JP2008115214A - Black ink composition for inkjet, method for producing photomask using the same and photomask - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a black ink composition for inkjet, exhibiting excellent fixing properties even when directly reached to the surface of a polyethylene terephthalate (PET) film. <P>SOLUTION: The black ink composition for inkjet comprises at least an aprotic polar solvent, a thermoplastic resin, a pigment, a cyclic amide compound, a surfactant and water and has an ultraviolet transmission density on a recording medium of ≥2.8. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a black ink composition for inkjet. The black ink composition of the present invention can be suitably used as a printing ink composition for a photomask (pattern original plate) used in a pattern exposure step, particularly in a plate making process of a printing original plate (screen mask) used in screen printing. .

  Since screen printing has excellent characteristics, it is widely used. For example, there are a wide variety of inks that can be used, and the printing medium is not limited, and if the surface is not subjected to water repellent treatment, almost all materials can be printed. It can be printed on metal, wood, acrylic board or fabric. Furthermore, since the layer thickness of the ink layer reaches 3 to 6 times that of letterpress printing or offset printing, the weather resistance is excellent. In addition, since there is little restriction on the size of the printing original plate (or screen mask) and there is elasticity, printing media of various sizes, curved surfaces, and the like can be printed.

  In the process (plate making process) for producing the printing original plate (screen mask), after the tensioning process for fixing the screen mesh to the frame, a photosensitive emulsion coating process for uniformly coating the photosensitive emulsion on the entire screen mesh, film or glass plate The photomask (pattern original plate) is closely attached to the photosensitive emulsion surface, and a pattern exposure process for printing the pattern with a parallel exposure machine or the like is successively performed. Subsequently, a printing original plate in which a part of the screen mesh is sealed can be obtained by a development step in which the unexposed photosensitive emulsion is developed and removed by washing with water. When screen printing is performed using the printing original plate (screen mask) thus obtained, ink is pushed out from the unexposed portion (non-sealed portion) to become an image portion, and ink passes through the exposed portion (sealed portion). Is blocked to become a non-image portion.

  In the photomask (pattern original plate) used in the pattern exposure step, it is necessary to distinguish between an exposed portion and an unexposed portion with high resolution. Therefore, a mask layer having excellent exposure shielding properties is provided on a transparent film. Is required. Therefore, a photomask (pattern original plate) has been conventionally manufactured by a resist method. Although the resist method is superior in terms of the ability to form dense images, it is more expensive than the inkjet recording method, and if a small quantity of various types of photomasks (pattern originals) is required, they are manufactured. Inappropriate as a way to do.

On the other hand, since the transparent film used as a base material for the photomask (pattern original plate) is a non-absorbing medium such as polyethylene terephthalate (PET), the photomask (pattern original plate) is produced by an inkjet recording method. Needs to use an ink that can be fixed to a non-absorbing medium substrate. As such an inkjet recording ink for a non-absorbing medium, for example, an inkjet recording ink containing a graft copolymer binder has been proposed (Patent Document 1). However, in this method using ink jet recording ink, since the binder is fixed on the surface of the recording medium without allowing the ink to penetrate into the recording medium, compared with a monomer curable type such as UV curable ink or two-component curable ink. There is a problem that adhesion to a recording medium is small. Ink jet recording inks containing lactam or lactone as a carrier medium have also been proposed (Patent Document 2). However, lactams and lactones are merely examples of solvents for dissolving the colorant of the ink composition, and it has been suggested that printing on a recording medium whose recording surface is a plastic film is performed. Absent. In addition, the inkjet recording inks described in Patent Document 1 and Patent Document 2 are not necessarily satisfactory in fixing properties to polyethylene terephthalate (PET) films that are widely used as transparent films for the photomask (pattern original plate). It's not something you can do.

  As a transparent film for inkjet recording, a polyethylene terephthalate (PET) film having an ink absorption layer on the surface is also known. However, this has the disadvantage that it is expensive and cannot be recorded at high resolution.

JP 2000-44858 A JP 2002-103785 A

  Accordingly, an object of the present invention is to have excellent fixability when landed directly on the surface of a polyethylene terephthalate (PET) film that does not carry an ink absorbing layer. An object of the present invention is to provide an ink composition suitable as an ink composition for ink jet recording of a photomask (pattern original plate) used in a pattern exposure process of a platemaking process of a screen mask.

  The above-described problems include at least an aprotic polar solvent, a thermoplastic resin, a pigment, a cyclic amide compound, a surfactant, and water according to the present invention, and an ultraviolet transmission density on a recording medium of 2.8. This can be solved by the black ink composition for inkjet, which is characterized by the above.

In a preferred embodiment of the ink composition according to the present invention, the aprotic polar solvent is 1,1,3,3-tetramethylurea, dimethyl sulfoxide, N, N-dimethylformamide, hexamethylphosphoric triamide, and 1 , 3-dimethyl-2-imidazolidinone, at least one compound selected from the group consisting of
In a further preferred aspect of the ink composition according to the present invention, the cyclic amide compound is at least one selected from the group consisting of 2-pyrrolidone, N-methyl-2-pyrrolidone, and N-ethyl-2-pyrrolidone. A compound.
In still another preferred embodiment of the ink composition according to the present invention, the surfactant is at least one compound selected from the group consisting of a polyether-modified polysiloxane compound and an acetylene glycol compound.
In still another preferred embodiment of the ink composition according to the present invention, the low surface tension organic solvent is at least one compound selected from the group consisting of an alkanediol compound and a glycol ether compound.
In still another preferred embodiment of the ink composition according to the present invention, the content of the aprotic polar solvent is 1.0 to 50.0% by weight.
In still another preferred embodiment of the ink composition according to the present invention, the glass transition temperature of the thermoplastic resin is 80 ° C. or higher.

In addition, the above-described problems can be solved by the photomask used in the plate making process of the printing original plate for screen printing manufactured by the ink jet recording method using the ink composition according to the present invention.
In a preferred embodiment of the ink composition according to the present invention, the photomask substrate is a transparent film made of polyethylene terephthalate.

Furthermore, the said subject is the manufacturing method of the photomask which prints by discharging and adhering the droplet of an ink composition on the photomask base-material surface by this invention, Comprising: The manufacturing method of any one of Claims 1-6 This can be solved by a photomask manufacturing method using the ink composition according to one item.
In a preferred embodiment of the ink composition according to the present invention, the method includes a heat printing step for attaching the ink composition to the heated photomask substrate and / or a step for heating the photomask substrate to which the ink composition is attached. .

  The black ink composition for inkjet according to the present invention exhibits excellent fixability even when it is directly landed on the surface of a polyethylene terephthalate (PET) film, for example. Therefore, it is particularly suitable as an ink composition for ink jet recording of a photomask (pattern original plate) used in a pattern exposure step of a plate making step of a screen printing printing original plate (screen mask).

<UV transmission density>
The black ink composition for inkjet according to the present invention has an ultraviolet transmission density on the recording medium of 2.8 or more, preferably 3.0 or more, more preferably 3.5 or more.
In the present specification, the ultraviolet transmission density is a value measured by the following method.

<Ink composition>
As described above, the black ink composition according to the present invention comprises at least an aprotic polar solvent, a thermoplastic resin, a pigment, a cyclic amide compound, a surfactant, a low surface tension organic solvent, and water. . Generally, a black pigment such as carbon black is used.

  The black ink composition according to the present invention can be used for printing on a recording medium whose recording surface is a non-water-absorbing plastic film, in particular, in a photolithographic process used in a pattern exposure process in a plate making process of a printing original plate (screen mask) used in screen printing. It can be suitably used as an ink composition for printing a mask (pattern original plate).

  Examples of the substrate of the photomask (pattern original plate) include saturated polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), or poly 1,4-cyclohexylene dimethylene terephthalate.

  Resin capable of forming a film by curing the ink composition when the aprotic polar solvent dissolves the recording surface when the ink composition according to the present invention is printed on a recording medium such as polyethylene terephthalate (PET). Since the component is contained, when the volatile component in the ink evaporates, the resin component in the ink composition is cured and a film is formed. At this time, a mixed layer of polyethylene terephthalate (PET) on the recording surface that has been melted and a resin formed into a film is formed, but the polyethylene terephthalate (PET) and the resin film that do not form a mixed layer are formed through this mixed layer. Bond firmly. For this reason, the ink film is hardly rubbed due to external force and water hardly enters the interface between the ink film and the recording surface, and a recorded matter having excellent weather resistance such as adhesion, scratch resistance, and water resistance can be formed. it can.

In the ink composition according to the present invention, since the aprotic polar solvent is diluted with water, the liquid contact member constituting the printer is hardly destroyed or damaged.
Since the ink composition of the present invention has a low surface tension due to the inclusion of a surfactant, it does not agglomerate on the surface of a recording medium having no water absorbability, such as polyethylene terephthalate (PET), even if it is a water-based ink. Thus, the recording surface is evenly spread and good recording quality is obtained.

<Aprotic polar solvent>
The ink composition according to the present invention comprises an aprotic polar solvent. In the ink jet recording, fine droplets of a liquid ink composition are attached to a recording medium, and moisture of the droplets is evaporated or permeated into the recording medium and dried to perform recording. The aprotic polar solvent used in the present invention has a vapor pressure lower than that of water, and therefore evaporates more slowly than water. When moisture of the ink composition printed at the time of recording evaporates, the concentration of the aprotic polar solvent becomes high in the printed portion. The aprotic polar solvent in the ink composition according to the present invention has a property of dissolving plastic, and in the ink adhering to the recording surface, the recording surface is constituted when the concentration of the aprotic polar solvent is increased. The action of dissolving the plastic is enhanced.

The reason why a specific aprotic polar solvent is used as a component for dissolving the plastic in the ink composition of the present invention is as follows. 1) It is water soluble. 2) A 100% concentration of aprotic polar solvent dissolves or swells the plastic, but an aqueous solution having a concentration lower than that added to the ink composition does not destroy the ink contact parts of the printer. 3) Below the concentration added to the ink composition, the dispersed components such as the pigment dispersion, the pigment dispersant, and the resin emulsion are not aggregated. 4) The vapor pressure is below water. In the present invention, when the plastic soaked in the solvent is deformed, it is determined that it has dissolved or swollen.
The aprotic polar solvent used in the ink composition of the present invention is preferably 1,1,3,3-tetramethylurea, dimethyl sulfoxide, N, N-dimethylformamide, hexamethylphosphoric triamide, 1,3-dimethyl. -2-Imidazolidinone. These aprotic polar solvents may be used as a mixture of two or more. The aprotic polar solvent has a limited effect even if it is 1% or less with respect to the total amount of the ink composition, but is preferably 1.0 to 50.0% by weight, more preferably 2. 0 to 25.0% by weight.

<Thermoplastic resin>
The ink composition according to the present invention comprises a thermoplastic resin. The thermoplastic resin includes an amorphous part that is not crystallized or cross-linked, and the amorphous part has a characteristic that its shape changes due to melting by heating or dissolution in a specific solvent. When the molten or dissolved thermoplastic resin is solidified again, the amorphous parts are welded together to form a strong resin layer.
Since the thermoplastic resin in the ink composition of the present invention is dissolved in a specific aprotic polar solvent, the thermoplastic resin is dissolved and solidified during the drying process of the ink composition of the present invention. The thermoplastic resin and the plastic film are welded to each other to form a strong film of the thermoplastic resin on the surface of the plastic film.

As the thermoplastic resin that can be used in the present invention, in addition to water-soluble resins, water-insoluble resins can also be used. As the resin soluble in water, a resin dispersant used to disperse the pigment can be preferably used. Moreover, it is preferable that the resin insoluble in water is added to the ink composition in the form of a resin emulsion. Here, the resin emulsion is composed of water as a continuous phase and a resin component as a dispersed phase.
According to a preferred embodiment of the present invention, the thermoplastic resin component is preferably a polymer having both a hydrophilic portion and a hydrophobic portion. When a resin emulsion is used, the particle diameter is not particularly limited as long as the emulsion is formed, but is preferably about 150 nm or less, more preferably about 5 to 100 nm.

  The glass transition temperature of the thermoplastic resin that can be used in the present invention is preferably 80 ° C. or higher. By using a thermoplastic resin having a glass transition temperature of 80 ° C. or higher, good film fixability can be obtained.

  As the resin, the same resin component as the resin emulsion conventionally used in the ink composition for ink jet recording can be used. Specific examples of the resin component include acrylic polymers such as polyacrylate esters or copolymers thereof, polymethacrylate esters or copolymers thereof, polyacrylonitrile or copolymers thereof, polycyanoacrylates, and polyacrylamides. , Polyacrylic acid, or polymethacrylic acid; polyolefin polymers such as polyethylene, polypropylene, polybutene, polyisobutylene, polystyrene, or copolymers thereof, petroleum resins, coumarone-indene resins, or terpene resins; vinyl acetate vinyl Alcohol-based polymers such as polyvinyl acetate or copolymers thereof, polyvinyl alcohol, polyvinyl acetal, or polyvinyl ether; halogen-containing polymers such as polyvinyl chloride or copolymers thereof, polymers Vinylidene chloride, fluororesin, or fluororubber; nitrogen-containing vinyl-based polymer, such as polyvinyl carbazole, polyvinyl pyrrolidone or copolymer thereof, polyvinyl pyridine, or polyvinyl imidazole; diene-based polymer, such as polybutadiene or copolymer thereof , Polychloroprene, or polyisoprene (butyl rubber); or other ring-opening polymerization resin, condensation polymerization resin, natural polymer resin, or the like can be used.

  If the resin is obtained in the form of an emulsion, it can be prepared by mixing the resin particles in water, optionally with a surfactant. For example, an emulsion of an acrylic resin or a styrene-acrylic acid copolymer resin is composed of a (meth) acrylic acid ester resin or a styrene- (meth) acrylic acid ester resin, and optionally a (meth) acrylic acid resin, and an interface. It can be obtained by mixing the active agent with water. The mixing ratio of the resin component and the surfactant is usually preferably about 50: 1 to 5: 1. When the amount of the surfactant used is less than the above range, it is difficult to form an emulsion, and when the amount exceeds the above range, the water resistance of the ink tends to decrease or the adhesion tends to deteriorate. Absent.

  The surfactant used in the preparation of the resin emulsion is not particularly limited, but preferred examples include anionic surfactants (for example, sodium dodecylbenzansulfonate, sodium laurylate, ammonium salt of polyoxyethylene alkyl ether sulfate, etc.) ), Nonionic surfactants (eg, polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylphenyl ether, polyoxyethylene alkylamine, polyoxyethylene alkylamide, etc.) These can be used as a mixture of two or more.

The resin emulsion can also be obtained by emulsion polymerization of the above resin component monomers in water in the presence of a polymerization catalyst and an emulsifier. A polymerization initiator, an emulsifier, and a molecular weight modifier used in the emulsion polymerization can be used according to a conventional method.
As the polymerization initiator, those used for normal radical polymerization are used, for example, potassium persulfate, ammonium persulfate, hydrogen peroxide, azobisisobutyronitrile, benzoyl peroxide, dibutyl peroxide, Examples include peracetic acid, cumene hydroperoxide, t-butyl hydroxy peroxide, paramentane hydroxy peroxide, and the like. When the polymerization reaction is performed in water, a water-soluble polymerization initiator is preferable. Examples of the emulsifier include sodium lauryl sulfate, those generally used as an anionic surfactant, nonionic surfactant or amphoteric surfactant, and mixtures thereof. These can be used in combination of two or more.

The ratio of the resin and water as the dispersed phase component is preferably 60 to 400 parts by weight, more preferably 100 to 200 parts by weight of water with respect to 100 parts by weight of the resin.
When a resin emulsion is used as the resin, a known resin emulsion can also be used. For example, JP-B-62-1426, JP-A-3-56573, JP-A-3-79.
Resin emulsions described in JP-A No. 678, JP-A No. 3-160068, JP-A No. 4-18462 and the like can be used as they are. Commercially available resin emulsions can also be used. For example, Microgel E-1002, E-5002 (styrene-acrylic resin emulsion; manufactured by Nippon Paint Co., Ltd.), Boncoat 4001 (acrylic resin emulsion; Dainippon) Ink Chemical Co., Ltd.), Boncoat 5454 (styrene-acrylic resin emulsion; Dainippon Ink and Chemicals Co., Ltd.), SAE1014 (styrene-acrylic resin emulsion; manufactured by Nippon Zeon Co., Ltd.), or Cybinol SK-200 ( Acrylic resin emulsion (manufactured by Seiden Chemical Co., Ltd.).
In the present invention, the resin may be mixed as a fine particle powder with other components in the ink composition. However, after the resin fine particles are dispersed in an aqueous medium to form a resin emulsion, the other components of the ink composition are used. It is more preferable to mix with.

From the viewpoint of long-term storage stability and ejection stability of the ink composition, the resin fine particles preferably used in the present invention have a particle size in the range of 5 to 400 nm, more preferably in the range of 50 to 200 nm.
The resin is preferably contained in the range of 0.1 to 15.0% by weight in terms of solid content, and more preferably in the range of 0.5 to 10.0% by weight, based on the total amount of the ink composition. preferable. In the ink composition, if the resin component is too small, the ink film formed on the recording surface may become thin and adhesion to the recording surface may be insufficient. If the resin component is too much, the dispersion of the resin may become unstable during storage of the ink composition, or the resin component may agglomerate and solidify due to the slight evaporation of water, making it impossible to form a uniform film.

<Pigment>
The ink composition according to the present invention comprises a pigment. As the pigment, any pigment conventionally used in water-based ink jet recording ink compositions can be used, and examples thereof include organic pigments and inorganic pigments. The pigment is a resin-dispersed pigment dispersed together with a dispersant such as a water-soluble resin or a surfactant, or a surface-treated pigment that has a hydrophilic group introduced into the pigment surface and can be dispersed or dissolved in an aqueous medium without the use of a dispersant. Can be added to the ink composition. The pigment dispersant resin can be used as a thermoplastic resin as described above. Two or more kinds of pigments may be used in combination.

  As the inorganic pigment, titanium oxide and iron oxide, or carbon black produced by a known method such as a contact method, a furnace method, or a thermal method can be used.

  Examples of organic pigments include azo pigments (for example, azo lakes, insoluble azo pigments, condensed azo pigments, or chelate azo pigments), polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, verinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, A thioindigo pigment, an isoindolinone pigment, or a quinophthalone pigment), a dye chelate (for example, a basic dye chelate or an acid dye chelate), a nitro pigment, a nitroso pigment, or aniline black can be used. Of these pigments, it is preferable to use a pigment having good affinity with water.

More specifically, as a pigment for black ink, for example, carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, or channel black, or copper oxide, iron oxide ( CI pigment black 11), metals such as titanium oxide, and organic pigments such as aniline black (CI pigment black 1).
Specific examples of suitable carbon black include carbon black manufactured by Mitsubishi Chemical Corporation, No. 2300, 900, MCF88, no. 20B, no. 33, no. 40,
No. 45, no. 52, MA7, MA8, MA100, No2200B and the like. Examples of carbon blacks manufactured by Degussa include color blacks FW1, FW2, FW2V, FW18, FW200, S150, S160, S170, Pretex 35, U, V, 140U, Special Black 6, 5, 4A, 4, 250, etc. It is done. Examples of carbon black manufactured by Columbia Carbon include Conductex SC, Raven 1255, 5750, 5250, 5000, 3500, 1255, 700, and the like. Examples of the carbon black manufactured by Cabot include Regal 400R, 330R, 660R, Mogul L, Monarch 700, 800, 880, 900, 1000, 1100, 1300, 1400, Elftex 12 and the like manufactured by Cabot.

The particle diameter of the pigment is not particularly limited, but the average particle diameter is preferably 25 μm or less, more preferably 1 μm or less. By using a pigment having an average particle diameter of 25 μm or less, the occurrence of clogging can be suppressed, and further sufficient ejection stability can be realized.
The content of the pigment is preferably 0.5 to 15.0% by weight, more preferably 1.0 to 10.0% by weight, based on the entire ink composition.

<Dispersant>
When the above pigment is used, it is preferable to add a dispersant to the ink so that the pigment is completely dispersed in an aqueous medium. As the dispersant used here, for example, a polymer dispersant and a surfactant can be used.
Preferred examples of the polymer dispersant include synthetic polymers, such as polyvinyl alcohols, polyvinyl pyrrolidones, polyacrylic acid, acrylic acid-acrylonitrile copolymer, potassium acrylate-acrylonitrile copolymer, vinyl acetate- Acrylic resins such as acrylic acid ester copolymers, acrylic acid-acrylic acid ester copolymers, styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, styrene-methacrylic acid-acrylic acid ester copolymers, Styrene-acrylic resins such as styrene-α-methylstyrene-acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymer, styrene-maleic acid copolymer, styrene-maleic anhydride copolymer Polymer, vinylnaphthalene-acrylic acid copolymer, vinyl Nylnaphthalene-maleic acid copolymer, vinyl acetate-ethylene copolymer, vinyl acetate-fatty acid vinyl ethylene copolymer, vinyl acetate-maleic acid ester copolymer, vinyl acetate-crotonic acid copolymer, vinyl acetate- Examples thereof include vinyl acetate copolymers such as acrylic acid copolymers and salts thereof. Among these, a copolymer of a monomer having a hydrophobic group and a monomer having a hydrophilic group, and a polymer comprising a monomer having both a hydrophobic group and a hydrophilic group in the molecular structure are preferable. The coalescence may be either a random copolymer or a block copolymer. Examples of the salt include salts of diethylamine, ammonia, ethylamine, triethylamine, propylamine, isopropylamine, dipropylamine, butylamine, isobutylamine, triethanolamine, diethanolamine, aminomethylpropanol, morpholine, and the like. These compounds for forming a salt may be equal to or more than the neutralization equivalent of a dispersant composed of an organic substance before forming a salt. These copolymers preferably have a weight average molecular weight of 1,000 to 50,000, more preferably 3,000 to 10,000.

Specific examples of surfactants as dispersants include sulfonic acids such as alkane sulfonates, α-olefin sulfonates, alkyl benzene sulfonates, alkyl naphthalene sulfonic acids, acylmethyl tauric acids, and dialkyl sulfosuccinic acids. Type, alkyl sulfate ester salt, sulfated oil, sulfated olefin, polyoxyethylene alkyl ether sulfate salt; carboxylic acid type such as fatty acid salt, alkyl sarcosine salt; alkyl phosphate ester salt, polyoxyethylene alkyl ether phosphorus Phosphoric acid ester types such as acid ester salts and monoglycerite phosphoric acid ester salts; anionic surfactants typified by, etc .; and pyridium types such as alkyl pyridium salts; amino acid types such as alkyl amino acid salts; Solids such as alkyldimethylbetaine Zwitterionic surfactants typified by polyoxyethylene alkyl ethers, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl esters, polyoxyethylene alkyl amides, etc .; glycerin alkyl esters Nonionic surfactants typified by polyol ester type such as sorbitan alkyl ester, sugar alkyl ester; polyether type such as polyhydric alcohol alkyl ether; alkanolamide type such as alkanolamine fatty acid amide; . The amount of these dispersants added is preferably about 1 to 50% by weight, more preferably 2 to 30% by weight based on the pigment.

  In a preferred embodiment of the present invention, a styrene- (meth) acrylic acid copolymer salt is used as a dispersant. The salt of a styrene- (meth) acrylic acid copolymer basically indicates that the structure contains at least a styrene skeleton and a (meth) acrylic acid salt skeleton, and the structure contains (meth) acrylic. It may have a skeleton derived from a monomer having another unsaturated group such as an acid ester skeleton. The salt of the styrene- (meth) acrylic acid copolymer may be a random copolymer or a block copolymer, and is produced by a known polymerization method such as radical copolymerization or group transfer polymerization. The acid value of the salt of the styrene- (meth) acrylic acid copolymer is preferably in the range of 50 to 300, more preferably in the range of 70 to 150. Further, the molecular weight is preferably 1000 to 50000 in terms of weight average molecular weight, more preferably 1000 to 15000, and still more preferably 3000 to 10000.

Commercially available products can be used as the dispersant, and specific examples thereof include Johnson Polymer Co., Ltd., Jonkrill 68 (molecular weight 10,000, acid value 195), Jonkrill 680 (molecular weight 3900, acid value 215). ), Joncryl 682 (molecular weight 1600, acid value 235), Joncryl 550 (molecular weight 7500, acid value 200), Joncryl 555 (molecular weight 5000, acid value 200), Joncryl 586 (molecular weight 3100, acid value 105), Examples include Joncryl 683 (molecular weight 7300, acid value 150), B-36 (molecular weight 6800, acid value 250), and the like.
Dispersion of the pigment by the dispersant is performed by mixing the pigment, the above-described dispersant, water, and a water-soluble organic solvent with a ball mill, sand mill, attritor, roll mill, agitator mill, Henschel mixer, colloid mill, ultrasonic homogenizer, jet mill, ang mill, etc. It is carried out with a suitable disperser.

  A surface-treated pigment that has been introduced with a hydrophilic group on the pigment surface and can be dispersed or dissolved in an aqueous medium without the use of a dispersant, has a functional group or a salt thereof as a hydrophilicity-imparting group, either directly or polyvalently. By introducing (chemically bonding) via a group, it is possible to disperse or dissolve in water without a dispersant. The type and degree of the functional group or salt thereof to be introduced are aqueous. It may be appropriately determined in consideration of dispersion stability in the ink composition, color density, drying property on the entire surface of the inkjet head, and the like.

<Cyclic amide compound>
The ink composition according to the present invention comprises a cyclic amide compound. In consideration of the ease of storage and application of the ink composition, the ink composition for ink jet recording contains a wetting agent. The purpose of adding the wetting agent is to aggregate the pigment component and the resin component by evaporation of moisture during storage. It is to prevent solidification, prevent clogging of nozzles of the inkjet head during inkjet application, and ensure ejection stability. A cyclic amide compound is used as the wetting agent in the ink composition of the present invention.
Preferable specific examples of the cyclic amide compound contained in the ink composition of the present invention include 2-pyrrolidone, N-methyl-2-pyrrolidone, and N-ethyl-2-pyrrolidone. You may use these in combination of 2 or more types. The content of the cyclic amide compound is, for example, 0.1 to 40.0% by weight, preferably 1.0 to 30.0% by weight, based on the total amount of the ink composition. By setting it as such a range, clogging prevention property or discharge stability can be ensured. When there is too much content, it may become a dry defect.

<Surfactant>
The ink composition according to the present invention comprises a surfactant. The aqueous solution is usually repelled on the surface of the hydrophobic material, but when a surfactant is added, the aqueous solution, that is, the ink composition can be uniformly applied to the surface of the hydrophobic material. The aprotic polar solvent in the uniformly applied ink composition dissolves only the desired area surface. Further, by uniformly applying the ink composition, the contained resin can be uniformly formed on the recording surface.

  Preferable specific examples of the polyether-modified polysiloxane compound contained as a surfactant in the ink composition of the present invention include compounds represented by the following general formula (1).

〔式（１）中、Ｒ^１〜Ｒ^７は、独立して、炭素数１〜６のアルキル基を表し、ｊ及びｋは、独立して、１以上の整数を表し、ＥＯはエチレンオキシ基を表し、ＰＯはプロピレンオキシ基を表し、ｍ及びｎは０以上の正数を表すが、但し、ｍ＋ｎは１以上の整数を表し、ＥＯ及びＰＯは、［ ］内においてその順序は問わず、ランダムであってもブロックであってもよい。〕
式（１）中、Ｒ^１〜Ｒ^７のアルキル基は好ましくはメチル基、ｊ及びｋは、好ましくは１〜５、より好ましくは１〜４、最も好ましくは１又は２である。また、ｍ及びｎは好ましくは１〜５であり、好ましくはｍ＋ｎは２〜４である。本発明の記録方法に用いるインク組成物の好ましい形態によれば、式（１）の化合物として、ｊ＝ｋ＝１〜３、好ましくは１又は２を満足するものが好ましい。また、別の好ましい形態として、式（１）の化合物として、Ｒ^１〜Ｒ^７が全てメチル基を表し、ｊが１を表し、ｋが１を表し、ｌが１を表し、ｍが１以上の整数、好ましくは１〜５を表し、ｎが０を表すものが好ましい。前記一般式（１）で表される化合物は市販されており、それらを利用することが可能である。例えば、ビックケミー・ジャパン株式会社より市販されているシリコン系界面活性剤ＢＹＫ−３４７、ＢＹＫ−３４８が利用可能である。
同様に含まれるアセチレングリコール化合物の好ましい具体例としては、下記の一般式（２）で表される化合物が挙げられる。

[In formula (1), R ^{1 to} R ⁷ independently represent an alkyl group having 1 to 6 carbon atoms, j and k independently represent an integer of 1 or more, and EO represents an ethyleneoxy group. PO represents a propyleneoxy group, and m and n represent a positive number of 0 or more, provided that m + n represents an integer of 1 or more, and EO and PO are in any order within []. It may be random or block. ]
In formula (1), the alkyl group of R ^{1 to} R ⁷ is preferably a methyl group, and j and k are preferably 1 to 5, more preferably 1 to 4, and most preferably 1 or 2. M and n are preferably 1 to 5, and preferably m + n is 2 to 4. According to a preferred embodiment of the ink composition used in the recording method of the present invention, the compound represented by the formula (1) preferably satisfies j = k = 1 to 3, preferably 1 or 2. As another preferred embodiment, as the compound of formula (1), R ^{1 to} R ⁷ all represent a methyl group, j represents 1, k represents 1, l represents 1, and m represents 1 or more. , Preferably 1 to 5, and n is preferably 0. The compounds represented by the general formula (1) are commercially available and can be used. For example, silicon surfactants BYK-347 and BYK-348 commercially available from Big Chemie Japan, Inc. can be used.
Preferable specific examples of the acetylene glycol compound similarly included are compounds represented by the following general formula (2).

〔式（２）中、ｍ＋ｎは０以上５０以下であり、Ｒ^１１、Ｒ^１２、Ｒ^１３、及びＲ^１４はそれぞれ独立してアルキル基を表す。〕
前記一般式（２）で表される化合物の中で、特に好ましくは２，４，７，９−テトラメチル−５−デシン−４，７−ジオール、３，６−ジメチル−４−オクチン−３，６−ジオール、又は３，５−ジメチル−１−ヘキシン−３オールなどを挙げることができる。前記一般式（２）で表されるアセチレングリコール化合物及びその誘導体としては市販品を利用することも可能であり、その具体例としてはサーフィノール１０４、８２、４６５、４８５、又はＴＧ（いずれもＡｉｒ Ｐｒｏｄｕｃｔｓ ａｎｄ Ｃｈｅｍｉｃａｌｓ．Ｉｎｃ．より入手可能）、オルフィンＳＴＧ、オルフィンＥ１０１０（いずれも日信化学社製の商品名）を挙げることができる。
前記のポリエーテル変性ポリシロキサン化合物とアセチレングリコール化合物は、単独で使ってもまた２種以上を併用しても構わない。本発明のインクジェット記録方法に用いるインク組成物中の界面活性剤として、ポリエーテル変性ポリシロキサン化合物及び／又はアセチレングリコール化合物の界面活性剤を用いるときの添加量は適宜決定されてよいが、インク組成物に対して０．０１〜５．０重量％の範囲が好ましく、より好ましくは０．１〜２．０重量％の範囲である。

[In formula (2), m + n is 0 or more and 50 or less, and R ¹¹ , R ¹² , R ¹³ , and R ¹⁴ each independently represents an alkyl group. ]
Among the compounds represented by the general formula (2), 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3 is particularly preferable. , 6-diol, or 3,5-dimethyl-1-hexyne-3ol. Commercially available products can also be used as the acetylene glycol compound represented by the general formula (2) and derivatives thereof. Specific examples thereof include Surfynol 104, 82, 465, 485, and TG (all are Air Products and Chemicals, Inc.), Orphine STG, and Olphine E1010 (all are trade names manufactured by Nissin Chemical).
The polyether-modified polysiloxane compound and the acetylene glycol compound may be used alone or in combination of two or more. The amount of addition of the polyether-modified polysiloxane compound and / or acetylene glycol compound surfactant as the surfactant in the ink composition used in the ink jet recording method of the present invention may be appropriately determined. The range of 0.01 to 5.0% by weight with respect to the product is preferable, and the range of 0.1 to 2.0% by weight is more preferable.

<Low surface tension organic solvent>
The ink composition according to the present invention comprises a low surface tension organic solvent. The low surface tension organic solvent used in the ink composition of the present invention is preferably at least one compound selected from alkanediol compounds or glycol ether compounds.
The alkanediol compound is preferably a 1,2-alkanediol having 1 to 6 carbon atoms. From the viewpoint of pigment dispersion stability, 1,2-butanediol, 1,2-pentanediol and 1,2-hexane are preferred. Diol etc. are mentioned.

  Examples of glycol ether compounds include diethylene glycol mono (C 1-8 alkyl) ether, triethylene glycol mono (C 1-8 alkyl) ether, propylene glycol mono (C 1-6 alkyl) ether, dipropylene. Glycol mono (C1-C6 alkyl) ether can be mentioned, These can be used as a 1 type, or 2 or more types of mixture.

Specifically, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-iso-propyl ether, ethylene glycol monobutyl ether, ethylene glycol mono-t-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl Ether, diethylene glycol mono-iso-propyl ether, diethylene glycol monobutyl ether, diethylene glycol mono-t-butyl ether, diethylene glycol monopentyl ether, diethylene glycol monohexyl ether, diethylene glycol monoheptyl ether, diethylene glycol monooctyl ether, triethylene glycol Cole monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monobutyl ether, triethylene glycol monopentyl ether, triethylene glycol monohexyl ether, triethylene glycol monoheptyl ether, triethylene glycol monooctyl Tityl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol mono-iso-propyl ether, propylene glycol monobutyl ether, propylene glycol mono-t-butyl ether, propylene glycol monopentyl ether, propylene glycol Mono hex Ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol mono-iso-propyl ether, dipropylene glycol monobutyl ether, dipropylene glycol monopentyl ether, dipropylene glycol monohexyl An ether etc. can be mentioned.

  The alkanediol compound or glycol ether compound can provide the ink composition with a complementary action between the action of the wetting agent and the action of the surfactant that uniformly applies the ink composition to the printing surface. The alkanediol compound or glycol ether compound can be added as appropriate, but the range is preferably about 1 to 20% by weight, more preferably 3 to 15% by weight, based on the ink composition.

<Other ingredients>
In order to apply a water-soluble organic solvent containing an aprotic polar solvent thinly and uniformly to the surface of the recording medium, it is diluted with a solvent and applied. As such a main solvent, water or a water-soluble organic solvent can be used, but in the present invention, the solvent is preferably water from the viewpoint of safety. As water used here, pure water such as ion exchange water, ultrafiltration water, reverse osmosis water, distilled water, or ultrapure water is used for the purpose of reducing ionic impurities as much as possible. it can. Further, when water sterilized by ultraviolet irradiation or addition of hydrogen peroxide is used, it is preferable because generation of mold and bacteria can be prevented when the aqueous ink composition is stored for a long period of time.

The ink composition of the present invention can achieve a desired effect by including the above-mentioned components, but if necessary, an antiseptic / antifungal agent, a pH adjuster, a dissolution aid, an antioxidant. And a clogging preventive agent for nozzles.
Examples of the pH adjuster include potassium dihydrogen phosphate and disodium hydrogen phosphate. Examples of preservatives and fungicides include sodium benzoate, sodium pentachlorophenol, sodium 2-pyridinethiol-1-oxide, sodium sorbate, sodium dehydroacetate, 1,2-dibenzisothiazoline-3-one (Proxel CRL, Proxel BDN, Proxel GXL, Proxel XL-2, Proxel TN from ICI) and the like. Furthermore, examples of the dissolution aid or antioxidant include amines such as diethanolamine, triethanolamine, propanolamine, morpholine and their modified products, and inorganic salts such as potassium hydroxide, sodium hydroxide, and lithium hydroxide. , Ammonium hydroxide, quaternary ammonium hydroxide (such as tetramethylammonium), carbonates such as potassium carbonate, sodium carbonate, lithium carbonate and other phosphates, ureas such as urea and thiourea, allophanates, methyl allophanates, etc. And L-ascorbic acid and salts thereof, such as allohanates, biurets such as biuret and dimethylbiuret. Furthermore, urea, thiourea, ethylene urea, or the like can be added for the purpose of preventing nozzle drying.

  Various physical properties of the ink composition according to the present invention can be appropriately controlled. According to a preferred embodiment of the present invention, the viscosity is preferably 25 mPa · sec or less, more preferably 10 mPa · sec or less (25 ° C.). is there. When the viscosity is within this range, the ink composition can be stably discharged from the ink discharge head. Further, the surface tension of the ink composition according to the present invention can be appropriately controlled, and the preferable surface tension is about 20 to 40 mN / m (25 ° C.), more preferably about 23 to 33 mN / m. .

<Manufacture of ink composition>
The ink composition of the present invention is prepared by appropriately mixing and dissolving (or dispersing) each of the above-described blending components individually or in the form of a pigment dispersion or resin emulsion in any order. It can be prepared by removing impurities by filtration.

In the ink composition according to the present invention,
The amount of aprotic polar solvent is sufficient to dissolve the plastic on the recording surface;
Viscosity and surface tension that can be discharged by an inkjet recording head;
The ink composition does not aggregate or solidify in the storage container or at the nozzle of the inkjet head;
Furthermore, the liquid contact member of the ink jet printer is not dissolved or destroyed,
The amount of each component described above can be appropriately set in consideration of the above points. Typical compositions of such ink compositions include, for example, the following:
0.5 to 15.0% by weight of pigment;
Resin 0.01-10.0 wt% (solid content);
Aprotic polar solvent 1.0-50.0 wt%;
Cyclic amide compound 0.1-40.0 wt%;
Surfactant 0.01-5.0% by weight;
Low surface tension organic solvent 1.0-20.0 wt%;
Water rest.

<Photomask manufacturing method>
Using the ink composition of the present invention, a photomask (pattern original plate) used in a pattern exposure step in a plate making step of a printing original plate (screen mask) used in screen printing can be suitably manufactured by an ink jet recording method.
In the ink jet recording method, printing is performed by ejecting droplets of an ink composition onto a recording surface (photomask substrate surface) and depositing the droplets on the recording surface.

According to a preferred embodiment of the method of the present invention, the production method includes either or both of a heat printing step in which the ink composition is attached to a heated recording medium and a step in which the recording medium to which the ink composition is attached is heated. These heating steps are included.
By heating the recording medium to which the ink composition is attached, dissolution of the plastic film on the recording surface is promoted when the ink composition is attached. By heating after the ink composition adheres, dissolution of the plastic film on the recording surface is promoted and evaporation of volatile components contained in the ink composition is also promoted. If the resin in the ink composition is a thermosetting resin, the adhesion between the recording surface and the formed resin film can be further strengthened.

Here, a heating means can be performed in accordance with a conventional method, using a conventional heating means, for example, well-known heating apparatuses, such as an infrared type heating apparatus and a hot air heating apparatus. In the present invention, heating may be performed under any conditions so long as the recording surface can be dissolved and the resin contained in the ink composition can be cured to form a resin film. The solvent concentration, the type of resin particles, and the like can be set as appropriate. For example, in the case of heater heating or hot air drying, heating is performed at 25 to 90 ° C. (preferably 40 to 70 ° C.) for 1 minute to 1 day (preferably 2 minutes to 8 hours) including printing. It can be carried out.

  The photomask according to the present invention can be manufactured by the ink jet recording method using the ink composition.

  EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but these do not limit the scope of the present invention.

<Examples 1-3>
Ink compositions of Examples 1 to 3 having the compositions shown in Table 1 were prepared. All compositions in Table 1 are weight percent.

<Physical property evaluation>
(1) Production of print sample A print sample was produced using each ink composition prepared in Examples 1 to 3 above.
Specifically, an ink jet printer “PX-G920 (manufactured by Seiko Epson Corporation)” modified so that it can be heated at the time of printing is used, a polyethylene terephthalate film, a 100% duty pattern and a human image (Japan Standards Association JIS X 9201). -1995-compliant SCID data). As heating conditions, the recording medium was heated to 50 ° C. prior to printing, and after printing, the recording medium was heated for 1 hour in an environment of 60 ° C. and a relative humidity of 20%.

(2) Adhesiveness Adhesive tape was affixed on the printing part of the print sample, and the adhesive tape was peeled off after rubbing 2 to 3 times with a finger. The printing state of the part was visually observed. Evaluation was made according to the following criteria, and the results are shown in Table 2.
○: There is no peeling of the ink (colorant) from the recording medium.
Δ: Part of the ink (colorant) peels from the recording medium.
X: The ink (colorant) largely peels from the recording medium.

(3) Scratch resistance / scratch resistance Using a pencil of each hardness, using a 750 g load pencil scratch tester specified in JIS K-5600-5-4, the printed part was scratched, and whether or not the print was scraped by scratching. I investigated. Evaluation was made according to the following criteria, and the results are shown in Table 2.
◯: Printing cannot be scraped with an H hardness pencil.
Δ: Printing can be scraped with an H hardness pencil, but printing cannot be scraped with an HB hardness pencil.
X: Printing can be scraped off with an HB hardness pencil.

(4) UV transmission density The transmission density meter 361T (V) was measured by X-Rite. The results are shown in Table 2.

  The black ink composition for inkjet according to the present invention exhibits excellent fixability even when it is directly landed on the surface of a polyethylene terephthalate (PET) film, for example. Therefore, it is particularly suitable as an ink composition for ink jet recording of a photomask (pattern original plate) used in a pattern exposure step of a plate making step of a screen printing printing original plate (screen mask).

Claims (11)

  It contains at least an aprotic polar solvent, a thermoplastic resin, a pigment, a cyclic amide compound, a surfactant, and water, and has an ultraviolet transmission density of 2.8 or more on a recording medium, Black ink composition for inkjet.   The aprotic polar solvent comprises 1,1,3,3-tetramethylurea, dimethyl sulfoxide, N, N-dimethylformamide, hexamethylphosphoric triamide, and 1,3-dimethyl-2-imidazolidinone. The ink composition according to claim 1, wherein the ink composition is at least one compound selected from the group.   The ink according to claim 1 or 2, wherein the cyclic amide compound is at least one compound selected from the group consisting of 2-pyrrolidone, N-methyl-2-pyrrolidone, and N-ethyl-2-pyrrolidone. Composition.   The ink composition according to any one of claims 1 to 3, wherein the surfactant is at least one compound selected from the group consisting of a polyether-modified polysiloxane compound and an acetylene glycol compound.   The ink composition according to any one of claims 1 to 4, wherein the low surface tension organic solvent is at least one compound selected from the group consisting of an alkanediol compound and a glycol ether compound.   The ink composition according to claim 1, wherein the content of the aprotic polar solvent is 1.0 to 50.0% by weight.   The ink composition according to any one of claims 1 to 6, wherein a glass transition temperature of the thermoplastic resin is 80 ° C or higher.   A photomask used in a plate-making process of a printing original plate for screen printing, produced by an ink jet recording method using the ink composition according to any one of claims 1 to 6.   The photomask according to claim 8, wherein the photomask substrate is a transparent film made of polyethylene terephthalate.   A method for producing a photomask for performing printing by ejecting and adhering droplets of an ink composition to a photomask substrate surface, wherein the ink composition according to any one of claims 1 to 6 is used. A photomask manufacturing method characterized by the above.   The manufacturing method of Claim 10 including the process of heating the photomask base material to which the ink composition was made to adhere to the heated photomask base material, and / or the photomask base material to which the ink composition was made to adhere.