JP2022031008A - Ink film forming original plate - Google Patents

Abstract

To provide an ink film forming original plate that can achieve both durability and rewrite responsiveness of a printing plate, is excellent in contract between a water repelling part and a hydrophilic part, and can be rapidly rewritten.SOLUTION: An ink film forming original plate comprises a substrate and a surface layer provided on the substrate, in which the surface layer contains an inorganic filler surface modified with a stimulation responsive compound that has hydrophilicity with water reversibly changing responding to an external stimulation.SELECTED DRAWING: None

Description

The present invention relates to an original plate for forming an ink film.

Offset printing is one of the typical lithographic printing. In offset printing, a hydrophilic part and a hydrophobic part are provided on the surface of a lithographic plate, the hydrophilic part is moistened with water, and ink that is immiscible with water is applied on the surface of the lithographic plate to transfer the ink of the hydrophobic part to paper or the like. ..

In the offset printing so far, a PS (Presented Plate) plate is used as an original plate (printing plate) for forming an ink film. This printing plate makes a difference between water repellency and hydrophilicity by using a stimulus such as ultraviolet rays, and a plate is produced based on the difference. In conventional printing plate production, even if one stimulus can produce a difference between water repellency and hydrophilicity at first, the difference between water repellency and hydrophilicity cannot be restored because there is only one stimulus. .. As a result, the PS plate creates a new plate each time a different image is printed. This has the problem that time is lost and the cost increases every time a planographic plate is made, and it also has an environmental disadvantage that the old plate is discarded every time a new plate is made. rice field.

In order to overcome such a disadvantage, a technique of rewriting a printing plate by two stimuli has been conventionally proposed. For example, Patent Document 1 proposes a pattern film forming method using first and second blankets having an ink film surface made of a single material.

On the other hand, in Patent Document 2, in order to improve the durability of the printing plate, an ink film having a surface layer containing a stimulus-responsive compound and a resin whose affinity with water changes reversibly in response to an external stimulus is formed. An original version has also been proposed.

Japanese Unexamined Patent Publication No. 2016-175192 Japanese Unexamined Patent Publication No. 2019-11905

However, in the technique described in Patent Document 1, although the printing plate can be rewritten, there is a problem that the durability of the printing plate is inferior because the surface of the printing plate is made of a single material.

Further, in the technique described in Patent Document 2, the durability of the printing plate is improved, but since the resin is contained in a relatively large amount, the structural conversion of the stimulus-responsive compound is unlikely to occur, and it is difficult to obtain high responsiveness. Had a problem. Further, in any of the techniques of Patent Documents 1 and 2, the contrast between the water-repellent portion and the hydrophilic portion cannot be sufficiently obtained, which may cause background stains on the printed matter.

Therefore, the present invention provides an original plate for forming an ink film, which can achieve both durability and rewrite responsiveness of a printing plate, has excellent contrast between a water-repellent portion and a hydrophilic portion, and can be quickly rewritten. The purpose.

The present inventors have accumulated extensive research. As a result, it was found that the above problem can be solved by an ink film forming original plate having a surface layer containing an inorganic filler surface-modified with a stimulus-responsive compound whose affinity with water changes reversibly in response to an external stimulus. , The present invention has been completed.

That is, the present invention has a substrate and a surface layer provided on the substrate, and the surface layer is made of a stimulus-responsive compound whose affinity with water changes reversibly in response to an external stimulus. An original plate for forming an ink film, which contains a surface-modified inorganic filler.

According to the present invention, it is possible to provide an ink film forming original plate which can achieve both durability and rewrite responsiveness of a printing plate, has excellent contrast between a water-repellent portion and a hydrophilic portion, and can be quickly rewritten.

(A) is a cross-sectional view schematically showing an original plate having a surface made of a "single material" of the prior art. (B) is a cross-sectional view schematically showing an original plate having a surface layer containing a stimulus-responsive compound and a resin of the prior art. (C) is a cross-sectional view schematically showing an original plate containing an inorganic filler surface-modified with a stimulus-responsive compound whose affinity with water changes reversibly in response to an external stimulus of the present invention. It is a figure which shows the outline of the reversible change of the affinity with water by an external stimulus in the inorganic filler surface-modified with a stimulus-responsive compound. It is a schematic diagram which shows the pattern film forming apparatus which concerns on one Embodiment of this invention. It is a figure which shows the image pattern used for evaluation. It is a figure which shows the intersection of the thin lines used for evaluation.

The present invention has a substrate and a surface layer provided on the substrate, and the surface layer is surfaced with a stimulus-responsive compound whose affinity with water changes reversibly in response to an external stimulus. An original plate for forming an ink film containing a modified inorganic filler. The ink film forming original plate having this structure can achieve both durability and rewrite responsiveness of the printing plate, has excellent contrast between the water-repellent portion and the hydrophilic portion, and can be rewritten quickly. The original plate for forming an ink film of the present invention is also hereinafter referred to as a "printing original plate" or an "original plate".

The reason why the above effect is obtained by the original version of the present invention is unknown, but the following mechanism can be considered. The following mechanism is speculative, and the present invention is not limited to the following mechanism.

FIG. 1A is a cross-sectional view schematically showing an original plate having a surface made of a single material. When using an original plate having a surface made of a single material as shown in FIG. 1 (A) as in the technique described in Patent Document 1, if rewriting and drawing are repeated, the deterioration of the single material causes. It turned out that there was a problem with the durability of the original plate, in which the surface of the original plate was damaged and became brittle, and the reproducibility of fine lines deteriorated.

FIG. 1B is a cross-sectional view schematically showing an original plate having a surface layer containing a stimulus-responsive compound and a resin. When an original plate having a surface layer containing a stimulus-responsive compound and a resin as shown in FIG. 1 (B) is used as in the technique described in Patent Document 2 described above, durability is improved, but hydrophilicity / hydrophilicity / There was a problem that the responsiveness of the water repellency control became insufficient, and it was found that there was a trade-off relationship between the durability of the original plate and the stimulus responsiveness. That is, since the resin is contained in a relatively large amount, the durability of the printing plate is improved, but the stimulus-responsive compound is buried in the resin, which makes it difficult for structural conversion to occur and the responsiveness is lowered. .. On the other hand, further improvement is required in terms of durability, which enables clear and reproducible printing of small characters and fine images even if the pattern is repeatedly rewritten.

Further, in any of the techniques of Patent Documents 1 and 2, it is difficult to sufficiently control the affinity of the surface of the original plate with water only by controlling the affinity with water by the stimulus-responsive compound. In some cases, the contrast of the hydrophilic portion was not sufficiently obtained, which caused background stains in the printed matter.

On the other hand, the original plate of the present invention has a surface layer containing an inorganic filler surface-treated with a stimulus-responsive compound whose affinity with water changes reversibly in response to an external stimulus. The inorganic filler surface-modified with the stimulus-responsive compound can reversibly change the wettability of the surface of the inorganic filler. For example, FIG. 2 shows an outline of changes when a photoresponsive compound is used as the stimulus-responsive compound. As shown in FIG. 2, UV / visible light irradiation causes the stimulus-responsive compound to undergo photoisomerization, the bipolar moment changes, and the wettability of the surface of the inorganic filler changes. Especially when the stimulus-responsive compound has a hydrophilic group, the change in wettability becomes larger. By this change in wettability, the water repellency and hydrophilicity of the surface of the inorganic filler can be reversibly changed. In the present invention, since the stimulus-responsive compound is immobilized on the inorganic filler, it is not buried in the resin as in the technique described in Patent Document 2, and the degree of freedom of structural conversion of the stimulus-responsive compound is high. Will be higher. As described above, the structural conversion occurs more flexibly and with a high degree of freedom, so that the responsiveness at the time of rewriting the image pattern can be improved. Therefore, by applying an external stimulus, the plate can be rewritten more quickly.

FIG. 1C is a cross-sectional view schematically showing an original plate containing an inorganic filler surface-modified with a stimulus-responsive compound whose affinity with water changes reversibly in response to an external stimulus of the present invention. be. As shown in FIG. 1 (C), the original plate for forming an ink film of the present invention has irregularities (roughness) due to an inorganic filler on the surface of the printing plate when viewed microscopically. When controlling the affinity of the stimulus-responsive compound with water by an external stimulus, this fine unevenness (roughness) plays a role of keeping water like grain. Further, since the specific surface area of the surface layer is increased by using the inorganic filler, the surface area of the original plate is increased, and the effect of controlling the wettability of the stimulus-responsive compound can be enhanced. As a result, the water-repellent / hydrophilic contrast on the surface of the original plate can be sufficiently obtained.

Furthermore, inorganic materials such as inorganic fillers have higher hardness than organic materials, and by using such materials on the surface of the ink film forming original plate in contact with ink or blanket, the hardness can be increased and the durability can be improved. ..

Hereinafter, the configuration of the original plate for forming an ink film of the present invention will be described in detail.

In the present specification, "X to Y" indicating a range means "X or more and Y or less". Unless otherwise specified in the present specification, the operation and the measurement of physical properties are performed under the conditions of room temperature (20 to 25 ° C.) / relative humidity of 40 to 50% RH.

[Original plate for forming ink film]
[Composition of original plate]
The original plate for forming an ink film of the present invention preferably has a surface layer containing an inorganic filler surface-modified with a stimulus-responsive compound arranged on a substrate. A plurality of layers may be arranged between the substrate and the surface layer.

(substrate)
The shape of the substrate is not particularly limited, and examples thereof include a flat plate shape and a cylindrical shape.

The material of the substrate is also not particularly limited, and is, for example, aluminum, an aluminum alloy (such as an alloy of aluminum and magnesium or / and silicon), a metal such as iron or stainless steel, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and the like. Examples thereof include plastics such as polyacrylonitrile, polyvinyl chloride, epoxy resin, phenol resin, and styrene-butadiene rubber. These may be used alone or in combination of two or more.

The substrate may have either a single layer or a multi-layered form. Further, in the case of multiple layers, each layer may be composed of different materials.

(Surface layer)
<Stimulation-responsive compound>
A stimulus-responsive compound is a compound that reversibly changes its properties in response to an external stimulus. In the present invention, a stimulus-responsive compound whose affinity with water changes reversibly in response to an external stimulus is used.

In addition, the fact that the affinity with water changes reversibly in response to an external stimulus means that the compound given the external stimulus changes reversibly between hydrophilicity and water repellency in response to the external stimulus. To do.

Here, "hydrophilicity" and "water repellency" are specifically defined as hydrophilicity when the contact angle is measured by the static drip method in the wettability test method of JISR3257: 1999 substrate glass surface and the temperature is 15 ° or less. When the temperature is 50 ° or more, the water repellency is considered.

Here, "reversibly changing between hydrophilicity and water repellency" specifically means that the state of existence of the molecule changes in response to an external stimulus, and the hydrophilicity and water repellency change. That is. The above-mentioned state of existence of a molecule refers to a molecular structure and a state of aggregation of molecules. For example, in the case of a photoresponsive compound, the molecular structure changes in response to light, which changes the dipole moment, and the orientation of the hydrophilic group to the surface changes, resulting in hydrophilicity and water repellency. In the case of a temperature-responsive compound, the hydrophilicity and water repellency can be controlled by changing the aggregated state of the molecule in response to the temperature.

The external stimulus is not particularly limited, and examples thereof include light, temperature change, pressure, electric field, and pH.

Examples of stimulus-responsive compounds are photo-responsive compounds whose affinity with water changes reversibly in response to light, and temperature-responsive compounds whose affinity with water changes reversibly in response to temperature changes. Examples thereof include compounds, electric field responsive compounds whose affinity with water changes reversibly in response to an electric field, and pH responsive compounds whose affinity with water changes reversibly in response to pH.

As the stimulus-responsive compound, a synthetic product or a commercially available product may be used. In addition, the stimulus-responsive compound can be used alone or in combination of two or more. Among them, a photoresponsive compound or a temperature-responsive compound is preferable from the viewpoint of a rapid change rate of affinity with water. Further, a photoresponsive compound is preferable from the viewpoints that it is difficult to diffuse due to temperature changes, it is easy to digitally process with light, and it is easy to pattern.

Hereinafter, photo-responsive compounds and temperature-responsive compounds, which are suitable stimulus-responsive compounds, will be described.

<Photoresponsive compound>
The photoresponsive compound according to the present invention is a compound that undergoes stereoisomerization or structural isomerization (cis-trans isomerization, photoopening reaction, etc.) by light irradiation, and its affinity with water is reversibly changed. .. Specific examples of such a compound include a compound having an azobenzene structure, a compound having a spiropyran structure, a compound having a stelvene structure, a compound having a diarylethene structure, a compound having an azomethine structure, and a compound having a heterocyclic structure. Can be mentioned. These compounds may be in the form of macromolecules or crosslinked macromolecules.

Among these, a compound having the structure of the following chemical formula (I), which causes cis-trans isomerization by light irradiation, is preferable from the viewpoint of the rapid change rate of affinity with water.

In the above chemical formula (I), Z _a and Z _b are both nitrogen atoms, or Z _a and Z _b are independently N or CH, respectively, and Z _a ≠ Z _b , R. ₁ to R ₅ are groups each independently having a hydrogen atom, an alkyl group, an alkoxy group, a halogen group, a hydrophilic group or a surface modification functional group, and R ₆ is a group having a cyclic structure. In this case, at least one of R ₁ to R ₅ is a group having a surface-modifying functional group, or R ₆ contains a group having at least one surface-modifying functional group.

The compound represented by the above chemical formula (I) contains a group having at least one surface-modified functional group, and at least one of R ₁ to R ₅ may be a group having a surface-modified functional group, and R ₆ may be a group. It may have a group containing at least one surface-modifying functional group. It is more preferable that at least one of R ₁ to R ₅ is a group having a surface-modifying functional group. Further, the compound represented by the above chemical formula (I) preferably has at least one hydrophilic group, and at this time, at least one of R ₁ to R ₅ may be a hydrophilic group, and R ₆ may be a hydrophilic group. It may have at least one hydrophilic group.

Further, since the photoresponsive compound according to the present invention is surface-modified to an inorganic filler, it is preferable that the photoresponsive compound has a surface-modifying functional group. The surface-modified functional group referred to here represents a group having a bondability to a polar group such as a hydroxy group existing on the surface of the metal oxide particles. Examples of the surface-modifying functional group include a carboxy group, a hydroxy group, a silyl halide group, an alkoxysilyl group and the like, and among these, a silyl group halide because it reacts quickly with the surface of metal oxide particles. An alkoxysilyl group is preferred. Here, examples of the alkoxysilyl group include, but are not limited to, a trimethoxysilyl group, a triethoxysilyl group, a triisopropoxysilyl group, and a trin-propoxysilyl group. The carboxy group and the hydroxy group have both a surface-modifying functional group and a hydrophilic group.

As will be described later, it is preferable that a surface-modifying functional group is introduced into the stimulus-responsive compound by a urethanization reaction. Therefore, the stimulus-responsive compound preferably contains a urethane bond (NH-COO).

That is, in one embodiment of the present invention, the stimulus-responsive compound has —O (CO) NH-Rd'-Re as a group having a surface-modified functional group. Here, Rd'is a divalent hydrocarbon group, for example, a linear or branched alkylene group having 2 to 8 carbon atoms or a linear or branched alkaneylene group having 2 to 8 carbon atoms. Re is a surface-modifying functional group, preferably selected from the group consisting of a carboxy group, a hydroxy group, a halogenated silyl group, and an alkoxysilyl group.

Further, the stimulus-responsive compound preferably has a hydrophilic group from the viewpoints of a rapid change in affinity with water and a large change in affinity with water. The hydrophilic group is a functional group capable of forming a hydrogen bond with water and improving the affinity with water. Examples of the hydrophilic group include a hydroxy group, a carboxy group, a mercapto group, a sulfonic acid group, a sulfate group, a phosphoric acid group, an amino group and the like. These hydrophilic groups may be used alone or in combination of two or more. Among them, the hydrophilic group is preferably a hydroxy group or a carboxy group from the viewpoint that the change rate of the affinity with water is fast.

When both Z _a and Z _b in the above chemical formula (I) are nitrogen atoms, R ₆ has a cyclic structure such as, for example, a benzene ring, a pyrazole ring, a pyrrole ring, an imidazole ring, a triazole ring, or a tetrazole ring. The group is mentioned. When one of Z _a and Z _b is N and the other is CH in the above chemical formula (I), examples of R ₆ include groups having a cyclic structure such as a pyrrole ring, a thiophene ring, and a furan ring. Such a compound is preferable because the structural change can be easily maintained.

Above all, the photoresponsive compound used in the present invention is preferably a compound represented by the following chemical formula (Ia).

In the above chemical formula (Ia), the definitions of R ₁ to R ₆ are the same as those of the above chemical formula (I).

Specific examples of the photoresponsive compound used in the present invention include a compound having an azomethine structure represented by the following chemical formula (1), a compound having an azobenzene structure represented by the following chemical formula (2), and a heterocyclic structure. Compounds having the above are preferred.

(Compound with azomethine structure)
Examples of the compound having an azomethine structure used in the present invention include compounds represented by the following chemical formula (1).

In the chemical formula (1), X is NR ₂₀ , O or S. R ₂₀ is a hydrogen atom, a halogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxycarbonyl group having 2 to 19 carbon atoms, or a hydroxy group.

Z ₁ and Z ₂ are independently N or CH, and Z ₁ ≠ Z ₂ .

R ₁₁ and R ₁₂ are independently each of a group represented by the chemical formula (1a), a hydrophilic group, a group having a surface-modifying functional group, a hydrogen atom, a halogen atom, an alkyl group having 1 to 18 carbon atoms, and the like. It is an alkoxy group having 1 to 18 carbon atoms, an acyl group having 2 to 19 carbon atoms, an alkoxycarbonyl group having 2 to 19 carbon atoms, a cyano group, or a nitro group.

In one embodiment, R ₁₁ and R ₁₂ are independently each of a group represented by the chemical formula (1a), a hydrogen atom, a halogen atom, an alkyl group having 1 to 18 carbon atoms, and an alkoxy having 1 to 18 carbon atoms. A group, an acyl group having 2 to 19 carbon atoms, an alkoxycarbonyl group having 2 to 19 carbon atoms, a cyano group, a nitro group, a hydroxy group or a carboxy group.

At this time, either R ₁₁ or R ₁₂ is a group represented by the chemical formula (1a).

Independently, R ₁₃ and R ₁₄ have a hydrophilic group, a group having a surface-modifying functional group, a hydrogen atom, a halogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, and a carbon number of carbon atoms. It is an acyl group of 2 to 19, an alkoxycarbonyl group having 2 to 19 carbon atoms, a cyano group, or a nitro group. At this time, at least one of R ₁₃ and R ₁₄ and R ₁₅ to R ₁₉ described later is a group having a surface-modifying functional group, and at least one of R ₁₃ and R ₁₄ is a group having a surface-modifying functional group. Is preferable.

In the chemical formula (1a), R ₁₅ to R ₁₉ are independently hydrophilic groups, groups having a surface-modifying functional group, hydrogen atoms, halogen atoms, alkyl groups having 1 to 18 carbon atoms, and 1 to 1 carbon atoms. It is an alkoxy group of 18, an acyl group having 2 to 19 carbon atoms, an alkoxycarbonyl group having 2 to 19 carbon atoms, a cyano group, or a nitro group.

Examples of surface-modified functional groups are as described above. When a group having a plurality of surface-modifying functional groups is contained, these may be the same or different from each other. Further, the example of the hydrophilic group is the same as described above. Among them, as the hydrophilic group, a hydroxy group, a carboxy group, a sulfonic acid group, or an amino group is preferable, and a hydroxy group or a carboxy group is particularly preferable. When a plurality of hydrophilic groups are contained, they may be the same or different from each other.

Examples of alkyl groups having 1 to 18 carbon atoms include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group and n. -Linear alkyl groups such as nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group; isopropyl group, Isobutyl group, sec-butyl group, t-butyl group, isoamyl group, t-pentyl group, neopentyl group, 1-methylpentyl group, 4-methyl-2-pentyl group, 3,3-dimethylbutyl group, 2-ethylbutyl Group, 1-methylhexyl group, t-octyl group, 1-methylheptyl group, 2-ethylhexyl group, 2-propylpentyl group, 2,2-dimethylheptyl group, 2,6-dimethyl-4-heptyl group, 3 , 5,5-trimethylhexyl group, 1-methyldecyl group, 1-hexylheptyl group and other branched alkyl groups; and the like.

Examples of alkoxy groups having 1 to 18 carbon atoms are methoxy group, ethoxy group, n-propoxy group, n-butoxy group, n-pentyloxy group, n-hexyloxy group, n-heptyloxy group and n-octyl. Oxy group, n-nonyloxy group, n-decyloxy group, n-undecyloxy group, n-dodecyloxy group, n-tridecyloxy group, n-tetradecyloxy group, n-pentadecyloxy group, n-hexa Linear alkoxy groups such as decyloxy groups: isopropoxy group, t-butoxy group, 1-methylpentyloxy group, 4-methyl-2-pentyloxy group, 3,3-dimethylbutyloxy group, 2-ethyl Butyloxy group, 1-methylhexyloxy group, t-octyloxy group, 1-methylheptyloxy group, 2-ethylhexyloxy group, 2-propylpentyloxy group, 2,2-dimethylheptyloxy group, 2,6- Examples thereof include branched alkoxy groups such as a dimethyl-4-heptyloxy group, a 3,5,5-trimethylhexyloxy group, a 1-methyldecyloxy group and a 1-hexylheptyloxy group; and the like.

Examples of acyl groups having 2 to 19 carbon atoms are saturated or unsaturated linear or branched acyl groups, such as acetyl groups, propanoyl groups (propionyl groups), butanoyl groups (butyryl groups), isobutanoyl groups. (Isobutyryl group), pentanoyl group (valeryl group), isopentanoyl group (isovaleryl group), sec-pentanoyl group (2-methylbutyryl group), t-pentanoyl group (pivaloyl group), hexanoyl group, heptanoyle group, octanoyl group, t-octanoyl group (2,2-dimethylhexanoyl group), 2-ethylhexanoyl group, nonanoyl group, isononanoyl group, decanoyl group, isodecanoyl group, undecanoyl group, lauroyl group, myristoyl group, palmitoyl group, stearoyl group, behenoyle Examples include groups, undecylenoyl groups, oleoyl groups and the like.

Examples of alkoxycarbonyl groups having 2 to 19 carbon atoms are linear or branched, and are, for example, methoxycarbonyl groups, ethoxycarbonyl groups, n-butoxycarbonyl groups, n-hexyloxycarbonyl groups, n-heptyloxy. Carbonyl group, n-octyloxycarbonyl group, n-nonyloxycarbonyl group, n-decyloxycarbonyl group, n-undecyloxycarbonyl group, n-dodecyloxycarbonyl group, n-tridecyloxycarbonyl group, n-tetra Linear alkoxycarbonyl groups such as decyloxycarbonyl group, n-pentadecyloxycarbonyl group, n-hexadecyloxycarbonyl group: 1-methylpentyloxycarbonyl group, 4-methyl-2-pentyloxycarbonyl group, 3 , 3-Dimethylbutyloxycarbonyl group, 2-ethylbutyloxycarbonyl group, 1-methylhexyloxycarbonyl group, t-octyloxycarbonyl group, 1-methiheptyloxycarbonyl group, 2-ethylhexyloxycarbonyl group, 2-propyl Pentyloxycarbonyl group, 2,2-dimethylheptyloxycarbonyl group, 2,6-dimethyl-4-heptyloxycarbonyl group, 3,5,5-trimethylhexyloxycarbonyl group, 1-methyldecyloxycarbonyl group, 1- Examples thereof include branched alkoxycarbonyl groups such as hexylheptyloxycarbonyl groups.

More specific examples of the compound having an azomethine structure include the following compound (1).

(Compound having an azobenzene structure)
Specifically, the compound having an azobenzene structure used in the present invention is preferably a compound represented by the following chemical formula (2).

In the above chemical formula (2), R ₂₁ to R ₃₀ are independently hydrophilic groups, groups having a surface-modifying functional group, hydrogen atoms, halogen atoms, alkyl groups having 1 to 18 carbon atoms, and 1 to 1 carbon atoms. It is an alkoxy group of 18, an acyl group having 2 to 19 carbon atoms, an alkoxycarbonyl group having 2 to 19 carbon atoms, a cyano group, or a nitro group. At this time, at least one of R ₂₁ to R ₃₀ is a group having a surface-modifying functional group.

Examples of hydrophilic groups are as described above. When a plurality of hydrophilic groups are contained, they may be the same or different from each other.

In the above chemical formula (2), from the viewpoint of reactivity with the surface of the inorganic filler, it is preferable that at least one of R ₂₂ to R ₂₄ and R ₂₇ to R ₂₉ is a group having a surface-modifying functional group, and R ₂₃ and R are preferable. It is more preferable that at least one of ₂₈ is a group having a surface-modifying functional group.

Examples of surface-modified functional groups are as described above. When a group having a plurality of surface-modifying functional groups is contained, these may be the same or different from each other.

Examples of an alkyl group having 1 to 18 carbon atoms, an example of an alkoxy group having 1 to 18 carbon atoms, an example of an acyl group having 2 to 19 carbon atoms, and an example of an alkoxycarbonyl group having 2 to 19 carbon atoms are as described above. be.

More specific examples of the compound having an azobenzene structure include the following compounds (2), (4) and (5).

(Compound having a heterocyclic structure)
Examples of the compound having a heterocyclic structure used in the present invention include compounds in which one of the compounds represented by the chemical formula (2) is replaced with a pyrazole ring. The pyrazole ring may or may not be substituted. For example, the pyrazole ring has a hydrophilic group, a group having a surface-modifying functional group, a halogen atom, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, and an acyl having 2 to 19 carbon atoms as substituents. It may have a group, an alkoxycarbonyl group having 2 to 19 carbon atoms, a cyano group, or a nitro group.

Specific examples of the compound having a heterocyclic structure include the following compounds (3) and (6).

The photoresponsive compound may be used alone or in combination of two or more. Further, as the photoresponsive compound, a commercially available product or a synthetic product may be used.

Examples of the method for synthesizing the photoresponsive compound include the following methods. For example, as a compound having an azomethine structure represented by the chemical formula (1), the compound (1) has an aniline derivative and a furan having an aldehyde group in an alcohol such as ethanol or methanol as shown in the reaction formula below. It can be synthesized by reacting a heterocyclic compound such as a derivative.

For example, aniline and 5-bromo-2-flualdehyde are heated and stirred in ethanol to react, the reaction solution is filtered, and the obtained powder is recrystallized in a mixed solvent of methanol / ethanol. An azomethine compound (intermediate A) can be obtained.

The method for introducing a surface-modifying functional group into the azomethin compound is not particularly limited. For example, a method using the urethanization reaction which is a reaction between the hydroxy group and the isocyanate group described above and a method using the hydrosilylation reaction can be mentioned, but the method using the urethanization reaction is preferable because of the ease of synthesis. ..

When the urethanization reaction is used, for example, a group having a surface-modifying functional group can be introduced into the azomethin compound by reacting the azomethine compound having a hydroxy group with an isocyanate group-containing silane coupling agent.

The method for obtaining the azomethin compound having a hydroxy group is not particularly limited, but as shown in the following scheme, the azomethin compound (intermediate A) having a halogen atom is reacted with an aqueous solution of sodium hydroxide under high temperature and high pressure and treated with an acid. By doing so, a method for obtaining an azomethine compound (intermediate B) having a hydroxy group can be adopted.

Examples of the isocyanate group-containing silane coupling agent include 3-isocyanatepropyltriethoxysilane and 3-isocyanatepropyltrimethoxysilane. As the isocyanate group-containing silane coupling agent, a commercially available product may be used, and for example, KBE-9007N manufactured by Shin-Etsu Chemical Co., Ltd. may be used. The amount of the isocyanate group-containing silane coupling agent used is not particularly limited and can be appropriately adjusted.

A reaction catalyst may be used to enhance the reactivity of the isocyanate group. The reaction catalyst is not particularly limited, but an organic tin catalyst is preferable, and tin octylate, tin naphthenate, dibutyltin dioctate, dibutyltin dilaurate, dibutyltin diacetate, dibutyltin zimareate, dibutyltin distearate, dioctyltin dilaurate and the like are preferable. It can be used, but is not limited to these. The above reaction catalyst may be used in combination of two or more. The amount of the reaction catalyst used is not particularly limited, but is, for example, 0.01 to 0.5 parts by mass with respect to 100 parts by mass of the isocyanate group-containing silane coupling agent.

The reaction solvent is not particularly limited, but is limited to aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; aliphatic or alicyclic hydrocarbons such as hexane, cyclohexane and methylcyclohexane; 1 , 2-Dichloroethane and other halogenated alkanes; ethers such as t-butylmethyl ether; methylethyl ketone, methylisobutylketone, cyclohexanone, cyclopentanone, acetylacetone and other ketones; and the like.

The reaction temperature and time are not particularly limited. For example, it can be carried out at a temperature of 40 to 80 ° C., preferably 50 to 70 ° C., for example, in the range of 1 to 12 hours, preferably 2 to 10 hours.

The desired compound represented by the above chemical formula (1) can be obtained by appropriately changing the raw material with reference to the above reaction formula. Depending on the selection of the raw material, the reaction for obtaining the intermediate B can be omitted. Further, for example, in the reaction for obtaining the above intermediate A, the above chemical formula (1) is obtained by reacting benzaldehyde with 5-bromo-2-aminofuran instead of the reaction between aniline and 5-bromo-2-flualdehyde. In 1), a compound in which Z ₁ is N and Z ₂ is CH can be obtained.

For example, as a method for synthesizing the azobenzene compound (compound (5)) having a hydrophilic group represented by the above chemical formula (2), a method represented by the following reaction formula can be mentioned. 2-Chloro-4-aminophenol and sodium nitrite are reacted under cooling to synthesize a diazonium salt, which is then reacted with 2-chlorophenol to obtain Intermediate D, to which n-bromohexane is added. The reaction is carried out to synthesize intermediate E. When a hydroxy group, which is a hydrophilic group, is introduced, the obtained intermediate E is reacted with an aqueous sodium hydroxide solution under high temperature and high pressure, and treated with an acid to obtain an intermediate F having a hydrophilic group. .. Then, the target compound (5) can be obtained by introducing a group having a surface-modifying functional group by the same method as described above.

In the above reaction formula, an azobenzene compound having a desired substituent can be obtained by appropriately changing the raw material. Further, an azobenzene compound such as a commercially available product may be separately prepared and a group having a surface-modifying functional group may be introduced by a urethanization reaction or the like.

For example, as a method for synthesizing the compound having the above heterocyclic structure, a method represented by the following reaction formula can be mentioned. 5-Amino-o-cresol and sodium nitrite are reacted under cooling to synthesize a diazonium salt, which is then reacted with 1-methyl-1H-pyrazole to synthesize intermediate C. Next, the target compound (3) can be obtained by introducing a group having a surface-modifying functional group into Intermediate C by the same method as described above.

In the above reaction formula, a compound having a desired heterocyclic structure can be obtained by appropriately changing the raw material. Further, a compound having a heterocyclic structure such as a commercially available product may be separately prepared, and a group having a surface-modifying functional group may be introduced by a urethanization reaction or the like.

<Temperature-responsive compound>
The temperature-responsive compound used in the present invention is a compound whose affinity with water changes reversibly in response to a temperature change. The temperature-responsive compound reversibly changes from water-repellent (or hydrophilic) to hydrophilic (or water-repellent) at the critical dissolution temperature (CST) in water. As a temperature-responsive compound,
(1) A temperature-responsive compound that exhibits hydrophilicity at a temperature lower than the critical melting temperature (the critical melting temperature at this time is particularly referred to as "lower limit critical melting temperature (LCST)"), but exhibits water repellency at a temperature equal to or higher than the same temperature. (2) A temperature-responsive compound that exhibits hydrophilicity at a temperature equal to or higher than the critical melting temperature (the critical melting temperature at this time is particularly referred to as "upper critical melting temperature (UCST)"), but exhibits water repellency at a temperature lower than the same temperature. Any of these can be used.

The temperature-responsive compound is not particularly limited, and examples thereof include acrylic polymers and methacrylic polymers. Specific examples include, for example, poly (Nn-propylacrylamide) (LCST: 21 ° C.), poly (Nn-propylmethacrylamide) (LCST: 27 ° C.), poly (N-isopropylacrylamide) (LCST:). 32 ° C.), Poly (N-isopropylmethacrylamide) (LCST: 43 ° C.), Poly (N-ethoxyethylacrylamide) (LCST: approx. 35 ° C.), Poly (N-tetrahydrofurfurylacrylamide) (LCST: approx. 28 ° C.) ), Poly (N-tetrahydrofurfurylmethacrylamide) (LCST: about 35 ° C), Poly (N, N-diethylacrylamide) (LCST: 32 ° C), Poly-N, N-ethylmethylacrylamide (LCST: 56 ° C) ), Poly (N-ethylacrylamide), Poly (N-cyclopropylacrylamide) (LCST: 45 ° C.), Poly (N-cyclopropylmethacrylamide), etc. Examples thereof include molecules, poly (N-acrylamide), poly (N-acrylamide), polymethylvinyl ethers, and copolymers thereof. Specifically, a copolymer having the above-mentioned structural unit derived from N-substituted (meth) acrylamide and the above-mentioned structural unit derived from (meth) acrylic acid having a surface-modified functional group introduced therein, or the above-mentioned N-. A polymer having a constituent unit derived from substituted (meth) acrylamide and having a surface-modifying functional group introduced at the terminal can be used. The form of the surface-modified functional group is the same as described above. Further, the method for introducing the surface-modifying functional group is not particularly limited, and a conventionally known method can be appropriately adopted.

Examples of the temperature-responsive compound include alkyl substituted cellulose derivatives such as methyl cellulose, ethyl cellulose and hydroxypropyl cellulose, and polyalkylene oxide block copolymers such as block copolymers of polypropylene oxide and polyethylene oxide.

Among these temperature-responsive compounds, from the viewpoint that the terminal can be easily modified to a functional group such as a carboxylic acid group, an amine group, or a maleimide group, or by copolymerizing with methacrylic acid, pH responsiveness is imparted. A polymer having a structural unit derived from N-substituted (meth) acrylamide is preferable from the viewpoint of being able to form a polymer.

These temperature-responsive compounds are not particularly limited, but can be obtained by polymerizing the monomers by irradiation or by solution polymerization.

As the monomer, one in which the homopolymer obtained by polymerizing the monomer exhibits temperature responsiveness (hereinafter, also referred to as “temperature responsive monomer”) can be used. The temperature-responsive monomer is not particularly limited, and examples thereof include N- (or N, N-di) substituted (meth) acrylamide compounds, (meth) acrylamide compounds having a cyclic group, vinyl ether compounds, and the like. .. The temperature-responsive compound may be a homopolymer obtained by polymerizing one kind of temperature-responsive monomer, or may be a copolymer obtained by polymerizing two or more kinds of temperature-responsive monomers. It may be a polymer. The copolymer may be a graft copolymer, a block copolymer, or a random copolymer.

In addition to the above-mentioned temperature-responsive monomer, the temperature-responsive compound itself does not correspond to the temperature-responsive monomer as long as it does not inhibit the temperature-responsiveness. It may be a copolymer obtained by polymerizing the components. The copolymer may be any of a random copolymer, a block copolymer, and a graft copolymer.

Further, the temperature-responsive compound may be a crosslinked product of these polymers. When the temperature-responsive polymer is a cross-linked product, such cross-linked product includes, for example, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-n-propyl (meth) acrylamide, and N-isopropyl ( N-alkyl (meth) acrylamides such as meta) acrylamide, Nn-butyl (meth) acrylamide, N-isobutyl (meth) acrylamide, Nt-butyl (meth) acrylamide; N-vinylisopropylamide, N-vinyl N-vinylalkylamides such as -n-propylamide, N-vinyl-n-butylamide, N-vinylisobutylamide, N-vinyl-t-butylamide; vinylalkyl ethers such as vinylmethyl ether and vinylethyl ether; ethylene oxide. , Acrylamides such as propylene oxide; monomers such as 2-alkyl-2-oxazoline such as 2-ethyl-2-oxazoline, 2-n-propyl-2-oxazoline, 2-isopropyl-2-oxazoline or simplex thereof. Examples thereof include polymers obtained by polymerizing two or more kinds of monomers in the presence of a cross-linking agent.

As the above-mentioned cross-linking agent, conventionally known ones may be appropriately selected and used, and for example, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, N, N'-methylenebis (meth) acrylamide, and tri. Crosslinkable monomers with polymerizable functional groups such as range isocyanate, divinylbenzene, polyethylene glycol di (meth) acrylate; glutaaldehyde; polyhydric alcohols; polyvalent amines; polyvalent carboxylic acids; metals such as calcium ions and zinc ions. Ions and the like can be preferably used. These cross-linking agents may be used alone or in combination of two or more.

The molecular weight of the temperature-responsive compound is not particularly limited, but it is preferable that the number average molecular weight measured by gel permeation chromatography (GPC) is 3,000 or more.

The temperature-responsive compound may be used alone or in combination of two or more. Further, as the temperature-responsive compound, a commercially available product may be used, or a compound obtained by synthesis may be used.

Specific examples of the temperature-responsive compound include the following compound (7).

<Inorganic filler>
In the present invention, the inorganic filler is a particle whose surface is composed of a metal oxide at least, and is preferably a metal oxide particle.

The shape of the particles is not particularly limited, and may be any shape such as powder, sphere, rod, needle, plate, columnar, indefinite shape, flaky shape, spindle shape and the like.

Examples of the metal oxide constituting the metal oxide particles are not particularly limited, but silica (silicon oxide), magnesium oxide, zinc oxide, lead oxide, alumina (aluminum oxide), tin oxide, tantalum oxide, indium oxide, and the like. Bismus oxide, yttrium oxide, cobalt oxide, copper oxide, manganese oxide, selenium oxide, iron oxide, zirconium oxide, germanium oxide, titanium dioxide, niobium oxide, molybdenum oxide, vanadium oxide and copper aluminum oxide, antimony-doped tin oxide, etc. Can be mentioned.

Among these, tin oxide particles, titanium dioxide particles, silica (silicon oxide) particles, alumina (aluminum oxide) particles, and zinc oxide particles are preferable from the viewpoint of dispersion stability of the inorganic filler and durability during film formation. .. These metal oxide particles can be used alone or in combination of two or more.

The average primary particle size of the number of inorganic fillers is preferably in the range of 5 to 100 nm. When the average primary particle size of the number of inorganic fillers is 5 nm or more, sufficient scratch resistance can be obtained. In addition, since the surface area does not become too large, aggregation of the inorganic filler is unlikely to occur when preparing the dispersion liquid for producing the surface layer. As a result, uneven coating during film formation can be reduced, and fine line reproducibility and durability can be improved, which is preferable. On the other hand, when the number average primary particle size of the inorganic filler is 100 nm or less, the inorganic filler is less likely to settle in the dispersion liquid when the inorganic filler is dispersed in the solvent when the surface layer is formed. As a result, uneven coating during film formation can be reduced, and fine line reproducibility and durability can be improved. In addition, the original plate can be stably manufactured.

The number average primary particle size of the inorganic filler is defined as the number average primary particle size measured by the following method.

First, a 10000 times magnified photograph of a sample (metal oxide particles, etc.) taken by a scanning electron microscope (manufactured by JEOL Ltd.) is captured in a scanner.

Next, from the obtained photographic images, images of 300 inorganic filler particles excluding agglomerated particles were randomly obtained from the automatic image processing analysis system Luzex AP Software Ver. A binarization process is performed using 1.32 (manufactured by Nireco Corporation) to calculate the horizontal ferret diameter of each image of the particles of the inorganic filler. Then, the average value of the horizontal ferret diameters of the images of the particles of the inorganic filler is calculated and used as the number average primary particle size. Here, the horizontal ferret diameter refers to the length of the side of the circumscribed rectangle parallel to the x-axis when the image of the particles of the inorganic filler is binarized.

Further, the measurement of the average primary particle size of the particles of the inorganic filler shall be performed on the particles of the inorganic filler that do not contain the chemical species (coating layer) derived from the surface modifier. It is considered that the particles of the inorganic filler have a thickness within the error range (generally about 1/10000 of the particle size of the particles of the inorganic filler) with respect to the particles of the inorganic filler even if the surface modification treatment is applied. Therefore, it is assumed that there is no change in the number average primary particle size by applying the surface modification treatment.

(Inorganic filler surface-modified with a stimulus-responsive compound)
The inorganic filler surface-modified with a stimulus-responsive compound (hereinafter, also referred to as a surface modifier) is an inorganic filler such as metal oxide particles as a raw material, which has been surface-modified with a surface modifier. As used herein, surface modification refers to physically or chemically adhering a surface modifier to the surface of an inorganic filler.

The surface modification method, that is, the method of adhering the surface modifier to the surface of the inorganic filler, is mainly classified into two methods, a wet treatment method and a dry treatment method.

The wet treatment method is a method of adhering the surface modifier to the surface of the inorganic filler by dispersing the inorganic filler and the surface modifier in an appropriate solvent. As a method of dispersing in the solvent, for example, a usual dispersion means such as a ball mill or a sand mill can be used. After the dispersion treatment, the dispersion liquid is dried to remove the solvent, and then heat treatment is further performed to react and fix the surface modifier on the surface of the inorganic filler.

In the dry treatment method, the surface modifier is attached to the surface of the inorganic filler by kneading the surface modifier and the inorganic filler without using a solvent. Other steps are performed in the same manner as the wet treatment described above.

The details of the surface modifier are as described above for the stimulus-responsive compound.

The amount of the surface modifier used is preferably in the range of 0.5 to 20 parts by mass, more preferably in the range of 1 to 10 parts by mass with respect to 100 parts by mass of the unmodified inorganic filler. If it is 0.5 parts by mass or more, the function of the surface modifier can be sufficiently obtained. Further, if the amount is 20 parts by mass or less, the amount of unreacted surface modifier increases, which causes aggregation of the inorganic filler in the dispersion liquid, or aggregates when the film is formed and becomes a plasticizer, which adversely affects the quality. Can be prevented from giving.

It can be confirmed by differential thermal / thermogravimetric (TG / DTA) measurement that the surface modification of the inorganic filler is performed by the surface modifier.

The wet treatment method is a method of adhering (or binding) the surface modifier to the surface of the inorganic filler by dispersing the inorganic filler and the surface modifier in a solvent. As the method, a method of dispersing the inorganic filler and the surface modifier in a solvent and drying the obtained dispersion to remove the solvent is preferable, and then further heat treatment is performed to obtain the surface modifier and the inorganic filler. A method of adhering (or binding) the surface modifier on the surface of the inorganic filler by reacting with the above is more preferable. Further, the surface modifier and the inorganic filler may be dispersed in a solvent, and then the obtained dispersion liquid may be wet-ground to make the inorganic filler finer and at the same time proceed with the surface modification.

As the means for dispersing the inorganic filler and the surface modifier in the solvent, known means can be used without particular limitation, and examples thereof include general dispersion means such as a homogenizer, a ball mill, and a sand mill. can.

As the solvent, a known solvent can be used without particular limitation, and preferred examples thereof include methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol (2-butanol), t-butanol, and the like. Examples thereof include alcohol solvents such as benzyl alcohol, aromatic hydrocarbon solvents such as toluene and xylene, methyl ethyl ketone, and tetrahydrofuran. These may be used alone or in combination of two or more.

The method for removing the solvent is not particularly limited, and a known method can be used. Examples thereof include a method using an evaporator and a method for volatilizing the solvent at room temperature.

The heating temperature is not particularly limited, but is preferably in the range of 50 to 250 ° C, more preferably in the range of 70 to 200 ° C, and further preferably in the range of 80 to 150 ° C. .. The heating time is not particularly limited, but is preferably in the range of 1 to 600 minutes, more preferably in the range of 10 to 300 minutes, and preferably in the range of 30 to 90 minutes. More preferred. The heating method is not particularly limited, and a known method can be used.

The dry treatment method is a method in which the surface modifier is attached (or bonded) to the surface of the inorganic filler by kneading the surface modifier and the inorganic filler without using a solvent. In this method, the surface modifier and the inorganic filler are kneaded and then heat-treated, and the surface modifier and the inorganic filler are reacted to adhere the surface modifier to the surface of the inorganic filler (or). It may be a method of combining). Further, when the inorganic filler and the surface modifier are kneaded, the inorganic filler may be refined and the surface modification may be promoted at the same time by dry pulverizing the inorganic filler.

The surface modification method for surface-modifying an inorganic filler surface-modified with a polymerizable surface modifier described later with a stimulus-responsive compound as a non-polymerizable surface modifier is on the surface of the inorganic filler or polymerizable. Any method may be used as long as the non-polymerizable surface modifier can be attached (or bonded) to the surface modifier.

Therefore, when a polymerizable surface modifier and a non-polymerizable surface modifier are used in combination with the inorganic filler, the surface is first modified with the polymerizable surface modifier, and then the surface is modified with the non-polymerizable surface modifier. Is preferable.

<Method of surface modification with a surface modifier having a polymerizable group (polymerizable surface modifier)>
The inorganic filler preferably has a polymerizable group. By having a polymerizable group, the inorganic fillers can be crosslinked with each other to form a strong film, and it is considered that the durability can be further improved.

The method for introducing the polymerizable group is not particularly limited, but a method of surface modification with a polymerizable surface modifier is preferable. At this time, the inorganic filler may be surface-modified with a surface modifier having a polymerizable group and then surface-modified with a stimulus-responsive compound, or may be surface-modified with a stimulus-responsive compound and then surface-modified with a polymerizable group. The surface may be modified with a modifier. Preferably, the surface is modified with a surface modifier having a polymerizable group, and then the surface is modified with a stimulus-responsive compound.

The "polymerizable group of the polymerizable surface modifier" refers to a polymerizable monomer or a group having a polymerizable property with respect to a resin as a component of the resin. For example, the radically polymerizable group described later corresponds to this. Further, the "non-polymerizable surface modifier" means a surface modifier that does not have the polymerizable group.

The polymerizable surface modifier according to the present invention has a polymerizable group and a surface modifying functional group. The type of polymerizable group applicable in the present invention is not particularly limited, but a radically polymerizable group is preferable. Here, the radically polymerizable group represents a radically polymerizable group having a carbon-carbon double bond. Examples of the radically polymerizable group include an epoxy group, a vinyl group, a (meth) acryloyl group, and the like, and among these, a methacryloyl group is preferable.

Further, the surface-modified functional group referred to here represents a group having a polymerizable property to a polar group such as a hydroxy group existing on the surface of an inorganic filler such as metal oxide particles. Examples of the surface-modified functional group include a carboxy group, a hydroxy group, a halide silyl group, an alkoxysilyl group and the like, and among these, a halide silyl group and an alkoxysilyl group are preferable.

The polymerizable surface modifier is preferably a silane coupling agent having a radically polymerizable group, and examples of the silane coupling agent having a radically polymerizable group include the compounds shown in S-1 to S-34 below.

The polymerizable surface modifier may be a synthetic product or a commercially available product. Specific examples of commercially available products include KBM-502, KBM-503, KBE-502, KBE-503, KBM-5103 (all manufactured by Shin-Etsu Chemical Co., Ltd.) and the like. Further, the polymerizable surface modifier can be used alone or in combination of two or more.

The method of surface modification using the polymerizable surface modifier is not particularly limited, and is the same as the method described for the non-polymerizable surface modifier (stimulus-responsive compound described above) except that the polymerizable surface modifier is used. The method can be adopted. Further, a known surface modification technique for metal oxide particles may be used.

The amount of the polymerizable surface modifier used is the inorganic filler before the surface modification with the polymerizable surface modifier (when the inorganic filler after the surface modification with the non-polymerizable surface modifier is further surface-modified with the polymerizable surface modifier). , Inorganic filler after surface modification with a non-polymerizable surface modifier) 0.5 parts by mass or more, more preferably 1 part by mass or more, and 1.5 parts by mass with respect to 100 parts by mass. The above is more preferable. Within this range, the film strength of the surface layer is improved and the wear of the printing plate is further reduced. In addition, an inorganic filler before surface modification with a polymerizable surface modifier (when the inorganic filler after surface modification with a non-polymerizable surface modifier is further surface-modified with a polymerizable surface modifier, a non-polymerizable surface modifier is used. It is preferably 15 parts by mass or less, more preferably 10 parts by mass or less, and further preferably 8 parts by mass or less with respect to the surface-modified inorganic filler). Within this range, the amount of the polymerizable surface modifier does not become excessive with respect to the number of hydroxy groups on the particle surface and becomes a more appropriate range, and the film strength of the surface layer is lowered by the unreacted polymerizable surface modifier. It is suppressed, the film strength of the surface layer is improved, and the wear of the printing plate is further reduced.

A typical method for preparing metal oxide particles surface-modified with a surface modifier is shown in Examples described later. In the same manner, the type of untreated metal oxide particles, the type of surface modifier, and a combination thereof can be used to obtain metal oxide particles surface-modified with a surface modifier having a desired constitution.

The content of the inorganic filler surface-modified with the stimulus-responsive compound in the surface layer is preferably more than 50% by mass, more preferably 70 to 99% by mass, and further, with respect to the total mass of the surface layer. It is preferably 80 to 95% by mass. Within the above range, the effect of the present invention can be obtained more remarkably.

The content of the inorganic filler when the surface is modified with a stimulus-responsive compound and a polymerizable surface modifier is also preferably in the above range.

<Resin>
The surface layer of the original plate for forming an ink film of the present invention may contain a resin as long as the amount does not impair the rapid stimulus response. The resin contained in the surface layer is not particularly limited, and either a thermoplastic resin or a thermosetting resin can be used.

Examples of thermoplastic resins include polyolefin resins such as polyethylene and polypropylene, cyclic polyolefin resins, polyethylene terephthalates, polyester resins such as polybutylene terephthalate, polyvinyl chloride resins, vinylidene chloride resins, polytetrafluoroethylene resins, and polystyrenes. Resin, polyether resin, polyvinyl acetate resin, acrylonitrile-butadiene-styrene (ABS) resin, acrylonitrile-styrene (AS) resin, acrylic resin, styrene acrylic resin, polyamide resin, polyacetal resin, polycarbonate resin, modified polyphenylene ether resin, Polybutylene terephthalate resin, polyethylene terephthalate resin, polyphenylene sulfide resin, polysulfone resin, polyether sulfone resin, amorphous polyarylate resin, liquid crystal polymer, polyether ether ketone resin, thermoplastic polyimide resin, polyamideimide resin, and both of them. Examples include polymers.

Examples of thermosetting resins include solid epoxy resin, silicone resin, silicone modified resin, formaldehyde resin, phenol resin, melamine resin, urea resin (urea resin), benzoguanamine resin, unsaturated polyester resin, alkyd resin, and diallyl. Ftalate resin, polyurethane resin, thermosetting polyimide resin, crosslinked acrylic resin (for example, crosslinked polymethylmethacrylate resin), crosslinked polystyrene resin, and polyamic acid resin (resin that is imidized by heating to form a polyimide structure). And so on.

The above resin can be used alone or in combination of two or more. Further, for example, a hybrid resin in which two or more kinds of polymerization segments (resin segments) are bonded to each other, such as a resin having a vinyl polymerization segment (vinyl resin segment) and a polyester polymerization segment (polyester resin segment), may be used. ..

Among these, a thermoplastic resin is preferable, and a styrene acrylic resin, a polycarbonate resin, a polyethylene terephthalate resin, and a polyolefin resin are more preferable from the viewpoint that the affinity of the stimulus-responsive compound with water is more likely to change.

As the resin contained in the surface layer, a synthetic product or a commercially available product may be used. Examples of commercially available resins include VS-1063 (weight average molecular weight: 5,500), US-1071 (weight average molecular weight: 10,000), X-1 (weight average molecular weight: 18) manufactured by Seikou PMC Co., Ltd. , 000), YS-1274 (weight average molecular weight: 19,000), VS-1047 (weight average molecular weight: 10,000), RS-1191 (weight average molecular weight: 6,500) and the like.

The weight average molecular weight of the resin contained in the surface layer is not particularly limited, but is preferably 5,000 to 30,000, more preferably 8,000 to 20,000.

In addition, in this specification, the value measured by gel permeation chromatography (GPC) is adopted as the weight average molecular weight.

In a preferred embodiment of the present invention, the resin is a polymer of a polymerizable monomer, particularly a radically polymerizable monomer. As a result, the surface layer is composed of an integral polymer obtained by polymerizing the polymerizable monomer, and has a structure in which an inorganic filler or the like is dispersed therein. Therefore, the durability can be further improved.

At this time, from the viewpoint of improving the wear resistance, the inorganic filler surface-modified with the above-mentioned stimulus-responsive compound preferably has a polymerizable group on the surface. The surface layer is preferably composed of a polymer of a composition containing an inorganic filler further having a polymerizable group and a polymerizable monomer. With this configuration, the inorganic filler can be bonded to the above polymer by a covalent bond due to a polymerization reaction between the polymerizable group on the surface of the inorganic filler and the polymerizable monomer. That is, an inorganic filler having a polymerizable group on the surface and a radically polymerizable monomer can form a three-dimensional crosslinked inorganic-organic hybrid film. This makes it possible to further improve the durability of the original plate for forming an ink film.

The polymerizable monomer may be used alone or in combination of two or more.

The polymerizable monomer is a compound having a polymerizable group and polymerizing (curing) to become a resin by irradiation with active rays such as ultraviolet rays, visible light, and electron beams, or by addition of energy such as heating.

The polymerizable monomer is preferably a radically polymerizable monomer that is cured through a radical polymerization reaction. Examples of the polymerizable monomer include styrene-based monomers, acrylic-based monomers, methacrylic-based monomers, vinyl toluene-based monomers, vinyl acetate-based monomers, N-vinylpyrrolidone-based monomers, and examples of the binder resin include polystyrene and the like. Examples include polyacrylate.

The polymerizable group of the polymerizable monomer has a carbon-carbon double bond and is a polymerizable group. The polymerizable group is particularly preferably an acryloyl group (CH ₂ = CHCO−) or a methacryloyl group (CH ₂ = C (CH ₃ ) CO−) because it can be cured with a small amount of light or in a short time. ..

Specific examples of the polymerizable monomer include, but are not limited to, the following compounds M1 to M11. In each of the following formulas, R represents an acryloyl group and R'represents a methacryloyl group.

The above-mentioned polymerizable monomer can be synthesized by a known method, and can also be obtained as a commercially available product.

Further, the polymerizable monomer is preferably a compound having three or more polymerizable groups from the viewpoint of forming a protective layer having a high crosslink density and a high hardness.

As a method for curing the above-mentioned polymerizable monomer, a curing reaction can be carried out by a method using an electron beam cleavage reaction, a method using light or heat in the presence of a radical polymerization initiator, or the like.

When the curing reaction is carried out using a radical polymerization initiator, either a photopolymerization initiator or a thermal polymerization initiator can be used as the polymerization initiator. In addition, both light and heat initiators can be used in combination.

Examples of the polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis (2,4-dimethylazobisvaleronitrile), and 2,2'-azobis (2-methylbutyronitrile). Azo compounds such as, benzoyl peroxide (BPO), di-t-butylhydroperoxide, t-butylhydroperoxide, chlorobenzoyl peroxide, dichlorobenzoyl peroxide, bromomethylbenzoyl peroxide, lauroyl peroxide and the like. Examples thereof include thermal polymerization initiators such as.

Examples of the photopolymerization initiator include diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, and 4- (2-hydroxyethoxy) phenyl-. (2-Hydroxy-2-propyl) Ketone, 2-Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -1-butanone (Omnirad® 369: IGM Resins B.V.) , 2-Hydroxy-2-methyl-1-phenylpropan-1-one, 2-methyl-2-morpholino (4-methylthiophenyl) propan-1-one, 1-phenyl-1,2-propanedione-2- Acetophenone-based or ketal-based photopolymerization initiators such as (o-ethoxycarbonyl) oxime, benzoin ether-based photopolymerization initiators such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether, and benzoin isopropyl ether, benzophenone, 4-. Benzophenone-based photopolymerization initiators such as hydroxybenzophenone, methyl o-benzoylbenzoate, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoylphenyl ether, acrylicized benzophenone, 1,4-benzoylbenzene, 2-isopropylthioxanthone, Examples thereof include thioxanthone-based photopolymerization initiators such as 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, and 2,4-dichlorothioxanthone.

Other photopolymerization initiators include ethylanthraquinone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide, and bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide. Oxide (Omnirad® 819: IGM Resins B.V.), Bis (2,4-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, Methylphenylglioxyester, 9,10- Examples thereof include phenylanthrene, aclysine-based compounds, triazine-based compounds, and imidazole-based compounds.

Further, those having a photopolymerization promoting effect can be used alone or in combination with the above-mentioned photopolymerization initiator. For example, triethanolamine, methyldiethanolamine, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, ethyl benzoate (2-dimethylamino), 4,4'-dimethylaminobenzophenone and the like can be mentioned.

These polymerization initiators may be used alone or in admixture of two or more. The content of the polymerization initiator is in the range of 0.1 to 40 parts by mass, preferably in the range of 0.5 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

When the surface layer contains a resin, the content of the resin in the surface layer is preferably 1 to 30% by mass, more preferably 5 to 20% by mass, based on the total mass of the surface layer. By containing the resin, the elastic deformation rate of the entire surface layer can be improved and the durability can be improved because the resin is present in the gaps between the inorganic filler particles. When the content of the resin is 1% by mass or more, the above effect can be easily obtained, which is preferable. Further, when the content of the resin is 30% by mass or less, the degree of freedom of the stimulus-responsive compound is sufficiently high, so that the responsiveness is excellent. Further, it is preferable because the durability can be ensured because the amount of the plastic component on the film surface does not increase too much.

When the resin is a polymer of a polymerizable monomer, the inorganic filler modified with a stimulus-responsive compound (and, if necessary, a polymerizable surface modifier) constituting the surface layer, and the polymerizable monomer are used. The ratio of the mass of the polymerizable monomer to the total mass is preferably 1 to 30% by mass, more preferably 5 to 20% by mass.

(Other ingredients)
The surface layer may further contain an antioxidant, a plasticizer, metal oxide particles and the like as long as the effects of the present invention are not impaired.

(Thickness of surface layer)
The thickness (dry thickness) of the surface layer is not particularly limited, but is preferably 3 to 30 μm, and more preferably 5 to 10 μm.

[Adhesive layer]
The original plate for forming an ink film of the present invention may have a surface layer arranged on a substrate via an adhesive layer.

The adhesive used for forming the adhesive layer (hereinafter, also referred to as an adhesive for forming the adhesive layer) is not particularly limited, and is a curable composition containing a curable resin and, if necessary, a polymerization initiator, a solvent and the like. Is preferable. The specific forms of the curable resin, the polymerization initiator, and the solvent, and the conditions for curing the adhesive are not particularly limited, and conventionally known findings can be appropriately referred to. The thickness (dry thickness) of the adhesive layer is also not particularly limited, but is preferably 0.5 to 3 μm.

[Manufacturing method of original plate for forming ink film]
The method for producing the original plate for forming an ink film is not particularly limited. For example, after preparing a dispersion liquid for forming a surface layer containing an inorganic filler surface-modified with a stimulus-responsive compound, the solution is applied onto a substrate and dried. By doing so, a method of providing a surface layer can be mentioned. If necessary, the resin may be further mixed to prepare a dispersion liquid for forming a surface layer.

The solvent used for the dispersion liquid for forming the surface layer is not particularly limited, and for example, an aliphatic solvent such as n-pentane, n-hexane, n-heptane, n-octane, cyclohexane, and methylcyclohexane; methylethylketone and acetone. , Cyclohexanone and other ketone solvents; diethyl ether, isopropyl ether, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether, anisole, phenetol and other ether solvents; ethyl acetate. , Ester-based solvents such as butyl acetate and ethylene glycol diacetate; Aromatic solvents such as toluene and xylene; Cellosolve-based solvents such as methyl cellosolve, ethyl cellosolve and butyl cellosolve; methanol, ethanol, propanol, isopropyl alcohol, 2-butanol and the like. Alcohol-based solvents; ether-based solvents such as tetrahydrofuran and dioxane; halogen-based solvents such as dichloromethane and chloroform; nitrile-based solvents such as acetonitrile and propionitrile; N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, Examples thereof include polar solvents such as N, N-dimethylformamide and N, N-dimethylacetamide. These solvents can be used alone or in combination of two or more.

The content of the inorganic filler surface-modified with the stimulus-responsive compound in the dispersion liquid for forming the surface layer is not particularly limited, but is preferably 20 to 60% by mass. The method for preparing the dispersion liquid for forming the surface layer is not particularly limited, but it is preferable to disperse the inorganic filler surface-modified with the stimulus-responsive compound in the solvent by using a known dispersion means such as a homogenizer, a ball mill, and a sand mill.

As a method of applying the dispersion liquid for forming the surface layer on the substrate, for example, a rotary coating method; a dipping method; a dripping method; a roll coater, a rod coater, a curtain coater, a slide coater, a doctor knife, a screen coater, a slot coater, and an extrusion method. A method using a liquid film coating device such as a coater, a blade coater, a gravure coater, and an inkjet coater; and the like.

An original plate for forming an ink film can be obtained by applying a dispersion liquid for forming a surface layer, air-drying as necessary, and then drying using a vacuum dryer or the like. When a vacuum dryer is used, the drying temperature is not particularly limited, but is preferably 25 to 40 ° C. Further, the drying time is not particularly limited, but 1 to 4 hours is preferable.

When a polymerizable surface modifier is used, a surface layer forming dispersion containing a polymerization initiator is prepared, applied onto the substrate in the same manner as described above, and naturally dried or heat-dried as necessary. Then, it can be cured to prepare an ink film forming original plate. When preparing a dispersion liquid for forming a surface layer further containing a polymerization initiator, it is preferable to disperse the surface-modified inorganic filler in a solvent, then add the polymerization initiator and further mix.

When a resin is obtained by polymerizing a radically polymerizable monomer, an inorganic filler surface-modified with a stimulus-responsive compound (and a polymerizable surface modifier, if necessary), a radically polymerizable monomer, a polymerization initiator, etc. are used. The dispersion liquid added and prepared in the same manner as above can be applied onto the substrate in the same manner as above, naturally dried or heat-dried as necessary, and then cured to prepare an ink film forming original plate. can.

As the curing treatment, it is preferable to irradiate the coating film with active rays to generate radicals for polymerization, and to form cross-linking bonds by a cross-linking reaction between and within the molecules to cure the resin. As the active ray, light such as ultraviolet rays and visible light and an electron beam are preferable, and ultraviolet rays are particularly preferable from the viewpoint of ease of use and the like.

As the ultraviolet light source, any light source that generates ultraviolet rays can be used without limitation. For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, a flash (pulse) xenon, an ultraviolet LED, or the like can be used.

The irradiation conditions differ depending on each lamp, but the irradiation amount of the active ray is usually in the range of 1 to 20 mJ / cm ² , preferably in the range of 5 to 15 mJ / cm ² . The output voltage of the light source is preferably in the range of 0.1 to 5 kW, and particularly preferably in the range of 0.5 to 3 kW.

The irradiation time of the active ray is a time during which the required irradiation amount of the active ray can be obtained, specifically, it is preferably in the range of 0.1 second to 10 minutes, and 1 second to 5 minutes from the viewpoint of curing efficiency or work efficiency. The range of is more preferable.

When producing an original plate having an adhesive layer between a substrate and a surface layer, an adhesive layer is provided on the substrate by the method described in the above [adhesive layer] section, and then a surface layer is formed on the adhesive layer. do it.

[Pattern film forming apparatus and pattern film forming method]
The present invention also provides a pattern film forming apparatus (printing apparatus) using the original plate of the present invention. The apparatus comprises an ink film forming original plate of the present invention, a writing means for applying an external stimulus to the surface layer of the original plate to form a pattern having different affinity for water, and an ink film formed on the pattern. By relatively pressing and separating the ink film surface of the blanket against the ink film forming means and the original plate on which the ink film is formed, the ink film surface of the blanket is applied to the water-repellent portion of the pattern. By relatively pressing and pulling the object to be printed against the first transfer means for transferring only the ink film formed on the surface and the blanket having the transferred ink film, the ink is applied to the surface of the object to be printed. It is preferable to have a second transfer means for transferring the film.

The present invention also provides a pattern film forming method (printing method) using the above-mentioned original plate. In this method, a first writing step of applying an external stimulus to the surface layer of the original plate for forming an ink film of the present invention to form a pattern having different affinity for water, and a step of forming an ink film on the pattern. The ink formed on the water-repellent portion of the pattern on the surface of the blanket for the ink film by relatively pressing and pulling the surface of the blanket for the ink film against the original plate on which the ink film was formed. It has a step of transferring only the film and a step of transferring the ink film to the surface of the printed object by relatively pressing and pulling the printed object against the blanket having the transferred ink film. Is preferable.

Hereinafter, each means (or step) constituting the pattern film forming apparatus (or method) according to the present invention will be described with reference to FIG. 3 as appropriate. However, the pattern film forming apparatus used in the present invention is not limited to the following forms and illustrated examples. FIG. 3 shows an example in which the blanket 3 is used, but the present invention is not limited to this, and the ink is directly adhered from the ink roller 5 to the original plate 1 mounted on the plate cylinder 2 without using the blanket 3. After forming the film, the ink film may be directly transferred to the object to be printed. Further, although an example of supplying ink from above the printed object 8 will be described below, ink may be supplied from below the printed object 8.

FIG. 3 is a schematic view showing a pattern film forming apparatus 10 according to an embodiment of the present invention. The pattern film forming apparatus 10 includes an ink film forming original plate 1, a plate cylinder 2, a blanket 3, an impression cylinder 4, an ink roller 5, a water roller 6, and a monochromatic laser light source 7 as a writing means.

In the pattern film forming method according to the embodiment of the present invention, light emitted from a monochromatic laser light source 7 (external stimulus, arrow in FIG. 3) is applied to the surface layer of the original plate 1 mounted on the plate cylinder 2. A pattern having different affinity for water (for example, a pattern consisting of a hydrophilic part and a water-repellent part) is formed.

After the water supplied from the water roller 6 adheres to the hydrophilic portion formed on the surface layer of the original plate 1, the ink supplied from the ink roller 5 is attached to the plate cylinder 2 at the contact point with the plate cylinder 2. It adheres to the surface layer of the original plate 1. As a result, an ink film is formed on the original plate 1. The formed ink film is transferred to the ink film surface of the blanket 3 at the contact point with the blanket 3. The ink film attached to the blanket 3 is transferred to the printed body 8 at the contact point with the printed body 8 arranged on the impression cylinder 4. A printed matter is obtained by drying the printed matter 8 as necessary. The rotation speed of the ink roller, each body, and the blanket is not particularly limited, and can be appropriately set according to the properties of the ink and the object to be printed.

[Writing means (first writing step, second writing step)]
When the surface layer of the original plate 1 contains a photoresponsive compound, the writing means may be a known light source such as a light emitting diode (LED) or a monochromatic laser light source. When the surface layer of the original plate 1 contains a temperature-responsive compound, the writing means may be an infrared lamp, a monochromatic laser light source, or the like. The writing means may be installed alone or in combination of two or more.

By partially applying an external stimulus to the ink film forming original plate 1 provided on the plate cylinder 2 from the writing means, a pattern having a different affinity for water is formed on the surface layer of the original plate 1. In the present specification, "partially applying an external stimulus" means applying an external stimulus to either the image portion or the non-image portion of the image pattern to be written.

As described above, the stimulus-responsive compound used in the present invention is preferably a photo-responsive compound or a temperature-responsive compound. That is, the external stimulus applied by the writing means is preferably light or a temperature change.

When the surface layer of the original plate 1 contains a photoresponsive compound, the external stimulus is light. At that time, the wavelength region of the light emitted from the writing means (preferably a monochromatic laser light source) is preferably 200 to 400 nm, and more preferably 280 to 400 nm. In such a wavelength region, it is possible to irradiate a finer region with light, and it is possible to reproduce small characters and fine images more clearly. Further, since the energy received by the surface layer is not too large, the surface layer is less likely to deteriorate and can withstand repeated rewriting operations.

The amount of irradiation light at the time of writing is preferably in the range of, for example, 1 to 10 J / cm ² . Within this range, small characters and fine images can be clearly written, and writing can be performed without overloading the surface layer.

If the surface layer of the original plate contains a temperature-responsive compound, the external stimulus is a temperature change. As described above, since the temperature-responsive compound used in the present invention has a critical dissolution temperature, a temperature change is applied to the surface layer so as to pass this critical dissolution temperature, and the surface layer of the original plate 1 is exposed to water. Form patterns with different affinities. At this time, the writing means used is preferably a monochromatic laser light source that emits light having a wavelength of 700 to 900 nm. Partial heating is performed by this writing means to form the above pattern.

When various light sources are used as the writing means, it is preferable to irradiate the light emitted from the light source in a pin spot manner so that only the stimulus-responsive compound to which an external stimulus is applied changes the affinity with water. Examples of such a method include an irradiation method in which light from a light source is guided by an optical fiber. However, it is also possible to adopt an irradiation method by projecting an image pattern or the like as long as it can supply a required amount of light.

By performing the writing step (first writing step) as described above, a pattern having a different affinity for water is formed on the surface layer of the original plate 1. Therefore, the present invention also has a pattern forming method having a writing step (first writing step) of applying an external stimulus to the surface layer of the original plate of the present invention to form a pattern having a different affinity for water. offer. As described above, the external stimulus applied in the forming method is preferably light or a temperature change, and more preferably light. Further, as described above, the external stimulus applied in the forming method is preferably light in the wavelength region of 280 to 400 nm.

The writing means may be activated at least when printing different printed matter by changing the image pattern, and may not be used when printing a plurality of the same printed matter. That is, since the pattern formed on the surface layer is maintained as it is by writing once, it is possible to print a plurality of sheets without rewriting by continuously transferring the ink film by the transfer means. .. Further, the pattern formed on the surface layer is erased by an erasing step described later, and further, an external stimulus is applied to the same surface layer, and a second writing step of forming a pattern having a different affinity for water is performed. , Can be easily rewritten. By repeating the erasing step and the writing step in this way, a plurality of print patterns can be formed on one original plate surface. The original plate of the present invention is excellent in durability that small characters and fine images can be printed clearly and with good reproducibility even if such repetition is performed.

The patterns formed on the surface layer of the original plate 1 having different affinities for water move with the rotation of the plate cylinder 2 and are used for forming an ink film.

[Ink film forming means (process)]
In the pattern film forming apparatus according to the embodiment of the present invention, the ink film forming means is, for example, an ink roller 5 as shown in FIG.

The ink film forming means applies ink to the pattern formed in the writing step to form an ink film. In addition, in this specification, "ink film formation" means that the ink is held in a predetermined position (for example, a hydrophilic part or a water-repellent part) of a pattern in a state where it can be transferred to an object 8 to be printed.

The ink is not particularly limited as long as it can be transferred to the object to be printed 8, and known inks such as water-based inks, oil-based inks, and emulsion inks can be used. When water-based ink is used, an ink film is formed on the hydrophilic portion of the pattern. When oil-based ink or emulsion ink is used, an ink film is formed on the water-repellent portion of the pattern.

The formed ink film moves with the rotation of the plate cylinder 2 provided with the original plate 1 and is sent so as to come into contact with the blanket 3.

[First transfer means (process)]
In the pattern film forming apparatus according to the embodiment of the present invention, the first transfer means is, for example, a blanket 3 as shown in FIG.

In the first transfer step, the ink formed on the pattern is formed by relatively pressing and pulling the ink film surface of the blanket 3 against the original plate 1 having the ink film formed in the ink film forming step. Transfer the membrane.

As described above, the position where the ink film is formed may be a hydrophilic part or a water-repellent part depending on the type of ink, but the hydrophobic ink has a relatively high viscosity and is less likely to cause image collapse during transfer. From the viewpoint, a form in which only the ink film on the water-repellent portion is transferred to the blanket is preferable.

The material of the blanket 3 is not particularly limited as long as the ink film is transferred, and known materials can be used.

The ink film remaining on the blanket 3 is removed by, for example, a cleaning blade (not shown).

[Second transfer means (process)]
In the pattern film forming apparatus according to the embodiment of the present invention, the second transfer means is, for example, an impression cylinder 4 as shown in FIG.

In the second transfer step, the ink film is transferred to the surface of the printed body 8 by relatively pressing and pulling the printed body 8 against the blanket 3 having the transferred ink film by the impression cylinder 4. To.

The material of the impression cylinder 4 is not particularly limited, and known materials can be used.

The object to be printed 8 is not particularly limited as long as the ink film is transferred, and for example, paper, a resin film, a resin or metal plate-like material (sheet or the like), cloth, or the like can be used.

[Erasing means (process)]
It is preferable that the pattern film forming apparatus of the present invention further has an erasing means for erasing the pattern by applying an external stimulus to the surface layer of the original plate 1.

When the surface layer of the original plate contains a photoresponsive compound, the erasing means is a monochromatic laser light source that emits visible light (preferably visible light in the wavelength region of 400 to 600 nm) from the viewpoint of the rate of change in affinity with water. Or a light emitting diode.

When the surface layer of the original plate contains a temperature-responsive compound, examples of the erasing means include a cold air generator capable of generating cold air at 5 to 20 ° C. and a constant temperature bath at 5 to 20 ° C.

The pattern is erased by such an erasing means, and the surface layer of the original plate has the same properties as before the external stimulus is applied. After that, by performing the above-mentioned writing step again, a new pattern can be formed on the surface layer. That is, the original version of the present invention can easily rewrite the pattern digitally.

Therefore, it is preferable that the pattern film forming method according to the present invention further includes an erasing step of erasing the pattern by applying an external stimulus to the surface layer of the original plate after the transfer step. Further, the external stimulus used in this erasing step is preferably light or a temperature change. Further, the external stimulus used in this erasing step is preferably visible light.

The erasing means may be activated at least when printing different printed matter by changing the image pattern, and may not be used when printing a plurality of the same printed matter. As described above, the pattern formed on the surface layer by the first writing step is erased by the erasing step, and an external stimulus is applied to the same surface layer to form a pattern having a different affinity for water. Rewriting can be easily performed by further performing the writing process. By repeating the erasing step and the writing step in this way, a plurality of print patterns can be formed on one original plate surface. The original plate of the present invention is excellent in durability that small characters and fine images can be printed clearly and with good reproducibility even if such repetition is performed.

The writing means and the erasing means may be provided in the same housing as the housing in which the plate cylinder 2, the blanket 3, and the impression cylinder 4 are provided, or the plate cylinder 2, the blanket 3, and the impression cylinder 4 may be provided. It may be provided outside the housing in which 4 is provided. If the writing means and the erasing means are provided in the same housing as the housing in which the plate cylinder 2, the blanket 3, and the impression cylinder 4 are provided, the first with respect to the surface layer of the original plate 1 installed in the plate cylinder 2. The writing step, the erasing step, and the second writing step after that can be continuously repeated. If it is desired to print the same image pattern continuously, it is possible to print without performing the erasing step and the subsequent second writing step. Further, it is also possible to continuously print the same image pattern by once transferring to the object to be printed 8 and then writing the same image on the surface layer of the original plate 1 again through an erasing step.

The pattern film forming apparatus (method) of the present invention may have means (steps) other than the above means (steps). For example, in the pattern film forming method, before the first writing step, an external stimulus is applied to the entire surface layer of the original plate to change the affinity of the stimulus-responsive compound contained in the entire surface layer with water ( A method may be adopted in which the steps after the first writing step are performed after the water repellency → hydrophilicity or the hydrophilicity → water repellency).

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "parts" or "%" is used in the examples, it represents "parts by mass" or "% by mass" unless otherwise specified.

<Synthesis of a compound having an azomethine structure represented by the above chemical formula (1) (compound (1))>
Aniline (6.52 g, 70 mmol), 5-bromo-2-flualdehyde (12.25 g, 70 mmol) and ethanol (280 mL) were mixed and heated and stirred at 50 ° C. The reaction solution was suction-filtered, and the obtained powder was recrystallized in a mixed solvent of methanol / ethanol to obtain Intermediate A. Next, a 20% aqueous sodium hydroxide solution (180 mL) was added to Intermediate A (15.00 g, 60 mol), and the mixture was stirred at 340 ° C. and 150 atm for 2 hours, then 1.2N hydrochloric acid (150 mL) was added, and the mixture was added at room temperature for 1 hour. Stirred. The mixture was extracted with ethyl acetate, the organic layer was washed with saturated brine, and dried over anhydrous magnesium sulfate. The solvent was distilled off, and the mixture was purified by silica gel chromatography using a mixed solution of ethyl acetate and hexane as a developing solvent to obtain Intermediate B. Finally, Intermediate B (9.36 g, 50 mmol), dibutyltin dilaurate (0.01 g) and methyl ethyl ketone (50 mL) were mixed, and then 3-isocyanatepropyltriethoxysilane KBE-9007N (12.) manufactured by Shin-Etsu Chemical Co., Ltd. 37 g, 50 mmol) was added. After reacting at 60 ° C. for 6 hours, the solvent was distilled off to obtain compound (1).

<Synthesis of a compound having an azobenzene structure represented by the above chemical formula (2) (compound (2))>
4-Phenylazophenol P0149 (9.91 g, 50 mmol) manufactured by Tokyo Chemical Industry Co., Ltd., dibutyltin dilaurate (0.01 g) and methyl ethyl ketone (50 mL) are mixed, and then 3-isocyanatepropyltriethoxysilane manufactured by Shin-Etsu Chemical Co., Ltd. KBE-9007N (12.37 g, 50 mmol) was added. After reacting at 60 ° C. for 6 hours, the solvent was distilled off to obtain compound (2).

<Synthesis of compound having a heterocyclic structure (compound (3))>
After adding 2.4N hydrochloric acid (75 mL) to 5-amino-o-cresol (7.39 g, 60 mmol), distilled water (6 mL) of sodium nitrite (4.98 g, 72 mmol) while cooling and stirring at 0 ° C. ) Was added, and the mixture was stirred at 0 ° C. for 60 minutes. A mixed solution of 1-methyl-1H-pyrazole (4.93 g, 60 mmol) and a 20% aqueous sodium hydroxide solution (24 mL) was added to this solution, and the mixture was stirred for 20 hours. The precipitated precipitate was filtered and the solid was washed with water. The obtained solid was purified by silica gel chromatography using a mixture of ethyl acetate and hexane as a developing solvent to obtain Intermediate C. Finally, Intermediate C (10.81 g, 50 mmol), dibutyltin dilaurate (0.01 g) and methyl ethyl ketone (50 mL) were mixed, and then 3-isocyanatepropyltriethoxysilane KBE-9007N (12.) manufactured by Shin-Etsu Chemical Co., Ltd. 37 g, 50 mmol) was added. After reacting at 60 ° C. for 6 hours, the solvent was distilled off to obtain compound (3).

<Synthesis of a compound having an azobenzene structure represented by the above chemical formula (2) (compound (4))>
4'-Hydroxyazobenzene-2-carboxylic acid H0586 (12.11 g, 50 mmol) manufactured by Tokyo Kasei Kogyo Co., Ltd., dibutyltin dilaurate (0.01 g), and methylethylketone (50 mL) are mixed, and then 3-by Shin-Etsu Chemical Co., Ltd. Isocyanatepropyltriethoxysilane KBE-9007N (12.37 g, 50 mmol) was added. After reacting at 60 ° C. for 6 hours, the solvent was distilled off to obtain compound (4).

<Synthesis of a compound having an azobenzene structure (compound (5)) containing a hydrophilic group represented by the above chemical formula (2)>
After adding 2.4N hydrochloric acid (100 mL) to 4-amino-2-chlorophenol (11.49 g, 80 m mmol), distilled water (6.62 g, 96 mmol) of sodium nitrite (6.62 g, 96 mmol) while cooling and stirring at 0 ° C. The dissolved solution was added to 8 mL), and stirring was continued at 0 ° C. for 60 minutes. A mixed solution of 2-chlorophenol (10.28 g, 80 mmol) and a 20% aqueous sodium hydroxide solution (32 mL) was added to this solution, and the mixture was stirred for 20 hours. The precipitated precipitate was filtered and the solid was washed with water. The obtained solid was purified by silica gel chromatography using a mixture of ethyl acetate and hexane as a developing solvent to obtain Intermediate D. DMF (300 mL), 1-bromohexane (27.73 g, 168 mmol) and potassium carbonate (23.22 g, 168 mmol) were added to this intermediate D (19.82 g, 70 mmol), and the mixture was stirred at 80 ° C. for 2 hours. Then, the mixture was stirred at room temperature for 20 hours. After distilling off the solvent, the mixture was extracted with ethyl acetate, the organic layer was washed with saturated brine, and dried over anhydrous magnesium sulfate. The solvent was distilled off, and the mixture was purified by silica gel chromatography using a mixed solution of ethyl acetate and hexane as a developing solvent to obtain Intermediate E. To this intermediate E (17.09 g, 60 mmol), a 20% aqueous sodium hydroxide solution (140 mL) was added, and the mixture was stirred at 340 ° C. and 150 atm for 2 hours, then 1.2N hydrochloric acid (120 mL) was added, and the mixture was stirred at room temperature for 1 hour. did. The solvent was distilled off, and the mixture was purified by silica gel chromatography using a mixed solution of ethyl acetate and hexane as a developing solvent to obtain Intermediate F. Finally, Intermediate F (20.73 g, 50 mmol), dibutyltin dilaurate (0.01 g) and methyl ethyl ketone (50 mL) were mixed, and then 3-isocyanatepropyltriethoxysilane KBE-9007N (12.) manufactured by Shin-Etsu Chemical Co., Ltd. 37 g, 50 mmol) was added. After reacting at 60 ° C. for 6 hours, the solvent was distilled off, and the mixture was purified by silica gel chromatography using a mixed solution of ethyl acetate and hexane as a developing solvent to obtain compound (5).

<Compound having a heterocyclic structure containing a hydrophilic group (Synthesis of compound (6)>
After adding 2.4N hydrochloric acid (75 mL) to 5-amino-o-cresol (7.39 g, 60 mmol), distilled water (6 mL) of sodium nitrite (4.98 g, 72 mmol) while cooling and stirring at 0 ° C. ) Was added, and the mixture was stirred at 0 ° C. for 60 minutes. A mixed solution of 5-hydroxy-1-methyl-1H-pyrazole (5.89 g, 60 mmol) and a 20% aqueous sodium hydroxide solution (24 mL) was added to this solution, and the mixture was stirred for 20 hours. The precipitated precipitate was filtered and the solid was washed with water. The obtained solid was purified by silica gel chromatography using a mixture of ethyl acetate and hexane as a developing solvent to obtain Intermediate G. Finally, Intermediate G (11.61 g, 50 mmol), dibutyltin dilaurate (0.01 g) and methyl ethyl ketone (50 mL) were mixed, and then 3-isocyanatepropyltriethoxysilane KBE-9007N (12.) manufactured by Shin-Etsu Chemical Co., Ltd. 37 g, 50 mmol) was added. After reacting at 60 ° C. for 6 hours, the solvent was distilled off, and the mixture was purified by silica gel chromatography using a mixed solution of ethyl acetate and hexane as a developing solvent to obtain compound (6).

<Temperature-responsive compound (Compound (7))>
Poly (N-isopropylacrylamide-co-3- (trimethoxysilyl) propylmethacrylate) (manufactured by SIGMA-ALDRICH, 900189-1G) (compound (7) above) was used.

<Preparation of Inorganic Filler A Surface-Modified with Compound (1)>
To 100 mL of ethanol, 10 g of tin oxide (number average primary particle size = 20 nm) was added and dispersed for 60 minutes using a US homogenizer. Then, 0.3 g of compound (1) and 10 mL of ethanol were added as a non-polymerizable surface modifier, and the mixture was dispersed for 30 minutes using a US homogenizer. After removing the solvent by the evaporator, the mixture was heated at 120 ° C. for 1 hour to obtain an inorganic filler A surface-modified with the compound (1) which is a non-polymerizable surface modifier.

<Preparation of Inorganic Filler B Surface-Modified with Polymerizable Surface Modifier and Compound (5)>
10 g of tin oxide (number average primary particle size = 20 nm) was added to 100 mL of ethanol, and the mixture was dispersed for 60 minutes using a US homogenizer. Next, 0.3 g of 3-methacryloxypropyltrimethoxysilane (“KBM-503” manufactured by Shin-Etsu Chemical Co., Ltd.) and 10 mL of ethanol were added as a polymerizable surface modifier, and the mixture was dispersed for 30 minutes using a US homogenizer. .. After removing the solvent by an evaporator, the mixture was heated at 120 ° C. for 1 hour to obtain an inorganic filler having a polymerizable group.

5 g of the above-mentioned inorganic filler having a polymerizable group was added to 50 mL of 2-butanol and dispersed for 60 minutes using a US homogenizer. Then, 0.15 g of compound (5) was added and dispersed for 60 minutes using a US homogenizer. After removing the solvent with an evaporator, the mixture was heated at 120 ° C. for 1 hour to obtain an inorganic filler B having surface modification with compound (5) and having a polymerizable group.

(Example 1: Preparation of original plate 1 for forming an ink film)
2-Butanol 360 parts by mass, toluene 360 parts by mass, and 570 parts by mass of the inorganic filler A surface-modified with the compound (1) prepared above were mixed and dispersed for 60 minutes using a US homogenizer to make the uniform inorganic filler A uniform. The dispersion liquid of was obtained. Then, it was applied to an aluminum substrate (length 360 mm × width 180 mm) on an electropolished flat plate, which is a substrate, so that the thickness after drying would be 6 μm using a blade coater. After the coating, the mixture was air-dried for 30 minutes and then dried at 30 ° C. for 2 hours using a vacuum dryer to obtain an ink film forming original plate 1.

(Examples 2 to 10, 12 to 15: Preparation of original plates 2 to 10, 12 to 15 for forming an ink film)
Original plates 2 to 10 and 12 to 15 for forming an ink film were obtained in the same manner as in Example 1 except that the stimulus-responsive compound and the inorganic filler were changed as shown in Table 1 below. As the surface-modified inorganic filler, the same procedure is performed using the stimulus-responsive compound and the inorganic filler shown in Table 1 with reference to the above <Preparation of the surface-modified inorganic filler A by the compound (1)>. Each of the inorganic fillers prepared in the above was used. In Table 1, the particle size of the inorganic filler is the number average primary particle size.

(Example 11: Preparation of original plate 11 for forming an ink film)
2-Butanol 360 parts by mass, toluene 360 parts by mass, and 553 parts by mass of the inorganic filler B surface-modified with the above-mentioned polymerizable surface modifier and compound (5) were mixed and dispersed for 60 minutes using a US homogenizer to be uniform. A dispersion of the inorganic filler B was obtained. Then, 17 parts by mass of Omnirad819 (manufactured by IGM Resins B.V.), which is a polymerization initiator, was added and mixed uniformly, and then an aluminum substrate (length 360 mm × width 180 mm) on an electrolytically polished flat plate, which was a substrate, was added. ) Was coated with a blade coater so that the thickness after drying was 6 μm. Next, the formed coating film was irradiated with ultraviolet rays for 1 minute with a metal halide lamp to cure the coating film, thereby obtaining an ink film forming original plate 11.

(Example 16: Preparation of original plate 16 for forming an ink film)
The surface of tin oxide (number average primary particle size = 20 nm) was surface-modified with compound (5) in the same manner as in the above <Preparation of inorganic filler A surface-modified with compound (1)>. Next, 360 parts by mass of 2-butanol, 360 parts by mass of toluene, 553 parts by mass of an inorganic filler surface-modified with compound (5), and a styrene acrylic resin (manufactured by Seikou PMC Co., Ltd., US-1071, weight average) which is a thermoplastic resin. Molecular weight: 10,000) 17 parts by mass was mixed and dispersed for 60 minutes using a US homogenizer to obtain a uniform dispersion of an inorganic filler. Then, it was applied to an aluminum substrate (length 360 mm × width 180 mm) on an electropolished flat plate, which is a substrate, so that the thickness after drying would be 6 μm using a blade coater. After the coating, the mixture was air-dried for 30 minutes and then dried at 30 ° C. for 2 hours using a vacuum dryer to obtain an ink film forming original plate 16.

(Examples 17 to 20: Preparation of original plates 17 to 20 for forming an ink film)
Original plates 17 to 20 for forming an ink film were prepared in the same manner as in Example 16 except that the contents of the surface-modified inorganic filler and the styrene acrylic resin were changed as shown in Table 1 below. In Table 1, the content of each component is a ratio (mass%) to the total mass of the surface layer.

(Example 21: Preparation of original plate 21 for forming an ink film)
The surface of tin oxide (number average primary particle size = 20 nm) was surface-modified with compound (5) in the same manner as in the above <Preparation of inorganic filler A surface-modified with compound (1)>. Next, 360 parts by mass of 2-butanol, 360 parts by mass of toluene, 485 parts by mass of an inorganic filler surface-modified with compound (5), and 85 parts by mass of a solid epoxy resin (7050 manufactured by DIC Co., Ltd.) which is a thermosetting resin were added. The mixture was mixed and dispersed for 60 minutes using a US homogenizer to obtain a uniform dispersion of an inorganic filler. Then, it was applied to an aluminum substrate (length 360 mm × width 180 mm) on an electropolished flat plate, which is a substrate, so that the thickness after drying would be 6 μm using a blade coater. After the coating, the mixture was air-dried for 30 minutes and then dried at 30 ° C. for 2 hours using a vacuum dryer to obtain an ink film forming original plate 21.

(Example 22: Preparation of original plate 22 for forming an ink film)
2-Butanol 360 parts by mass, toluene 360 parts by mass, inorganic filler B 467 parts by mass surface-modified with the above-mentioned polymerizable surface modifier and compound (5), 85 parts by mass of the above-mentioned exemplary compound M2 which is a radically polymerizable monomer. Was mixed and dispersed for 60 minutes using a US homogenizer to obtain a uniform dispersion of the inorganic filler B. Then, 17 parts by mass of Omnirad819 (manufactured by IGM Resins B.V.), which is a polymerization initiator, was added and mixed uniformly, and then an aluminum substrate (length 360 mm × width 180 mm) on an electrolytically polished flat plate, which was a substrate, was added. ) Was coated with a blade coater so that the thickness after drying was 6 μm. Next, the formed coating film was irradiated with ultraviolet rays for 1 minute with a metal halide lamp to cure the coating film, thereby obtaining an ink film forming original plate 22.

(Comparative Example 1: Preparation of Original Plate 23 for Ink Film Formation)
360 parts by mass of dichloromethane, 360 parts by mass of toluene, and 570 parts by mass of the following compound (8), which is a photoresponsive compound, were stirred and mixed at 50 ° C. for 1 hour to obtain a solution. This solution was well dispersed at room temperature (25 ° C.) for 30 minutes using a paint shaker, and then dried using a blade coater on an electropolished flat aluminum substrate (length 360 mm × width 180 mm). After that, it was applied so that the thickness was 6 μm. After the coating, the mixture was air-dried for 30 minutes and then dried at 30 ° C. for 2 hours using a vacuum dryer to obtain an ink film forming original plate 23.

(Comparative Example 2: Preparation of Original Plate 24 for Ink Film Formation)
1200 parts by mass of dichloromethane, 1200 parts by mass of toluene, 570 parts by mass of the above compound (8) which is a photoresponsive compound, and 1330 parts by mass of styrene acrylic resin (US-1071 manufactured by Starlight PMC Co., Ltd.) which is a thermoplastic resin. The mixture was stirred and mixed at ° C. for 1 hour to obtain a solution for forming a surface layer. This solution was well dispersed at room temperature (25 ° C.) for 30 minutes using a paint shaker, and then placed on an electropolished flat aluminum substrate (length 360 mm x width 180 mm x thickness 30 mm) with a blade coater. Was applied so that the thickness after drying was 6 μm. After the coating, the mixture was air-dried for 30 minutes and then dried at 30 ° C. for 2 hours using a vacuum dryer to obtain an ink film forming original plate 24.

(Comparative Example 3: Preparation of Original Plate 25 for Ink Film Formation)
1200 parts by mass of dichloromethane, 1200 parts by mass of toluene, 570 parts by mass of the above compound (8) which is a photoresponsive compound, 1140 parts by mass of a styrene acrylic resin (manufactured by Starlight PMC Co., Ltd., US-1071) which is a thermoplastic resin, and oxidation. 190 parts by mass of tin (number average primary particle size = 20 nm) was stirred and mixed at 50 ° C. for 1 hour to obtain a dispersion liquid for forming a surface layer. This solution was well dispersed at room temperature (25 ° C.) for 30 minutes using a paint shaker, and then placed on an electropolished flat aluminum substrate (length 360 mm x width 180 mm x thickness 30 mm) with a blade coater. Was applied so that the thickness after drying was 6 μm. After the coating, the mixture was air-dried for 30 minutes and then dried at 30 ° C. for 2 hours using a vacuum dryer to obtain an ink film forming original plate 25.

The configurations of the original plates 1 to 25 for forming an ink film are shown in Table 1 below.

[Evaluation of responsiveness to external stimuli]
The responsiveness to the external stimulus to the surface layer was confirmed for each of the ink film forming original plates 1 to 25 of the examples and comparative examples prepared above. Specifically, the contact angle of each of the prepared original plates was measured with pure water by the static drip method in the wettability test method for the surface of the substrate glass described in JIS R3257: 1999. Next, after applying an external stimulus (light or heat) for a predetermined time, the contact angle of pure water was measured again by the same method, and the difference in contact angle before and after applying the external stimulus was ranked as follows. If the judgment is D when the external stimulus application time is 20 seconds, it is rejected. As an external stimulus, the ink film forming original plates 1 to 6 and 8 to 25 were irradiated with a monochromatic laser beam having a wavelength of 365 nm at an irradiation amount of 2 J / cm ² . The original plate 7 for forming an ink film was irradiated with a monochromatic laser beam having a wavelength of 800 nm so that the temperature of the irradiated portion was 40 ° C.
A: Difference in contact angle from before external stimulus application is 50 ° or more B: Difference in contact angle from before external stimulus application is 35 ° or more and less than 50 ° C: Difference in contact angle from before external stimulus application is 20 ° More than 35 ° D: The difference in contact angle from before external stimulus is applied is less than 20 °.

As for the surface layer of the ink film forming original plate, in the ink film forming original plates 1 to 8 and 9 to 25, the contact angle of pure water measured as described above before applying an external stimulus is 50 ° or more. It was water repellent and became hydrophilic at 15 ° or less after the stimulation was applied. Further, in the ink film forming original plate 7, the contact angle of pure water was hydrophilic at 15 ° or less before the external stimulus was applied, and became water repellent at 50 ° or more after the stimulus was applied.

[Evaluation of fine line reproducibility]
(Example 1)
An adhesive layer is provided on the surface of the plate cylinder of the pattern film forming apparatus having the configuration as shown in FIG. 3, and the ink film forming original plate 1 produced above is attached and installed on the adhesive layer, and a monochromatic laser having a wavelength of 365 nm is installed. The non-image portion of the image pattern (thin line width: 60 μm) shown in FIG. 4 was irradiated with light at an irradiation amount of 2 J / cm ² . As a result, an ink film forming surface (m1) having a pattern in which the light irradiation portion, that is, the non-image portion becomes a hydrophilic portion and the image portion becomes a water-repellent portion is formed.

Hydrophobic ink was applied to the image portion (water-repellent portion) of the ink film forming surface (m1) using an ink roller to form an ink film. The ink film was transferred to the blanket by relatively pressing and pulling the surface of the blanket for the ink film against the ink film forming original plate 1 having the ink film. The ink film was transferred to the surface of the paper by relatively pressing and pulling the J paper A3 as the object to be printed against the blanket having the ink film, and a printed image was obtained (this printed image is "initial"). The same shall apply hereinafter). Further, 10000 sheets of this printed image were continuously output (the 10000th printed image is referred to as "after 10000 sheets are printed (after printing)"; the same applies hereinafter). Then, as an erasing step, the entire surface of the ink film forming surface (m1) was irradiated with a monochromatic laser beam having a wavelength of 465 nm at an irradiation amount of 2 J / cm ² . After irradiating with a monochromatic laser beam having a wavelength of 465 nm, the contact angle of the surface of the ink film forming surface (m1) with pure water was measured by the same method as described above. It was confirmed that a water-repellent surface similar to that of the original plate before the writing operation was obtained.

Further, the photoresponsive compound is structurally changed (photoisomerized) by writing by irradiating the non-image portion of the output image with a monochromatic laser beam having a wavelength of 365 nm at an irradiation amount of 2 J / cm ² , and the light irradiation portion, that is, A pattern was formed in which the non-imaged part became a hydrophilic part and the imaged part became a water-repellent part.

Ink was applied to the water-repellent portion of this pattern using an ink roller to form an ink film. The ink film was transferred to the blanket by relatively pressing and pulling the surface of the blanket for the ink film against the original plate having the ink film. Further, the ink film is transferred to the surface of the paper by relatively pressing and pulling the paper as the object to be printed against the blanket having the ink film to obtain a printed image, and the printed image is continuously printed on 10,000 sheets. Output (this 10000th printed image is referred to as "after the writing step and printing 10000 sheets (writing step and after printing". The same shall apply hereinafter).

(Examples 2 to 6, 8 to 22, Comparative Examples 1 to 3)
The printed image was output in the same manner as in Example 1 except that the ink film forming original plates 2 to 6 and 8 to 25 were used instead of the ink film forming original plate 1.

(Example 7)
An ink film forming original plate 7 is installed on a plate cylinder of a pattern film forming apparatus having a configuration as shown in FIG. 3, and a monochromatic laser beam having a wavelength of 800 nm is emitted in FIG. 4 so that the image portion of the output image becomes 40 ° C. The image portion of the image pattern shown (thin line width: 60 μm) was irradiated. By this light irradiation, the image part was heated to become a water-repellent part, and the non-image part not irradiated with light (not heated) became a hydrophilic part, and a pattern was formed. In this way, the ink film forming surface (m7) was produced.

Hydrophobic ink was applied to the image portion (water-repellent portion) of the ink film forming surface (m7) using an ink roller to form an ink film. The ink film was transferred to the blanket by relatively pressing and pulling the surface of the blanket for the ink film against the ink film forming original plate 7 having the ink film. The ink film was transferred to the surface of the paper by relatively pressing and pulling the paper as the object to be printed against the blanket having the ink film, and a printed image was obtained (this printed image is referred to as "initial"). ). Further, 10,000 sheets of this printed image were continuously output (the 10000th printed image is referred to as "after 10,000 sheets are printed (after printing)"). Then, the cold air (cold air temperature: 10 ° C.) generated from the cold air generator was applied to the ink film forming surface (m7), and the temperature of the surface (m7) was set to 30 ° C. After that, the contact angle of the surface of the ink film forming surface (m7) with pure water was measured by the same method as above, and since it was 15 ° or less, the hydrophilic surface was the same as that of the original plate before the writing operation. Was obtained.

Further, by writing to irradiate the image portion with a monochromatic laser beam having a wavelength of 800 nm so that the irradiation portion becomes 40 ° C. and the image portion of the output image becomes 40 ° C., the image portion becomes a water-repellent portion and is irradiated with light. A pattern was formed in which the non-imaged part was a hydrophilic part.

Ink was applied to the water-repellent portion of this pattern using an ink roller to form an ink film. The ink film was transferred to the blanket by relatively pressing and pulling the surface of the blanket for the ink film against the original plate having the ink film. Further, the ink film is transferred to the surface of the paper by relatively pressing and pulling the paper as the object to be printed against the blanket having the ink film to obtain a printed image, and the printed image is continuously printed on 10,000 sheets. Output (this 10000th printed image is referred to as "after the writing step and printing 10000 sheets (writing step and after printing").

(Example 5-2)
The ink film forming original plate 5 is installed on the plate cylinder of the pattern film forming apparatus as shown in FIG. 3, and a monochromatic laser beam having a wavelength of 365 nm is applied to the entire surface layer of the ink film forming original plate 5 at an irradiation amount of 2 J / cm ² . Irradiated. As a result, the entire surface layer of the ink film forming original plate 5 became a hydrophilic portion. Next, a monochromatic laser beam having a wavelength of 465 nm was applied to the image portion of the image pattern (thin line width: 60 μm) shown in FIG. 4 at an irradiation amount of 2 J / cm ² . As a result, an ink film forming surface (m5-2) having a pattern in which the light irradiation portion, that is, the image portion becomes a water-repellent portion and the non-image portion becomes a hydrophilic portion was formed.

Ink was applied to the image portion (water-repellent portion) of the ink film forming surface (m5-2) using an ink roller to form an ink film. The ink film was transferred to the blanket by relatively pressing and separating the ink film surface of the blanket against the ink film forming original plate 5-2) having the ink film. Further, the ink film was transferred to the surface of the paper by relatively pressing and pulling the paper as the object to be printed against the blanket having the ink film, and a printed image was obtained (this printed image is "initial"). ). Further, 10,000 sheets of this printed image were continuously output (the 10000th printed image is referred to as "after 10,000 sheets are printed (after printing)"). Then, as an erasing step, the surface for forming the ink film (m5-2) was irradiated with a monochromatic laser beam having a wavelength of 365 nm. After irradiating with light, the contact angle of the surface for forming the ink film (m5-2) with pure water was measured by the same method as above, and since it was 15 ° or less, the original plate before the writing operation was performed. It was confirmed that a hydrophilic surface similar to that of the above was obtained.

Further, by writing by irradiating the image portion of the output image with a monochromatic laser beam having a wavelength of 465 nm at an irradiation amount of 2 J / cm ² , the photoresponsive compound is structurally changed (photoisomerized), and the non-image portion is a hydrophilic portion. Therefore, a pattern was formed in which the image portion, which is the irradiation portion, became the water-repellent portion.

Ink was applied to the water-repellent portion of this pattern using an ink roller to form an ink film. The ink film was transferred to the blanket by relatively pressing and pulling the surface of the blanket for the ink film against the original plate having the ink film. Further, the ink film is transferred to the surface of the paper by relatively pressing and pulling the paper as the object to be printed against the blanket having the ink film to obtain a printed image, and the printed image is continuously printed on 10,000 sheets. Output (this 10000th printed image is referred to as "after the writing step and printing 10000 sheets (writing step and after printing").

(Evaluation methods)
Printing of the image pattern obtained above at "initial", "after 10,000 sheets of image (after image)", and "writing process and after 10,000 sheets of image (writing process and after image)". The image was enlarged with a digital microscope "VHX-600" (manufactured by KEYENCE CORPORATION). From the obtained monitor image, the line width of the thin line and the line width of the thin line at the intersection were observed by the indicator and ranked according to the following criteria. Initially, in all of the writing process and after 10,000 sheets were printed, any one of A to D was accepted. Further, FIG. 5 is a diagram showing the intersections of the thin lines used for the evaluation, in which the thick solid line circles are the intersections of the four straight lines, the fine solid line circles are the intersections of the three straight lines, and the broken line circles are the intersections of the two straight lines:
A: There are no thin lines or intersections where the line width is thick. B: The line is thick at the intersection of 4 straight lines. C: The line is thick at the intersection of 3 straight lines. D: The intersection of 2 straight lines. The line is thicker with E: The thin line itself is thicker.

The evaluation results are shown in Tables 1 and 2 below. In Table 1, the surface modifier 1 is a stimulus-responsive compound. The surface modifier 2 is a polymerizable surface modifier. Other components are components other than inorganic fillers and resins surface-modified with stimulus-responsive compounds.

As is clear from Table 1 above, the ink film forming original plates of Examples 1 to 22 and Comparative Examples 1 to 3 having a stimulus-responsive compound in the surface layer both change their affinity with water by an external stimulus. I was able to confirm that. At this time, the original plates of Comparative Examples 2 and 3 in which the surface layer is mixed with a resin or an inorganic filler are applied with an external stimulus when the external stimulus application time is shorter than that of the original plate of Comparative Example 1 composed of only a stimulus-responsive compound. It can be seen that the change in the contact angle of pure water with the previous one tends to be small, and the response to the stimulus is low. On the other hand, it was found that all of the ink film forming original plates of Examples 1 to 22 using the inorganic filler surface-modified with the stimulus-responsive compound had excellent responsiveness.

Further, from the results of the fine line reproducibility in Table 1 above, it was found that when the original plate for forming an ink film of the present invention was used, the pattern could be easily rewritten digitally and the durability was excellent.

On the other hand, when the original plate of Comparative Example 1 is used, the printed images of "after 10,000 sheets are printed" and "after the writing process and 10,000 sheets are printed" are rejected, and it is difficult to rewrite the pattern digitally. It was found that the durability before and after rewriting was insufficient. This is because the hardness is relatively low because only the stimulus-responsive compound, which is an organic substance, is used. Conceivable.

Further, when the original plates of Comparative Example 2 and Comparative Example 3 are used, the printed image "after the writing process and printing of 10000 sheets" is unacceptable, and the durability after rewriting is insufficient. Do you get it. It is considered that this is because the content of the resin is high and the plastic component on the film surface is high.

Further, in Comparative Example 3, although the stimulus-responsive compound and the inorganic filler are used, if these are simply mixed, the stimulus-responsive compound may aggregate or be buried inside the inorganic filler when the original plate is prepared. It is thought that it will be done. Therefore, it is considered that the stimulus-responsive compound cannot be uniformly arranged on the surface of the inorganic filler, the responsiveness becomes insufficient, and it becomes difficult to produce a good image pattern.

As shown in Examples 1 to 7, good response was obtained in both the case where the photoresponsive compound was used as the stimulus-responsive compound (Examples 1 to 6) and the case where the temperature-responsive compound was used (Example 7). Although the properties and fine line reproducibility were shown, higher responsiveness, durability, and contrast were obtained in Examples 1 to 6 using the photoresponsive compound. Above all, in Examples 4 to 6 using the photoresponsive compound having a hydrophilic group, good fine line reproducibility was obtained even in the case of repeated printing or repeated printing after rewriting.

As shown in Examples 8 to 10 and 12 to 15, good responsiveness and fine line reproducibility were obtained in all cases even when the type of the inorganic filler and the number average primary particle size were changed. Among them, in Examples 9 and 12 to 15 in which the number average primary particle size is 5 to 100 nm, higher responsiveness, durability and contrast were obtained.

As shown in Examples 16 to 22, the ink film forming original plate of the present invention exhibits excellent responsiveness even when a resin is added in addition to an inorganic filler surface-modified with a stimulus-responsive compound. From the comparison of Examples 16 to 20, the durability is excellent when the resin content is 30% by mass or less with respect to the surface layer, and the excellent responsiveness and durability are obtained when the resin content is in the range of 5 to 20% by mass. Easy to obtain in a well-balanced manner.

Further, from the comparison of Examples 17, 21 and 22, it was found that the use of a resin which is a polymer of a thermoplastic resin or a radically polymerizable monomer is more excellent in responsiveness and durability.

As in Examples 11 and 22, the inorganic filler surface-modified with the stimulus-responsive compound further has a polymerizable group, so that the inorganic fillers can be crosslinked with each other to form a strong film, which is durable. It is considered that the sex can be further improved. In particular, when a radically polymerizable monomer is used to form a three-dimensional crosslinked inorganic-organic hybrid film as in Example 22, durability can be further improved.

As shown in Table 2 above, in Example 5, the light-irradiated portion changes to hydrophilicity by irradiating the non-image portion with light having a wavelength of 365 nm against the water-repellent surface layer of the entire surface of the original plate 5. A pattern film is formed. In Example 5-2, the entire surface of the surface layer is irradiated with light having a wavelength of 365 nm, the surface layer is once made hydrophilic, and then the surface layer is partially made water-repellent by irradiation with light having a wavelength of 465 nm to form a pattern film. This is an example of what I did. In any case, the original version of the present invention was found to have good performance.

1 Original plate for forming ink film,
2nd edition body,
3 blanket,
4 impression cylinder,
5 Ink roller,
6 water roller,
7 Monochromatic laser light source,
8 Printed material,
10 Pattern film forming apparatus.

Claims (14)

With the board
It has a surface layer provided on the substrate, and has.
The surface layer is an ink film forming original plate containing an inorganic filler surface-modified with a stimulus-responsive compound whose affinity with water changes reversibly in response to an external stimulus. The original plate for forming an ink film according to claim 1, wherein the stimulus-responsive compound is a photoresponsive compound. The original plate for forming an ink film according to claim 2, wherein the stimulus-responsive compound is a compound represented by the following chemical formula (I).

In the above chemical formula (I), Z _a and Z _b are both nitrogen atoms, or Z _a and Z _b are independently N or CH, respectively, and Z _a ≠ Z _b .
R ₁ to R ₅ are independent groups having a hydrogen atom, an alkyl group, an alkoxy group, a halogen group, a hydrophilic group or a surface-modifying functional group, and R ₆ is a group having a cyclic structure.
At this time, at least one of R ₁ to R ₅ is a group having a surface-modifying functional group, or R ₆ includes a group having at least one surface-modifying functional group. The original plate for forming an ink film according to claim 3, wherein the stimulus-responsive compound has the hydrophilic group. The original plate for forming an ink film according to any one of claims 1 to 4, wherein the number average primary particle size of the inorganic filler is 5 to 100 nm. The original plate for forming an ink film according to any one of claims 1 to 5, wherein the inorganic filler has a polymerizable group. The original plate for forming an ink film according to any one of claims 1 to 6, wherein the inorganic filler is tin oxide particles, titanium dioxide particles, silicon oxide particles, aluminum oxide particles, or zinc oxide particles. The surface layer further contains a resin and
The original plate for forming an ink film according to any one of claims 1 to 7, wherein the content of the resin is 1 to 30% by mass with respect to the total mass of 100% by mass of the surface layer. The original plate for forming an ink film according to claim 8, wherein the content of the resin is 5 to 20% by mass with respect to the total mass of 100% by mass of the surface layer. The original plate for forming an ink film according to claim 8 or 9, wherein the resin is a thermoplastic resin. The original plate for forming an ink film according to claim 8 or 9, wherein the resin is a polymer of a radically polymerizable monomer. A pattern forming method comprising a writing step of applying an external stimulus to the surface layer of the ink film forming original plate according to any one of claims 1 to 11 to form a pattern having a different affinity for water. The pattern forming method according to claim 12, wherein the external stimulus is light. The pattern forming method according to claim 13, wherein the external stimulus is light in a wavelength region of 280 to 400 nm.

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