JP3058471B2 - 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,
A region consisting of a circular or elliptical dot that selectively or selectively and reversibly exhibits a receding contact angle depending on the heating temperature.
The present invention relates to a recording method in which a (latent image) is formed, and then a recording agent containing a color developing material is supplied to this area to make it visible, and this is transferred to recording 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 low due to poor quantum efficiency. It has the drawbacks of being extremely long, slow in recording speed, and lacking stability, and has not yet reached a practical level.

Further, according to the method (3), the information recording member used therein has stability after recording, but may have a physical structure change due to a temperature change before recording. However, there is still 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.

[0007]

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 in contact with a liquid. Another object of the present invention is to provide a method for forming a desired pattern region having a dot shape selectively or selectively and reversibly by means.

Another object of the present invention is to supply a recording material (for example, a liquid ink) containing a color developing material to the pattern area to obtain a visible image faithful to the desired pattern. An object of the present invention is to provide a method in which a clear and high-quality image with gradation is obtained by transferring and fixing it on paper or the like.

Still another object of the present invention is to use a recording medium (A) having excellent storage stability and stability in all steps such as formation / erasing of a desired pattern area, visualization, and transfer. Another object of the present invention is to provide a novel recording method in which the above steps can be performed reversibly a plurality of times.

[0010]

According to the method of the present invention, the surface of the recording medium (A) is selectively heated while the surface of the recording medium (A) is in contact with the following contact member (B), or the surface of the recording medium (A) is heated. After selectively contacting the contact material (B) in a heated state and forming a latent image formed of a circular or elliptical dot on the surface of the recording medium (A), showing a receding contact angle corresponding to the heating temperature. The latent image is visualized with a recording material and transferred to a recording paper or the like. (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.

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 has been formed in the absence of the contact material (B). The image can be formed in the first place.

The present inventors have solved many defects as described in the above-mentioned prior art, and have conducted many studies and studies on a new recording method. As a result, when the recording medium is heated while being in contact with the liquid, the receding contact angle is reduced even after cooling, and the receding contact angle is increased by heating in the absence of the liquid. Was found to be useful. 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 material was oriented on the surface (Japanese Patent Application No. 2-43599).

[0013] The "surface self-orientation function" referred to in (1) means that when a solid formed by a certain compound on a support or a solid 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 - has a partial planar structures), 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-
Represents 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.

The results of these studies are summarized as follows. More preferably, 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 the 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 apparent from the above description, there is a relationship between the surface self-alignment state and 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 cos θr = γ (γs−γse−πe + γf) / γev (where γ: surface tension of solid in vacuum γse: solid-liquid interface 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 as 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 its surface. Therefore, in the apparatus of the present invention, since the recording medium (A) needs to form a desired pattern area on its surface and / or visualize with a recording agent, a member having a surface self-orientation function on the surface is inevitable. You have to be selected.

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 coating film having the above-mentioned properties is provided on a suitable cylindrical support or molded body. It does not matter. 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, and therefore, when a copy is obtained, Any of ink, water-based ink, and the like can be used as needed.

Here, FIG. 1 shows an example in which members or materials that form a surface that forms a surface where the receding contact angle θr decreases when it is brought into contact with a liquid in a heated state 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) is an example of a member in which the hydrophobic group is oriented on the surface of an organic compound having a hydrophobic group. 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) is 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 the side chain of a polymer. The main chain L is connected to the molecule by a bonding group J, and has a hydrophobic group R at its end. It is a compound having a molecular chain N having a structure 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 above-mentioned 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. Either fluorine-substitution or chlorine-substitution can be used, but fluorine-substitution is more effective. In these materials, when the number of carbon atoms is 3 or less, the function suitable for the recording method of the present invention is reduced in relation to the number of carbon atoms in the alkyl group and the function.

The principle of this function expression has not yet been completely elucidated, and thus there are many unclear points.

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 another state ("another alignment state" or "a state in which the alignment is disturbed" different from the original alignment state), the surface of the recording material (A) is removed in the absence of the contact material (B). When heated, there is no interaction with the contact material (B), so the original alignment (orientation)
It seems to return to the state.

Accordingly, the presence of the contact material (B) is not merely for quenching the surface of the recording medium (A) after heating, but causes some interaction with the compound on the surface of the recording medium (A). It is considered that a change to another state (a different alignment state or a state where the alignment is disordered) occurs only after this interaction.

As described above, when an alkyl group or a fluorine-substituted or chlorine-substituted alkyl group is employed 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.

Further, the surface of the recording medium (A) has a liquid repellency, which can be described by the surface energy of a solid. It has been confirmed that it is desirable as a recording method based on the above. At higher values, the recording medium
The surface of (A) sometimes gets wet and may cause soiling of the background.

Here, the compound forming the surface of the recording medium (A)
Object (contact material while the surface of the recording medium (A) is selectively heated)
(B) when contacted with the surface of the recording medium (A) according to the heating temperature
Compound that forms a latent image area showing a receding contact angle
Give details. First, about the type of Fig. 1 (a) and (d)
Alkyl group (fluorine substitution and / or
(Including those substituted with chlorine)
You. Specifically, formulas (I), (II), (III), (IV), (V), (VI) and (VI)
I) CH_Two= CR | (I) COORf CH_Two= CR | (II) OCORf CH_Two= CR | ... (III) O = C-Rf CH_Two= CR | ... (IV) O-Rf CH_Two= CR | ... (V) CONHRf R | CH_Two  ｜ CH_Two= C (VI) | COORf CH_Two= CR (VII) | (CH_Two) m-Rf R: -H, -CH_Three, -C_TwoH_Five, -CF_ThreeOr -C_TwoF_FiveRf: C_FourAlkyl over
Group or a fluorine-substituted or chlorine-substituted alkyl group
Group, or (-CF_Two−) P, (−CH_Two−) P
Is a hydrophobic group (P ≧ 4) having -Ph-
And the like.

Other polymers include compounds of the formulas (VIII) and (IX)
And (X). CH_Three CH_Three  | | (-Si-O-Si-) n ・ ・ ・ (VIII) | | CH_Two CH_Two  | | Rf Rf R | (−CH_Two―C―) n ・ ・ ・ (IX) | NH | O = C-Rf R | (−CH_Two―C―) n ・ ・ ・ (X) | CH_Two  | NH | O = C-Rf R: -H, -CH_Three, -C_TwoH_Five, -CF_ThreeOr -C_TwoF_FiveRf: C_FourMore archi
Contains a fluorinated or fluorinated or chlorinated alkyl group
Group, or (-CF_Two-) p, (-CH_Two-) p or
-Ph-containing hydrophobic group (P ≧ 4) n: integer of 10 or more

Rf in these specific examples is described in more detail below.
Examples of (1) to (20) can be given. (1) -CH_TwoCF_TwoCHFCF_Three  OH OF_ThreeC CF (CF_Three)_Two  ｜ ‖ ｜ ｜ (2) −CH_TwoCHCH_Two-C-O-Ph-OC = C-CF (CF_Three)_Two  (3) -CH_TwoCH_TwoOC-C₇F₁₅  ‖ O O ‖ (4) -CH_TwoCH_TwoNC- (CF_Two)₇CF (CF_Three)_Two  ｜ C (CH_Three)_Three  (5) -CH_TwoCHCH_Two(CF_Two)_FourCF_Three  | OH (6) -CH_Two(CF_Two)_TenH (7) − (CF_Two)₆-O-CF_TwoCF_Three  (8) − (CH_Two)_Four-NH-CF_TwoCF_Three  (9) − (CF_Two)₆-CF_Three  (10) − (CH_Two)_TenC₈F₁₇  (11) -CH_TwoN-SO_TwoC₈F₁₇  ｜ C_TwoH_Five  (12) − (CH_Two)_TenNSO_TwoC₈F₁₇  ｜ CH_Three  (13) -CH_TwoNHSO_TwoC₈F₁₇  (14) − (CF_Two)₈-Ph-F (15) cs-CH_TwoCH_Two− (CF_Three)₆CF (CF_Three)_Two  (16) -CH_TwoCF_TwoCF_TwoCF_Three  (17) -CH_TwoCH_TwoCH_TwoCH_TwoF (18) -CH_Two(CF_Two)₆CF_Three  (19) -CH_Two(CF_Two)_FiveCF_Three  (20) − (CH_Two)_ThreeCF_Three

Among these compounds, the following (X
It is desirable to use the material of I). H R¹  │ │ C = C ・ ・ ・ (XI) │ │ H C-OR^Two− (CF_Two) m-CF_Three  ‖ O [However, R¹: Hydrogen, -CxHy or -CxFy (n = 1 or 2 or more
The number, y = 2x + 1. ) R^Two: (-CH_Two-) p (p ≧ 1 integer) or (-CH
_Two-) q-N (R^Three) SO_Two-(R^ThreeIs -CH_ThreeOr -C_TwoH_Five, Q ≧ 1) m: 6 or more
Is the integer above. ]

Accordingly, the most preferred specific compound of the member on the surface of the recording medium (A) in the present invention is And the like.

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, a monomer of the formula (XI) and a polymerizable monomer having a functional group, for example, CH ₂ CC (CH ₃ ) COO (CH ₂ ) ₂ OH CH ₂ CC (CH ₃ ) COOCH ₂ CH (OH) CH ₃ CH ₂ = CHCOOCH ₂ CH (OH) C ₈ F ₁₇ and other copolymers are prepared and a large number of functional groups are introduced into the polymer. A crosslinkable polymer produced by forming a copolymer with a monomer and subsequently crosslinking the copolymer containing a large number of functional groups with a crosslinking reagent is also an excellent material.

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 in the following chemical formula 1.

Embedded image

In the crosslinked polymer represented by the chemical formula 1, A
The block is an alkyl group which causes the above-mentioned change in thermal properties, while the B block is a site which cross-links linear polymers (cross-linked using diisocyanate as a cross-linking reagent).

In order to obtain a crosslinked film, a solution obtained by mixing the above-mentioned copolymer and a crosslinking reagent is applied as a coating solution on a substrate, and a crosslinked polymer film is obtained by heating or irradiating an electron beam or light. What should I do?

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. 1 (b) will be described. Here, the formula (XII), (XII) and the material Rf-COOH · · · shown in (XIV) (XII) Rf- OH ··· (XIII) Rf- (CH 2) n-SiX ··· (XIV (Rf: a group containing an alkyl group having 4 or more carbon atoms 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 1 or more X: chlorine, methoxy group or ethoxy group) It is desirable to use a material (surface energy is preferably about 50 dyn / cm or less) which is physically adsorbed or chemically bonded to the surface of an inorganic material such as copper or an organic material such as polyimide, polyester or polyethylene terephthalate.

Specific examples of the formulas (XII), (XIII) and (XIV) include CF_Three− (CF_Two)_Five-COOH, CF_Three− (CF_Two)₇-COOH, CF_Three− (CF_Two)₇− (CH_Two)_TwoOH, H- (CF_Two)_Ten-COOH, H- (CF_Two)_Ten-CH_TwoOH, F- (CF_Two)₆-CH_TwoCH_Two-Si (CH_Three)_TwoCl, CF_TwoCl (CF_Three) CF (CF_Two)_FiveCOOH, CF_Three(CF_Two)₇(CH_Two)_TwoSiCl_Three  And so on.

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. The configuration of the recording body (A) is roughly classified into a configuration formed by the surface member itself and a configuration in which the surface member is formed on a support (preferably a heat-resistant support). In this embodiment, the compound (surface member) itself is formed into a film, plate, or 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 above compound may penetrate into the support to some extent. Recorded body (A)
The thickness of the film itself is preferably 30 mm to 1 mm. However, 100Å to 10μm in terms of thermal conductivity, 10μm to 1mm in terms of wear resistance
Is excellent. The heat resistant temperature of the support is 50 ° C ~ 30
0 ° C is desirable.

The shape of the support may be any of a belt shape, a plate shape, and a drum shape, and is selected according to the use of the apparatus.
In particular, the drum shape is excellent in that dimensional accuracy in the device can be obtained. 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 surface forming material 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, Pt
Metals and metal oxides are preferred. These supports may be smooth, rough or porous.

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 to decrease. The vapor generated from the solid is the record (A)
Is condensed on the surface of or near the surface to generate a liquid, as in the case described above.

More specifically, the contact material (B) is as follows. That is, as the liquid that is one of the contact materials (B), in addition to water, an aqueous solution containing an electrolyte, an alcohol such as ethanol and n-butanol, a polyhydric alcohol such as glycerin and ethylene glycol, and a ketone such as methyl ethyl ketone. And nonpolar liquids such as linear hydrocarbons such as n-nonane and n-octane, cyclic hydrocarbons such as cyclohexane, and 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. Further, it may be a polar liquid.

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 vapors 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).

Other solids which are other materials of the contact material (B) include higher fatty acids, low molecular weight polyethylene, polymer gels (polyacrylamide gel, polyvinyl alcohol gel), silica gel, and compounds containing water of crystallization. can give.

As will be more apparent from the description below, when a recording agent containing a developer such as the above-mentioned liquid ink is used as the contact material (B), the developer is simultaneously developed with the latent image. This is extremely advantageous because imaging will take place.

Next, the heating means will be described. As heating means for forming a latent image, there is contact heating using a heater, a thermal head, or the like. FIG. 2A shows a state in which a film 2 of the compound constituting the surface of the recording medium (A) is formed on a substrate 1 and, for example, a liquid 3 of the contact material (B) is present on the film surface. Is shown. 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 in accordance with the heating temperature, 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 the absence of the contact material (B), that is, in air, in a vacuum, or in an atmosphere of an inert gas (FIG. 2 (b)), the surface of the film 2 is brought into reverse contact. It can be seen that the angle θr increases and shows liquid repellency again.

As a phenomenon which is somewhat similar to such a phenomenon, there is a method described in Japanese Patent Publication No. 54-41902 mentioned above. However, the method disclosed herein is significantly different in mechanism in that it provides a substantially disordered and generally amorphous layer of memory material in the recording material. That is, in the present invention, a state change cannot occur on the surface of the recording medium (A) without the presence of the contact material (B). Further, according to the method described in Japanese Patent Publication No. 54-41902, reversibility cannot be obtained by a simple operation.

As shown in FIG. 3A, the liquid 3 is changed according to the image information.
Heat is applied to the membrane 2 under the contact of (as shown in FIGS. 3 (b-1) and (b-2),
The same applies to a case where the film 2 in which no liquid is present is brought into contact with a liquid in a state where heat is applied to the film 2 in accordance with image information). 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 FIGS. 3 (b-1) and (b-2) show an example in which the film is directly heated.

FIG. 4 shows an example of the change in 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 in 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 a state of being in contact with the contact material (B) when forming a latent image is 50 ° C. to 250 ° C.
Is more preferable, and more preferably 80 ° C to 150 ° C. The heating time is about 0.1 ms to 1 second, preferably 0.5 m
Seconds to 2 ms. As for the heating timing,
(A) After the surface is heated, the recording material (A) is brought into contact with the contact material (B) before cooling, and the surface of the recording material (A) is brought into contact with the surface of the recording material (A) in contact with the contact material (B). Heating.

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 a recording medium in response to an image signal in a liquid or vapor atmosphere.
The surface of (A) is heated to form a liquid adhering area on the surface of the recording medium (A) (latent image formation), and thereafter, the recording agent is applied to the latent image portion by means of contacting the recording agent with the latent image portion. In this method, the recording material on the surface of the recording medium (A) is transferred onto recording paper (indirect recording method). Further, in the above method,
If means for bringing the recording agent into contact with the latent image portion again after the transfer of the recording agent is performed, a printing method using the recording body (A) as a printing plate is obtained. The other is a recording medium in which a latent image is formed in the absence of liquid or vapor after transferring a recording agent in the above method.
By heating the surface of (A) and erasing the latent image,
(A) is a reproducible recording method. FIGS. 5A and 5B show typical processes of 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. The recording body (A) has a surface in which the receding contact angle decreases in accordance with the heating temperature when heated and in contact with a liquid (for convenience, `` film 2 '' or `` recording body (A) surface ''
Is not limited to that form. Therefore, the recording medium (A) may have 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 less likely to be displaced when the recording body (A) is operated. It is preferable to use the recording medium (A) having a shape. For producing such a recording body (A), a method in which the film 2 is formed on the substrate 1 or a method in which the recording body (A) is formed using the molded body itself are preferable. Particularly, a method of forming a film on a substrate is desirable because the molded body generally has low mechanical strength. It is needless to say that the film 2 must be formed on the surface even when the recording body (A) is formed by the molded body itself.

When a resin is used for the recording medium substrate, it is not a good conductor of heat, and it takes some time until the surface of the recording medium (A) is heated to have liquid adhesion. Therefore, it may be conceivable to use a good heat conductor for the entire substrate or for a portion on the substrate 1.

FIG. 6A 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)
By providing a good heat conductor section on the substrate 1, heat diffusion in the plane direction is prevented, and the portion 2a having liquid adhesion is miniaturized. 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, a contact heating source such as a heater or a thermal head (in particular, a thermal head is effective) is used as a heating source.

As a specific example of these, means for selectively heating the surface of the recording medium (A) in contact with the liquid ink 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, heating is performed from the surface side of the recording medium 7,
Means for immediately bringing the liquid ink into contact with the recording body heating section (the surface of the recording body (A)), or the liquid ink 3a is brought into contact with the surface of the recording body 7 in advance, and in the contact state, the base 1 side or the liquid ink 3a It is desirable to employ means for heating from the side (FIG. 7).

As a means for supplying the liquid ink 3a, a recording medium
(A) A plate is provided at the bottom to fill the liquid ink 3a so that the recording medium (A) is always in contact with the liquid ink 3a in the plate, and a heating source (thermal head 43) for forming a latent image is provided near or on the plate. Is the simplest configuration (FIG. 7). Instead of a dish, a sponge-like porous body filled with liquid ink may be used. In this way, the latent image (S) is formed on the surface of the recording medium (A).
Is formed and visualization is performed at the same time.

After forming the latent image (S) using the liquid 3, the latent image (S) may be formed into a latent image with the liquid ink 3a. However, the method shown in FIG. This is advantageous in that the size of the device can be reduced because the device can be integrated.

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), the recording agent 3a 'on the recording medium (A) is recorded on the recording paper P by the capillary action of the recording paper P by providing a means for directly contacting the recording paper P or the like. The agent 3a 'is transferred (transfer means). 3a ″ is a transfer image. The transfer position may be any position on the recording medium (A) as long as it is after development, but is preferably a position where transfer is performed immediately after development. After the transfer, if the development is repeated without erasing the latent image, the apparatus becomes a printing apparatus. When the printing of one image information is completed, the recording medium (A) can be exchanged or the latent image can be erased to record / print another image information.
Reference numeral 8 denotes a transfer roller, and 9 denotes a driving circuit.

After the transfer means, the latent image portion is heated in the absence of liquid (including liquid ink) or vapor, that is, by heating the vicinity of the latent image portion in air, vacuum, or inert gas. If the image is erased, the recording medium (A) becomes a recording device that can be used repeatedly. 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 41 'is desirable (FIG. 7). The heating may be performed on the entire surface of the recording medium (A), or may be performed only on the latent image portion. However, heating over the entire surface is more preferable because the device configuration can be simplified.
Incidentally, the latent image erasing means, after performing heating for erasing, again, during the time until forming a latent image, the recording medium (A)
It is provided at a position where the surface is substantially cooled. The heating temperature required for erasing depends on the material of the surface of the recording medium (A),
It is desirable that the temperature be higher than the starting temperature at which the receding contact angle of the material on the surface of the recording medium (A) becomes lower and lower than the decomposition point.

Examples of recording paper (transfer medium) include transparent or opaque resin films, plain paper, ink jet recording paper,
Type paper is suitable.

Next, the recording agent will be described. In order to obtain a visible image on the surface of the recording medium (A) in the method of the present invention, a recording agent
As the (liquid ink), select and use a recording agent that is compatible with this process from the recording agents used in conventional print recording methods, such as writing ink, ink jet recording ink, printing ink, and electrophotographic toner. can do.

More specifically, for example, the aqueous ink may be a water-soluble ink mainly composed of water, a wetting agent and a dye or an aqueous pigment mainly composed of water, a pigment, a polymer compound for dispersion and a wetting agent. A dispersion ink, an emulsion ink in which a pigment or dye is dispersed in water using a surfactant, and the like are used. 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, reactive dyes and the like in a color index are used. Examples of typical dyes include CI Acid Yellow 17,23,42,44,79,142 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 19,22,3
2,38,51,56,71,74,75,77,154,168 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 and organic pigments can 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 pigment dispersing compounds include polyacrylamide, polyacrylic acid and alkali metal salts thereof, acrylic resins such as water-soluble styrene acrylic resin, water-soluble styrene-maleic acid resin, water-soluble vinyl naphthalene acrylic resin, water-soluble vinyl naphthalene Maleic acid resin, polyvinylpyrrolidone, polyvinyl alcohol, alkali metal salts of β-naphthalenesulfonic acid formalin condensate, high molecular compounds containing salts of cationic functional groups such as quaternary ammonium and amino groups, polyethylene oxide, gelatin,
Proteins such as casein, gum arabic, natural gums such as tragacanth gum, glucooxides 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, 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 emulsified in an oil base. Things, etc. are used.

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.

The oil base for dissolving the dye or dispersing the pigment includes hydrocarbons such as n-octane, n-decane, mineralane spirit, ligroin, naphtha, benzene, toluene and xylene; Butyl ether,
Examples thereof include ethers such as dihexyl ether, anisole, phenetol, and dibenzyl ether; and alcohols such as methanol, ethanol, isopropyl alcohol, benzyl alcohol, ethylene glycol, diethylene glycol, and glycerin.

The pigments exemplified above can be used in the oil-based ink. 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, casein, and the like.

By the way, when the latent image formed by the thermal head is visualized in accordance with the image signal and is transferred to a recording paper or the like, depending on the type of the recording paper or the like, the recording medium (A) It is sometimes recognized that what is exactly as the ink image on the surface is not faithfully transferred to recording paper or the like. For example, the situation is as shown in FIG. In FIG. 10A, reference numeral 20 denotes a visible image on the surface of the recording medium (A), and reference numeral 21 in FIG. 10B denotes a transfer image when the visible image is transferred to a recording paper or the like. In such a case, there is also a disadvantage that the liquid ink remains on the surface of the recording medium (A) and special cleaning must be performed .

The present inventors have conducted further studies to solve these problems, and as a result, the latent image formed on the surface of the recording medium (A) has been transferred to a circular or elliptical shape. It has been found that the characteristics are dramatically improved.

As shown in FIG. 9A, when the latent image (S) is made circular or elliptical, no disturbance of the fixed image is observed. In FIG. 9A, reference numeral 22 denotes ink adhered to the circular latent image on the surface of the recording medium (A), and reference numeral 23 in FIG. 9B denotes an image obtained by transferring this ink image to recording paper or the like.

In order to form such a latent image, in the example of FIG. 7, the cross section of the heating resistor portion of the thermal head 43 is made circular or elliptical (preferably circular), and the latent image is formed by rotation of the recording medium 7. There is no trailing of the image (S). At this time, a circular or elliptical latent image as shown in FIG. 9A is formed on the recording body 7 and a latent image as shown in FIG .
Thus, a fixed image 23 was obtained. At this time, no residual liquid ink 3a was observed on the surface of the recording medium (A).

In order to form a circular / elliptical latent image on the surface of the recording medium (A) by the thermal head 43, a heat generating portion of a well-known thermal head for thermal transfer recording as shown in FIG.
The heat dissipating body 43 'which is turned into a circular shape is formed by depositing aluminum. Thereby, the temperature of the portion of the heat radiator 43 ′ is lower than that of the portion 43 ″ without the heat radiator, and a substantially desired circular latent image can be formed on the recording body 7, as shown in FIG. A stable fixed image 23 can be obtained on recording paper or the like.

The present inventors have not yet reached a definitive reason for the reason why such a phenomenon is observed, but at the present time speculate as follows. In the case of a rectangular latent image as shown in FIG. 10A, the surface of the attached ink 20 facing the recording paper or the like is approximately flat, and the position of the ink 20 that first contacts the recording paper or the like is the position of the recording paper or the like. Is unstable due to the roughness of the fiber on the surface, and it is considered that the instability of the contact with the recording or the like reflects the disturbance of the fixed image 21. On the other hand, in a circular / elliptical latent image as shown in FIG. 9 (a), the surface of the attached ink 22 has a curvature due to surface tension, and is always a circular / elliptical latent image with recording paper or the like. It is expected that they touch each other at the center, which can be inferred as the reason why a stable fixed image 23 is generated.

[0095]

According to the method of the present invention, the following effects can be obtained. (1) A reversible desired image can be obtained with a simple operation. (2) Not only an image faithful to the original document can be obtained, but also no special cleaning is required since no liquid ink is left on the surface of the recording medium (A).

[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 a diagram for basically explaining the method of the present invention.

FIG. 4 shows a receding contact angle observed on the surface of the recording medium (A) when the surface of the recording medium (A) is heated while a liquid is in contact with the surface of the recording medium (A) used in the embodiment of the present invention. The figure showing the change of (theta) r.

FIG. 5 shows two embodiments of the method of the present invention.

FIG. 6 is a diagram showing an embodiment of the method of the present invention.

FIG. 7 is a diagram showing an embodiment of the method of the present invention.

FIG. 8 is a plan view of a heat radiator (heat generating resistor) provided in a heat generating portion of the thermal head in implementing the present invention.

FIG. 9 is a view for explaining the relationship between an ink image formed on the surface of a recording medium (A) and a transfer image.

FIG. 10 is a diagram for explaining the relationship between an ink image formed on the surface of a recording medium (A) and a transfer image.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... Film 3 ... Liquid (3a ... Liquid ink) 4 ... Heater (43 ... Thermal head) 7 ... Recording medium (A) 8 ... Transfer roller 9 ... Driving circuit

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yasuyuki Okada 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Akira Oyamaguchi 1-3-6 Nakamagome, Ota-ku, Tokyo No. Ricoh Co., Ltd. (56) References JP-A-3-178478 (JP, A) German Patent Application Publication 4010275 (DE, A1) Shigeru Hasegawa "Photoengraving Technology" Printing and Printing Laboratory (Showa 43) (Issued June 10, 2010) P.167-171 (Particularly, refer to the shapes of the dots in FIGS. 172 to 174) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41M 5/00 B41C 1/055

Claims (3)

(57) [Claims] A surface of a recording medium (A) described below is contacted with a contact member (B) described below.
Contacting the contact material (B) with the surface of the recording medium (A) selectively heated while the surface of the recording medium (A) is selectively heated while being in contact with the recording medium (A); A recording method comprising forming a latent image having a circular or elliptical dot shape having a corner and then visualizing the latent image with a recording agent and transferring the latent image to recording paper or the like. (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) A liquid, a vapor, or a solid that becomes liquid or generates a liquid or a vapor at or below the temperature at which the receding contact angle of the recording medium (A) starts to decrease. 2. The recording method according to claim 1, wherein a thermal head having a circular or elliptical heating resistor is used as a heat source for heating the latent image. 3. The recording method according to claim 1, wherein the dots forming the latent image are arranged in a staggered pattern.