents a substituted or unsubstituted arylene group, and R ¹ and R ² each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted group. R ³ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, substituted or unsubstituted Represents an aryloxy group, a substituted or unsubstituted alkoxycarbonyl group, a substituted or unsubstituted aryloxycarbonyl group, or a substituted or unsubstituted carbamoyl group, and R ⁴ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted group. Represents an aryl group.)
General formula (P)
{(R ^1a O) (R ^2a O) P (═O) O} _m M
(In General Formula (P), M represents a hydrogen atom, a metal ion, or an ammonium ion. R ^1a represents a substituted or unsubstituted aliphatic group or a substituted or unsubstituted aryl group. R ^2a represents Represents a hydrogen atom, a metal ion, an ammonium ion, a substituted or unsubstituted aliphatic group, or a substituted or unsubstituted aryl group, and m is the same as the valence of M and represents a number of 1 to 6.   The thermal transfer sheet according to claim 1, wherein the maximum value of the intensity is at least 3.0 times or more than the minimum value, and the coefficient of variation of the distribution is 0.22 or less.   The heat-sensitive transfer sheet according to claim 1 or 2, wherein the compound represented by the general formula (P) contained in the heat-resistant slipping layer has a melting point of 40 ° C to 100 ° C.   The heat-sensitive transfer sheet according to any one of claims 1 to 3, wherein the heat-resistant slipping layer further contains a polyvalent metal salt of an alkyl carboxylic acid.   The thermal transfer sheet according to any one of claims 1 to 4, wherein the heat-resistant slipping layer further contains talc particles.   When the content of the talc particles and the content of the compound represented by the general formula (P) is 100 parts by mass of the content of the compound represented by the general formula (P), The thermal transfer sheet according to claim 5, wherein the content of talc particles is 30 parts by mass or more.   The heat-sensitive transfer sheet according to any one of claims 1 to 6, wherein the base film has an easy-adhesion layer on at least one surface of the base film.   The heat-sensitive transfer sheet according to any one of claims 1 to 7, wherein the resin of the heat-resistant slipping layer has two or more hydroxyl groups in the polymer chain length terminal or polymer structure of the resin.   The thermal transfer sheet according to claim 8, wherein the resin is a polyacryl polyol resin.   The thermal transfer sheet according to claim 8 or 9, wherein the resin of the heat resistant slipping layer is crosslinked.   The thermal transfer sheet according to claim 10, wherein the crosslinking reaction in the crosslinking is performed in a temperature range of 40 ° C. to 53 ° C. and in a period of 1 day to 20 days.   The thermal transfer sheet is a thermal transfer sheet used in combination with a thermal transfer image-receiving sheet having a heat insulating layer containing a hollow polymer latex and a receiving layer containing a polymer latex on a support. Item 12. The thermal transfer sheet according to any one of Items 1 to 11. On the support, a thermal transfer image-receiving sheet having a heat insulating layer containing a hollow polymer latex and a receiving layer containing a polymer latex, a dye layer containing a yellow dye on one side of the substrate film, and the other And a heat-sensitive transfer sheet having a heat-resistant slipping layer containing a lubricant and a resin on the surface of the heat-sensitive transfer image receiving sheet and the dye layer of the heat-sensitive transfer sheet are in contact with each other, and heat corresponding to the image signal An image forming method for forming an image by applying energy from the heat-resistant slipping layer side of the heat-sensitive transfer sheet, wherein at least one of the yellow dyes is a yellow dye represented by the following general formula (1) The heat-resistant slipping layer contains a compound represented by the following general formula (P) as a lubricant, and has a beam diameter of 1 μm or less accelerated to 20 kV from the heat-resistant slipping layer side of the heat-sensitive transfer sheet. When the characteristic X-ray intensity derived from the phosphorous element K-ray in the heat-resistant slip layer obtained by irradiating the electron beam is measured with an energy dispersive X-ray spectrometer at each point in a 200 μm square region In addition, there are a plurality of maximum regions in which the maximum value of the intensity in the region is at least 2.5 times the minimum value and the region has a maximum value of the characteristic X-ray intensity derived from the phosphorus element K-ray. An image forming method, wherein the coefficient of variation obtained by dividing the standard deviation of the maximum value of the characteristic X-ray intensity between these maximum areas by the average of the characteristic X-ray intensity is 0.25 or less.

(In General Formula (1), A represents a substituted or unsubstituted arylene group, and R ¹ and R ² each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted group. R ³ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, substituted or unsubstituted Represents an aryloxy group, a substituted or unsubstituted alkoxycarbonyl group, a substituted or unsubstituted aryloxycarbonyl group, or a substituted or unsubstituted carbamoyl group, and R ⁴ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted group. Represents an aryl group.)
General formula (P)
{(R ^1a O) (R ^2a O) P (═O) O} _m M
(In General Formula (P), M represents a hydrogen atom, a metal ion, or an ammonium ion. R ^1a represents a substituted or unsubstituted aliphatic group or a substituted or unsubstituted aryl group. R ^2a represents Represents a hydrogen atom, a metal ion, an ammonium ion, a substituted or unsubstituted aliphatic group, or a substituted or unsubstituted aryl group, and m is the same as the valence of M and represents a number of 1 to 6.