JP2001039039A - Laser thermal transfer material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser thermal transfer material which is free from the deterioration of density due to the heat decomposition of a coloring agent even during recording an image by laser thermal transfer and forms an image of good hue. SOLUTION: In the laser thermal transfer material having a photothermal conversion layer and an image forming layer formed on a support, the image forming layer contains a chemical compound which contains an isoindolinone ring expressed by the formula (wherein, Rh is idenpedently a hydrogen atom, a 1-5C alkyl group, a 1-5C alkoxy group, a halogen atom, a carboxylate with a 1-5C alkyl group or an amide group with a 1-5C alkyl group. The character u is an integer of 1-4. When u is 2 or more, Rh may be each the same or different).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser thermal transfer material for performing thermal transfer by laser irradiation, and more particularly, to laser irradiating based on a digital image signal to perform color proofing (DDCP: Direct Digital Printing) in the printing field.
Color proof) or a laser thermal transfer material for producing a mask image.

[0002]

2. Description of the Related Art Conventionally, as a thermal transfer recording technique, a thermal transfer material in which a heat-fusible color material layer or a color material layer containing a heat sublimable dye is provided on a support is laminated with a thermal transfer image-receiving material. There is a type in which an image is heated from the thermal transfer material side by a heating device controlled by an electric signal, such as an energizing head, and the image is transferred and recorded on the thermal transfer image receiving material.
Such a thermal transfer recording technology has features such as low noise, maintenance-free, low cost, easy colorization, and digital recording, and many types of printers, recorders, facsimiles, computer terminals, and the like. It is used in the field.

On the other hand, in recent years, in the fields of medical treatment, printing, and the like, a recording system capable of so-called digital recording, which has higher resolution, enables high-speed recording, and is capable of image processing, has been required. However, in the thermal transfer recording method using a heating device such as a thermal head or a current-carrying head, the resolution is limited by the arrangement density of the head heating elements. Characteristically, it has been difficult to obtain a higher-resolution image at a higher speed.

Therefore, in recent years, as a system capable of obtaining a higher-resolution image at a high speed, a laser recording technique utilizing a photothermal conversion effect by laser irradiation has attracted attention and has been commercialized. In an image forming system using this laser recording technology, a single mode laser is generally used, particularly from the viewpoint of obtaining a high-definition, small-focus beam, and a high-resolution image can be obtained by its good beam quality. In addition, the recording speed can be increased, and an image can be formed at a higher speed than the conventional recording using a heating device such as a thermal head.

However, in laser recording, since a focused beam diameter of a laser beam having relatively high energy is condensed to about 10 μm and used, a heating device such as a thermal head which is efficiently converted into light and heat and used for thermal recording is used. Much higher thermal energy is obtained. Therefore, the temperature of the region irradiated with the laser locally reaches an extremely high temperature, and the colorant (pigment) contained in the image forming layer in the irradiated region is thermally decomposed. The colorant is thermally decomposed and loses its hue, and an image having a desired density is not transferred on the image receiving layer to which the colorant is transferred, resulting in a decrease in the density of a formed image.

On the other hand, in JP-A-6-175361 and JP-A-10-292144, a sufficient concentration can be obtained.
A technique using an isoindolinone pigment excellent in dispersibility and color reproducibility is disclosed. However, the above publication does not disclose that the pigment is used in a high-temperature processing system, and the above-mentioned pigments have not been used in thermal transfer materials so far, and a reduction in image density due to improvement in heat resistance is prevented. It is not used for the purpose.

[0007] A single mode laser is generally used for laser recording.
Since it is relatively low, about 0 to 200 mW, it has not yet reached a satisfactory level in terms of productivity. Therefore, in recent years, in order to increase the laser power and increase the laser recording speed, a multi-mode semiconductor laser generally having a higher output than a single-mode laser has been used. In this multimode semiconductor laser,
It has a high output of 1 W or more, and can dramatically improve the power of the laser head.

However, a multimode semiconductor laser is
There is a problem that it is difficult to condense the laser beam in the width direction, and it is not possible to condense the focal beam diameter to 20 μm or less. Therefore, when using the multi-mode semiconductor laser to record a high-definition image such as a sub-scanning pitch of about 10 μm in the field of medicine, printing, and the like, adjacent beams overlap and overlap with each other. As a result of extreme heat generation in the portion, the thermal decomposition of the colorant as described above proceeds further, and the concentration is promoted. Therefore, even when recording is performed using a laser having such a high output and having adjacent beams overlap, a material that is not easily thermally decomposed even at a high temperature is required.

In an image recording method using a photothermal conversion effect by laser irradiation, a colorant has extremely high heat resistance, which is unlikely to cause thermal decomposition even at a high temperature, and forms a high-quality image with high image density. At present, there is no available thermal transfer material yet.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and achieve the following objects. That is, an object of the present invention is to provide a laser thermal transfer material capable of forming a clear and good hue image without a decrease in density due to thermal decomposition of a colorant even when a laser beam is used for image recording by thermal transfer. And

[0011]

Means for solving the above problems are as follows. <1> In a laser thermal transfer material having at least a light-to-heat conversion layer and an image forming layer on a support, the image forming layer contains a compound containing an isoindolinone ring represented by the following general formula (1). It is a laser thermal transfer material characterized by containing.

[0012]

Embedded image

[Wherein, R _h is a hydrogen atom, having 1 to 5 carbon atoms.
An alkyl group having 1 to 5 carbon atoms, a halogen atom, a carboxylic acid ester group having an alkyl group having 1 to 5 carbon atoms, or an amide group having an alkyl group having 1 to 5 carbon atoms. u represents an integer of 1 to 4. When u is 2 or more, R _h may be the same or different. ]

<2> A laser thermal transfer material having at least a light-to-heat conversion layer and an image forming layer on a support,
A laser thermal transfer material, wherein the image forming layer contains a disazo compound having a benzimidazolone ring represented by the following general formula (2).

[0015]

Embedded image

[Wherein, R ¹ and R ² each independently represent an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms, and R ⁵ and R ⁶ each independently represent a structural formula shown below. (A)
Represents a benzimidazolone ring group represented by R _i or R _j
Are bonded to each other by a divalent linking group X,
R _i and R _j each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a halogen atom. p and q each independently represent an integer of 1 to 4. When p and q are 2 or more, R _i and R _j may be the same or different. ]

[0017]

Embedded image

<3> In a laser thermal transfer material having at least a light-to-heat conversion layer and an image forming layer on a support,
A laser thermal transfer material, wherein the image forming layer contains a quinophthalone compound represented by the following general formula (3).

[0019]

Embedded image

Wherein R _k is a hydrogen atom, having 1 to 5 carbon atoms.
Represents an alkyl group or an alkoxy group having 1 to 5 carbon atoms.
r represents an integer of 1 or 2. When r is 2, R _k may be the same or different. R ₁ represents a tetrachlorophthalimidoyl group represented by the following structural formula (b). ]

[0021]

Embedded image

<4> A laser thermal transfer material having at least a light-to-heat conversion layer and an image forming layer on a support,
A laser thermal transfer material, wherein the image forming layer contains a monoazo compound having a benzimidazolone ring represented by the following general formula (4).

[0023]

Embedded image

[In the formula, R _m represents an alkoxycarbonyl group having 2 to 5 carbon atoms, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. s represents an integer of 1 to 5. When s is 2 or more, R _m may be the same or different. ]

<5> A laser thermal transfer material having at least a light-to-heat conversion layer and an image forming layer on a support,
A laser thermal transfer material, wherein the image forming layer contains a condensed azo compound represented by the following general formula (5).

[0026]

Embedded image

[In the formula, Ar represents an arylene group. R
_n represents a hydrogen atom, an alkoxycarbonyl group having 2 to 5 carbon atoms, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. t represents an integer of 1 to 5. R _x is
Hydrogen atom, alkyl group having 1 to 5 carbon atoms or 1 to 5 carbon atoms
Represents an alkoxy group. y represents an integer of 1 to 4.
When t or y is 2 or more, R _n or R _x may be the same or different. ]

<6> A laser thermal transfer material having at least a light-to-heat conversion layer and an image forming layer on a support,
Wherein the image forming layer comprises a compound containing an isoindolinone ring represented by the following general formula (1);
(5) A laser thermal transfer material characterized by containing at least one compound selected from the group consisting of:

[0029]

Embedded image

[In the formula, R _h is a hydrogen atom, and has 1 to 5 carbon atoms.
An alkyl group having 1 to 5 carbon atoms, a halogen atom, a carboxylic acid ester group having an alkyl group having 1 to 5 carbon atoms, or an amide group having an alkyl group having 1 to 5 carbon atoms. u represents an integer of 1 to 4. When u is 2 or more, R _h may be the same or different. ]

[0031]

Embedded image

[Wherein R ¹ and R ² each independently represent an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms, and R ⁵ and R ⁶ each independently represent a structural formula shown below. (A)
Represents a benzimidazolone ring group represented by R _i or R _j
Are bonded to each other by a divalent linking group X,
R _i and R _j each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a halogen atom. p and q each independently represent an integer of 1 to 4. When p and q are 2 or more, R _i and R _j may be the same or different. ]

[0033]

Embedded image

[0034]

Embedded image

Wherein R _k is a hydrogen atom, having 1 to 5 carbon atoms.
Represents an alkyl group or an alkoxy group having 1 to 5 carbon atoms.
r represents an integer of 1 or 2. When r is 2, R _k may be the same or different. R ₁ represents a tetrachlorophthalimidoyl group represented by the following structural formula (b). ]

[0036]

Embedded image

[0037]

Embedded image

[Wherein, R _m represents an alkoxycarbonyl group having 2 to 5 carbon atoms, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. s represents an integer of 1 to 5. When s is 2 or more, R _m may be the same or different. ]

[0039]

Embedded image

[Wherein, Ar represents an arylene group. R
_n represents a hydrogen atom, an alkoxycarbonyl group having 2 to 5 carbon atoms, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. t represents an integer of 1 to 5. R _x is
Hydrogen atom, alkyl group having 1 to 5 carbon atoms or 1 to 5 carbon atoms
Represents an alkoxy group. y represents an integer of 1 to 4.
When t or y is 2 or more, R _n or R _x may be the same or different. ]

<7> The content (X) of the compound having an isoindolinone ring represented by the general formula (1) in the image forming layer and the compound represented by the general formulas (2) to (5) The weight ratio (X: Y) to the total content (Y) of at least one compound selected from the above is 1:99 to 30:70.
<6> The laser thermal transfer material according to <6>, wherein

[0042]

BEST MODE FOR CARRYING OUT THE INVENTION The laser thermal transfer material of the present invention contains an extremely heat-resistant pigment in its image forming layer which does not cause a decrease in image density even when an image is recorded by a laser. Hereinafter, the laser thermal transfer material of the present invention will be described, and together with the description, the thermal transfer image-receiving material and thermal transfer recording method used together with thermal transfer recording will be clarified.

<Laser Thermal Transfer Material> The laser thermal transfer material of the present invention (hereinafter, sometimes simply referred to as “thermal transfer material”) has a function capable of forming an image on a thermal transfer image receiving material described later by thermal transfer. Either mode may be used.For example, on a support, at least a light-to-heat conversion layer and an image forming layer are laminated in this order, and if necessary, other layers such as a heat-sensitive release layer and a cushion layer may be used. It may be configured to have. -Image forming layer- The image forming layer, at least a pigment as a colorant,
And an amorphous organic polymer. The pigment used as the coloring agent is not limited to one kind, and a plurality of kinds can be used in combination. In the present invention, a compound containing an isoindolinone ring represented by the following general formula (1) (hereinafter, sometimes referred to as a “compound represented by the general formula (1)”) is used as the pigment.

[0044]

Embedded image

In the formula, R _h is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a halogen atom, a carboxylic acid ester having an alkyl group having 1 to 5 carbon atoms, It represents an amide group having 1 to 5 alkyl groups.

As the alkyl group having 1 to 5 carbon atoms,
For example, methyl group, ethyl group, propyl group, butyl group,
And a pentyl group. Among them, an alkyl group having 1 to 2 carbon atoms is preferable, and a methyl group and an ethyl group are particularly preferable. Examples of the alkoxy group having 1 to 5 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and a pentyloxy group. Among them, an alkoxy group having 1 to 2 carbon atoms is preferable, and a methoxy group and an ethoxy group are particularly preferable.

Examples of the carboxylic acid ester having an alkyl group having 1 to 5 carbon atoms include -OCOCH ₃ ,
_{-OCOC 2 H 5, -OCOC 3 H} 7, -OCOC 4 H 9, -
OCOC ₅ H ₁₁ and the like, among, -OCOCH ₃ are preferred.

Examples of the amide group having an alkyl group having 1 to 5 carbon atoms include, for example, -NHCOCH ₃ , -NHC
OC ₂ H _5, include -NHCOC ₃ H ₇ or the like.

In the formula, u represents an integer of 1 to 4;
In the above case, R _h may be the same or different.

The compound containing an isoindolinone ring represented by the general formula (1) is extremely excellent in heat resistance, and can be used for thermal recording utilizing heat generated by its light-to-heat conversion effect upon irradiation with laser light. A high-quality image having a desired density and free from image defects such as transfer unevenness can be stably formed without decomposition. Here, the transfer unevenness refers to a phenomenon in which the transfer density at the center of the scanning line of the laser beam is reduced during thermal transfer recording, and the transfer density at both ends of the scanning line is increased. Appears as uneven density.

In the present invention, used as a coloring agent
Instead of the compound containing an isoindolinone ring represented by the general formula (1), a compound (pigment) represented by any of the following general formulas (2) to (5) may be used. First, a disazo compound having a benzimidazolone ring represented by the general formula (2) will be described.

[0052]

Embedded image

In the formula, R ¹ and R ² each independently represent an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and a butyl group. Among them, an alkyl group having 1 to 2 carbon atoms is preferable, and a methyl group and an ethyl group are particularly preferable. Examples of the alkoxy group include a methoxy group, an ethoxy group,
And a propoxy group and a butoxy group. Among them, an alkoxy group having 1 to 2 carbon atoms is preferable, and a methoxy group and an ethoxy group are particularly preferable.

R ⁵ and R ⁶ in the formula represent a benzimidazolone ring group represented by the following structural formula (a). R ⁵ and R ⁶ may be compounds in which one of them is substituted by a benzimidazolone ring group, or both may be compounds in which both are substituted by a benzimidazolone ring.
However, it is more preferable that both are benzimidazolone rings from the viewpoint of the effect.

[0055]

Embedded image

R _i and R _j in the formula each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a halogen atom. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group and a butyl group. Among them, an alkyl group having 1 to 2 carbon atoms is preferable, and a methyl group and an ethyl group are particularly preferable. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group and the like. Among them, an alkoxy group having 1 to 2 carbon atoms is preferable, and a methoxy group and an ethoxy group are particularly preferable. Of the above, R _i and R _j are particularly preferably a hydrogen atom, a methyl group, or a methoxy group.

P and q in the formula are each independently 1 to 4
Represents an integer. When p is 2 or more, R _iAre the same
And when q is 2 or more, R
_jMay be the same or different.

Further, 2 including R _i and R _j in the general formula (2)
The aromatic groups are linked to each other by a divalent linking group X, and the linking group X can be appropriately selected depending on the application such as hue. Among them, it is preferable to use any one of the linking groups selected from the following groups, since a good hue is obtained and no harmful decomposition product is generated even when thermally decomposed.

[0059]

Embedded image

In the above formula, l and n are each independently 2 to 2
It represents an integer of 10, and among them, an integer of 2 to 4 is preferable. M represents an integer of 1 to 3, and among them,
It is preferably an integer of 1 to 2.

As described above, the pigment represented by the general formula (2) having a benzimidazolone ring group has extremely high heat resistance and can be used even when high-temperature recording is performed by thermal transfer recording using a laser. Since thermal decomposition is unlikely to occur, it is possible to suppress a decrease in image density and uneven density after transfer due to thermal decomposition of the pigment, and to stably produce high-quality images with high image density and no image defects such as transfer unevenness. Can be formed.

Next, the quinophthalone compound represented by the following general formula (3) will be described.

[0063]

Embedded image

In the general formula (3), R _k represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms. Examples of the alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a butyl group, and a pentyl group. Among them,
A methyl group and an ethyl group are preferred. Examples of the alkoxy group having 1 to 5 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and a pentyloxy group. Among them, a methoxy group and an ethoxy group are preferred. Among them, R _k is particularly preferably a hydrogen atom, a methyl group, or a methoxy group.

The above r represents an integer of 1 or 2. r is 2
In the case, R _k may be the same or different.

In the general formula (3), R ₁ represents a tetrachlorophthalimidoyl group represented by the following structural formula (b).

[0067]

Embedded image

Similar to the general formula (2), the pigment represented by the general formula (3) also has extremely high heat resistance, and hardly causes thermal decomposition even when performing high-temperature recording by thermal transfer recording using a laser. In addition, a high-quality image having a high image density and no image defects such as transfer unevenness can be stably formed.

Next, a monoazo compound having a benzimidazolone ring represented by the following general formula (4) will be described.

[0070]

Embedded image

In the general formula (4), R_mHas 2 to 2 carbon atoms
5 alkoxycarbonyl groups, alkyl having 1 to 5 carbon atoms
Represents a group or an alkoxy group having 1 to 5 carbon atoms. The carbon number
Examples of the 2 to 5 alkoxycarbonyl groups include, for example,-
COOCH _Three, -COOC_TwoH_Five, -COOC_ThreeH₇Etc.
And, among others, -COOCH_ThreeIs preferred. The carbon
An alkyl group having 1 to 5 carbon atoms and an alkoxy group having 1 to 5 carbon atoms
As the group, R in the general formula (3)_kSynonymous with
You.

The s represents an integer of 1 to 5. When s is 2 or more, R _m may be the same or different.

Similar to the general formulas (2) and (3), the pigment represented by the general formula (4) also has extremely high heat resistance. Even when high-temperature recording by thermal transfer recording using a laser is performed, heat is not applied. It is possible to stably form a high-quality image which is hardly decomposed, has a high image density, and has no image defects such as transfer unevenness.

Next, the condensed azo compound represented by the following general formula (5) will be described.

[0075]

Embedded image

In the general formula (5), Ar represents an arylene group. The arylene group may have a substituent, and the substituent R _x represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. Y in the formula represents an integer of 1 to 4, and when y is 2 or more,
R _x may be the same or different. The alkyl group having 1 to 5 carbon atoms and the alkoxy group having 1 to 5 carbon atoms have the same meaning as R _k in the general formula (3). Among the arylene groups which may have a substituent, a phenylene group in which R _x is a hydrogen atom is particularly preferred.

In the general formula (5), R_nIs a hydrogen atom,
An alkoxycarbonyl group having 2 to 5 carbon atoms, 1 to 5 carbon atoms
Represents an alkyl group or an alkoxy group having 1 to 5 carbon atoms.
The alkoxycarbonyl group having 2 to 5 carbon atoms may be
R in general formula (4) _mHas the same meaning as
And an alkyl group having 5 and an alkoxy group having 2 to 5 carbon atoms.
In the general formula (3), R_kIs synonymous with Ma
In addition, t in the formula represents an integer of 1 to 5. When t is 2 or more
If R_nMay be the same or different.

Similar to the general formulas (2) to (4), the pigment represented by the general formula (5) also exhibits extremely high heat resistance, and even when high-temperature recording is performed by thermal transfer recording using a laser, It is possible to stably form a high-quality image which is hardly decomposed, has a high image density, and has no image defects such as transfer unevenness.

In the laser thermal transfer recording method of recording an image with a laser beam, a laser having a high output energy is used, and the laser beam is further focused on a beam having a very small focal diameter of about 10 μm. In the irradiation area, a large amount of heat can be obtained and the recording speed can be increased, while the irradiation section reaches an extremely high temperature. In this case, energy having a higher calorific value is applied than a heating device such as a thermal head or a heat roller generally used for thermal recording. Conventionally, at such a high temperature, the pigment is thermally decomposed to lower the image density, but the above-mentioned pigment (compounds represented by the general formulas (1) to (5)) is used as a colorant. Thereby, loss of hue due to thermal decomposition of the pigment during thermal transfer recording can be prevented, and a high-density image without lowering the density of a formed image can be formed. When the pigment is thermally decomposed as described above, the density decrease and hue disappearance do not occur uniformly, so that the density of the formed image after thermal transfer becomes non-uniform, and the uniform high density becomes higher. A high-quality image cannot be formed. In addition, the transfer is not performed uniformly due to the generation of decomposition products that are thermally decomposed, and image defects such as transfer unevenness also occur.

When the compound represented by the general formula (1) is used as a coloring agent, it may be used in combination with other known pigments or the like so as to obtain a desired hue and concentration. In this case, the content ratio with other known pigments can be appropriately selected according to the hue and density of the image. In addition, the general formula (1)
Two or more compounds may be appropriately selected from the compounds represented by the formulas (5) to (5) and used in combination. Further, other known pigments and the like may be used in combination with the two or more compounds.

The total content (weight) of the pigment in the image forming layer is from 25 to 70 with respect to the total weight of the image forming layer.
% By weight, more preferably 30 to 60% by weight.
Of the total content of the pigment, the above general formulas (1) to (5)
The total amount (content weight) of the pigments selected from the compounds represented by the formula is preferably 50 to 100% by weight, more preferably 80 to 100% by weight of the total content of the pigments. If the total amount is less than 50% by weight, the amount of thermal decomposition of the pigment during thermal transfer recording is large, which may cause a decrease in image density and image defects.

Among the above combinations, in the present invention,
From the viewpoint of obtaining a better hue, in particular, the general formula (1)
And a compound (pigment) represented by the formula (2)
It is preferable to use together with at least one compound (pigment) selected from the compounds represented by (5). A compound represented by the general formula (1), and the above-mentioned general formulas (2) to (5)
By using in combination with at least one compound selected from the compounds represented by the following formulas, it is possible to prevent a decrease in the coloring concentration due to thermal decomposition, and at the same time, obtain a favorable hue due to the color mixing effect of the hue.

In order to obtain a good hue by using the compound represented by the general formula (1) in combination with the compounds represented by the general formulas (2) to (5), it is necessary to use each of the pigments in the image forming layer. The content ratio (weight) is preferably in the following range. That is, the content (X) of the compound containing an isoindolinone ring represented by the general formula (1) in the image forming layer and the compound represented by the general formulas (2) to (5) are selected. As a weight ratio (X: Y) to the total content (Y) of the compound to be prepared, 1:99 to 30:70 is preferable,
1:99 to 15:85 is more preferred. The weight ratio X:
When Y is out of the above range, a desired good hue may not be obtained.

The average particle size of the pigment contained in the image forming layer is preferably from 0.03 to 1 μm, more preferably from 0.05 to 0.5 μm.
Is more preferred. If the particle size is less than 0.03 μm, the dispersion cost may increase or the dispersion may gel, and if it is more than 1 μm, coarse particles in the pigment may adhere to the heat transfer layer and the image receiving layer. May interfere with sex.

Further, in the coating solution for the image forming layer, the particle diameter is 1 μm.
The content of the pigment particles of m or more is preferably 3% by weight or less based on the total solid weight. When the content of the pigment particles having a size of 1 μm or more exceeds 3% by weight, when the pigment is brought into close contact with an image receiving layer of a thermal transfer image receiving material described later, poor adhesion is likely to occur near the coarse pigment particles. , The thermal transferability of the toner may be reduced to cause micro transfer failure (transfer unevenness).

Examples of the amorphous organic high molecular polymer contained in the image forming layer include those having a softening point of 40 to 150 ° C., for example, butyral resin, polyamide resin, polyethyleneimine resin, sulfonamide resin, polyester Polyol resin, petroleum resin, styrene, vinyltoluene, α-methylstyrene, 2-methylstyrene, chlorostyrene, vinylbenzoic acid, vinylbenzenesulfonic acid soda, styrene such as aminostyrene, and derivatives thereof,
Homopolymers and copolymers of substituted products, methacrylates such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, and hydroxyethyl methacrylate, and acrylic acids such as methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, and α-ethylhexyl acrylate Esters and acrylic acid,
Dienes such as butadiene and isoprene, acrylonitrile, vinyl ethers, maleic acid and maleic esters, maleic anhydride, cinnamic acid, vinyl chloride, vinyl acetate and other vinyl monomers alone or other monomers And copolymers thereof. These resins can be used as a mixture of two or more kinds.

The content of the amorphous organic high molecular polymer is preferably from 70 to 30% by weight, more preferably from 60 to 40% by weight, based on the total solid weight of the image forming layer.

When a multi-color image is formed by repeatedly superposing a large number of image layers (image forming layers on which images are formed) on the same thermal transfer image-receiving material, it is necessary to improve the adhesion between the images. The image forming layer preferably also contains a plasticizer.
Examples of the plasticizer include phthalic acid esters such as dibutyl phthalate, di-n-octyl phthalate, di (2-ethylhexyl phthalate, dinonyl phthalate, dilauryl phthalate, butyllauryl phthalate, and butylbenzyl phthalate) , Di (2-ethylhexyl) adipate,
Aliphatic dibasic acid esters such as di (2-ethylhexyl) sebacate, tricresyl phosphate, and tri (2-ethylhexyl) phosphate
Examples thereof include phosphoric acid triesters such as ethylhexyl), polyol polyesters such as polyethylene glycol ester, and epoxy compounds such as epoxy fatty acid ester.

In addition to the above-mentioned general plasticizers, polyethylene glycol dimethacrylate, 1,2,4-butanetriol trimethacrylate, trimethylolethane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, Acrylic esters such as pentaerythritol-polyacrylate can also be suitably used depending on the type of binder used. Incidentally, two or more plasticizers may be used in combination.

The amount of the plasticizer added is generally such that the total amount of the pigment and the amorphous organic high molecular polymer in the image forming layer and the content ratio (weight ratio) of the plasticizer are 100:
It is preferably from 0.5 to 1: 1 and more preferably from 100: 2 to 3: 1.

Further, in the image forming layer, in addition to the above components,
If necessary, a surfactant, a thickener and the like can be added. The layer thickness (dry layer thickness) of the image forming layer is from 0.2 to
1.5 μm is preferable, and 0.3 to 1.0 μm is more preferable.

The above components are dissolved in a solvent to form a coating liquid solution (coating solution for image forming layer), which is coated on a support by a known coating method and dried to form an image forming layer. Can be formed. Solvents that can be used when preparing the coating solution for the image forming layer include, for example, alcohols such as ethyl alcohol and propyl alcohol;
Ketones such as acetone and methyl ethyl ketone; esters such as ethyl acetate; aromatic hydrocarbons such as toluene and xylene; ethers such as tetrahydrofuran and dioxane; amides such as DMF and N-methylpyrrolidone; cellosolve such as methyl cellosolve It can be appropriately selected from types and the like according to the presence or absence of the light-to-heat conversion layer and the like. The solvents may be used alone or in combination of two or more.

In order to prevent damage, a heat transfer image receiving material or a protective cover film such as a polyethylene terephthalate sheet or a polyethylene sheet can be usually laminated on the surface of the image forming layer.

In the case of performing image recording, a laminate is used in which a thermal transfer material and a thermal transfer image receiving material are laminated so that an image receiving layer of the thermal transfer image receiving material and an image forming layer of the thermal transfer material are in contact with each other, and the laminate is imaged with a laser. The image-forming layer of the thermal transfer material is transferred onto the image-receiving layer of the thermal transfer image-receiving material by performing the above exposure. Therefore, if the adhesion is not sufficient and uniform at the bonding interface between the thermal transfer image receiving material and the thermal transfer material of the formed laminate, heat conduction of the converted thermal energy of the irradiating laser to the image receiving layer is hindered, and particularly high output power is obtained. When a laser is used, the temperature of the image forming layer of the thermal transfer material rises excessively, and the pigment in the layer easily becomes thermally decomposed. However, by using a compound (pigment) represented by the general formula (1) and / or a pigment selected from compounds A to E as a coloring agent, thermal decomposition of the pigment can be suppressed, and the image density after thermal transfer can be reduced. It is possible to prevent the occurrence of image defects such as deterioration and transfer unevenness, and to stably form an image having good hue.

-Light-to-heat conversion layer-The light-to-heat conversion layer contains a light-to-heat conversion substance and a binder resin (hereinafter sometimes referred to as a "light-to-heat conversion layer binder polymer"), and may contain other components as necessary. It contains. The photothermal conversion material generally refers to a laser light absorbing material such as a dye that can absorb laser light, and such a dye (eg, a pigment) includes, for example,
Black pigments such as carbon black, phthalocyanines,
Pigments of macrocyclic compounds having absorption in the visible to near-infrared region such as naphthalocyanine, organic dyes used as laser absorbing materials for high-density laser recording such as optical disks (cyanine dyes such as indolenine dyes, anthraquinone dyes, Organic dyes such as azulene dyes and phthalocyanine dyes) and organic metal compound dyes such as dithiol nickel complexes can be mentioned. From the viewpoint of increasing the recording sensitivity, the light-to-heat conversion layer is preferably as thin as possible. Therefore, it is preferable to use an infrared absorbing dye such as a cyanine dye or a phthalocyanine dye having a large absorption coefficient in a laser light wavelength region.

As the laser light absorbing material, an inorganic material such as a metal material can be used. The metal material is used in a state of particles (for example, blackened silver). The optical density of the photothermal conversion substance at the laser absorption wavelength is 0.1 to
2.0 is preferable, and 0.3 to 1.2 is more preferable. If the optical density is less than 0.1, the sensitivity of the thermal transfer material may be low, and if it exceeds 2.0, the cost may be disadvantageous.

Examples of the photothermal conversion layer binder polymer include a resin having a high glass transition point and a high thermal conductivity.
For example, polymethyl methacrylate, polycarbonate,
Polystyrene, ethyl cellulose, nitrocellulose,
General heat-resistant resins such as polyvinyl alcohol, gelatin, polyvinylpyrrolidone, polyparabanic acid, polyvinyl chloride, polyamide, polyimide, polyetherimide, polysulfone, polyethersulfone, and aramid can be used. In particular, when recording a plurality of high-power lasers such as a multi-mode laser in an array, a polymer having excellent heat resistance is preferable, and the glass transition point Tg
Is 150-400 ° C. and 5% weight loss temperature Td
(TGA method, temperature rise rate in air at 10 ° C / min) is 250 ° C
The above polymer is more preferable, and Tg is 220 to 400.
Most preferred is a polymer having a Td of 400 ° C. or higher.

The light-to-heat conversion layer is provided by preparing a coating solution (coating solution for the light-to-heat conversion layer) in which the light-to-heat conversion substance and the binder polymer for the light-to-heat conversion layer are dissolved, and coating and drying the coating solution on the support. be able to. Examples of the organic solvent for dissolving the light-heat conversion layer binder polymer include 1,4-dioxane, 1,3-dioxolane, dimethyl acetate, N-methyl-2-pyrrolidone, dimethyl sulfoxide, dimethylformamide, and γ- Butyrolactone and the like.

The coating method for applying the coating solution for the light-to-heat conversion layer can be appropriately selected from known coating methods. Drying is usually performed at a temperature of 300 ° C. or less.
Preferably, the drying temperature is 200 ° C. or lower, and when using polyethylene terephthalate as the support,
The temperature is more preferably in the range of 80 to 150 ° C.

In the light-to-heat conversion layer formed as described above, the solid content weight ratio of the light-to-heat conversion substance and the light-to-heat conversion layer binder polymer dye (light-to-heat conversion substance: binder) is as follows.
1:20 to 2: 1 is preferable, and 1:10 to 2: 1 is more preferable. When the amount of the binder is too small, the cohesive force of the light-to-heat conversion layer is reduced, and when the formed image is transferred to the thermal transfer image-receiving material, the light-to-heat conversion layer is easily transferred together,
This may cause color mixing of images, and if the amount of the binder is too large, the layer thickness of the light-to-heat conversion layer becomes large in order to achieve a constant light absorptance, which may cause a decrease in sensitivity.

The layer thickness of the light-to-heat conversion layer is from 0.03 to
0.8 μm is preferred, and 0.05-0.3 μm is more preferred. The light-to-heat conversion layer has a wavelength in the range of 700 to 2000 nm in the range of 0.1 to 1.3 (preferably 0.2 to 1.3 nm).
It is preferable to have the maximum of the absorbance (optical density) of 1.1).

The heat resistance (for example, heat deformation temperature and thermal decomposition temperature) of the binder polymer of the light-to-heat conversion layer is preferably higher than the heat resistance of the material used for the layer provided on the light-to-heat conversion layer.

-Heat-sensitive release layer- On the light-to-heat conversion layer of the heat transfer material, a gas is generated by the action of heat generated in the light-to-heat conversion layer, or water or the like is released, whereby the light-to-heat conversion layer and the image forming layer are released. And a heat-sensitive release layer containing a heat-sensitive material that reduces the bonding strength between the heat-sensitive adhesive and the heat-sensitive adhesive. Examples of the heat-sensitive material include a compound (polymer or low-molecular compound) that itself decomposes or degrades by heat to generate a gas, and a compound (polymer or low-molecular compound) that absorbs or adsorbs a considerable amount of easily vaporizable gas such as moisture. Molecular compound) can be used. These may be used in combination.

Examples of the polymer which is decomposed or deteriorated by heat to generate a gas include a self-oxidizing polymer such as nitrocellulose, chlorinated polyolefin, chlorinated rubber, polyvinyl chloride, polyvinyl chloride and polyvinylidene chloride. Such halogen-containing polymers, acrylic polymers such as polyisobutyl methacrylate in which volatile compounds such as water are adsorbed, cellulose esters such as ethyl cellulose in which volatile compounds such as water are adsorbed, and volatile compounds such as water. Natural polymer compounds such as adsorbed gelatin can be exemplified. Examples of the low molecular weight compound which decomposes or degrades by heat to generate a gas include a compound which generates a gas upon exothermic decomposition such as a diazo compound or azide.
It is preferable that the heat-sensitive material is decomposed or deteriorated by heat at a temperature of 280 ° C. or less, and particularly at 230 ° C. or less.
It preferably occurs at a temperature of not more than ° C.

When a low molecular weight compound is used as the heat-sensitive material, it is desirable to combine it with a binder. As the binder, there can be used the above-mentioned polymer which itself decomposes or degrades by heat to generate a gas, and a general polymer binder having no such properties.

When a heat-sensitive low-molecular compound and a binder are used in combination, the weight ratio of the former to the latter is 0.0
2: 1 to 3: 1 are preferable, and 0.05: 1 to 2: 1 are more preferable. The heat-sensitive peeling layer preferably covers the light-to-heat conversion layer over substantially the entire surface, and the thickness thereof is generally 0.03 to 1 μm, and among them, 0.05 to 1 μm.
０．５0.5 μm is preferred.

On a support, a light-to-heat conversion layer, a heat-sensitive release layer,
In the case of a thermal transfer material having a configuration in which the image forming layers are stacked in this order, the heat-sensitive release layer is decomposed, deteriorated, and generates gas by heat transmitted from the light-to-heat conversion layer. And, due to this decomposition or generation of gas, the heat-sensitive release layer partially disappears,
Alternatively, cohesive failure occurs in the heat-sensitive release layer, and the bonding force between the light-to-heat conversion layer and the image forming layer decreases. For this reason, depending on the behavior of the heat-sensitive release layer, a part of the heat-sensitive release layer may adhere to the image forming layer and appear on the surface of a finally formed image, which may cause color mixing of the image. Therefore, even when such transfer of the heat-sensitive release layer occurs, the heat-sensitive release layer is hardly colored (that is, high in visible light) so that color mixture does not appear visually in the formed image. Showing transparency) is desirable. Specifically, the light absorption of the heat-sensitive release layer is preferably 50% or less, more preferably 10% or less with respect to visible light. Instead of providing a separate heat-sensitive release layer, a heat-sensitive material may be added to the light-to-heat conversion layer, and the light-to-heat conversion layer may also serve as the heat-sensitive release layer.

Cushion Layer A cushion layer is provided between the support of the thermal transfer material and the light-to-heat conversion layer as a cushioning intermediate layer for the purpose of improving the adhesion of the thermal transfer image-receiving material to the surface of the image-receiving layer. Is preferred. The cushion layer is a layer that is easily deformed when stress is applied to the image forming layer, and has an effect of improving the adhesion between the image forming layer and the image receiving layer during laser thermal transfer and improving the image quality. In addition, at the time of recording, even if foreign matter is mixed between the thermal transfer material and the thermal transfer image receiving material, the gap between the image receiving layer and the image forming layer is reduced due to the deformation of the cushion layer, and as a result, image white spot defect is generated. It also has the effect of reducing the size. Further, when an image is formed by transferring an image once, and then transferring the image to a separately prepared printing paper, the image receiving surface is deformed according to the uneven surface of the paper, so that the transferability of the image receiving layer is improved, and By lowering the gloss of the printed matter, the effect of improving the closeness to the printed matter can be provided.

In order to impart cushioning properties, a material having a low elastic modulus, a material having rubber elasticity, or a thermoplastic resin which is easily softened by heating may be used. The elastic modulus at room temperature is preferably 10 to 500 kgf / cm ² or less, more preferably 30 to 150 kgf / cm ² .

In order to sink foreign substances such as rubber, the penetration specified by JIS K2530 (25 ° C.,
(100 g, 5 seconds) is preferably 10 or more.
The glass transition temperature of the cushion layer is 80 ° C.
Or less, preferably 25 ° C. or less. It is also possible to suitably add a plasticizer to the polymer binder in order to adjust these physical properties, for example, Tg.

Examples of the binder constituting the cushion layer include rubbers such as urethane rubber, butadiene rubber, nitrile rubber, acrylic rubber, and natural rubber, as well as polyethylene, polypropylene, polyester and styrene rubber.
Butadiene copolymer, ethylene-vinyl acetate copolymer,
Examples thereof include an ethylene-acryl copolymer, a vinyl chloride-vinyl acetate copolymer, a vinylidene chloride resin, a vinyl chloride resin containing a plasticizer, a polyamide resin, and a phenol resin.

Although the thickness of the cushion layer varies depending on the resin used and other conditions, it is usually 3 to 100 μm.
Is preferably, and more preferably 10 to 50 μm.

—Support— The support that can be used for the thermal transfer material is not particularly limited, and various support materials can be appropriately selected according to the purpose. Examples of the support material include synthetic resin materials such as polyethylene terephthalate, polyethylene-2,6-naphthalate, polycarbonate, polyethylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, and styrene-acrylonitrile copolymer. In view of mechanical strength and dimensional stability against heat, biaxially stretched polyethylene terephthalate is preferred. When the thermal transfer material is used for producing a color proof using laser recording, the support is preferably a transparent synthetic resin material that transmits laser light.

Further, the support may be provided with a surface activation treatment and / or one or more undercoat layers for the purpose of improving the adhesion to the light-to-heat conversion layer provided thereon. Examples of the surface activation treatment include a glow discharge treatment and a corona discharge treatment. As a material for the undercoat layer, a material that exhibits high adhesiveness to both surfaces of the support and the light-to-heat conversion layer, has low thermal conductivity, and is excellent in heat resistance is preferable. Examples of such a material for the undercoat layer include styrene, styrene-butadiene copolymer, and gelatin. The layer thickness of the entire undercoat layer is usually 0.01 to 2 μm. Further, on the surface of the support on which the light-to-heat conversion layer is not provided, various functional layers such as an anti-reflection layer or the like, or a surface treatment can be applied as necessary.

As described above, by using the laser thermal transfer material of the present invention, thermal decomposition of the pigment during laser thermal transfer recording can be suppressed, and the image density after transfer decreases, and the image quality decreases due to uneven density. , And a high-quality image with good hue can be stably formed.

<Thermal Transfer Image-Receiving Material> The thermal transfer image-receiving material may have any form as long as it has a function of holding an image by thermal transfer from the laser thermal transfer material of the present invention. On a support different from the thermal transfer material, at least an image receiving layer is provided, and if necessary, between the support and the image receiving layer, another undercoat layer, a cushion layer, a release layer, an intermediate layer, etc. It may be configured to have a layer. In addition, the backing layer may be provided on the surface opposite to the side on which the image receiving layer is provided, and the surface of the image receiving layer may be roughened, for example, when the heat transfer image receiving material is wound up in a roll shape to improve transportability and integration. It is preferable because it can be converted. It is also preferable to provide an antistatic layer separately from these layers, or to add an antistatic agent to each of the above layers.

-Image-Receiving Layer- The image-receiving layer is a layer formed mainly of an organic polymer binder. The organic polymerizable binder (hereinafter, referred to as
It may be referred to as "image receiving layer binder polymer". )
Is preferably a thermoplastic resin, for example, acrylic acid, methacrylic acid, acrylic acid esters, homopolymers of acrylic monomers such as methacrylic acid esters and copolymers thereof, methylcellulose, ethylcellulose, such as cellulose acetate Cellulose polymers, homopolymers and copolymers of vinyl monomers such as polystyrene, polyvinylpyrrolidone, polyvinyl butyral, polyvinyl alcohol, polyvinyl chloride, etc., condensation polymers such as polyesters and polyamides, butadiene-styrene copolymers Rubber-based polymers such as polymers are exemplified.

The binder polymer of the image receiving layer is preferably a polymer having a glass transition temperature (Tg) lower than 90 ° C. from the viewpoint of obtaining an appropriate adhesive force with the image forming layer. For this purpose, a plasticizer can be added to the image receiving layer. Further, the Tg of the binder polymer of the image receiving layer is preferably 30 ° C. or more for the purpose of preventing blocking between sheets. As the image receiving layer binder polymer, at the time of laser recording, to improve the adhesiveness of the thermal transfer material to the image forming layer, to improve the sensitivity and image strength, the same or similar to the binder polymer used in the image forming layer It is particularly preferred to use polymers.

The thickness of the image receiving layer is 0.3 to 7 μm.
m is preferable, and 0.7 to 4 μm is more preferable. When the layer thickness is less than 0.3 μm, the film strength may be insufficient and the film may be easily broken when retransferring to printing paper.
If it exceeds m, the glossiness of the image after the retransfer of this paper may increase, and the approximation to the printed matter may decrease.

As the plasticizer, the same plasticizers that can be used in the image forming layer of the thermal transfer material described above can be used.

-Support-As the support used for the thermal transfer image-receiving material, a sheet-like substrate such as a plastic sheet, paper, a metal sheet, and a glass sheet is generally used. As the plastic sheet, for example, polyethylene terephthalate, polyethylene naphthalate, polyethylene, polycarbonate,
Sheets of polyvinyl chloride, polyvinylidene chloride, polystyrene and the like can be mentioned, among which a polyethylene terephthalate sheet is particularly preferable. As the paper, for example,
Printing paper, coated paper and the like can be mentioned.

Further, as the support, a white material having air bubbles therein is preferable in terms of cushioning property, image visibility, and the like. In particular, a foamed polyester support is most preferable in terms of mechanical properties. Further, the surface of the support may be subjected to a surface treatment such as a corona discharge treatment and a glow discharge treatment for the purpose of enhancing the adhesion to the image receiving layer. The thickness of the support is usually 10 to 400 μm, and particularly 25 to 20 μm.
0 μm is preferred.

-Back Layer- The back layer is made of fine particles such as silicon oxide, a surfactant or fine particles of tin oxide for the purpose of roughening the surface of the image receiving layer and improving transportability in the recording apparatus. An additive such as an antistatic agent may be added. In addition, these additives can be added not only to the back layer but also to the image receiving layer and other layers as needed.

Examples of the fine particles include silicon oxide, calcium carbonate, titanium dioxide, aluminum oxide, zinc oxide,
Inorganic fine particles such as barium sulfate and zinc sulfate; organic fine particles made of a resin such as a polyethylene resin, a silicone resin, a fluororesin, an acrylic resin, a methacrylic resin, and a melamine resin. Among them, titanium dioxide, calcium carbonate, silicon oxide, Silicone resin, acrylic resin, and methacrylic resin are preferred. As the average particle diameter of the fine particles,
0.5 to 10 μm is preferable, and 0.8 to 5 μm is more preferable. The content of the fine particles is preferably from 0.5 to 80% by weight, more preferably from 1 to 20% by weight, based on the total solid weight of the back layer or the image receiving layer.

The antistatic agent has a surface resistance of 10 ¹² Ω under the environmental conditions of 23 ° C. and 50% RH.
In the following, the surfactant can be appropriately selected from various surfactants and conductive agents so as to be 10 ⁹ Ω or less, and used.

Examples of the thermal transfer image-receiving material include, as described above, (1) an embodiment having an image-receiving layer on a support, and (2) having an image-receiving layer on one surface of the support and fine particles on the other surface. Embodiments having a back layer including the above are described, but the present invention is not limited thereto, and the following embodiments may be used. That is, (3)
A mode in which a cushion layer is provided between the support of the mode (2) and the image receiving layer may be used. (4) In the image receiving layer of the mode (3), further used for the back layer. An embodiment including fine particles similar to those described above may be used. Aspects (2) to (4)
In this case, the surface of the image receiving layer can be roughened by pressing with a back layer containing fine particles by winding the thermal transfer image receiving material into a roll. Further, by providing a cushion layer as an intermediate layer of the image receiving layer as in the above embodiments (3) and (4), it is possible to improve poor adhesion caused by a roughened image receiving layer surface, and the present invention Can also be suitably applied.

Cushion Layer A cushion layer is provided between the support of the thermal transfer image-receiving material and the image-receiving layer as an intermediate layer having cushioning properties for the purpose of improving the adhesion of the thermal transfer material to the image-receiving layer surface. Preferably, it is provided. As the components that can be used in the cushion layer, those similar to the cushion layer formed of the thermal transfer material can be used, and the same configuration can be used.

The image receiving layer and the cushion layer need to be adhered to each other up to the stage of laser recording, but are preferably provided so as to be peelable in order to transfer the image to the printing paper. In order to facilitate peeling, it is preferable to provide a peeling layer having a thickness of about 0.1 to 2 μm between the cushion layer and the image receiving layer. This release layer preferably has a function as a barrier for a coating solvent at the time of coating the image receiving layer.

An example in which a support / cushion layer / image-receiving layer is laminated as the structure of the thermal transfer image-receiving material has been described. In some cases, the support / cushion-type image-receiving layer in which the image-receiving layer also functions as a cushion, or a support. / Undercoat layer / cushionable image receiving layer. Also in this case, it is preferable that the cushioning image-receiving layer is provided so as to be releasable so that it can be re-transferred to the printing paper. In this case, the image after retransfer to the printing paper becomes an image having excellent gloss. The layer thickness of the cushion layer also serving as the image receiving layer is preferably from 5 to 100 μm, more preferably from 10 to 40 μm.

In the case where an image is once formed on the image receiving layer and then retransferred to printing paper or the like, it is preferable that at least one of the image receiving layers is formed of a photocurable material. Examples of the composition of such a photocurable material include: a) a photopolymerizable monomer comprising at least one of a polyfunctional vinyl or vinylidene compound capable of forming a photopolymer by addition polymerization;
Examples of the combination include b) an organic polymer, c) a photopolymerization initiator, and, if necessary, additives such as a thermal polymerization inhibitor. Examples of the polyfunctional vinyl monomer include unsaturated esters of polyols, particularly esters of acrylic acid or methacrylic acid (eg, ethylene glycol diacrylate, pentaerythritol tetraacrylate). Examples of the organic polymer include those similar to those usable as the image receiving layer binder polymer. As the photopolymerization initiator,
Benzophenone, ordinary photoradical polymerization initiators such as Michler's ketone, and the like, based on the total solid content weight in the layer,
It can be used in a ratio of 0.1 to 20% by weight.

When the cushion layer as described above is provided, it is difficult to deform when subjected to stress for the purpose of preventing the fine particles from sinking when the fine particles are contained in the roughened back layer or the image receiving layer. An intermediate layer may be provided. This layer needs to use a material that can be applied to the cushion layer, and can be configured to contain a polymer having a relatively high glass transition point, such as PMMA, polystyrene, or cellulose triacetate.

<Thermal Transfer Recording Method> Next, a laser thermal transfer recording method for recording an image using the laser thermal transfer material of the present invention will be described. In the laser thermal transfer recording method, a laminate is prepared by laminating a thermal transfer image receiving material on the surface of the image forming layer of the thermal transfer material so that the image receiving layer is in contact with the laminate, and from above the thermal transfer material of the laminate (on the support side of the thermal transfer material). The surface is irradiated with laser light in an image-wise manner in time series, and thereafter, the thermal transfer image receiving material is separated from the thermal transfer image receiving material to obtain a thermal transfer image receiving material to which the laser irradiation area of the image forming layer has been transferred.

When the laminate is formed, various methods may be used. For example, a vacuum contact method is required from the viewpoint that temperature control such as a heat roller is not required and rapid and uniform contact and lamination can be performed. May be used. in this case,
Although the surface roughness may be reduced for the purpose of enhancing the adhesion as described above, it is impossible to perform high-speed decompression during evacuation. Conversely, if the surface roughness of the bonding surface is increased to perform this evacuation at a high speed, the degree of decompression at the bonding surface between the image receiving layer of the thermal transfer image receiving material and the image forming layer of the thermal transfer material that is in contact with each other improves However, a large number of micro voids may be formed on the contact surface, and heat transfer may be hindered and transferability may be reduced. In order to obtain adhesion suitable for image recording, as the degree of decompression on the bonding surface increases, the shape of the layer surface on the bonding surface changes, and the image receiving layer and the image forming layer adhere completely and uniformly. It is preferable that it is in the state where it was done. Therefore, providing a cushion layer on the thermal transfer material and / or the thermal transfer image receiving material is useful in improving transferability and forming a high-quality image.

In addition to the above-mentioned vacuum adhesion method, as another method for forming a laminate, for example, the transfer side of the thermal transfer material (image forming layer side) and the image receiving side of the thermal transfer image receiving material (image receiving layer side) are overlapped. Also, a method of passing through a pressurizing and heating roller is preferable. The heating temperature in this case is preferably 160 ° C. or less, or 130 ° C. It is also preferable that the thermal transfer image receiving material is mechanically attached to the metal drum while being pulled, and the thermal transfer material is further mechanically attached to the metallic drum while being pulled and adhered. Among them, the vacuum contact method is particularly preferable. The close contact between the thermal transfer material and the thermal transfer image receiving material may be performed immediately before the laser beam irradiation operation.

In the case of the vacuum contact method, the thermal transfer image-receiving material side of the laminate is usually placed on the surface of a recording drum (a rotary drum having a vacuum forming mechanism inside and a large number of minute openings on the drum surface). A thermal transfer material having a size larger than that of the thermal transfer image receiving material is laminated so as to cover the entire thermal transfer image receiving material, and the contact interface is reduced in pressure by vacuum evacuation to adhere. The laser beam irradiating operation is performed by irradiating the laser beam from the outside of the laminate, that is, from above the thermal transfer material side in that state. The laser beam is irradiated so as to reciprocate in the width direction of the drum, and the recording drum is rotated at a constant rotation speed during the irradiation operation.

The laser thermal transfer recording method can be used for producing a black mask or forming a monochromatic image, but can also be advantageously used for forming a multicolor image. As a method of forming a multicolor image, for example, the following embodiments may be used. That is, in the first embodiment of the method for forming a multicolor image,
An image receiving material is fixed on a rotating drum of a recording apparatus by a vacuum decompression method, and a thermal transfer material is similarly applied to the image receiving material by a vacuum decompression method so that the image receiving layer and the image forming layer (hue 1) of the thermal transfer material are in contact with each other. Laminate. Next, a laser beam modulated based on the digital signal of the color separation image of the original image is irradiated from the support side of the thermal transfer material while rotating the drum, and then
The thermal transfer material is separated from the thermal transfer image receiving material while the thermal transfer image receiving material is fixed. The steps of laminating the thermal transfer material of hue 2, hue 3 and, if necessary, hue 4 on the thermal transfer image-receiving material on which the image of hue 1 is recorded by the same method as described above, laser-recording, and peeling are sequentially repeated. Thus, a thermal transfer image receiving material on which a multicolor image is formed can be obtained. In order to obtain a color proof image on the printing paper, the heat transfer image receiving material on which the multicolor image is formed from the above process is laminated so that the image surface thereof is in contact with the printing paper, and then heated and pressed through a laminator or the like, It can be obtained by peeling off this and transferring the image together with the image receiving layer onto the printing paper.

In the second embodiment of the method for forming a multicolor image, a laminate in which thermal transfer materials each having an image forming layer containing a colorant having a different hue are laminated is independently formed into three types (three colors).
Alternatively, four kinds (four colors) are prepared, and for each of them, laser irradiation is performed based on a digital signal of each color image corresponding to each laminate obtained through a color separation filter, and then the thermal transfer material and the thermal transfer image receiving material are irradiated. Peel off. After the color separation images of each color are independently formed on each thermal transfer image receiving material, the respective color separation images are sequentially laminated on an actual support such as printing paper separately prepared or a support similar thereto. Can be formed.

As a laser light source used for the image recording, a gas laser such as an argon ion laser, a helium neon laser, a helium cadmium laser, a solid laser such as a YAG laser beam, a direct laser such as a semiconductor laser, a dye laser, an excimer laser, etc. Light or laser light obtained by converting these lasers to a half wavelength through a second harmonic element can be used. Among them, a multimode semiconductor laser is preferable, and a refractive index guide type lateral multimode semiconductor laser is particularly preferable, from the viewpoint of high output and high-speed image formation. Further, in the laser thermal transfer recording method using the laser thermal transfer material of the present invention,
Laser irradiation is preferably performed under the condition that the beam diameter on the light-to-heat conversion layer is 3 to 50 μm, preferably 7 to 30 μm.

According to the laser thermal transfer recording method, even when a laser is used for image recording, a high-quality image with high image density and high image quality can be formed at a high speed without being affected by the thermal decomposition of the colorant.

[0140]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. still,
“Parts” and “%” in the examples all represent “parts by weight” and “% by weight”.

(Examples 1 to 9) <Preparation of Laser Thermal Transfer Material> A compound having the following composition was placed in a paint shaker (manufactured by Toyo Seiki Seisaku-sho, Ltd.) and dispersed for 3 hours to disperse a pigment having an average particle diameter of 300 nm. Liquid (1) was prepared.

—Preparation of Pigment Dispersion (1) — Compound E shown below: 12.9 parts Esrec BLSH: 7.1 parts (polyvinyl bratyl, manufactured by Sekisui Chemical Co., Ltd.) Solsperse 20000 (Pigment dispersant) 0.6 parts (manufactured by ICI Japan) n-Propyl alcohol 79.4 parts 3 mmφ glass beads (dispersion media)

-Preparation of Pigment Dispersion (2)-In the same manner as in Pigment Dispersion (1) except that Compound A shown below was used instead of Compound E used for preparation of Pigment Dispersion (1) A pigment dispersion (2) was prepared.

-Preparation of Pigment Dispersion (3)-In the same manner as in Pigment Dispersion (1), except that Compound B shown below was used in place of Compound E used for preparation of Pigment Dispersion (1) A pigment dispersion (3) was prepared.

-Preparation of Pigment Dispersion (4)-In the same manner as in Pigment Dispersion (1), except that Compound C shown below was used instead of Compound E used for preparing Pigment Dispersion (1) A pigment dispersion (4) was prepared.

-Preparation of Pigment Dispersion (5)-In the same manner as in Pigment Dispersion (1), except that Compound D shown below was used instead of Compound E used for preparation of Pigment Dispersion (1) A pigment dispersion (5) was prepared.

[0147]

Embedded image

[0148]

Embedded image

-Preparation of Coating Solution for Image Forming Layer- Next, compounds having the following compositions were mixed with a stirrer to prepare coating solutions (1) to (9) for image forming layer. (Composition of coating solution for image forming layer) ・ Pigment dispersion liquid A shown in Table 1 below: 10.6 parts ・ Pigment dispersion liquid B shown in Table 1 below: 0.6 parts ・ Slek BLSH ・0.3 parts (manufactured by Sekisui Chemical Co., Ltd .; polyvinyl bratyl)-KE311 ... 0.2 parts (manufactured by Arakawa Chemical Industries, Ltd .; ultra-light rosin ester)-NAA-222S (Nippon Yushi ( 0.2 parts, Megafac F-176PF 0.1 parts (manufactured by Dainippon Ink and Chemicals, Incorporated; fluorine-based surfactant) MEK 17 .6 parts ・ n-propyl alcohol 70.4 parts

[0150]

[Table 1]

The following compositions were mixed while stirring with a stirrer to prepare a coating solution for a photothermal conversion layer. (Composition of photothermal conversion layer coating solution)-NK-2014 ... 0.5 parts (Near-infrared absorbing dye manufactured by Nippon Kogaku Dye Co., Ltd.)-Ricacoat SN-20 (Polyimide manufactured by Nippon Rika Co., Ltd.) -9.1 parts-Megafac F-176PF ... 0.1 parts (manufactured by Dainippon Ink and Chemicals, Incorporated; fluorine-based surfactant)-n-methyl-2-pyrrolidone ... 41.5 parts・ MEK: 48.8 copies

Nine PET bases each having a thickness of 75 μm were prepared, and the coating liquid for a photothermal conversion layer obtained above was applied to each of the PET bases with an E-type gizer so that the dry layer thickness became 0.3 μm. After coating and drying, nine PET bases provided with a light-to-heat conversion layer were produced. Next, on each of the nine PET-based light-to-heat conversion layers provided with the light-to-heat conversion layers, the obtained coating solutions (1) to (9) for the image forming layer were each dried to a thickness of 0.3 μm. After coating and drying, nine types of laser thermal transfer materials (1) to (9) of the present invention were obtained in which an image forming layer was laminated on the light-to-heat conversion layer.

<Preparation of Thermal Transfer Image-Receiving Material> A coating solution for a cushioning intermediate layer and a coating solution for an image-receiving layer having the following compositions were prepared. (Composition of the coating solution for the cushioning intermediate layer) Solvain CL2: 15.1 parts (Nisshin Chemical Co., Ltd .; vinyl chloride / vinyl acetate copolymer) Paraplex G40: 16.9 parts (Made by CP.HALL.CONPANY) ・ MegaFac F178K ・ ・ ・ 0.5 part (manufactured by Dainippon Ink and Chemicals, Incorporated; fluorinated surfactant) ・ MEK ・ ・ ・ 51.3 parts ・ Toluene ・ ・ ・13.7 parts ・ Dimethylformamide 2.5 parts

(Preparation of Coating Solution for Image Receiving Layer) Eslek BLSH: 7.9 parts (Polyvinyl Bratyl manufactured by Sekisui Chemical Co., Ltd.) Megafaque F176PF: 0.1 part (Dainippon Ink Chemicals) (Manufactured by Kogyo Co., Ltd .; fluorinated surfactant) ・ n-propyl alcohol: 22.8 parts ・ MFG: 20.9 parts ・ Methanol: 48.3 parts

The cushioning intermediate layer coating solution obtained as described above was applied to PE by an extrusion type applicator.
T foam base (trade name: Lumirror E68L, Toray Industries, Inc.)
Co., Ltd.) and dried to form a cushioning intermediate layer. Next, on the formed cushioning intermediate layer, the coating liquid for the image receiving layer was dried to a thickness of 2 μm using an extrusion type applicator.
The resultant was coated and dried to provide an image receiving layer to obtain a thermal transfer image receiving material (1).

<Image Recording> The thermal transfer image-receiving material (1) (25 cm) obtained above was placed on a rotating drum having a diameter of 25 cm, in which a vacuum suction hole having a diameter of 1 mm (one area density in an area of 3 cm × 3 cm) was formed. × 35 cm) was wound around and adsorbed. Next, a laser thermal transfer material (1) of 30 cm × 40 cm is laminated so as to protrude from the thermal transfer image-receiving material (1) evenly and covered, and is squeezed by a squeeze roller while being closely attached so that air is sucked into suction holes. A laminate was formed. The degree of pressure reduction when the suction hole is closed is -150 mmH with respect to 1 atm.
g. The drum is rotated, and a semiconductor laser light (laser thermal transfer material) having a wavelength of 830 nm is applied from the support side of the laser thermal transfer material (1) using TC-P1080 (manufactured by Dainippon Screen Mfg. Co., Ltd.) on the surface of the laminate on the drum. Irradiation energy on the surface of the support 300 mJ / c
m ² ) was applied to the surface of the light-to-heat conversion layer so as to be condensed, and recording was performed imagewise while moving in the direction (sub-scanning direction) perpendicular to the rotating direction (main scanning direction) of the rotating drum.

As described above, the laminate on which the laser image recording was performed was removed from the drum, and the laser thermal transfer material (1) of the present invention and the thermal transfer image receiving material were peeled off.
It was confirmed that the image forming layer of the laser irradiated portion was transferred to the thermal transfer image-receiving material (1), and that a good image was formed. Further, with respect to the laser thermal transfer materials (2) to (9), images were recorded in the same manner using the thermal transfer image receiving material (1).

<Evaluation of Transferability> For the laser thermal transfer materials (1) to (9) before laser irradiation, the optical reflection density r of each image forming layer was measured with a Macbeth reflection densitometer (blue filter). Further, the optical reflection density R of the image formed on the thermal transfer image-receiving material (1) after thermal transfer and peeling as described above was measured in the same manner as above. From the obtained r and R, the transfer rate by laser thermal transfer [(R / r)
× 100] were obtained, and used as indices indicating transfer performance. The results obtained are shown in Table 3 below.

<Evaluation of Image Hue> The hue of the obtained image was evaluated using a Japan Color Standard color sample (Ver.
The hue of 2) was visually observed and compared, and the hue difference was sensory evaluated according to the following criteria. The evaluation results are shown in Table 3 below.
Shown in -Criterion- A: The hue of the formed image was almost the same as the standard color sample. Fair: Although the hue of the formed image was slightly different from the standard color sample, it was a practically good hue. X: The hue of the formed image was significantly different from the standard color sample.

Comparative Example 1 Preparation of Pigment Dispersion (6) The above pigment was prepared in the same manner as in Example 1 except that the following compound F was used in place of compound E used for preparing pigment dispersion (1). Pigment dispersion liquid (6) was prepared in the same manner as dispersion liquid (1). Using the obtained pigment dispersion (6), a pigment dispersion A and a pigment dispersion B were prepared as shown in Table 2 below. In the same manner as in Example 1 and the like, except that the pigment dispersions A and B shown in Table 1 were replaced with the pigment dispersions A and B shown in Table 2, the coating liquid for an image forming layer (10) was used. Was prepared.

Coating Solution for Image Forming Layer Used in Examples (1)
Instead of the above, the coating liquid for an image forming layer obtained from the above (10)
A laser thermal transfer material (10) was obtained in the same manner as in the example, except that was used.

[0162]

Embedded image

[0163]

[Table 2]

Using the thermal transfer image-receiving material (1) produced in Examples 1 to 9, laser irradiation was performed in the same manner as in Examples 1 to 9 to record the image in an image-like manner.
An image was formed thereon. The transferability and the image hue were evaluated in the same manner as in Examples 1 to 9, and the results are shown in Table 3 below.

[0165]

[Table 3]

From the results shown in Table 3 above, pigments or compounds A to D having an isoindolinone ring in the structure were used as colorants.
In the laser thermal transfer materials (1) to (5) of the present invention containing any one of the above pigments, the thermal decomposition of the pigment is small, the transferability during thermal transfer is excellent, the image density is high, and an image having a good hue can be obtained. Was completed. Further, in the laser thermal transfer materials (6) to (9) of the present invention in which the pigment having the isoindolinone ring and a compound selected from the above compounds A to D are used in combination, the thermal decomposition of the pigment is small and the thermal transfer It was possible to obtain a clear image having excellent transferability and high density and having a better hue at the same time. On the other hand, in the case of the laser thermal transfer material (10) in which the pigment having an isoindolinone ring and the pigments of the compounds A to D were not used, the amount of thermal decomposition of the pigment during thermal transfer was large, and a sufficient transfer rate could not be obtained. Was. Therefore, the formed image has a large decrease in image density, and image defects due to transfer unevenness have occurred, and a high-quality image cannot be obtained.

[0167]

According to the present invention, there is provided a laser thermal transfer material capable of forming a high-quality image with good hue without a decrease in density due to thermal decomposition of a pigment even when a laser beam is used for image recording by thermal transfer. Can be provided.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tamotsu Suzuki 200 F. Onakazato, Fujinomiya-shi, Shizuoka Fuji Photo Film Co., Ltd. F-term (reference) 2H111 AA26 AA35 BA03 BA38 BA74 4J038 EA011 JB16 JB27 JB32 JB33 NA18 PB11

Claims (7)

[Claims] 1. A laser thermal transfer material having at least a light-to-heat conversion layer and an image forming layer on a support, wherein the image forming layer contains a compound containing an isoindolinone ring represented by the following general formula (1). A laser thermal transfer material characterized by containing. Embedded image [Wherein, R _h is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a halogen atom, a carboxylic acid ester group having an alkyl group having 1 to 5 carbon atoms,
Or an amide group having an alkyl group having 1 to 5 carbon atoms. u represents an integer of 1 to 4. When u is 2 or more, R
_h may be the same or different. ] 2. A laser thermal transfer material having at least a light-to-heat conversion layer and an image forming layer on a support, wherein the image forming layer has a disazo having a benzimidazolone ring represented by the following general formula (2). A laser thermal transfer material characterized by containing a system compound. Embedded image [Wherein, R ¹ and R ² each independently represent an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms,
R ⁵ and R ⁶ each independently represent a benzimidazolone ring group represented by the following structural formula (a). The aromatic groups containing R _i or R _j are linked to each other by a divalent linking group X, and R _i , R _j
Each independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a halogen atom. p and q each independently represent an integer of 1 to 4.
When p and q are 2 or more, R _i and R _j may be the same or different. [Chemical formula 3] 3. A laser thermal transfer material having at least a light-to-heat conversion layer and an image forming layer on a support, wherein the image forming layer contains a quinophthalone compound represented by the following general formula (3). Characteristic laser thermal transfer material. Embedded image [In the formula, R _k represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. r represents an integer of 1 or 2. When r is 2, R _k may be the same or different. R ₁ represents a tetrachlorophthalimidoyl group represented by the following structural formula (b). [Chemical formula 5] 4. A laser thermal transfer material having at least a light-to-heat conversion layer and an image forming layer on a support, wherein the image forming layer has a benzimidazolone ring represented by the following general formula (4): A laser thermal transfer material characterized by containing a system compound. Embedded image [In the formula, R _m represents an alkoxycarbonyl group having 2 to 5 carbon atoms, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. s represents an integer of 1 to 5. When s is 2 or more, R _m may be the same or different. ] 5. A laser thermal transfer material having at least a photothermal conversion layer and an image forming layer on a support, wherein the image forming layer contains a condensed azo compound represented by the following general formula (5). A laser thermal transfer material characterized by the following. Embedded image [In the formula, Ar represents an arylene group. R _n represents a hydrogen atom, an alkoxycarbonyl group having 2 to 5 carbon atoms,
Represents an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms. t represents an integer of 1 to 5. R _x represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms. y represents an integer of 1 to 4. t or y is 2
In the above case, R _n or R _x may be the same or different. ] 6. A laser thermal transfer material having at least a light-to-heat conversion layer and an image forming layer on a support, wherein the image forming layer comprises a compound containing an isoindolinone ring represented by the following general formula (1): And at least one compound selected from the following general formulas (2) to (5): Embedded image [Wherein, R _h is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a halogen atom, a carboxylic acid ester group having an alkyl group having 1 to 5 carbon atoms,
Or an amide group having an alkyl group having 1 to 5 carbon atoms. u represents an integer of 1 to 4. When u is 2 or more, R
_h may be the same or different. Embedded image [Wherein, R ¹ and R ² each independently represent an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms,
R ⁵ and R ⁶ each independently represent a benzimidazolone ring group represented by the following structural formula (a). The aromatic groups containing R _i or R _j are linked to each other by a divalent linking group X, and R _i , R _j
Each independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a halogen atom. p and q each independently represent an integer of 1 to 4.
When p and q are 2 or more, R _i and R _j may be the same or different. ] Embedded image [In the formula, R _k represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. r represents an integer of 1 or 2. When r is 2, R _k may be the same or different. R ₁ represents a tetrachlorophthalimidoyl group represented by the following structural formula (b). Embedded image Embedded image [In the formula, R _m represents an alkoxycarbonyl group having 2 to 5 carbon atoms, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. s represents an integer of 1 to 5. When s is 2 or more, R _m may be the same or different. [Formula 14] [In the formula, Ar represents an arylene group. R _n represents a hydrogen atom, an alkoxycarbonyl group having 2 to 5 carbon atoms,
Represents an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms. t represents an integer of 1 to 5. R _x represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms. y represents an integer of 1 to 4. When t or 2 is 2 or more, R _n or R _x may be the same or different. ] 7. The content of the compound containing an isoindolinone ring represented by the general formula (1) (X) in the image forming layer and the compound represented by the general formulas (2) to (5) The laser thermal transfer material according to claim 6, wherein the weight ratio (X: Y) to the total content (Y) of the at least one compound selected is 1:99 to 30:70.