阅读说明：本技术 抗蚀墨及抗蚀印刷物的制造方法 (Resist ink and method for producing resist printed matter ) 是由 小林智惠 冈田守弘 于 2021-04-01 设计创作，主要内容包括：本发明的目的在于提供抗蚀墨及抗蚀印刷物的制造方法。所述抗蚀墨即使用于掩模的抗蚀覆膜为薄膜,也能够兼具与形成电路的金属箔的密合性和耐酸性蚀刻性。所述抗蚀墨含有聚酯树脂、氧化钛和硅烷偶联剂,上述聚酯树脂的数均分子量为3000～10000,并且上述聚酯树脂的羟值为15mgKOH/g以上和/或酸值为15mgKOH/g以上,上述氧化钛的含量为抗蚀墨总量的5～30质量％。(The invention aims to provide a resist ink and a method for producing a resist printed matter. The resist ink can have both adhesion to a metal foil forming a circuit and acid etching resistance even when the resist film used for a mask is a thin film. The resist ink contains a polyester resin, titanium oxide and a silane coupling agent, wherein the polyester resin has a number average molecular weight of 3000 to 10000, the polyester resin has a hydroxyl value of 15mgKOH/g or more and/or an acid value of 15mgKOH/g or more, and the content of the titanium oxide is 5 to 30% by mass of the total amount of the resist ink.)

1. A resist ink comprising a polyester resin, titanium oxide and a silane coupling agent, wherein the polyester resin has a number average molecular weight of 3000 to 10000, the polyester resin has a hydroxyl value of 15mgKOH/g or more and/or an acid value of 15mgKOH/g or more, and the titanium oxide is contained in an amount of 5 to 30% by mass based on the total amount of the resist ink.

2. The resist ink according to claim 1, wherein the silane coupling agent is 1 or more selected from the group consisting of 3-mercaptopropyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, decyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, phenyltriethoxysilane, p-styryltrimethoxysilane, and 3-chloropropyltrimethoxysilane.

3. The resist ink according to claim 1 or 2, wherein the mass ratio of the titanium oxide to the silane coupling agent is in the range of 0.1: 13 to 4: 13.

4. The resist ink according to any one of claims 1 to 3, further comprising nitrocellulose.

5. A method for producing a resist print, comprising the following steps in this order:

printing the metal foil with a resist ink;

a step of heating a coating film of a resist ink formed by printing to 100 ℃ or higher to cure the coating film; and

a step of etching the cured resist ink film with an acidic etching solution,

the resist ink according to any one of claims 1 to 4, wherein the amount of the resist ink printed on the metal foil is about 0.5g/m²～2g/m²。

Technical Field

The present invention relates to a resist ink used for producing a circuit board having a circuit pattern from a metal foil.

Background

In recent years, EAS (Electronic Article surveillance) devices called "Electronic Article surveillance device", and "Electronic Article surveillance device" have been introduced to automate manual handling, eliminate shortage of human resources, and reduce labor costs in retail stores and libraries in various business states such as video tape rental stores, pharmaceutical and cosmetic stores, and home electric appliance mass merchandisers.

It is the following system: if a special label is attached to a commodity and a payment is properly paid at a checkout counter, the label is removed on the spot or invalidated. If the article is to be taken away illegally, the tag that has not been processed is detected, an alarm sound is generated, and the abnormality is notified to the manager, so that when the article is stolen (the article is stolen), the abnormality is notified by the alarm sound or the like.

In addition, in RFID (radio frequency identification) using an automatic identification technology of short-range wireless communication, a system for identifying and managing various objects to which IC tags are attached using wireless communication and related parts thereof are generally widespread throughout the world, and the demand is increasing year by year in japan as well. In manufacturing IC tags used for EAS devices and RFID devices, resist ink is used.

IC tags are generally produced by performing a coil-like mask printing of a circuit pattern on a metal foil with a resist ink, curing the metal foil with ultraviolet rays and heat as necessary, immersing the metal foil in an acidic or alkaline etching solution, and etching away unnecessary portions of the circuit pattern to produce a desired circuit pattern (for example, patent document 1: japanese patent laid-open No. 2015-65384).

In the type of thermosetting a printing film to be a resist in etching, baking is generally performed at 170 to 200 ℃ using an oven.

In recent years, a mask having a higher resolution and excellent reproducibility is desired, and the mask is about 2.2 to 3.0g/m²The coating amount of (2) (for example, patent document 2: Japanese patent No. 6117457) is required to be 2g/m²On the other hand, if the following thin film is formed, a phenomenon of ink peeling is observed at the time of acid etching, and therefore, it is desired that adhesion to the metal foil and acid etching resistance can be satisfied at the same time even at the time of forming the thin film.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2015-65384

Patent document 2: japanese patent No. 6117457

Disclosure of Invention

Problems to be solved by the invention

The purpose of the present invention is to provide a resist ink that, even when a resist film used for a mask is a thin film, can achieve both adhesion to a metal foil to be a circuit and acid etching resistance.

Means for solving the problems

The present inventors have conducted extensive studies to solve the above problems, and as a result, have found that it is effective to contain a specific polyester resin, titanium oxide and a silane coupling agent as essential components in a resist ink to solve the problems.

That is, the present invention relates to a resist ink containing a polyester resin, titanium oxide and a silane coupling agent, wherein the polyester resin has a number average molecular weight of 3000 to 10000, a hydroxyl value of the polyester resin is 15mgKOH/g or more and/or an acid value of 15mgKOH/g or more, and a content of the titanium oxide is 5 to 30% by mass of a total amount of the resist ink.

The present invention also relates to a resist ink, wherein the silane coupling agent is at least 1 selected from the group consisting of 3-mercaptopropyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, decyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, phenyltriethoxysilane, p-styryltrimethoxysilane and 3-chloropropyltrimethoxysilane.

The present invention also relates to a resist ink, wherein the mass ratio of the titanium oxide to the silane coupling agent is in the range of 0.1: 13 to 4: 13.

In addition, the present invention relates to a resist ink containing nitrocellulose.

The present invention also relates to a method for producing a resist print, comprising the following steps in this order: printing the metal foil with a resist ink; a step of heating a coating film of a resist ink formed by printing to 100 ℃ or higher to cure the coating film; and a step of etching the cured resist ink film with an acidic etching solution, wherein the amount of the ink for printing the resist ink on the metal foil is about 0.5 to 2g/m²。

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a resist ink having both adhesion to a metal foil to be a circuit and acid etching resistance can be obtained even when a resist film used for a mask is a thin film.

Detailed Description

The present invention will be described in detail. The "ink" used in the following description is entirely referred to as "resist ink". Further, "parts" all represent "parts by mass".

The present invention is a resist ink characterized by containing a polyester resin, titanium oxide and a silane coupling agent, wherein the polyester resin has a number average molecular weight of 3000 to 10000, a hydroxyl value of 15mgKOH/g or more and/or an acid value of 15mgKOH/g or more, and the content of the titanium oxide is 5 to 30% by mass of the total amount of the resist ink.

Specifically, the resist ink of the present invention is obtained by dissolving a binder resin containing the polyester resin in various organic solvents such as ethyl acetate, methyl ethyl ketone, and toluene. Titanium oxide was kneaded with the binder resin and the various organic solvents to prepare ink. The ink is charged with a coloring pigment and various additives, and further stirred to obtain a sufficiently dispersed resist ink.

In the resist ink of the present invention, it is necessary that the known polyester resin has a number average molecular weight in the range of 3000 to 10000, and has a hydroxyl value of 15mgKOH/g or more and/or an acid value of 15mgKOH/g or more. The polyester resin may be a polyester resin obtained by esterification of a polybasic acid component and a polyhydric alcohol component. As the polybasic acid component, for example, 1 or more kinds of dibasic acids such as phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, fumaric acid, adipic acid, azelaic acid, sebacic acid, and dimer acid, and lower alkyl esters of these acids are mainly used, and 3 or more-membered polybasic acids such as benzoic acid, crotonic acid, p-tert-butylbenzoic acid, trimellitic anhydride, methylcyclohexene tricarboxylic acid, pyromellitic anhydride, and the like are used in combination as necessary.

Examples of the polyol component include diols such as ethylene glycol, diethylene glycol, propylene glycol, 1, 4-butanediol, neopentyl glycol, 3-methylpentanediol, 1, 4-hexanediol, 1, 6-hexanediol, and cyclohexanedimethanol, and 3-or more-membered polyols such as glycerol, trimethylolethane, trimethylolpropane, and pentaerythritol may be used in combination as necessary. These polyols may be used singly or in combination of 2 or more.

The content of the polyester resin having a number average molecular weight of 3000 to 10000, a hydroxyl value of 15mgKOH/g or more and/or an acid value of 15mgKOH/g or more is preferably 70% by mass or more of the total amount of the polyester resin.

If the hydroxyl value derived from the terminal structure of the polyester resin is as high as 15mgKOH/g or more, it becomes a reactive group, and the reactivity with the reactive functional group of the silane coupling agent used in combination is further improved, and the bonding becomes strong, so from the viewpoint of achieving both the adhesion to the metal foil to be a circuit and the etching resistance in forming a resist film, the hydroxyl value is preferably 15mgKOH/g or more, more preferably 20mgKOH/g or more, and most preferably 40mgKOH/g or more.

Further, if the acid value derived from the terminal structure of the polyester resin is as high as 15mgKOH/g or more, it becomes a reactive group, and the reactivity with the reactive functional group of the silane coupling agent used in combination is further improved, and the bonding becomes strong, so from the viewpoint of combining both the adhesion with the metal foil to be a circuit and the etching resistance at the time of forming a resist film, the acid value is preferably 15mgKOH/g or more, and more preferably 20mgKOH/g or more.

The number average molecular weight of the polyester resin is more preferably 3000 to 8000. When the number average molecular weight of the polyester resin is less than 3000, the adhesion of the obtained ink composition to a metal foil and the etching resistance in forming a resist film tend to decrease, and when it exceeds 10000, it is difficult to increase the hydroxyl value and acid value per 1g in the structure of the polyester resin, and the viscosity of the obtained resist ink becomes high, and the coating amount is 2g/m²The following films tend to have low reproducibility, low coatability, and low gloss of printed films.

Crystalline polyester is structurally high in cohesive force, so that it is difficult to ensure solubility in general-purpose organic solvents, and an amorphous polyester resin is preferable to a crystalline polyester resin in terms of being able to achieve both adhesion to a metal foil and acid etching resistance of a cured resist film when used in a resist ink.

In the resist ink of the present invention, titanium oxide is required as a pigment. Among them, the surface-treated titanium oxide is preferable because it exhibits relatively good dispersibility. Particularly preferred is titanium oxide surface-treated with an inorganic substance, and preferred is titanium oxide surface-treated with silica and alumina.

Among titanium oxides surface-treated with silica and alumina, known rutile-type and anatase-type titanium oxides can be used as the titanium oxide, and rutile-type titanium dioxide is more preferable.

The average particle size of the titanium oxide is preferably 100 to 500nm, more preferably 150 to 400 nm. If the average particle size is less than 100nm, dispersion stability becomes easier to achieve, but the whiteness is reduced, and color control becomes difficult when the ink is applied to a color IC chip, while if the average particle size exceeds 500nm, smoothness of the ink coating film and glossiness of appearance tend to be reduced. The particle size is more preferably 200 to 300nm in practical use.

The average particle size of the titanium oxide as a raw material was measured by 20 particle sizes in an electron micrograph and averaged.

In titanium oxide surface-treated with silica and alumina, silica is generally used for the purpose of adjusting the acid/alkali state of the titanium oxide surface and for imparting durability to the resulting ink/paint film, and alumina is used for improving the wetting of titanium oxide at the time of dispersion. Further, as a surface treatment method of titanium oxide, an aqueous treatment, a gas phase treatment, and the like can be given. The ratio of the amount of treated silica to the amount of treated alumina is preferably 35 mass% or more and 80 mass% or less from the viewpoint of dispersion stability. The amount of the inorganic substance to titanium oxide is not necessarily limited, and is usually 30 parts or less to 100 parts of titanium oxide.

The content of titanium oxide used in the resist ink of the present invention is 5 mass% or more of the total amount of the resist ink from the viewpoint of sufficiently maintaining etching resistance in forming a resist film, and is preferably 30 mass% or less, and more preferably in the range of 10 to 25 mass% from the viewpoint of appropriate ink viscosity and work efficiency in ink production and printing.

The titanium oxide surface-treated with silica and alumina is commercially available, for example, from the manufacturers of titanium oxide available from stone industries, TaYCA and the like. For example, commercially available species having a larger silica treatment amount than alumina treatment amount, species having a larger alumina treatment amount than silica treatment amount, and titanium oxide having an alumina treatment amount falling within the above ratio can also be obtained.

The silane coupling agent used in the resist ink of the present invention is represented by the chemical formula of YSiX. Here, X represents an alkoxy group and is a hydrolyzable site. Y is a site having 1 reactive functional group selected from an alkyl group, an alkylene group, a cumulative alkylene group, an aryl group, an amino group, an isocyanate group, an epoxy group, a chlorine group, a mercapto group, and the like.

The Y is more preferably a functional group having high polarity from the viewpoint of adhesion to the substrate. Therefore, it is further preferable to have 1 kind of functional group selected from aryl group, amino group, isocyanate group, epoxy group and mercapto group.

Further, by utilizing the characteristic structure of the silane coupling agent, the site Y having the reactive functional group forms a chemical bond with an organic polymer or the like through the site Y, and the site X having the hydrolyzability is hydrolyzed and reacted to form a chemical bond with an inorganic surface or the like, and in the resist ink of the present invention, the site Y and the polyester resin are bonded to each other, while the site X is bonded to titanium oxide or a metal foil serving as a circuit used in combination, whereby both of the sites having different chemical properties can be firmly bonded to each other.

The terminal structure of the polyester resin having a higher polar functional group and a high hydroxyl value and an acid value of 15mgKOH/g or more in the site Y having a reactive functional group is a reactive group, and the bonding between both tends to be stronger.

Further, since the site X having the hydrolyzability reacts mainly with the oxidized surface or hydroxyl group of the inorganic substance by a similar mechanism, for example, titanium oxide used in combination, a trace amount of moisture contained in an organic solvent, or moisture in the atmosphere causes alkoxy groups to hydrolyze, thereby generating silanol groups, which are then transferred to the surface of a metal foil to be a circuit via hydrogen bonds with hydroxyl groups located on the surface of titanium, and further undergo a dehydration condensation reaction, thereby generating strong covalent bonds with titanium on the surface of the inorganic substance and a metal foil to be a circuit.

The resist ink of the present invention can accelerate these reactions by heat-setting after printing and transferring to a metal foil, and can remove by-produced water, alcohol, and the like out of the system by heating.

The strength of the coating film of the resist ink of the present invention on which the silane coupling agent is favorably applied is more preferably 0.05% by mass or more of the total amount of the resist ink from the viewpoint of improving the adhesion to a metal foil to be a circuit, and is preferably 5% by mass or less from the viewpoint of stability of the resist ink.

Examples of the silane coupling agent include 3-mercaptopropyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, decyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, phenyltriethoxysilane, p-styryltrimethoxysilane, and 3-chloropropyltrimethoxysilane, and these may be used alone or in combination of two or more. Among these, from the viewpoint of adhesion of the ink cured film to the aluminum deposition film substrate and etching resistance in forming the resist film, 3-glycidoxypropyltrimethoxysilane and 3-aminopropyltrimethoxysilane are preferable, and 3-glycidoxypropyltrimethoxysilane in which the site Y having a reactive functional group is an epoxy group is more preferable.

The mass ratio of the titanium oxide to the silane coupling agent is preferably in the range of 0.1: 13 to 4: 13. If the amount is within the above range, the etching resistance in forming the resist film is not lowered, and conversely, the decrease in workability or gelation due to the high viscosity of the resist ink resulting from the mass ratio of titanium being too large as compared with the above range can be suppressed.

The solvent that can be used in the resist ink of the present invention is not particularly limited, and examples thereof include aromatic hydrocarbon solvents such as toluene, xylene, SOLVESSO #100 and SOLVESSO #150, aliphatic hydrocarbon solvents such as hexane, heptane, octane and decane, and ester-based organic solvents such as methyl acetate, ethyl acetate, isopropyl acetate, butyl acetate, amyl acetate, ethyl formate and butyl propionate. Examples of the water-miscible organic solvent include alcohol-based organic solvents such as methanol, ethanol, propanol, and butanol, ketone-based organic solvents such as acetone, methyl ethyl ketone, and cyclohexanone, glycol-based organic solvents such as ethylene glycol (mono, di) methyl ether, ethylene glycol (mono, di) ethyl ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, monobutyl ether, diethylene glycol (mono, di) methyl ether, diethylene glycol (mono, di) ethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, triethylene glycol (mono, di) methyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, and dipropylene glycol (mono, di) methyl ether. Among them, a mixed solution of toluene/methyl ethyl ketone/ethyl acetate is more preferable from the viewpoint of solubility in the polyester resin.

In addition, in the resist ink of the present invention, acid etching resistance can be further maintained by using an appropriate amount of nitrocellulose in combination. The amount of the nitrocellulose added is preferably 1 to 10% by mass, and more preferably 2 to 5% by mass, of the total amount of the solid components of the resist ink.

The resist ink of the present invention can be colored as needed for color IC tags using organic and inorganic pigments and dyes used in general inks, paints, recording agents, and the like. Examples of the organic pigment include azo-based, phthalocyanine-based, anthraquinone-based, perylene-based, perinone-based, quinacridone-based, thioindigo-based, dioxazine-based, isoindolinone-based, quinophthalone-based, azomethine azo-based, diketopyrrolopyrrole-based, isoindoline-based pigments. Copper phthalocyanine is preferably used as the blue ink, and c.i. pigment No. Yellow83 is preferably used as the transparent Yellow ink from the viewpoint of cost and light resistance. The content of the colorant is preferably an amount sufficient to ensure the concentration and coloring power of the ink, that is, a ratio of 1 to 50% by mass with respect to the total mass of the ink. Further, the coloring agent may be used alone or in combination of 2 or more.

In the present invention, an extender pigment, a pigment dispersant, a leveling agent, an antifoaming agent, a wax, a plasticizer, an infrared absorber, an ultraviolet absorber, an aromatic agent, a flame retardant, and the like may be further included as necessary.

The particle size distribution of the pigment can be adjusted by appropriately adjusting the size of the grinding medium in the dispersing machine, the filling rate of the grinding medium, the dispersing treatment time, the ejection speed, the viscosity, and the like. As the dispersing machine, for example, a commonly used roll mill, ball mill, pebble mill, attritor, sand mill, or the like can be used. When the ink contains air bubbles, unexpected coarse particles, or the like, it is preferable to remove the ink by filtration or the like because the quality of the printed matter is degraded. The filter may be a conventionally known filter.

The metal foil to be printed with the resist ink of the present invention may be previously bonded to a plastic film such as a polyester resin film or may be bonded to various resin films after printing, etching, and circuit formation. In either case, the surface to be bonded with the resist ink is a metal foil. The thickness of the metal foil and the thickness of the plastic film to be bonded are various thicknesses of several μm to several tens μm depending on the application.

As a method for producing a resist print using the resist ink of the present invention, a resist print is obtained by a production method comprising the following steps in this order: first, a step of printing a metal foil with a resist ink, a step of heating a coating film of the resist ink formed by printing to 100 ℃ or higher to cure the coating film, and a step of etching the cured coating film of the resist ink with an acidic etching solution are performed.

The step of printing the metal foil with the resist ink is useful as an ink for gravure printing using a gravure printing plate such as an electronic engraved plate or an ink for flexographic printing using a flexographic printing plate such as a resin plate.

When the heating temperature is preferably 100 ℃ or higher, more preferably 150 ℃ or higher, and still more preferably 170 ℃ or higher, the adhesion to the substrate is further improved.

The coating amount of the commonly used resist ink is usually about 2.2 to 3.0g/m²In contrast, the resist ink of the present invention can cope with a coating amount of about 0.5 to 2g/m²The thin film of (3) can give a resist print maintaining a higher resolution.

Examples

The present invention is further specifically illustrated by examples. Hereinafter, "part(s)" and "%" are based on mass.

In the present invention, the number average molecular weight (in terms of polystyrene) Mn by GPC (gel permeation chromatography) was measured under the following conditions using the system HLC8220 manufactured by tokyo co.

Separating the column: TSKgelGMHHR-N, manufactured by 4 Tosoh corporation, was used. Column temperature: at 40 ℃. Mobile phase: and tetrahydrofuran manufactured by Wako pure chemical industries, Ltd. Flow rate: 1.0 ml/min. Sample concentration: 1.0% by mass. Sample injection amount: 100 microliters. A detector: a differential refractometer.

The hydroxyl value is the amount of hydroxyl groups in 1g of the resin calculated by back titration of an acid residue obtained when acetylating hydroxyl groups in a polyester resin with an excess amount of an acetyl agent, expressed in mg of potassium hydroxide (KOH), with a base, and is in accordance with jis k 0070.

Further, the acid value is expressed in terms of JIS K0070 by mg of KOH required for neutralizing free carboxyl groups contained in 1g of the solid content of the polyester resin.

[ production of polyester resin solution ]

43 parts of amorphous polyester resin A1 (hydroxyl value 50mgKOH/g, acid value 2mgKOH/g, number average molecular weight 3000), 50 parts of toluene, 30 parts of methyl ethyl ketone, and 20 parts of ethyl acetate were put into a 4-neck flask, heated to 80 ℃ and then kept warm for 2 hours, after confirming that the resin was completely dissolved, the mixture was cooled to room temperature, and amorphous polyester resin A1 having a solid content of 30% was obtained.

Similarly, the resins and solvents were mixed at the same ratio and subjected to the same procedure to obtain amorphous polyester resins a2 to a6, X1 and X2 each having a solid content of 30%.

The physical property values of A2 to A6 are as follows.

Amorphous polyester resin A2 (hydroxyl value: 20mgKOH/g, acid value: 2mgKOH/g, number average molecular weight: 8000)

Amorphous polyester resin A3 (hydroxyl value: 37mgKOH/g, acid value: 1mgKOH/g, number average molecular weight: 8000)

Amorphous polyester resin A4 (hydroxyl value: 16mgKOH/g, acid value: 2mgKOH/g, number average molecular weight: 3000)

Amorphous polyester resin A5 (hydroxyl value 0mgKOH/g, acid value 22mgKOH/g, number average molecule 6000)

Amorphous polyester resin A6 (hydroxyl value 5mgKOH/g, acid value 15mgKOH/g, number average molecular weight 8000)

Amorphous polyester resin X1 (hydroxyl value: 6mgKOH/g, acid value: 2mgKOH/g, number average molecular weight: 17000)

Amorphous polyester resin X2 (hydroxyl value 5mgKOH/g, acid value 4mgKOH/g, number average molecular weight 18000)

[ preparation of Nitro-cotton varnish liquid ]

To 37.5 parts of industrial nitrocellulose DHX3-5 (nitrocellulose, 70% nonvolatile matter, manufactured by Nobel NC, ltd.), 62.5 parts of a mixed solution of toluene/methyl ethyl ketone/ethyl acetate (ratio 50/30/20 by mass) was added and mixed thoroughly to prepare a nitrocellulose varnish (S).

[ example 1]

A total of 100 parts of 26.4 parts of the solid content of the obtained polyester resin A1, 13 parts of titanium white R-830 (rutile type titanium oxide having an average particle diameter of 250nm, oil absorption 21, available from Shikoku corporation), 1 part of a silane coupling agent Z6040 (3-glycidoxypropyltrimethoxysilane, available from Toray Dow Coating Co., Ltd.), 2.8 parts of the solid content of the nitrocellulose varnish (S), 36 parts of toluene, 5.5 parts of methyl ethyl ketone, and 15.3 parts of ethyl acetate were mixed and kneaded to prepare a white resist ink.

Examples 2 to 16 and comparative examples 1 to 4

Resist inks were prepared in the same manner as in example 1 for examples 2 to 16 and comparative examples 1 to 4, based on the composition shown in tables 1 and 2.

In examples 6 and 16, no nitrocellulose varnish was added during the production.

The mixed solution of toluene/methyl ethyl ketone/ethyl acetate in a mass ratio of 50/30/20 was further added to each of the obtained resist inks, the viscosity was adjusted to 18 seconds (25 ℃) by a Zen cup #3 (manufactured by Conn Seisakusho Co., Ltd.), and an intaglio correction machine having a Helio Direct engraved gravure intaglio (Japanese text: ヘリオダイレクト engraved ダラビア intaglio) (225 lines/inch) was used on a metal foil (size: 20 cm. times.10 cm. horizontal), so that the amount of the coating film became 2.0g/m²The printing is performed in a solid state over the entire surface.

1) Adhesion Property

Using a nasebel environmental tester hipspec HT310, a metal foil with a solid printed resist ink was heated in an oven at 170 ℃ for 8 minutes, and then left at room temperature (25 ℃) for 2 hours, and then a transparent tape (manufactured by nicoiban) was attached to the printed surface, and the state of the appearance of the resist print coating when the film was rapidly peeled off was visually checked. The determination criteria are set to the following 7 levels.

(evaluation criteria)

7: the resist film was not peeled off at all.

6: 80% to 90% of the resist film remains in the metal foil.

5: 70% to 80% of the resist film remains in the metal foil.

4: 60% to 70% of the resist film remains in the metal foil.

3: 50% or more and less than 60% of the resist film remains in the metal foil.

2: 30% or more and less than 50% of the resist film remains in the metal foil.

1: 30% or less of the resist film remains in the metal foil.

2) Acid etch resistance

The metal foil solid-printed with the resist ink was immersed in a hydrochloric acid solution having a concentration of 15% at a liquid temperature of 40 ℃ for 30 minutes in an acid-resistant tray, then pulled up and washed with water, and the state of the appearance of the resist print coating was visually evaluated in 7 stages according to the following evaluation criteria.

(evaluation criteria)

7: the resist film was not peeled off at all.

6: 80% to 90% of the resist film remains in the metal foil.

5: 70% to 80% of the resist film remains in the metal foil.

4: 60% to 70% of the resist film remains in the metal foil.

3: 50% or more and less than 60% of the resist film remains in the metal foil.

2: 30% or more and less than 50% of the resist film remains in the metal foil.

1: 30% or less of the resist film remains in the metal foil.

The compounding and evaluation results of each resist ink are shown in tables 1 and 2. All the organic solvents except the numerical values in the table represent the mass of the solid content.

[ TABLE 1]

[ TABLE 2 ]

In the resist inks shown in examples, even if the coating film amount was 2.0g/m²The film of (3) can also have both adhesion to a metal foil to be a circuit and acid etching resistance.