JP2740821B2 - Recording method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel recording method,
Specifically, on the surface of the recording medium whose surface shows specific properties,
Selectively or selectively and reversibly, heating so that the size or temperature of the heating area on the surface of the recording medium changes according to the image information signal, and if necessary, a developing material is applied to this area (latent image). Supplying the recording agent solution or dispersion containing to visualize,
Further, the present invention relates to a recording method in which this is transferred onto plain paper or the like.

[0002]

2. Description of the Related Art An offset printing method using a lithographic printing plate is a typical example of a means for dividing a surface into a liquid-adhesive area and a non-liquid-adhesive area for image formation. However, with this offset printing method, it is difficult to incorporate the plate making process from the original plate and the printing process from the printing plate (printing plate) into one device, and it is difficult to reduce the size of the plate making and printing device. ing. For example, even in a relatively small office offset plate making press, the plate making device and the printing device are usually separate.

In order to eliminate such a defect of the offset printing method, a liquid-adhesive area and a non-liquid-adhesive area corresponding to image information can be formed, and can be used repeatedly (reversible). Recording methods and apparatuses have been proposed. Some of them are as follows. (1) Aqueous development method After applying a charge from the outside to the hydrophobic photoconductor layer, exposure is performed to form a pattern having a hydrophobic part and a hydrophilic part on the surface of the photoconductor layer, and only the hydrophilic part is formed. Transfer to a paper etc. by attaching aqueous developer (Japanese Patent Publication No. 40-18992)
No., JP-B-40-18993, JP-B-44-9512, JP-A-63-26
Publications such as 4392). (2) A method utilizing photochemical reaction of photochromic material A layer containing materials such as spiropyran and azo dye is irradiated with ultraviolet rays, and these photochromic compounds are hydrophilized by the photochemical reaction (for example, “Polymer Papers” No. 37). Volume 4
Issue, p. 287 (1980)]. (3) An amorphous state and a crystalline state utilizing the action of an internal bias force are formed by a physical change to form a liquid ink adhesion / non-adhesion region (Japanese Patent Publication No. 54-41902).

According to the method (1), after the aqueous ink is transferred onto paper or the like, the hydrophilic portion is erased by static elimination, and another image information can be recorded. That is, it is possible to repeatedly use one master (photoconductor). However, since this method is based on the electrophotographic process, charging → exposure →
It requires a long process of development → transfer → discharge, and has drawbacks in that it is difficult to reduce the size and cost of the apparatus and to make maintenance free. According to the method (2), hydrophilicity and hydrophobicity can be freely and reversibly controlled by selectively changing the irradiation of ultraviolet light and visible light, but the reaction time is extremely long due to poor quantum efficiency. However, the recording speed is slow and the stability is lacking, so that it has not yet reached the practical level. Further, according to the method (3), although the information recording member used there is stable after recording,
Before recording, there is a possibility that a physical structure change may occur due to a temperature change, so that there is a problem in storage stability.
In addition, since a means for applying a heat pulse and then quenching to erase the recorded information pattern is employed, there is an inconvenience that repetitive image formation cannot mimic the complexity.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a recording medium (A) having a surface having a reduced receding contact angle when heated and brought into contact with a contact material (B). Another object of the present invention is to provide a recording method capable of forming a desired pattern area (latent image) with good gradation selectively or easily and selectively and reversibly by easy means. Another object of the present invention is to provide a visible image having good gradation from the beginning by supplying a recording agent solution or a dispersion liquid (for example, an ink liquid) containing a color developing material to the pattern area. May be fixed to the surface of the recording medium (A) as it is, or a visible image is transferred to plain paper or the like without being fixed, and a clear image with gradation is obtained. Is provided. Still another object of the present invention is to provide a recording medium (A) having excellent preservability and stability in all steps of forming, erasing, developing (developing), and transferring a desired pattern area having gradation. The present invention provides a novel recording method in which the above steps can be performed reversibly a plurality of times.

[0006]

According to a first recording method of the present invention, a recording medium (A) is contacted with the following recording medium (A) and the following contact material (B) in accordance with an image information signal. By heating so that the size of the heating area on the surface changes, or so that the size of the heating area on the surface of the recording medium (A) changes in accordance with the image information signal on the surface of the recording medium (A). By contacting the contact material (B) in a heated state, a region showing a receding contact angle lower than the non-heated region is formed on the surface of the recording medium (A) according to the size of the heated region. I have.
(A) A recording medium having a surface in which the receding contact angle is reduced when heated and brought into contact with a liquid. (B) Liquid, vapor, or solid that becomes liquid or generates liquid or vapor at a temperature equal to or lower than the temperature at which the receding contact angle of the recording medium (A) starts to decrease.

A second recording method according to the present invention is directed to a method for producing an image information signal in a state where the surface of the recording medium (A) according to the first invention is brought into contact with a recording agent solution or dispersion containing a color developing material. By heating so that the size of the heating area on the surface of the recording medium (A) changes accordingly, or by heating the surface of the recording medium (A) on the surface of the recording medium (A) according to an image information signal. A visible image corresponding to the size of the heated area is formed on the surface of the recording medium (A) by bringing the recording medium (A) into contact with a recording agent solution or dispersion containing a color developer while being heated so that the size changes. It is characterized by.

The third recording method according to the present invention is directed to the recording medium (A) according to an image information signal in a state where the surface of the recording medium (A) and the contact material (B) are in contact with each other. By heating so that the temperature of the heating area on the surface changes, or heating the surface of the recording body (A) so that the temperature of the heating area on the surface of the recording body (A) changes according to the image information signal. By contacting the contact material (B) in this state, a region having a receding contact angle lower than that of the non-heated region is formed on the surface of the recording material (A) in accordance with the temperature of the heated region.

A fourth recording method according to the present invention is directed to a method for producing an image information signal in a state where the surface of the recording medium (A) according to the first invention is brought into contact with a recording agent solution or dispersion containing a color developing material. By heating so that the temperature of the heating area on the surface of the recording medium (A) changes according to the temperature of the heating area on the surface of the recording medium (A) according to the image information signal or by heating the surface of the recording medium (A). By contacting with a recording agent solution or dispersion containing a color developer in a heated state so as to change, a visible image corresponding to the heating area temperature is formed on the surface of the recording medium (A). .

In the method of the present invention, as in the second and fourth aspects of the present invention, if the recording material solution or dispersion liquid is used, for example, a liquid ink, the supply of the contact material (B) Means can be omitted, and if a material such as liquid ink is used as the contact material (B), the image is visualized at the same time as the formation of the latent image, so that the recording material applying means can be omitted. In the method of the present invention, the latent image can be erased by heating the surface of the recording medium (A) on which the latent image is formed in the absence of the contact material (B), so that the image is formed reversibly. Can be done.

The inventor of the present invention has conducted many researches and studies on a new recording method by eliminating the defects as described in the above-mentioned prior art. As a result, the receding contact angle becomes low even after cooling when the heating area is heated so that the size or the temperature of the heating area changes in accordance with the image information signal in contact with the liquid, and in the absence of the liquid. It has been found that a member having a function of increasing the receding contact angle by heating on the surface is useful as a recording medium. The recording medium (A) having such a function has a surface (1) a member containing an organic compound having a surface self-orientation function of a hydrophobic group, or (2) an organic compound having a hydrophobic group and having a hydrophobic group. It was also confirmed that the member was oriented on the surface.

The "surface self-orientation function" referred to in (1) means that when a solid formed by forming a certain compound on a support or a solid formed by a certain compound itself is heated in the air, the hydrophobic group on the surface is changed to the air side (freely). (Surface side). This can be similarly applied to (2). Generally, in an organic compound, a hydrophobic group has a property of easily moving toward a hydrophobic atmosphere. This is a phenomenon that occurs because the surface energy of the solid-gas interface decreases. This phenomenon is more likely to occur as the molecular length of the hydrophobic group becomes longer, because the longer the molecular length, the higher the mobility of the molecules during heating.

More specifically, it has a hydrophobic group at a terminal.
Molecules (that lower surface energy)
(Free surface side) and easy surface orientation. Similarly, (−CH ₂
-) The linear molecule containing n (-CH ₂ CH ₂ - and form a partial plane structure), each other molecular chain is easily oriented. In addition, the molecule containing (-Ph-) n also has a planar structure in the -Ph- portion, and the molecular chains are easily oriented. Note that -Ph
-Is a p-phenylene group (the same applies hereinafter). In particular, a linear molecule containing an element having a high electronegativity such as fluorine has a high self-aggregation property and the molecular chains are easily oriented.

Summarizing the results of these studies, it is more preferable that a linear molecule containing a molecule having a high self-aggregating property or a molecule having a planar structure and having a hydrophobic group at a terminal, or such a linear molecule A compound containing a dendritic molecule can be said to be a compound having a high surface self-orientation function.

As is clear from the above description, the surface self-alignment state is related to the receding contact angle, and also between the receding contact angle and the liquid adhesion. That is, the adhesion of the liquid on the solid surface occurs mainly by tacking of the liquid on the solid surface. This tacking can be considered as a kind of frictional force when a liquid slides on a solid surface. Therefore, the “receding contact angle” θr in the present invention is given by cosθr = γ (γs−γse−πe + γf) / γev (where γ: surface tension of solid in vacuum γse: solid-liquid interfacial tension γev liquid Πe: Equilibrium surface tension γf: Friction tension γs: Surface tension of a solid without an adsorbed layer) (Saito, Kitazaki et al., Journal of the Adhesion Society of Japan) Vol.22,
No. 12, 1986).

Accordingly, the value of γf increases when the value of θr decreases. That is, the liquid is less likely to slide on the solid surface, and as a result, the liquid adheres to the solid surface. As can be inferred from these mutual relations, the liquid adhesion depends on the receding contact angle θr, and the receding contact angle θr is determined by any member having a surface self-orienting function on the surface. Therefore, in the method of the present invention,
In the case of (A), a member having a surface self-orienting function on the surface must be selected because of the necessity of forming a desired pattern area on the surface and / or visualizing with a recording agent.

As described above, the recording medium (A) used in the method of the present invention has a "surface where the receding contact angle θr decreases when it is in a heated state and comes into contact with a liquid". The shape of the recording medium (A) is arbitrary as long as the surface has the above-mentioned properties. Therefore, even if the recording medium (A) is in the form of a belt (including an endless belt), another surface having the above-mentioned properties on a suitable support (including a cylindrical support) or a molded body is required. A coating film or the like may be provided. The molded body itself may be used, but its surface is required to have the above-described properties except for the whole or a part thereof.

In the recording medium (A), depending on the type of the contact material (B), the liquid-adhering portion in the latent image area becomes either lipophilic or hydrophilic. Any of ink, water-based ink, liquid developer for electrophotography and the like are used as needed.

Here, FIG. 1 shows an example in which members or materials that "form a surface where the receding contact angle θr decreases when heated and brought into contact with a liquid" are classified into several members.

FIG. 1 (a) shows an example of a compound having a self-orienting function, which is a compound having a hydrophobic group on a side chain of a high molecular polymer, and a main chain L and a hydrophobic group R are bonded by a bonding group J. doing.

FIG. 1 (b) shows an example of a member in which an organic compound having a hydrophobic group has the hydrophobic group oriented on the surface. The member is attached to the surface of the organic or inorganic material M by physical or chemical bonding.
A member on which the compound O having a hydrophobic group is formed.

FIG. 1 (c) shows an example of a member made of only the organic compound O having a hydrophobic group shown in FIG. 1 (b).

FIG. 1 (d) shows an example in which a linear molecule is present in a side chain of a polymer, and the main chain L and the molecule are connected by a bonding group J.
This is a compound in which a molecular chain N having a self-aggregating or planar structure having a hydrophobic group R at the terminal is in the middle.

In the examples shown in FIGS. 1 (a) and 1 (d), the main chain L of the polymer compound may have a linear shape or a mesh structure.
In the example of FIG. 1B, the hydrophobic group-containing compound O may be further laminated on the hydrophobic group-containing compound O like a cumulative LB film. In the example of FIG. 1 (c), without having a main chain (L) or binding to an organic / inorganic material (M), etc.
This is a structure using only the hydrophobic group-containing compound O.

As the hydrophobic group, the terminal of the molecule is preferably -CH ₃ , -CF ₃ , -CF ₂ H, -CFH ₂ , -C (CF ₃ ) ₃ , -C (CH ₃ ) ₃
It is more preferable that the molecular length is long in terms of high molecular mobility. Among them, as the hydrophobic group, -F and / or -Cl is (may be as _{-CF 2 CF 2 C (Cl)} FCF 2 CF 2) 1 or more is a substituted alkyl group or unsubstituted alkyl group And those having 4 or more carbon atoms are desirable. Both fluorine substitution and chlorine substitution are used, but fluorine substitution is more effective. In these materials, the relationship between the number of carbon atoms in the alkyl group and the function is as follows:
If the number of carbon atoms is 3 or less, the function suitable for the recording method of the present invention will be reduced.

Although the principle of this function expression has not yet been completely elucidated, and thus there are many unclear points, the following is presumed.

First, a recording medium formed by the above compound
It is considered that the surface of (A) is a surface in which the hydrophobic groups are considerably oriented. Therefore, this surface has liquid repellency (because hydrophobic groups have low surface energy). In this state, when the surface of the recording medium (A) comes into contact with the contact material (B) and is heated, the molecular motion of the hydrophobic group due to the heating becomes active, and the interaction with the contact material (B) occurs. , Recording body
It is likely that at least part of the orientation (alignment) state of the surface of (A) changes to another state (i.e., another orientation state or a state in which the orientation is disordered), and to maintain that other state even after cooling. .
In addition, heating under the condition that the contact material (B) is in contact with the surface of the recording material (A) depends on the form of the contact material (B), depending on the form of the contact material (B). The liquid comes into contact under the pressure. Before this heating, the surface energy of the surface of the recording medium (A) is extremely small because the hydrophobic groups are aligned (oriented) on the surface.

However, the heating in the state where the contact material (B) is in contact with the contact material disturbs the orientation state and increases the surface energy. The receding contact angle θr is determined by the balance between the surface energies of the solid and the liquid, regardless of the type of the liquid. Therefore, if the surface energy of the solid increases,
Regardless of the type of liquid, the receding contact angle θr decreases.
Therefore, the adhesion to the liquid will increase. Further, when the surface of the recording medium (A) is in a different state (another alignment state different from the original alignment state or an alignment disorder state), the contact material
When heated in the absence of (B), interaction with the contact material (B) does not occur, so that it is likely to return to the original alignment (orientation) state. Therefore, the presence of the contact material (B) is merely a record (A)
This is not for quenching after heating the surface, but for any interaction with the compound on the surface of the recording medium (A).
(A different alignment state or a state in which the alignment is disturbed).

As described above, when an alkyl group or a fluorine-substituted or chlorine-substituted alkyl group is used as the hydrophobic group of the member (compound) forming the surface of the recording medium (A), the carbon number of the alkyl group is It is considered that the reason why the number is preferably 4 or more is based on the number necessary for the alkyl groups to be aligned (orientated) to some extent on the surface of the recording medium (A) and to perform active molecular motion during heating. When the contact material (B) is heated together with the surface of the recording medium (A), the molecules of the contact material (B) may be incorporated into the molecules on the surface of the recording medium (A). Furthermore, if fluorine or chlorine having a high electronegativity is present in the alkyl group, the interaction with a liquid, particularly a polar liquid, becomes large, so that a greater change in adhesion can be obtained than with a compound containing an alkyl group containing only hydrogen. In addition, an alkyl group containing fluorine has a strong self-aggregating property, has a high surface self-orientation function, and has a low surface energy, and thus is excellent in preventing background contamination.

Furthermore, the surface of the recording medium (A) has a liquid repellency, which can be described by the surface energy of a solid. According to the study of the present inventors, the recording medium (A) has a recording energy of 50 dyn / cm or less. We have confirmed that it is desirable as a method.
If the value is higher than this, the surface of the recording medium (A) sometimes gets wet with respect to the recording agent, possibly causing soiling of the background.

Here, the compound forming the surface of the recording medium (A) (contact material is selectively heated while the surface of the recording medium (A) is selectively heated).
The details of the compound that forms a latent image area having a receding contact angle according to the heating temperature on the surface of the recording medium (A) when contacted with (B) will be described. First, for the types shown in FIGS. 1A and 1D, compounds having an alkyl group (including those substituted with fluorine and / or chlorine) on the side chain of the vinyl polymer can be considered. Specifically, formulas (I), (II), (III), (IV), (V), (VI) and (VI)
I) R: -H, -CH ₃ , -C ₂ H ₅ , -CF ₃ or -C ₂ F ₅ Rf: a group containing a C ₄ or more alkyl group or a fluorine-substituted or chlorine-substituted alkyl group, or in the molecular chain And a polymer having an integer of 1 or more as a hydrophobic group (P ≧ 4) having (—CF ₂ —) p, (—CH ₂ —) p or —Ph—.

Other polymers include compounds of the formulas (VIII) and (IX)
And (X). R: —H, —CH ₃ , —C ₂ H ₅ , —CF _3, or —C ₂ F ₅ Rf: a group containing a C ₄ or more alkyl group or a fluorine-substituted or chlorine-substituted alkyl group, or in the molecular chain (-CF _2- ) p, (-CH _2- ) p
Or a hydrophobic group containing -Ph- (P ≧ 4) n: an integer of 10 or more

Rf in these specific examples is described in more detail below.
Examples of (1) to (20) can be given.

Among these compounds, the following (X
It is desirable to use the material of I). (However, R ¹ : hydrogen, -CxHy or -CxFy (x = 1 or an integer of 2 or more, y = 2x + 1.) R ² : (-CH _2- ) p (p ≧ 1 integer) or ( -CH
_2- ) qN (R ³ ) SO _2- (R ³ is -CH ₃ or -C ₂ H ₅ , q ≧ 1 is an integer) m: an integer of 6 or more. ]

Representative examples of the compound represented by the formula (XI) include the following compounds.

Further, these formulas (I) (II) (III (IV) (V) (V
(I) In addition to the monomers of (VII) and (XI) (copolymer of two or more monomers), other monomers such as ethylene, vinyl chloride, styrene, butadiene, isoprene, chloroprene, vinyl alkyl ether, and vinyl acetate And a copolymer with vinyl alcohol and the like are also suitable as the above compound.

Further, it has a monomer of the formula (XI) and a functional group.
Polymerizable monomers such as CH_Two= C (CH_Three) COO (CH_Two)_TwoOH CH_Two= C (CH_Three) COOCH_TwoCH (OH) CH_Three  CH_Two= CHCOOCH_TwoCH (OH) C₈F₁₇  To form a copolymer with at least one of
Or have a monomer and a functional group of formula (XI)
A copolymer with a polymerizable monomer is made, followed by a functional group.
Crosslinking of Copolymers Containing a Large Number of Using a Crosslinking Reagent
The cross-linkable polymer produced by
Have been.

Examples of the crosslinking reagent include formaldehyde, dialdehyde, N-methylol compound, dicarboxylic acid, dicarboxylic acid chloride, bishalogen compound, bisepoxide, bisaziridine, diisocyanate and the like.

An example of the crosslinked polymer thus obtained is shown below.

Embedded image

In the crosslinked polymer represented by the chemical formula 1, A
The block is an alkyl group that causes the above-mentioned change in thermal properties, while the B block is a site that cross-links linear polymers (cross-linked using diisocyanate as a cross-linking reagent). To obtain a crosslinked membrane,
What is necessary is just to apply a solution obtained by mixing the above-mentioned copolymer and the crosslinking reagent on a substrate as a coating solution, and to obtain a crosslinked polymer film by heating or irradiation with electron beam or light.

In order to obtain a polymer from the above monomers, solution polymerization, electrolytic polymerization, emulsion polymerization, photopolymerization, radiation polymerization, plasma polymerization, graft polymerization, plasma-initiated polymerization,
An appropriate method is selected depending on the material, such as vapor deposition polymerization.

Next, the compound shown in FIG. 1B will be described. Here, the formulas (XII), (XII) and (X
Material shown in IV) Rf-COOH ··· (XII ) Rf-OH ··· (XIII) Rf- (CH 2) n-Si X 1 X 2 X 3 ··· (XIV) (Rf: 4 carbons or more alkyl groups or a fluorine-substituted or chlorine-substituted alkyl group group containing or, in the molecular chain _{(-CF 2 -) p, (} - CH 2 -) p or -Ph-
N: an integer of 1 or more X ₁ , X ₂ , X ₃ : chlorine, methoxy group, ethoxy group or
A material obtained by physically adsorbing or chemically bonding an alkyl group) or the like to the surface of an inorganic material such as glass, gold, or copper, or an organic material such as polyimide, polyester, or polyethylene terephthalate (preferably having a surface energy of about 50 dyn / cm or less). Desirably.

[0043] Formula (XII) (XIII) and Specific examples of _{(XIV) CF 3 - (CF} 2) 5 -COOH, CF 3 - (CF 2) 7 -COOH, CF 3 - (CF 2) 7 - _{(CH 2) 2 OH, H-} (CF 2) 10 -COOH, H- (CF 2) 10 -CH 2 OH, F- (CF 2) 6 -CH 2 CH 2 -Si (CH 3) 2 Cl, CF ₂ Cl (CF ₃ ) CF (CF ₂ ) ₅ COOH, CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ SiCl _{3 and the} like.

The compound shown in FIG. 1 (c) is represented by the formula (XII),
Examples of the structure include only the material of the formula (XIII) or the formula (XIV).

Next, the recording medium (A) using the above compound will be described. As mentioned above, the configuration of the recording body (A) is formed by the surface member itself,
The above-mentioned surface members are formed on a support (preferably a heat-resistant support). Is an embodiment of the above compound
The (surface member) itself is formed into a film shape, a plate shape, or a column shape. At this time, in the case of a film, the thickness of the film is desirably 1 μm to 5 mm.
In the embodiment, the compound may penetrate into the support to some extent. The thickness of the recording medium (A) itself is 30
Å ~ 1mm is desirable. However, in terms of thermal conductivity, 100Å
10 μm and 10 μm to 1 mm are excellent in terms of wear resistance. The heat-resistant temperature of the support is desirably 50 ° C to 300 ° C.

The shape of the support may be any of a belt shape (including an endless belt shape), a plate shape, and a drum shape.
Select according to the intended use of the equipment. In particular, the drum-shaped one is excellent in that the dimensional accuracy in the device can be obtained.
An endless belt is advantageous for miniaturization of the apparatus. The size of the plate may be determined according to the size of the recording paper.

Further, when a mixture of the above compound (the material for forming the surface of the recording medium (A)) and another member, for example, a hydrophobic polymer or a hydrophobic inorganic material, is formed on a support, it is possible to prevent background smearing in printing. Is excellent. Further, in order to increase the thermal conductivity, it is preferable to mix a metal powder with the above compound. Further, a primer layer can be provided between the support and the compound in order to improve the adhesion between the support and the compound. As the heat-resistant support, resin films such as polyimide and polyester, glass, Ni, Al, Cu, Cr, P
Metals such as t and metal oxides are preferred. These supports may be smooth, rough or porous. The coating film of the above compound (the material for forming the surface of the recording medium (A)) is 0.01 to
It is 100 μm, preferably 1 to 10 μm.

Next, the contact material (B) will be described. The contact material (B) is as described above, but in short, it is a liquid or a vapor from the beginning, or the result is below the temperature at which the receding contact angle θr of the recording medium (A) starts to decrease. It is a solid that gives rise to a liquid. The vapor here is at least partially condensed on or near the surface of the recording medium (A) to generate a liquid, and the liquid can wet the surface of the recording medium (A). Is enough. On the other hand, the solid here becomes a liquid, generates a liquid, or generates a vapor below the temperature at which the receding contact angle θr starts decreasing. The vapor generated from the solid is a recording medium
Condensation at or near the surface of (A) to produce a liquid is the same as in the above case.

More specifically, the contact material (B) is as follows.

That is, as the liquid which is one of the contact materials (B), in addition to water, an aqueous solution containing an electrolyte, ethanol, n-
Polar liquids such as alcohols such as butanol, polyhydric alcohols such as glycerin and ethylene glycol, ketones such as methyl ethyl ketone, and linear hydrocarbons such as n-nonane and n-octane, and cyclic hydrocarbons such as cyclohexane And non-polar liquids such as aromatic hydrocarbons such as m-xylene and benzene. Further, a mixture of these may be used, and various dispersion liquids and liquid inks may be used. More desirably, polar liquids are better.

As the vapor which is another one of the contact material (B), in addition to water vapor, any liquid vapor of the contact material (B) can be used. In particular, organic vapor such as ethanol vapor and m-xylene vapor can be used. Compound vapors (including those in the nebulized state) are mentioned. The temperature of the organic compound vapor must be lower than the melting point or softening point of the compound forming the surface of the recording medium (A).

Examples of the solid which is another contact material (B) include higher fatty acids, low molecular weight polyethylene, polymer gel (polyacrylamide gel, polyvinyl alcohol gel), silica gel, and compounds containing water of crystallization. can give.

As will be clear from the description below, when a recording agent (solution or dispersion) containing a “color developer” such as the liquid ink is used as the contact material (B), The visualization is performed simultaneously with the formation of the latent image, which is extremely advantageous in practical use.

Next, the heating means will be described.

As a heating means for forming a latent image, in addition to contact heating using a heater, a thermal head, or the like,
There is non-contact heating by (light from a light source such as a laser light source or an infrared lamp is condensed by a lens). However,
The most reliable heating means is a thermal head having a heating element.

FIG. 2A shows that a film 2 of the above-mentioned compound constituting the surface of the recording medium (A) is formed on a substrate 1, and a liquid 3 of the contact material (B) is present on the film surface. It shows the state where it is. In this state, when the film 2 is heated, it is recognized that the receding contact angle θr of the surface of the film 2 is reduced and the film 2 shows remarkable wetting, so that the film 2 has liquid adhesion. Further, when the film 2 having the liquid adhesion property is heated again in air, in a vacuum or in an inert gas atmosphere (FIG. 2B), the surface of the film 2 has a receding contact angle θr.
And the liquid repellency is again observed.

The method described in Japanese Patent Publication No. 54-41902 mentioned above shows a phenomenon somewhat similar to such a phenomenon. However, in the method disclosed herein, the recording material differs mechanistically in that it provides a layer of substantially disordered and generally amorphous memory material. That is, in the method of the present invention, a state change cannot occur on the surface of the recording medium (A) without the presence of the contact material (B). Also, Japanese Patent Publication No. 54-41902
According to the method described in Japanese Patent Application Laid-Open Publication No. H06-115, reversibility cannot be obtained by a simple operation.

As shown in FIG. 3A, heat is applied to the film 2 under the contact of the liquid 3 according to the image information signal ((b-1) and (b-
The same applies to the case where the film 2 in the absence of liquid is brought into contact with the liquid 3 in a state where heat is applied to the film 2 in accordance with the image information signal as in 2)) Are made liquid adherent. In the figure, 4 is a heater, 31 is a liquid supply port, 41 is an infrared lamp, 5 is a lens, and 6 is a shutter. FIG. 3 (a) shows an example in which the film 2 is heated through the substrate 1, while the examples shown in FIGS. 3 (b-1) and (b-2) show an example in which the film 2 is directly heated. It is.

FIG. 4 shows an example of the change of the contact angle of the aqueous solution before and after the heating of the film 2 under the contact with the aqueous solution, and the change of the contact angle of the aqueous solution when the film 2 is further heated in the air. In FIG. 4, ○ indicates a forward contact angle, and △ indicates a receding contact angle. In general, when the receding contact angle is a high value of 90 ° or more, the surface shows liquid repellency, and when the receding contact angle is a low value of 90 ° or less, the surface shows liquid adhesion.

The heating temperature of the surface of the recording medium (A) in contact with the contact material (B) is preferably in the range of 50 ° C. to 250 ° C., more preferably 80 ° C. to 150 ° C. The heating time is
It is about 0.1 ms to 1 second, preferably 0.5 ms to 2 ms. As for the heating timing, after the surface of the recording medium (A) is heated, it is brought into contact with the contact material (B) before cooling, and the recording material (A) is brought into contact with the contact material (B) on the surface thereof. Or heating the surface of the recording medium (A).

On the other hand, in the case of erasing the latent image, the contact material (B)
Surface of the recording medium (A) in the absence of
What is necessary is just to heat to 0-180 degreeC. The heating time is about 1 to 10 seconds, preferably 10 to 1 second.

Next, the means for actually recording image information on the surface of the recording medium (A) will be described in more detail.

One is that the surface of the recording medium (A) is heated in response to an image information signal in a liquid or vapor atmosphere to form a liquid adhering area (latent image formation) on the surface of the recording medium (A). Thereafter, a recording agent is attached to the latent image portion by means of bringing the recording agent solution or dispersion liquid into contact with the latent image portion (development), and this recording is directly fixed on the surface of the recording medium (A) ( Direct recording method). The other is to heat the surface of the recording medium (A) according to the image information signal under a liquid or vapor atmosphere to form a liquid adhesion region on the surface of the recording medium (A) (latent image formation), A method in which a recording agent is attached to the latent image portion by means of contacting the recording agent solution or dispersion liquid with the latent image portion (development), and thereafter, the recording agent on the surface of the recording medium (A) is transferred to a recording paper or the like. (Indirect recording method). Further, in the above method, after the transfer of the recording agent,
If a means for bringing the recording agent solution or the dispersion liquid into contact with the latent image portion is performed again, a printing method using the recording medium (A) as a printing plate is obtained.

In the above method, after transferring the recording material, the surface of the recording medium (A) on which the latent image has been formed in the absence of liquid or vapor is heated to erase the latent image, thereby obtaining the recording medium (A). Is a reproducible recording method (repeated recording method). Fig. 5 (a),
(b) and (c) show typical processes of a direct recording method, an indirect recording method (printing method), and a reversible recording method of a recording medium (repeated recording method).

Next, the apparatus configuration in the recording method including the recording medium (A) will be described.

As described above, the recording medium (A) has a surface on which the receding contact angle is reduced when heated and in contact with a liquid.
It is not limited to this form as long as it has (for convenience, "film 2" or "recording member (A) surface" for convenience). Therefore, the support substrate of the recording body (A) may be a rigid cylindrical shape or a flexible film shape. The rigid cylindrical recording body (the one in which the film 2 is formed on the surface of the cylindrical rigid body) is excellent in controllability since the recording body (A) is hardly displaced when the recording body (A) is operated. Shaped recording medium (A) is good. For the production of such a recording body (A), a method of forming the film 2 on a substrate or a method of producing the molded body itself is preferable. In particular, the recording body (A) formed by the molded body itself generally has low mechanical strength, and thus a method of forming a film on a substrate is desirable. Incidentally, even when the recording body (A) is formed by the molded body itself, the film 2 is formed on the surface thereof.
Needless to say, it must be formed.

When a resin is used for the support substrate of the recording medium (A), this is not a good conductor of heat, but in the case of heating from the substrate side, the surface of the recording medium (A) has It takes some time to be heated and have liquid adhesion. Therefore, apply a good heat conductor to the entire board or
It may be considered for use in the upper part.

FIG. 6 (a) shows a case where a good heat conductor such as a metal is used as a substrate (metal substrate 11), an organic thin film 12 is deposited thereon, and a film 2 is further formed thereon. The heat conduction speed in the vertical direction is improved. Examples of the organic thin film 12 include polyimide, polyester, phthalocyanine, and the like. This configuration is sufficient when the print dots can be relatively large, but is not suitable for the purpose of higher density printing because the portion having liquid adhesion is expanded by heat diffusion in the plane direction. .

FIG. 6 (b) shows a structure in which a good heat conducting portion is provided on the substrate 1 so as to prevent heat diffusion in the plane direction and to miniaturize the portion 2a having liquid adhesion. . In FIG. 6B, reference numeral 11a denotes a miniaturized metal film.

Next, means for forming a latent image by heating will be described. As described above, as the heating source, a contact heating source such as a heater or a thermal head, or a non-contact heating source using electromagnetic waves such as a laser or an infrared lamp is desirable.
As a specific example of these, the recording medium (A)
The means for heating the surface will be described. For the sake of convenience, the description will be given by taking a recording medium (A) of the type in which the film 2 is formed on the base 1 as an example. First, the liquid 3 is brought into contact with the surface of the recording body 7 in advance, and heating is performed from the substrate 1 side or the liquid 3 side in the contact state ((a) and (b) of FIG. 7). (A) It is desirable to employ means ((c) and (d) in FIG. 7) for heating from the front side and immediately bringing the liquid 3 into contact with the recording body heating section (the surface of the recording body (A)).

As a means for supplying the liquid 3, a dish is provided below the recording medium (A) so that the recording medium 7 is filled with the liquid 3 so that the recording medium 7 is always in contact with the liquid 3 in the dish. Is the simplest configuration. Instead of the dish, a sponge-like porous body 34 containing a liquid may be used. The latent image forming means using light or an electron beam is basically the same as the above configuration. In FIG. 7, reference numeral 42 denotes a laser light source, and 43 denotes a thermal head. Thus, the latent image is formed on the surface of the recording medium (A).
(S) is formed.

The means for adhering the recording agent solution or dispersion liquid (for example, ink liquid) to the liquid adhering area of the recording medium (A) selectively applied in accordance with the image information signal by the above means includes the recording agent 3a The simplest configuration is to arrange the tray 3b filled with the ink in the traveling direction of the recording medium (A) with respect to the position of the latent image forming means and to always contact the surface of the recording medium (A) (FIGS. 8 and 9). . As shown in FIG. 9, if the liquid used for forming the latent image is also used as the recording agent 3a such as an ink liquid, the formation of the latent image and the visualization thereof can be integrated with one dish, thus miniaturizing the apparatus. it can.

In the case of direct recording, a flexible film or a rigid film is used as a recording medium substrate, and a film 2 is formed on the substrate 1 to obtain a recording medium (A). This record (A)
The latent image is formed and visualized by the above means. Thereafter, natural drying or heat drying is performed to fix the recording agent 3a 'attached to the recording medium (A). FIG. 10 shows a desirable example for implementing the direct recording method. In FIG. 10, the latent image forming means and the color developing means are fixed as a single unit, and the recording body 7 is moved. In the figure, 3a ″ represents a fixed image on the recording medium (A).

Further, when the recording medium substrate on which the recording agent is fixed after the direct recording is a transparent film, the recording medium substrate can be used as an original plate of an apparatus such as a slide projector by irradiating transmitted light (FIG. 11) . It can also be used as an information storage medium by irradiating beam-like reflected light or transmitted light and detecting a change in light intensity due to the presence or absence of a recording agent (FIG. 12). 11 and 12, 52 is a screen, 53 is a light source, 54 is a detector, and 55 is a motor.

In the case of indirect recording, as described above, for example, a rigid cylindrical tube is advantageously used as the recording substrate. After the latent image formation and development (visualization), for example, the recording material 3a 'on the recording medium (A) is transferred to the recording paper or the like 61 by providing means for directly contacting the recording paper 61 ( Transfer means). If the transfer position is after development,
Although any position on the recording medium (A) may be used, a position where transfer is performed immediately after development is desirable. After the transfer, if the development is repeated without erasing the latent image, the apparatus becomes a printing apparatus. FIG. 13 shows an example of the printing apparatus. In the figure, 3a 'represents an ink droplet attached to the latent image (S), and 3a "represents a transferred image. When printing of one image information is completed, the recording medium (A) is replaced or the latent image is replaced. By performing image erasure, recording / printing of other image information becomes possible.

After the transfer means, the latent image is erased by heating the vicinity of the latent image portion (S) in the absence of liquid or vapor, that is, in the air, in a vacuum, or in an inert gas. Then, the recording medium (A) becomes a recording device that can be used repeatedly (Fig. 1
Four).

As a heating source for erasing a latent image, a contact heating source such as a heater or a thermal head, or a non-contact heating source using electromagnetic waves such as a laser or an infrared lamp is desirable. Heating may be performed only on the latent image portion, or may be performed on the entire surface of the recording medium (A). Rather, heating over the entire surface is more desirable because the device configuration can be simplified.

The latent image erasing means is provided at a position where the surface of the recording medium (A) is substantially cooled during the time from when heating for erasing is performed to when the latent image is formed again. The heating temperature necessary for erasing the latent image is as described above, but it depends on the material of the surface of the recording medium (A). A temperature below the point is desirable.

As the recording paper (transfer object) 61, a transparent or opaque resin film, plain paper, synthetic paper, ink jet recording paper, type paper, or the like can be used.

Next, the recording agent (solution or dispersion) will be described. In the recording method of the present invention, in order to obtain a visible image on the surface of the recording medium (A), a recording agent is used in a conventional printing recording system such as a writing ink, an ink jet recording ink, a printing ink, and an electrophotographic toner. From the recording agents (in the state of a dispersion or a solution) which have been obtained, those which are suitable for the method of the present invention can be selected and used.

More specifically, preferred examples of the aqueous ink include, for example, water-based inks mainly composed of water, wetting agents and dyes, or water-based inks mainly composed of water, pigments, polymer compounds for dispersing pigments, and wetting agents. Aqueous pigment-dispersed ink, an emulsion ink in which a pigment or dye is dispersed in water using a surfactant, and the like. Examples of the wetting agent used in the aqueous ink include the following water-soluble organic liquid compounds.

Monohydric alcohols such as ethanol, methanol and propanol; polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol and glycerin; ethylene glycol monobutyl ether , Diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, tetraethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, tetraethylene glycol monoethyl ether, propylene glycol monoethyl ether, etc. Polyvalent alcohol Ethers; heterocyclic compounds such as N-methyl-2-pyrrolidone, 1,3-dimethylimidazolidinone, ε-caprolactam; amines such as monoethanolamine, diethanolamine, triethanolamine, monoethylamine, diethylamine, triethylamine Kind.

As the water-soluble dye, dyes classified into acid dyes, direct dyes, basic dyes, and reactive dyes in a color index are used. Examples of typical dyes include CI Acid Yellow 17,23,42,44,79,14
2 CI Acid Red 1,8,13,14,18,26,27,35,37,42,52,
82,87,89,92,97,106,111,114,115,134,186,249,254,289 CI Acid Blue 9,29,45,92,249,890 CI Acid Black 1,2,7,24,26,94 CI Food Yellow 3,4 CI Food Red 7,9, 14 CI Food Black 2 CI Direct Yellow 1,12,24,26,33,44,50,142,14
4,865 CI Direct Red 1,4,9,13,17,20,28,31,39,80,8
1,83,89,225,227 CI Direct Orange 26,29,62,102 CI Direct Blue 1,2,6,15,22,25,71,76,79,86,8
7,90,98,163,165,202 CI Direct Black 19,22,32,38,51,56,71,74,75,
77,154,168 CI Basic Yellow 1,2,11,13,14,15,19,21,23,2
4,25,28,29,32,36,40,41,45,49,51,53,63,65,67,70,73,
77,87,91 CI Basic Red 2,12,13,14,15,18,22,23,24,27,
29,35,36,38,39,46,49,51,52,54,59,68,69,70,73,78,8
2,102,104,109,112 CI Basic Blue 1,3,5,7,9,21,22,26,35,41,45,4
7,54,62,65,66,67,69,75,77,78,89,92,93,105,117,120,
122, 124, 129, 137, 141, 147, 155 Basic Black 2, 8 and the like.

As the pigments, azo-based, phthalocyanine-based, anthraquinone-based, quinacridone-based organic pigments may be used.
Dioxazine-based, indigo-based, thioindigo-based, perinone-based, perylene-based, isoindolenone-based, aniline black, azomethineazo-based, carbon black, and the like.Examples of inorganic pigments include iron oxide, titanium oxide, calcium carbonate, and barium sulfate. Aluminum hydroxide, barium yellow, navy blue, cadmium red, chrome yellow,
Metal powder.

Examples of the pigment-dispersing polymer compound include polyacrylamide, polyacrylic acid and alkali metal salts thereof, and acrylic resins such as water-soluble styrene acrylic resin.
Water-soluble styrene maleate resin, water-soluble vinyl naphthalene acrylic resin, water-soluble vinyl naphthalene maleate resin, polyvinyl pyrrolidone, polyvinyl alcohol, β
-An alkali metal salt of a naphthalenesulfonic acid formalin condensate, a polymer compound containing a salt of a cationic functional group such as a quaternary ammonium or an amino group, polyethylene oxide,
Gelatin, proteins such as casein, gum arabic, natural gums such as tragacanth gum, glucoxides such as saponin, carboxymethylcellulose, hydroxyethylcellulose, cellulose derivatives such as methylcellulose, ligninsulfonic acid and salts thereof, natural polymer compounds such as ceramics, And the like.

As the oil-based recording agent solution or dispersion, as in the case of the aqueous ink, an oil-soluble dye dissolved in an organic liquid compound, a pigment dispersed in an organic liquid compound, and a pigment or dye dispersed in an oil-based ink are used. And the like emulsified in water.

Representative examples of oily dyes include CI Solvent Yellow 1,2,3,4,5,6,7,8,9,10,11,12,
14,16,17,26,27,29,30,39,40,46,49,50,51,56,61,80,8
6,87,89,96 CI Solvent Orange 12,23,31,43,51,61 CI Solvent Red 1,2,3,16,17,18,19,20,22,24,2
5,26,40,52,59,60,63,67,68,121 CI Solvent Violet 7,16,17 CI Solvent Blue 2,6,11,15,20,30,31,32,35,36, Five
5,58,71,72 CI Solvent Brown 2,10,15,21,22 CI Solvent Black 3,10,11,12,13 and the like.

[0088] In addition, or by dissolving the dye, as an oily base for dispersing the pigment, n- octane, n- decane, minerals Le spirits, ligroin, naphtha, hydrocarbons such as benzene, toluene, xylene and the like; di Ethers such as butyl ether, dihexyl ether, anisole, phenetole, and dibenzyl ether; methanol,
Examples include alcohols such as ethanol, isopropyl alcohol, benzyl alcohol, ethylene glycol, diethylene glycol, and glycerin.

The pigments exemplified above can also be used in oil-based inks. Examples of oil-based pigment dispersants include:
Polymethacrylate, polyacrylate,
Methacrylic acid ester-acrylic acid ester copolymer,
Polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, polyvinyl pyrrolidone, vinyl copolymers such as polyvinyl butyral,
Cellulose resins such as ethylcellulose and methylcellulose; polycondensation resins such as polyester, polyamide and phenolic resins; and natural resins such as rosin, ceramic, gelatin and casein.

The recording method according to the present invention described above utilizes the fact that the adhesion of ink (recording agent) causes a difference in the tacking force to the liquid between the latent image portion and the non-latent image portion. Things. For this reason, the ink does not always adhere to the entire surface of the latent image portion, and the area where the ink adheres often becomes slightly smaller than the latent image area. In addition, it was also found that the attachment position may slightly deviate from the latent image position. FIG. 15 shows a specific example of this state of adhesion. A portion surrounded by a square is a latent image portion (S), and a dark portion is attached ink. As described above, the latent image area does not always match the attached ink area.

Further, the present inventor examined the state of ink adhesion to the latent image areas of various sizes. As a result, although the area of the attached ink was slightly smaller than each latent image area, the area of the latent image area was smaller. It was also recognized that the size of the area of the attached ink changed accordingly.

That is, in this latent image area, the adhesive strength of the recording material can be changed depending on the size of the heated area. One of the methods of the present invention utilizes this phenomenon to obtain a new gradation expression of an image.

In various heating regions formed on the surface of the recording medium (A), the heating temperature and the amount of the liquid (including the recording agent solution or dispersion) adhering thereto are not necessarily the same. Often do not match. The present inventor has studied again why such a phenomenon occurs. As a result,
(A) It has been found that the liquid adhesion can be controlled by controlling the heating temperature of the surface. FIG. 16 shows a representative example of the contact angle of pure water on the surface of the recording medium (A) after heating when the surface of the recording medium (A) is heated at various temperatures in contact with the liquid. Between the temperature T ₁ of the T ₂ it is observed to be reduced is the receding contact angle with increasing temperature. That is, in this temperature range, the liquid adhesion can be changed by the heating temperature. Another method of the present invention utilizes this phenomenon to obtain a new gradation expression of an image.

As one method of expressing an image, a method of expressing dots by arranging them in a matrix is known. This method is intended to represent one pixel with a certain dot arrangement. Therefore, for example, when one pixel is represented by a 2 × 2 dot matrix, a latent image area (S ₁ ) is formed on the recording medium (A) as shown in FIG.
If the recording agent attached to this area is transferred to recording paper or the like, a 2 × 2 dot matrix is formed as shown in FIG. 17 (b). In the figure, 3a ″ is an ink dot.

Now, as shown in FIG. 18 (a), FIG.
By forming a latent image area (S ₂ ) smaller than the latent image area (S ₁ ) of FIG. 17 (a) by controlling the heating amount or the heating temperature for the same heating portion as shown in the above, Due to the phenomenon described above, the amount of the attached recording agent decreases, and as shown in FIG. 18 (b), the dot diameter after transfer to the recording paper becomes smaller.
9 (b) has a lower optical density of one pixel. In other words, the optical density per pixel can be changed by controlling the heating amount or the heating temperature to change the size of the latent image area. In other words, the gradation can be expressed.

As described above, in the method of the present invention, means for expressing the gradation by changing the size of the latent image area on the recording medium (A) or the temperature of the heated area is employed. When the size of the latent image area or the heating temperature of the heating area is changed to, for example, 16 steps, and one pixel is represented by a 2 × 2 dot matrix, 64 gradations can be expressed, but when the recording material (A) is used. ,
Since the size of the latent image area or the heating temperature of the heating area can be easily and continuously varied, 16-step changes can be easily made. Expression becomes possible. Further, if the size of the latent image area is changed and the temperature of the heating area is changed at the same time, a more desirable gradation expression can be achieved by a synergistic effect.

Next, a heating amount or a heating control method for making the size of the latent image area or the temperature of the heating area variable will be described. Therefore, as shown in FIG. 19, a configuration in which a thermal head 43 or a laser 42 is used as a heating source and the surface of the recording medium 7 is heated through, for example, a liquid is considered. At this time, if the heating action intensity within a certain period of time, for example, the driving voltage of the thermal element 21 in the case of the thermal head 43, or the emission intensity in the case of the laser 42, the heating temperature to the surface of the recording medium (A) can be changed.
(See FIG. 20). In the figure, reference numeral 13 denotes a transparent glass. If the heating temperature is high, the latent image area becomes wider due to heat conduction on the recording medium (A) even if the heating area is constant. For example, as shown in FIG. 21, heating at a higher temperature is compared to heating at a lower temperature (a).
In (b), the size of the latent image area is larger even in the same heating action area = heating action area (in the figure, the dark black area indicates the thermal head heating section, and the dark black area indicates the laser spot section) . As described above, the size of the latent image area can be changed by changing the heating action intensity within a certain time.

As another method, the latent image area can be varied by changing the area of the heating section. For example, when a thermal head is used as a heating source, as shown in FIG.
The latent image area A can be wider than the latent image area A driven three times and the latent image area B driven three times. When a laser is used, the latent image area can be varied by changing the spot size using an aperture or the like.

Another method is to vary the latent image area by changing the operation time of the heating section. As shown in FIG. 23, the longer the operation time of the heating section is, the longer the heating time is. On the other hand, as shown in FIGS. 10 and 13, the recording medium 7 is moving at a certain constant speed. Therefore, the longer the heating time, the larger the latent image area with the movement of the recording medium (A). For example, as shown in FIG. 23, it can be seen that the longer the heating time, the larger the latent image area is compared to the heating action area ((a) and (b) in the figure correspond to the times of (a) and (b) in FIG. 24). ). The upward arrow in FIG. 24 indicates the moving direction of the recording medium (A).

It is easy to understand that the relationship between the latent image area and the optical density is divided into a case where the size of the heat source is fixed and a case where the size of the heat source is variable.

First, as described above, means for controlling the driving power of the heat source by using the heat source as a heating resistor is used.
Here, for example, when a thermal head is used as the heat source, the temperature of the heating resistor surface varies according to the pulse waveform. Fig. 20
Represents an example in which the temperature of the thermal element is variable by varying the pulse height. FIG. 23 shows an example in which the pulse width is variable and the thermal element temperature is variable.

In this case, the gradation control signal processing system uses the number of gradations (6
4 gradations) with thermal head (10 thermal elements / mm, total number of 3 per line)
FIG. 25 is a block diagram of FIG. 25, using 072 (corresponding to A3 vertical) and 64 bits × 48 driving IC towers. In FIG. 25, the command and the status are transferred by the μCPU, and after the recording is started, the recording data is received from the host by the DMA. It has a line buffer of 3072 bits for two lines, so that recording data can be received even during recording. The image data from the host is modulated by the pulse width or pulse height by the gradation control circuit to obtain 64 gradations, and 3032 byte serial data for one line is divided into 24 bytes of 128 byte serial data, and is converted into parallel data. The data is transferred to the shift register of the thermal head.

Actual means when the size of the heat source is fixed include the following. (-
1) The size of the latent image is made constant and the temperature of the latent image portion is made variable. Here, as shown in FIG. 26, a contrivance is made to impart thermal anisotropy to the base 1 of the recording medium 7. That is, the good heat conductor 1b (good heat conductivity range: 0.01 ca) in the poor heat conductor 1a
(l / cm · sec · ° C. or more) is uniaxially oriented and embedded to form a thermally anisotropic substrate, on which a film 2 is formed is used as a recording medium (A). A typical example of the good heat conductor is a conductive rubber containing a metal filler or carbon, and a typical example of the bad heat conductor is a resin or rubber. Further, in the figure, h, l ₁ and l ₂ , n are good heat conductors 1b, respectively.
, Spacing, and diameter (size). It is desirable that l ₁ and l _{2 be} equal to or smaller than the pitch of the latent image. The good heat conductor 1b may be either circular or polygonal, and the size (n) is suitably equal to or smaller than the latent image.

(-2) The size of the latent image is made constant and the temperature of the latent image portion is made variable. In this case, the recording body is formed of a good thermal conductor 11 (metal, ceramic, conductive rubber, conductive resin, or the like) on the entire surface of the base 1 and a film 2 (thickness: several hundreds of μm to several μm) formed thereon. Used as (A). In this recording medium (A), the heat readily diffuses on the surface of the substrate 11, so that the substrate temperature does not easily rise. Conversely, it is possible to broaden the surface at a certain temperature. Therefore, the temperature can be varied while the size of the latent image is constant (FIGS. 27A and 27B). On the other hand, when the defective heat conductor 12 is used for the substrate, the size of the latent image can be made variable (FIG. 28).

(-3) The size of the latent image is variable and the temperature of the latent image portion is variable. Here, a recording medium with poor thermal conductivity
(A) 72 or a recording medium in which the film 2 is formed on a substrate of a poor thermal conductor
(A) 72 is used. This type of recording medium (A) can easily raise the substrate surface temperature because heat is not easily diffused. However, the heat distribution is likely to be non-uniform, and the size of the latent image can be changed simultaneously with the latent image temperature by changing the pulse waveform (the magnitude of the applied voltage). FIG. 29 and FIG. 30- (a) show an example in the case of low applied power, and (b) shows an example in the case of high applied power.

(-4) The size of the latent image is made constant and the temperature of the latent image portion is made variable. The intention is that the above (-
Same as 2). However, in this example, a method of applying a pulse having a minimum pulse width to the thermal element is employed. When a pulse having a minimum pulse width is applied to the thermal element, thermal diffusion hardly occurs regardless of the form of the recording medium (A),
Variable temperature. Actual pulse width range is 0.05m
Seconds to about 0.5 ms. FIGS. 31 (a), (b) and (c) illustrate such a situation. FIGS. 31 (a), (b) and (c) show examples in which an extremely small pulse width is applied. If V ₂ > V ₁ and t ₁ > t ₂ , T ₂ > T ₁
Becomes

On the other hand, as the actual means when the size of the heat source is made variable, the following can be mentioned. (-
1) A heat source is a heating resistor, and the heating resistor is selectively driven (driving is performed by a pulse waveform (pulse width or pulse height)) to make the pulse waveform constant and change the size of the latent image. The image portion temperature is fixed, or the pulse waveform is variable, and the size of the latent image is variable to change the latent image portion temperature. Here, as shown in FIG. 33 (a), it is assumed that recording is performed by a thermal head having a thermal element having a density of 40 dots / mm (a size of 20 μm in length × 20 μm in width), for example. The dot density of the recording paper is 200 DPI (8 dots / mm). 1,2,3,4,5 are thermal elements (the interval from 1 to the next thermal element was 125 μm). Assuming that the drive energy for one thermal element 21 is constant for each pulse,
When all of the heating elements shown in the drawing are driven, the heating area on the recording medium (A) is represented as shown in FIG. 33 (b), and the optical density per dot becomes large. However, the heating area on the recording medium (A) when the 2, 3, and 4 heating elements were driven (1, 5 was not driven) is shown in FIG. 33 (c), and the optical density per dot is It will be small. Table 1 shows the change in the heating area and the change in the optical density after development when the heating element is selectively driven.

[0108]

[Table 1]

(-2) The heat source uses a light source (laser, lamp, etc.). One is an example in which the light source power is made constant by changing the spot diameter by condensing with a lens, the size of the latent image is made variable, and the temperature of the latent image portion is made constant. This is an example in which the latent image portion temperature is made variable while the size of the latent image is constant. Figure 34
Represents a typical main part of a recording device useful for dot diameter modulation of the semiconductor laser 42. The constituent materials and the like here are as follows. Insulating substrate (9): Polyimide film (Dupont Toray, Kapton thickness: about 75 μm), Light absorber (8): Carbon black mixed with epoxy resin, applied and cured (thickness: about 20 μm) Recording layer (Layer 2): Polymer of fluorine-containing acrylate monomer (Biscoat 17F, manufactured by Osaka Organic Chemical Industry Co., Ltd.) (thickness: about 1000 水) Water (3): Pure water (thickness: about 1 μm) Transparent glass (13): Commercial flat glass (Thickness: about 1.8 μm) Semiconductor laser (42): (Panasonic LN98, manufactured by Matsushita Electric Industrial Co., Ltd.)
50)

In order to form a latent image by driving the apparatus shown in FIG. 33, for example, (i) a lens is prepared, a spot diameter is set to about 40 μm on the surface of the recording layer, an operating current is 70 mA, and a pulse width is Obtain a latent image by irradiating one pulse at 40 ms, (ii) adjusting the lens, setting the spot diameter to about 100 μm on the recording layer surface, irradiating one pulse at an operating current of 150 mA, and a pulse width of 10 ms to obtain a latent image. And the like. Then, the latent image formed by these (i) and (ii) is, for example, an aqueous ink (having a viscosity of 5 at 25 ° C.).
(0cp, surface tension 48dym / cm) and then transferred to plain paper (Ricoh Type6200), the dot diameter of (ii) was found to be about twice as large as that of (i) above. Was.

[0111]

Example 1 A recording medium (A) was prepared by using a member in which a polyimide resin was coated on a cylindrical aluminum tube of φ100 mm as a substrate, and a fluorine-containing methacrylate-based material (“Texgard” manufactured by Daikin Industries, Ltd.) TG-702 ”) was prepared by dip coating and drying at 90 ° C. for 30 minutes. Using a thermal head of 8 dots / mm as a heating means, as shown in FIG. 13, in contact with the recording medium 7 via aqueous ink, a pulse width of 0.5 msec, a drive electrode 12V and a pulse width of 0.5 msec, a drive voltage of 10 V Heating was performed under two types of driving conditions, and then the adhered ink was transferred to paper. The higher the driving voltage, the larger the ink dot diameter by 1.3 times. When a pixel was formed by a 2 × 2 dot matrix under these driving conditions, the optical density of the pixel was twice as high as the driving voltage was higher. In addition, the pulse width is 0.5msec to 1m
When the pixels were formed in exactly the same manner except that sec was used, the optical density became higher.

Example 2 A recording medium (A) was produced using the same method as in Example 1.
As shown in FIG. 19 (b), a configuration is adopted in which the recording medium 7 is irradiated with laser light squeezed by a lens through the aqueous ink and heated by moving the lens, and the spot size is changed to φ30 μm and φ80 by moving the lens.
The two types of irradiation of μm were performed for 10 msec each, and the adhered ink was transferred to paper. As a result, the dot diameter was twice as large as the larger spot size.

Example 3 A recording medium (A) was produced using the same method as in Example 1.
Using a thermal head of 8 dots / mm as heating means,
As shown in FIG. 13, the recording medium 7 is in contact with the recording medium 7 via the aqueous ink 3a, and while the recording medium 7 is moving at a speed of 50 mm / sec, the pulse width is
0.5msec, drive voltage 12V and pulse width 1.0msec, drive voltage 12V
Heating was performed under the two driving conditions described above, and the adhered ink was transferred to paper. The larger the pulse width, the larger the dot diameter was 1.3 times. The pixels were formed in exactly the same manner except that the pulse width was changed from 0.5 msec to 1 msec, and the optical density was further increased.

Example 4 A recording medium (A) was prepared by using a member in which a polyimide resin was coated on a cylindrical aluminum tube having a diameter of 100 mm as a substrate.
An A-type material ("Tex Guard TG-702" manufactured by Daikin Industries, Ltd.) was dip-coated and dried at 90 ° C for 30 minutes. Using a thermal head of 8 dots / mm as a heating means,
As shown in the figure, in contact with the recording body 7 via the aqueous ink,
Heating was performed under two driving conditions: a pulse width of 0.3 msec, a driving voltage of 10 V, a pulse width of 0.3 msec, and a driving voltage of 7 V, and then the attached ink was transferred to paper.
The double ink dot diameter was large. When a pixel was formed by a 2 × 2 dot matrix under these driving conditions, the optical density of the pixel was twice as high as the driving voltage was higher. In addition, except that the pulse width was changed from 0.3 msec to 0.1 msec, and the driving voltage was changed from 10 V to 22 V and from 7 V to 15 V, pixels were formed in exactly the same way, on the surface of the photoconductor (A), the former was closer to the former. Although the expansion of the heating area was hardly recognized, the temperature was increased.

Example 5 A recording medium (A) was produced using the same method as in Example 1.
As shown in FIG. 19 (b), the recording medium 7 is irradiated with laser light focused by a lens through the aqueous ink and heated, and the lens is used to fix the spot size to φ30 μm,
10 msec each with two types of irradiation power of 20 mW and 50 mW
Irradiation and transfer of the attached ink to paper,
The ink dot diameter was twice as large with the 50 mW power.

Example 6 A recording medium (A) was produced by the same method as in Example 1.
Using a thermal head of 8 dots / mm as heating means,
As shown in Fig. 13, heating is performed under two types of driving conditions: a pulse width of 0.5 msec, a driving voltage of 5 V, a pulse width of 0.7 msec, and a driving voltage of 5 V, in contact with the recording medium 7 via the aqueous ink, and the adhered ink is transferred to paper. When the pulse width was wider, the dot diameter was 1.
3 times bigger. The pixels were formed in exactly the same manner except that the pulse width was changed to 1 msec, and the optical density was further increased.

Example 7 A 1 μm thick screw coat 17F was formed on the recording substrate shown in FIG.
The recording medium (A) was prepared by providing a film 2 made of the polymer of
The recording substrate used herein was prepared by using conductive rubber for the good heat conductor 11 and rubber for the bad heat conductor, and pressing them and then cutting them. However, l ₁ = l ₂ = 125μm, n = 80μm, h = 1mm
And Using a thermal head having a thermal element with a pitch of 8 dots / mm with the aqueous ink in contact with this recording medium (A), pulse width 1 msec, pulse height 10 V, pulse width 0.5 msec
When driving at a pulse height of 10 V, a difference was observed in the optical density between the two printings.

Example 8 The same film as in Example 7 having a thickness of about 1 μm was formed on an aluminum cylinder having a diameter of 100 mm.
Record 2 (A) was made with 2 provided. An image was formed on plain paper by changing the pulse width and pulse height on the recording medium (A). Note that oil ink was used as the ink liquid. Table 2 shows the results.

[Table 2]

Example 9 Two latent images were separately formed by using the apparatus shown in FIG. One is to adjust the lens and make the spot diameter about 4 on the recording layer surface.
Set to 0 μm, irradiate one pulse with an operating current of 70 mA and a pulse width of 10 msec to form a latent image, and adjust the lens and set the spot diameter to about 100 μm on the recording layer surface.
One pulse was irradiated at 0 mA and a pulse width of 10 msec to form a latent image. An aqueous ink (viscosity at 25 ° C. was 50 cp and surface tension was 48 dyn / cm) was used for visualization, and Ricoh Type 6200 was used as the transfer paper. As a result, it was recognized that the dot diameter was about twice as large in the driving.

[0120]

According to the method of the present invention, a desired image having excellent gradation can be obtained reversibly with a simple operation.

[Brief description of the drawings]

FIG. 1 is a diagram of four typical examples of a form having a surface self-orientation function.

FIG. 2 is a diagram for basically explaining the method of the present invention.

FIG. 3 is another diagram for basically explaining the method of the present invention.

FIG. 4 shows an example of a recording medium (A) used in an embodiment of the present invention.
FIG. 9 is a diagram showing a change in receding contact θr observed on the surface of the recording medium (A) when the surface of the recording medium (A) is heated in a state where the liquid is in contact with the surface.

FIG. 5 is a diagram showing three embodiments of the method of the present invention.

FIG. 6 is a diagram of two examples in a case where heating is performed from the support substrate side.

FIG. 7 is a diagram of four examples for forming a latent image on a recording medium (A).

FIG. 8 is a diagram showing how a latent image is visualized.

FIG. 9 is a diagram illustrating a state in which a latent image is formed and the image is visualized.

FIG. 10 is a diagram illustrating a state in which a visible image is directly formed on a recording medium (A).

FIG. 11 is a diagram showing an application example of a recorded matter produced by the method of the present invention.

FIG. 12 is a diagram showing another application example of the recorded matter produced by the method of the present invention.

FIG. 13 is a diagram showing an embodiment of the method of the present invention.

FIG. 14 is a diagram showing another embodiment of the method of the present invention.

FIG. 15 is a diagram for explaining the operation and effect of the present invention.

FIG. 16 is a diagram for explaining another operation and effect of the method of the present invention.

FIG. 17 is a diagram for explaining the relationship between a latent image on a recording medium (A) and an image.

FIG. 18 is a view for explaining another relationship between a latent image and an image on a recording medium (A).

FIG. 19 is a diagram illustrating two examples for obtaining a latent image or a visible image on a recording medium.

FIG. 20 is a diagram for explaining the operation and effect of the method of the present invention.

FIG. 21 is a diagram for explaining a relationship between a heating area and a latent image area on a recording medium (A).

FIG. 22 is a diagram for explaining the operation and effect of the method of the present invention.

FIG. 23 is a diagram for explaining the operation and effect of the method of the present invention from another point.

FIG. 24 is a diagram for explaining that a latent image area is formed by the method of the present invention.

FIG. 25 is a block diagram in which gradation control signal processing is added to an image obtained by the method of the present invention.

FIG. 26 is a diagram illustrating an example of a substrate of a recording medium (A) used in the method of the present invention.

FIG. 27 is an explanatory diagram showing that the size of the latent image is constant and the temperature for forming the latent image can be varied according to the recording body (A) in which the recording body substrate is a good thermal conductor.

FIG. 28 shows a recording medium (A) in which the recording medium substrate is a poor heat conductor.
FIG. 2 is a diagram showing that heat diffusion hardly occurs and the temperature inside the recording body can be easily increased.

FIG. 29 is an explanatory view showing that when a poor thermal conductive recording medium (A) is used, the size of the latent image and the temperature of the latent image portion can be simultaneously changed by changing the pulse waveform.

FIG. 30 is another explanatory view showing that when a poor thermal conductive recording material (A) is used, the size of the latent image and the temperature of the latent image portion can be simultaneously changed by changing the pulse waveform.

FIG. 31 is a diagram illustrating a relationship between a temperature in a recording medium surface and a heating region when a minimum pulse is applied to a thermal element.

FIG. 32 is a diagram showing the relationship between the in-plane temperature of the recording medium and the heating area when a normal pulse is applied to the heating element.

FIG. 33 is a diagram illustrating a relationship between driving energy applied to a thermal element of a thermal head and an optical density per dot.

FIG. 34 is a diagram for explaining dot diameter modulation when laser light is used.

[Explanation of symbols]

 Reference Signs List 1 substrate 2 film 3 liquid (3a recording agent solution or dispersion) 4 heater

Claims (4)

(57) [Claims] 1. The surface of the following recording medium (A) and the following contact material (B)
And the recording medium (A) according to the image information signal
By heating so that the size of the heating area on the surface changes, or so that the size of the heating area on the surface of the recording medium (A) changes in accordance with the image information signal on the surface of the recording medium (A). By contacting with the contact material (B) in a heated state,
A recording method comprising: forming a region having a receding contact angle lower than that of a non-heated region on the surface of a recording material (A) in accordance with the size of the heated region. (A) A recording medium having a surface in which the receding contact angle is reduced when heated and brought into contact with a liquid. (B) Liquid, vapor, or solid that becomes liquid or generates liquid or vapor at a temperature equal to or lower than the temperature at which the receding contact angle of the recording medium (A) starts to decrease. 2. The size of a heated area on the surface of the recording medium (A) according to an image information signal in a state where the surface of the recording medium (A) described below is brought into contact with a recording agent solution or a dispersion containing a color developing material. By heating so that the size of the heating area on the surface of the recording medium (A) changes according to the image information signal. A recording method characterized by forming a visible image according to the size of a heated area on the surface of a recording medium (A) by contacting with a recording agent solution or dispersion containing a material. (A) A recording medium having a surface in which the receding contact angle is reduced when heated and brought into contact with a liquid. 3. The surface of the following recording medium (A) and the following contact material (B)
And the recording medium (A) according to the image information signal
By heating so that the temperature of the heating area on the surface changes, or heating the surface of the recording body (A) so that the temperature of the heating area on the surface of the recording body (A) changes according to the image information signal. A recording method characterized by forming a region having a receding contact angle lower than the unheated region on the surface of the recording material (A) according to the temperature of the heated region by contacting the contact material (B) in a state. . (A) A recording medium having a surface in which the receding contact angle is reduced when heated and brought into contact with a liquid. (B) Liquid, vapor, or solid that becomes liquid or generates liquid or vapor at a temperature equal to or lower than the temperature at which the receding contact angle of the recording medium (A) starts to decrease. 4. The temperature of a heated area on the surface of the recording medium (A) according to an image information signal in a state where the surface of the recording medium (A) and a recording agent solution or dispersion containing a color developing material are in contact with each other. The developer is heated so that the developer changes, or the developer is heated in such a way that the temperature of the heating area on the surface of the recording medium (A) changes according to the image information signal. The recording medium is brought into contact with the contained recording agent solution or dispersion liquid.
(A) A recording method comprising forming a visible image on a surface in accordance with the temperature of a heated area. (A) A recording medium having a surface in which the receding contact angle is reduced when heated and brought into contact with a liquid.