JP2007321028A - Resist ink composition and method of etching by using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resist composition without damaging masking performances which conventional alkali soluble type or solvent soluble resist ink has, such as close adhesion to a substrate material, chemical resistance against treating liquid, resist-peeling property, etc., having a good uniformity of the thickness of coated film and a high accuracy of patterns, and also capable of being removed without using an organic solvent harmful to a living body or an aqueous alkali solution having a problem of waste water treatment. <P>SOLUTION: This resist ink composition containing a polymer having a phase transition temperature in water, an organic solvent and an inorganic compound as essential components is used for forming the resist coated film having a good uniformity of the thickness of coated film and a high accuracy of patterns without damaging the close adhesion to the substrate material, chemical resistance against treating liquid, resist peeling property, etc. Further, the coated film can be removed easily by washing with water at a temperature lower than the phase transition temperature of the polymer having the phase transition temperature in water. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a resist ink composition. More specifically, the present invention relates to a resist ink composition capable of performing the entire process in an aqueous system.
Furthermore, the present invention relates to an etching method using the resist ink composition.

As a method for producing a printed wiring board, conventionally, a conductive metal layer such as a copper foil is formed on the entire surface of an insulating substrate (the conductive metal layer may contain a metal other than copper. A substrate on which a conductive metal layer is formed is simply described as a “copper-clad substrate”.), A resist layer is provided on a portion to be left as a wiring, and other unnecessary copper foil portions are removed by etching or the like, A method of leaving only a necessary circuit pattern is mainly used.
As described above, the resist layer serves as a protective film for protecting a necessary copper foil portion from a processing solution such as an etching solution.

The resist used at this time is roughly classified into a dry film resist and a liquid resist due to the difference in form.
The dry film resist is a film type resist obtained by applying a liquid resist to a protective film such as polyethylene terephthalate (PET) and then evaporating the solvent. The liquid resist is a liquid composition (generally, The resist composition of the present invention is this liquid resist composition. The resist composition of the present invention is often directly applied to an adherend using a printing machine such as screen printing.

As a method for forming a resist pattern layer using a liquid resist composition, there are the following methods.
(1) A liquid resist composition is applied on one surface of a copper-clad substrate by a roll coating method or a screen printing method, a volatile component is evaporated to form a resist layer, and exposure is performed through a photomask having a desired pattern. And (2) a resist composition patterned on a copper-clad substrate by screen printing using a pre-patterned printing plate. A method of forming a resist layer by applying and evaporating volatile components.

  In any of the above methods, after that, unnecessary portions of the conductive metal layer (copper foil) not covered with the resist are removed by etching or the like, and then the resist is peeled off using an alkaline aqueous solution or an organic solvent. A desired wiring pattern is formed.

  However, when a conventional resist ink composition used for such an alkali-soluble resist coating film or solvent-soluble resist layer is used, the alkaline aqueous solution and the organic solvent material used for removing the resist layer are used. There are problems with respect to impact and safety to living organisms during work, as well as wastewater treatment.

As means for solving the above problems, Japanese Patent No. 2885925 (Patent Document 1) discloses a co-polymer containing poly (N-isopropylacrylamide) or N-isopropylacrylamide, which is a polymer having a phase transition temperature in water, as a main component. Resist inks containing polymers have been proposed.
This resist ink containing poly-N-isopropylacrylamide or a copolymer containing N-isopropylacrylamide as a main component as an essential component is applied to a substrate in the form of an aqueous solution at a temperature lower than the temperature showing a change in water / water insolubility. The substrate can be processed by etching, plating, etc. at a temperature higher than the temperature showing a change in water solubility / water insolubility after drying, and washed with water below the temperature showing the change in water solubility / water insolubility after the treatment is completed. It is a resist ink that can be removed without adversely affecting the water and the like, and the entire process can be carried out in an aqueous system.

  In the present invention, when a resist composition patterned on a copper-clad substrate is applied and dried, when it is dried at a temperature higher than the phase transition temperature, poly (N-isopropylacrylamide) or N-isopropylacrylamide is mainly used. Since the copolymer as a component is insoluble in water, it must be dried at a temperature lower than the phase transition temperature. However, since the diluting component is only water having a low evaporation rate, it takes a long time to dry at a temperature lower than the phase transition temperature. Furthermore, the applied resist solution has a so-called “sag” during drying, resulting in a non-uniform thickness of the resist layer, and as a result, the accuracy of the pattern shape is impaired.

  From the above viewpoints, the masking performance of conventional alkali-soluble or solvent-soluble resist inks, that is, adhesion to materials, chemical resistance to processing solutions, resist stripping, etc., is not impaired. Development of resist ink compositions that have good uniformity, high pattern accuracy, and can be easily removed without using organic solvents that are harmful to living organisms or alkaline aqueous solutions that have problems with wastewater treatment is eagerly desired. .

Japanese Patent No. 2885925

  The present invention provides a uniform layer thickness without impairing the masking performance of conventional alkali-soluble or solvent-soluble resist inks, that is, adhesion to materials, chemical resistance to processing solutions, resist stripping properties, etc. An object of the present invention is to provide a resist ink composition that has good properties, has high pattern accuracy, and can be easily removed without using an organic solvent harmful to living organisms or an alkaline aqueous solution having a problem of wastewater treatment. .

  As a result of intensive studies on the above problems, the present inventors are characterized by containing, as essential components, a polymer (a) having a phase transition temperature in water, an organic solvent (b), and an inorganic compound (c). By using the resist ink composition, the layer thickness uniformity is good and the pattern accuracy is high without impairing the adhesion to the material, the chemical resistance to the treatment liquid, the resist peelability, etc. Furthermore, it was discovered that the resist layer can be easily removed with water having a temperature lower than the phase transition temperature of the polymer having a phase transition temperature in water, and the present invention has been achieved.

That is, this invention relates to the resist ink composition shown by the following [1]-[5], and the etching method shown by [6].
1. (A) a polymer having a phase transition temperature in water;
A resist ink composition comprising (b) an organic solvent, and (c) an inorganic compound as an essential component.
2. (A) a polymer having a phase transition temperature in water;
(B) an organic solvent,
A resist ink composition comprising (c) an inorganic compound, and (d) an antifoaming agent as an essential component.
3. 3. The resist ink composition according to 1 or 2 above, wherein the phase transition temperature in a 5% by mass aqueous solution of the polymer (a) having a phase transition temperature in water is 30 to 45 ° C.
4). Polymer (a) having a phase transition temperature in water is poly (N-isopropylacrylamide), poly (N-vinylcaprolactam), poly (vinyl methyl ether), and partially saponified polyvinyl having a saponification degree of 40 to 60% 4. The resist ink composition according to any one of 1 to 3, which is at least one selected from the group consisting of alcohols and copolymers containing monomer components thereof.
5. The resist ink composition at 5.25 ° C., wherein the ratio of the viscosity at a rotation speed of 10 rpm and the viscosity at a rotation speed of 50 rpm is in the range of 1.2 to 4.0. The resist ink composition as described.
6). An etching method comprising the following steps (a) to (d):
Process (I): The process of printing the resist ink composition of any one of said 1-5, and forming the resist coating film in which the pattern was formed on the board | substrate.
Step (b): A step of evaporating the volatile components in the resist coating obtained in step (a) to obtain a substrate having a resist coating from which a part or all of the volatile components have been removed.
Step (c): A step of etching the substrate obtained in step (b) using a ferric chloride aqueous solution or a cupric chloride solution having a temperature higher than the phase transition temperature of the polymer having a phase transition temperature in water. .
Step (d): A step of peeling the resist coating film from the substrate obtained in step (c) using water or an aqueous solution having a temperature lower than the phase transition temperature of the polymer having a phase transition temperature in water.

  The resist ink composition of the present invention can form a resist coating film having high pattern accuracy with good adhesion to the material, chemical resistance to the treatment liquid, resist releasability, and uniformity of layer thickness. This coating film can be easily removed without using an organic solvent harmful to living organisms or an alkaline aqueous solution having a problem of wastewater treatment.

The present invention will be specifically described below.
[Resist ink composition]
First, the resist ink compositions (I) and (II) of the present invention will be described.
The present invention comprises a resist ink composition (I) comprising a polymer (a) having a phase transition temperature in water, an organic solvent (b) and an inorganic compound (c) as essential components, and a phase transition in water. The present invention relates to a resist ink composition (II) comprising a polymer (a) having a temperature, an organic solvent (b), an inorganic compound (c) and an antifoaming agent (d) as essential components.

(A) Polymer having a phase transition temperature in water First, the polymer (a) having a phase transition temperature in water, which is an essential component of the present invention (I) and the present invention (II), will be described.

In addition, the “phase transition temperature” described in the present specification means a temperature described below.
For example, poly (N-isopropylacrylamide) readily dissolves in water at temperatures below 32 ° C., but becomes insoluble in water above 32 ° C. In this case, the temperature of 32 ° C. is the “phase transition temperature” of poly (N-isopropylacrylamide). The property of changing to water / water insoluble depending on the phase transition temperature is reversible.

The “phase transition temperature” described in the present specification is a constant speed (for example, 1 ° C./min) of a 5 mass% polymer aqueous solution completely dissolved using a heat measurement device FP81HT (manufactured by METTLER TOLEDO). The temperature is defined as the temperature at which the light transmittance decreases by 4% with respect to the light transmittance at the time of complete dissolution due to a decrease in solubility.
Further, “having a phase transition temperature in water” described in the present specification means that the phase transition temperature of the aqueous polymer solution falls within the range of 0 ° C. to 100 ° C. when the phase transition temperature is measured by the above method. It means to exist.

  Examples of the polymer (a) having a phase transition temperature in water which is an essential component of the resist ink compositions (I) and (II) of the present invention include poly (N-isopropylacrylamide), N-isopropylacrylamide and acrylamide. Copolymer, copolymer of N-isopropylacrylamide and N, N-dimethylacrylamide, poly (N-vinylcaprolactam), copolymer of N-vinylcaprolactam and N-vinylpyrrolidone, polyvinyl methyl ether, methylcellulose, part Examples thereof include saponified polyvinyl alcohol.

The amount of the polymer (a) having a phase transition temperature in water in the resist ink composition of the present invention is the kind and molecular weight of the polymer (a) having a phase transition temperature in water, or the present invention (I) and (II). The viscosity of the resist ink composition (measured at 25 ° C. and 50 rpm) is 5,000 to 100,000 mPa · s, although it cannot be mentioned in general because it varies depending on the type of organic solvent (b) that is an essential component of It is preferable to adjust in the range, and it is more preferable to adjust in the range of 10,000 to 60,000 mPa · s.
In the present specification, the viscosity is measured using a digital viscometer model HBDV-E manufactured by Brookfield.

The phase transition temperature of a 5% by mass aqueous solution of the polymer (a) having a phase transition temperature in water, which is an essential component of the resist ink compositions (I) and (II) of the present invention, is 30 to 45 ° C. Is preferred.
When the temperature is lower than 30 ° C., it is desirable that the temperature be as high as possible in consideration of the removal time of the resist coating film.
When a polymer having a phase transition temperature of less than 30 ° C. is used, it is necessary to maintain the temperature of water for removing the resist coating film below the phase transition temperature of the polymer. Will be required.
On the other hand, if the phase transition temperature is higher than 45 ° C., it is not preferable in terms of energy because the temperature of the etching solution needs to be controlled at a temperature higher than the phase transition temperature.

  Considering the above, preferred examples of the polymer (a) having a phase transition temperature in water which is an essential component of the present invention (I) and (II) include poly (N-isopropylacrylamide), poly (N- Vinyl caprolactam), poly (vinyl methyl ether) and partially saponified polyvinyl alcohol having a saponification degree of 40 to 60%.

(B) Organic solvent Next, the organic solvent (b) which is an essential component of the resist ink compositions (I) and (II) of the present invention will be described.
The organic solvent (b) that is an essential component of the resist ink compositions (I) and (II) of the present invention is not particularly limited as long as it is an organic solvent that can dissolve the polymer (a) having a phase transition temperature in water. For example, alcohol solvents such as methanol, ethanol, isopropanol, n-butanol, 2-ethoxyethanol, 2-butoxyethanol, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, ethylene glycol, propylene glycol, N, N-dimethylformamide, N Amide solvents such as N-dimethylacetamide and N-methylpyrrolidone, ester solvents such as methoxyethyl acetate and diethylene glycol monoethyl ether acetate, ethylene glycol dimethyl ether and diethylene glycol It may be mentioned ether solvents such as dimethyl ether, ethyl acetate, ester solvents such as γ- butyrolactone.

  Moreover, in this specification, even if it is a solvent which cannot melt | dissolve the polymer (a) which has a phase transition temperature in water when it is used independently, it mixes with another organic solvent or water. When the polymer (a) having a phase transition temperature in water can be dissolved, it is included in the organic solvent (b) which is an essential component of the resist ink compositions (I) and (II) of the present invention. Define.

Among these organic solvents (b), an organic solvent having a boiling point in the range of 130 to 230 ° C. under atmospheric pressure is preferable. When only an organic solvent having a boiling point of less than 130 ° C. is used, the solvent rapidly evaporates when screen printing is continuously performed, which may change the printability, which is not preferable. Moreover, it is not preferable to use an organic solvent having a boiling point higher than 230 ° C. as a main component because a large amount of energy is required to evaporate the solvent in the step of removing the solvent which is a volatile component after printing.
Specific examples of these preferred organic solvents include N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, ethylene glycol monobutyl ether, γ-butyl lactone, diethylene glycol monoethyl ether acetate, 2- Examples include butoxyethanol.

  Although the amount of the organic solvent (b) used varies depending on the type and molecular weight of the polymer (a) having a phase transition temperature in water and the type of the organic solvent, it cannot be generally mentioned. The viscosity of the composition (measured at 25 ° C. and 50 rpm) is preferably adjusted in the range of 5000 to 100,000 mPa · s, more preferably in the range of 10,000 to 60,000 mPa · s.

  In addition, when considering the reduction of VOC (Volatile Organic Compounds) that cause wastewater treatment and air pollution, water may be mixed in the organic solvent (b) to reduce the amount of organic solvent used. Is possible. In this case, of course, the organic solvent (b) must be soluble in water.

(C) Inorganic Compound Next, the inorganic compound (c), which is an essential component of the present invention (I) and (II), will be described.
The inorganic compound (c), which is an essential component of the resist ink compositions (I) and (II) of the present invention, is used for the purpose of imparting an appropriate thixotropy to the composition or increasing the viscosity. Examples thereof include inorganic materials having various shapes such as powder, spherical shape, whisker shape, and scale shape.

  Further, in the present specification, the organic compound is taken into the inorganic compound (c) between the layers of the organic / inorganic composite or the inorganic intercalation compound that is physically coated with the organic compound and chemically surface-treated with the organic compound. Are defined as those contained in the inorganic compound (c) which is an essential component of the resist ink compositions (I) and (II) of the present invention.

  Specific examples of the inorganic compound (c) include, for example, calcium carbonate, talc, clay, glass powder, silica, aluminum hydroxide, magnesium hydroxide, barium sulfate, titanium oxide, alumina and surface modified products thereof, bentonite, Known materials such as zeolite, smectite, or modified products such as compounds in which the surface or organic substance thereof is incorporated between layers are used, and these may be used alone or in combination of two or more.

  Among these, preferred are aluminum hydroxide, magnesium hydroxide, barium sulfate, silica, bentonite, zeolite, smectite and modified products thereof, and more preferred are barium sulfate, silica, bentonite, zeolite. , Smectites and their modified products.

  The content of these inorganic compounds (c) is in the range of 0.1 to 30 parts by mass when the mass excluding the mass of the organic solvent (b) from the total mass of the resist ink composition is 100 parts by mass. It is preferable that the range is 0.1 to 20 parts by mass. When the content of the inorganic compound (c) is less than 0.1 parts by mass, the added effect is not so much observed, and when it exceeds 30 parts by mass, the adhesion of the resist coating film to the material may be deteriorated. It is not preferable.

(D) Defoamer Next, the defoamer (d), which is an essential component of the resist ink composition of the resist ink composition (II) of the present invention, will be described.
The antifoaming agent (d), which is an essential component of the resist ink composition (II) of the present invention, is literally limited as long as it literally has an action of eliminating bubbles generated when the resist ink composition is applied. Absent.

Specific examples of the antifoaming agent (d), which is an essential component of the resist ink composition (II) of the present invention, include, for example, BYK-077 (manufactured by Big Chemie Japan), SN deformer 470 (San Nopco) Manufactured), TSA-750S (manufactured by GE Toshiba Silicone), silicone-based antifoaming agent such as silicone oil SH-203 (manufactured by Toray Silicone), Dappo SN-348 (manufactured by San Nopco), Acrylic polymer antifoaming agents such as Dappo SN-354 (manufactured by San Nopco), Dappo SN-368 (manufactured by San Nopco), Surfynol DF-110D (manufactured by Nisshin Chemical Industry Co., Ltd.), Surfynol Acetylene diol type antifoaming agents such as DF-37 (manufactured by Nissin Chemical Industry Co., Ltd.), fluorine-containing silicone type antifoaming agents such as FA-630, etc. That.
Among these, a preferable antifoaming agent is a silicone-based antifoaming agent or a fluorine-containing silicone-based antifoaming agent, and more preferably a silicon corn-based antifoaming agent.

(E) Other Additives Further, the resist ink compositions (I) and (II) of the present invention include phthalocyanine blue, phthalocyanine green, iodin green, and disazo yellow as necessary. In addition, known colorants such as kustal violet, titanium oxide, carbon black and naphthalene black, and polymerization inhibitors such as hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, catechol and pyrogallol can be added.

[Kneading method]
The resist ink compositions (I) and (II) of the present invention can be obtained by uniformly kneading and mixing part or all of the blending components with a roll mill, a bead mill or the like.

[viscosity]
In addition, from the viewpoint of fluidity at the time of coating, the viscosity of the resist ink compositions (I) and (II) of the present invention is the ratio of the viscosity at a rotation speed of 10 rpm and the viscosity at a rotation speed of 50 rpm at 25 ° C. It is preferable that it is the range of 1.2-3.0.
When the ratio of the viscosity at a rotation speed of 10 rpm and the viscosity at a rotation speed of 50 rpm at 25 ° C. is less than 1.2, after the resist ink composition is applied, the composition flows and the film thickness becomes constant. Or the print pattern may not be maintained. Moreover, when the ratio of the viscosity at a rotation speed of 10 rpm and the viscosity at a rotation speed of 50 rpm at 25 ° C. is larger than 3.0, the defoaming property of the resist coating film may be deteriorated.

[Etching method]
Further, the etching method (III) using the resist ink compositions (I) and (II) of the present invention will be described.
The present invention (III) includes the following steps (a) to (d).
Step (I): A step of printing the resist ink composition (I) or (II) of the present invention to form a resist coating film having a pattern formed on the substrate.
Step (b): A step of evaporating the volatile components in the resist coating film obtained in step (a) to obtain a substrate having a resist coating film from which part or all of the volatile components have been removed.
Step (c): Using the aqueous ferric chloride solution or cupric chloride solution having a temperature higher than the phase transition temperature of the polymer (a) having a phase transition temperature in water, the substrate obtained in the step (b) Etching process.
Step (d): A step of peeling the resist coating film from the substrate obtained in step (c) using water or an aqueous solution having a temperature lower than the phase transition temperature of the polymer (a) having a phase transition temperature in water.

Step (A) is a step of printing a resist ink composition (I) or (II) of the present invention to form a resist coating film having a pattern formed on a substrate.
As a printing method of the resist ink composition (I) or (II) of the present invention, for example, a resist ink composition patterned by screen printing on a copper-clad substrate using a patterned printing plate Can be applied.

Step (b) is a step of obtaining a substrate having a resist coating film in which the volatile components in the resist coating film obtained in step (a) are evaporated to remove a part or all of the volatile components.
Although there is no restriction | limiting in particular in the drying temperature at the time of evaporating a volatile component, It is common to evaporate a volatile component in 50 to 100 degreeC atmosphere. Further, it is not always necessary to remove the entire amount of the organic solvent, and there is no problem even if it remains as long as the coating film does not have tack and does not affect the phase transition temperature.

In the step (c), a substrate obtained in the step (b) using a ferric chloride aqueous solution or a cupric chloride solution having a temperature higher than the phase transition temperature of the polymer (a) having a phase transition temperature in water. Is a step of etching.
The concentration of the ferric chloride aqueous solution is generally 2.0 to 4.0 M.
The concentration of the cupric chloride aqueous solution is generally 1.5 to 3.0M. At that time, the concentration of hydrochloric acid is generally adjusted to 1.0 to 5.0 M and used.

  Step (d) is a step of peeling the resist coating film from the substrate obtained in step (c) using water or an aqueous solution having a temperature lower than the phase transition temperature (a) of the polymer having a phase transition temperature in water. is there. The temperature of the water or aqueous solution used for stripping must be lower than the phase transition temperature of the polymer (a) having a phase transition temperature in water. By using water or an aqueous solution having a temperature lower than the phase transition temperature of the polymer, the resist film can be peeled off.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not restrict | limited only to a following example.

Synthesis example 1
In a reaction vessel equipped with a stirrer and a reflux condenser, 35 g of N-isopropylacrylamide and 70 g of γ-butyrolactone were placed and thoroughly purged with nitrogen. After stirring, 35 mg of azobisisobutyronitrile (polymerization initiator) was added and the temperature was raised. The polymerization reaction was carried out at 60 ° C. for 7 hours. After completion of the reaction, a γ-butyrolactone solution (resin solution A) of poly (N-isopropylacrylamide) was obtained.
The water-soluble / water-insoluble phase transition temperature of a 5% by mass aqueous solution of the obtained polymer was 32 ° C.

Synthesis example 2
In a reaction vessel equipped with a stirrer and a refluxer, 35 g of N-vinylcaprolactam, 30 g of γ-butyrolactone, and 40 g of water were placed and thoroughly purged with nitrogen, followed by VA-044 (polymerization initiator: Wako Pure Chemical Industries, Ltd.). )) 35 mg was added, the temperature was raised, and a polymerization reaction was carried out at 40 ° C. for 7 hours. After completion of the reaction, a mixed solution of γ-butyrolactone / water (resin solution B) of poly (N-vinylcaprolactam) was obtained.
The water-soluble / water-insoluble phase transition temperature of a 5% by mass aqueous solution of the obtained polymer was 40 ° C.

Synthesis example 3
In a reaction vessel equipped with a stirrer and a reflux condenser, 31.5 g of N-isopropylacrylamide, 3.5 g of acrylamide, and 70 g of γ-butyrolactone were placed and thoroughly purged with nitrogen, followed by azobisisobutyronitrile (polymerization initiation) Agent) 35 mg was added, the temperature was raised, and a polymerization reaction was carried out at 60 ° C. for 7 hours. After completion of the reaction, a γ-butyrolactone solution (resin solution C) of N-isopropylacrylamide-acrylamide copolymer was obtained.
The water-soluble / water-insoluble phase transition temperature of a 5% by mass aqueous solution of the obtained polymer was 41 ° C.

Synthesis example 4
In a reaction vessel equipped with a stirrer and a refluxer, 30 g of N-isopropylacrylamide and 150 g of methanol were placed and sufficiently purged with nitrogen, and then 9 mg of azobisisobutyronitrile (polymerization initiator) was added and the temperature was raised. The polymerization reaction was performed for 6 hours under reflux.
The obtained polymer had a water / water-insoluble phase transition temperature of 32 ° C.
After removing methanol, the polymer was dissolved in 10 times the amount of water at 20 ° C. to obtain a poly (N-isopropylacrylamide) aqueous solution (resin solution D).

で示されるビスフェノールＦ型エポキシ含有化合物４００ｇ（式中のｂの平均値＝５．８、エポキシ当量８００、軟化点７９℃）をエピクロルヒドリン９２５ｇとジメチルスルホキシド４６２．５ｇの混合液に溶解させた後、撹拌下７０℃で９８．５質量％のＮａＯＨ８１．２ｇを１００分間かけて添加した。 Synthesis example 5
The following general formula (1)

400 g (average value of b in the formula = 5.8, epoxy equivalent 800, softening point 79 ° C.) in a mixture of 925 g of epichlorohydrin and 462.5 g of dimethyl sulfoxide, Under stirring, 81.2 g of 98.5% by weight NaOH was added at 70 ° C. over 100 minutes.

  After the addition, the reaction is further carried out at 70 ° C. for 3 hours, and then most of the excess unreacted epichlorohydrin and dimethyl sulfoxide are distilled off under reduced pressure. Further, 10 g of 30% by mass NaOH was added and reacted at 70 ° C. for 1 hour.

  After completion of the reaction, washing was performed twice with 200 parts by mass of water. After oil-water separation, methyl isobutyl ketone was recovered by distillation from the oil layer to obtain 370 g of an epoxy group-containing compound having an epoxy equivalent of 290 and a softening point of 62 ° C. When the obtained epoxy group-containing compound is calculated from the epoxy equivalent, about 5.2 of 5.8 alcoholic hydroxyl groups in the general formula (1) are epoxidized. Next, 290 g of this epoxy group-containing compound, 72 g of acrylic acid, 0.28 g of p-methoxyphenol, and 195 g of ethyl carbitol acetate were charged and heated and stirred at 90 ° C. to dissolve the reaction mixture. Next, the reaction solution was cooled to 60 ° C., 1.67 g of triphenylphosphine was charged, heated to 100 ° C., and reacted for about 32 hours. As a result, a reaction product having an acid value of 1.0 mgKOH / g was obtained.

  Next, 78.6 g of succinic anhydride and 42.3 parts by mass of ethyl carbitol acetate were added to this reaction product, heated to 95 ° C., reacted for about 6 hours, cooled, and solidified with a solid content acid value of 100 mg KOH / g. A carboxyl group-containing epoxy acrylate solution (resin solution F) having a partial concentration of 65% by mass was obtained. The resulting polymer was insoluble in water at 0-100 ° C.

Mixing example 1
In a container equipped with a stirrer and a reflux condenser, 35 g of polyvinyl methyl ether (manufactured by Sanko Chemical Co., Ltd.) and 70 g of γ-butyrolactone are placed and stirred until a uniform solution is obtained, whereby a γ-butyrolactone solution of polyvinyl methyl ether ( Resin solution E) was obtained. The obtained polymer had a water / water insoluble phase transition temperature of 38 ° C.

Examples 1-7 and Comparative Examples 1-2
Using the resin solutions A to F obtained in Synthesis Examples 1 to 5 and Mixing Example 1, each component except the antifoaming agent (d) was blended according to the blending composition shown in Table 1, and a three roll mill (trade name: 230 type transmission bench roll BR-230V, manufactured by Imex Co., Ltd.). Thereafter, an antifoaming agent (d) was added, and the resist ink composition was prepared by mixing uniformly using a spatula.
In addition, the unit of the number of each component described in Table 1 is “part by mass”.

Viscosity measurement (ratio of viscosity at 10 rpm and viscosity at 50 rpm)
Using a digital viscometer HBDV-E type (manufactured by Brookfield), the viscosity at a rotation speed of 10 rpm and the viscosity at a rotation speed of 50 rpm were measured, and the ratio was determined. The results are shown in Table 2. In addition, the sample used for the measurement used what was 25 degreeC using the constant temperature water tank.

Defoaming property test Resist ink compositions of Examples 1 to 7 and Comparative Examples 1 and 2 were kept at 20 ° C., respectively, and screen-printed with copper-clad printed circuit boards (trade name: UPISEL-NB E1310: Ube Industries, Ltd.) A pattern was printed on top. A printing plate having a 250 mesh and a printing area of 75 mm × 115 mm was used.
It was visually confirmed whether or not the bubbles disappeared within 1 minute after printing. Evaluation was performed according to the following criteria.
○: Completely defoamed within 1 minute after printing.
Δ: Bubbles did not completely disappear even after 1 minute from printing.

Evaluation of Uniformity of Film Thickness and Exudence of Existence The resist ink compositions of Examples 1 to 7 and Comparative Examples 1 and 2 were kept at 20 ° C., respectively, by screen printing, respectively, to a copper-clad printed board (trade name: UPISEL- (NBE1310: manufactured by Ube Industries, Ltd.). A printing plate having 250 mesh and a printing area of 75 mm × 115 mm was used.
After drying at 80 ° C. for 10 minutes, film thicknesses at 5 locations were randomly measured.
Moreover, it visually observed about the presence or absence of the exudation of the edge part of an application surface.
The results are shown in Table 2.
Furthermore, the same test was conducted by changing the drying conditions at 30 ° C. for 3 hours. The results are shown in Table 2.

Cleaning test using ion-exchanged water at 25 ° C. The resist ink compositions of Examples 1 to 7 and Comparative Examples 1 and 2 were kept at 20 ° C., and each was screen-printed to produce a copper-clad printed circuit board (trade name: UPISEL-N BE1310). A line width / space width = 300 μm / 300 μm pattern was printed on Ube Industries, Ltd.). A 250-mesh printing plate was used for printing.

The substrate after application of the resist ink composition was dried at 80 ° C. for 10 minutes, and then ion-exchanged water at 25 ° C. was sprayed for 100 seconds at a pressure of 110 kPa. Thereafter, it was confirmed whether or not the resist ink remained. The results are shown in Table 2.
Furthermore, the same test was conducted by changing the drying conditions at 30 ° C. for 3 hours. The results are also shown in Table 2.
About the evaluation, the following criteria evaluated.
○: The resist film was completely removed by washing.
X: Some or all of the resist film remained without being removed after washing.

Etching Test The resist ink compositions of Examples 1 to 7 and Comparative Examples 1 to 2 were kept at 20 ° C., and each was screen-printed on a copper-clad printed circuit board (trade name: UPISEL-N BE1310, manufactured by Ube Industries, Ltd.). Printing was performed with a pattern of line width / space width = 300 μm / 300 μm. A 250-mesh printing plate was used for printing.
The substrate after application of the resist ink composition was dried at 80 ° C. for 10 minutes and then immersed in a 2.3 M aqueous cupric chloride solution (hydrochloric acid concentration 2 mol / l) at 50 ° C. for 3 minutes for etching. After the etching, ion exchange water at 25 ° C. was sprayed for 100 seconds at a pressure of 110 kPa. It was confirmed whether or not the resist ink remained.
Thereafter, the linearity of the formed copper pattern was measured with a microscope. The results are shown in Table 2.
Furthermore, the same test was conducted by changing the drying conditions at 30 ° C. for 3 hours. The results are also shown in Table 2.

The resist ink composition of the present invention can form a resist coating film having high pattern accuracy and high adhesion to a material, chemical resistance to a processing solution, resist releasability, and uniformity of layer thickness. This coating film can be easily removed without using an organic solvent harmful to living organisms or an alkaline aqueous solution having a problem of wastewater treatment.

Claims (6)

(A) a polymer having a phase transition temperature in water;
A resist ink composition comprising (b) an organic solvent, and (c) an inorganic compound as an essential component. (A) a polymer having a phase transition temperature in water;
(B) an organic solvent,
A resist ink composition comprising (c) an inorganic compound, and (d) an antifoaming agent as an essential component.   The resist ink composition according to claim 1 or 2, wherein the phase transition temperature in a 5% by mass aqueous solution of the polymer (a) having a phase transition temperature in water is 30 to 45 ° C.   Polymer (a) having a phase transition temperature in water is poly (N-isopropylacrylamide), poly (N-vinylcaprolactam), poly (vinyl methyl ether), and partially saponified polyvinyl having a saponification degree of 40 to 60% The resist ink composition according to any one of claims 1 to 3, wherein the resist ink composition is at least one selected from the group consisting of alcohols and copolymers containing monomer components thereof.   5. The resist ink composition at 25 ° C. has a viscosity ratio at a rotation speed of 10 rpm and a viscosity at a rotation speed of 50 rpm in the range of 1.2 to 4.0. 5. Resist ink composition. An etching method comprising the following steps (a) to (d):
Step (a): A step of printing the resist ink composition according to any one of claims 1 to 5 to form a resist coating film having a pattern formed on a substrate.
Step (b): A step of evaporating the volatile components in the resist coating film obtained in step (a) to obtain a substrate having a resist coating film from which part or all of the volatile components have been removed.
Step (c): A step of etching the substrate obtained in step (b) using a ferric chloride aqueous solution or a cupric chloride solution having a temperature higher than the phase transition temperature of the polymer having a phase transition temperature in water. .
Step (d): A step of peeling the resist coating film from the substrate obtained in step (c) using water or an aqueous solution having a temperature lower than the phase transition temperature of the polymer having a phase transition temperature in water.