CN100418995C - Photosensitive resin composition and photosensitive element - Google Patents

Abstract

The present invention provides a modified epoxy resin having a repeating unit represented by the following general formula (1), wherein ^R1 represents a divalent organic group that is a diglycidyl ether-type epoxy compound residue, ^R2 represents a divalent organic group that is a dibasic acid residue, ^R3 represents a hydrogen atom or a group represented by the following general formula (2), n represents an integer greater than or equal to 1, and in formula (2), ^R4 represents an acid anhydride residue.

Description

Photosensitive resin composition and photosensitive element

technical field

The present invention relates to modified epoxy resin, its production method, photosensitive resin composition and photosensitive element.

Background technique

In the past, film-shaped printed circuit boards called flexible printed circuit boards (Flexible Printed Circuit, hereinafter referred to as "FPC") were especially used in small devices such as cameras, magnetic heads, and mobile phones. This is because the FPC can maintain its function even if it is bent, and thus is suitable as a printed circuit board housed in a small machine as described above. In particular, in recent years, various electronic machines have been required to be further miniaturized and lightweight. If FPC is used for the circuits of these machines, the size and weight of the small machines can be reduced, the cost of products can be reduced, and the design can be realized. simplification etc.

The solder resist used for this FPC is the same as the solder resist used for ordinary printed circuit boards, requiring developability, high resolution, insulation, solder heat resistance, plating resistance, etc. In addition, bending FPC is also required flexibility not to be destroyed.

At present, as a solder resist in FPC, a cover film formed by punching a polyimide film with an adhesive is most commonly used because it satisfies the above-mentioned various characteristics. However, this cover film has a problem that the mold used for mold release is very expensive, and the position alignment and bonding are manually performed when laminating the cover film, so that the production cost is high. Furthermore, there is also a problem that although FPC is adopted in response to the demand for miniaturization of electronic equipment, if the FPC has a solder resist using a cover film, it is difficult to form a fine pattern.

In order to solve these problems, there has been proposed a liquid FPC ink composition containing an unsaturated group-containing polycarboxylic acid resin obtained by reacting an addition product of a specific epoxy resin and an unsaturated monocarboxylic acid with succinic anhydride or the like (e.g. Refer to Patent Documents 1 and 2).

In addition, in order to form a solder resist having flexibility, a product obtained by reacting a mixture of a novolak epoxy resin and a rubber-modified bisphenol A type epoxy resin with an ethylenically unsaturated carboxylic acid has been proposed containing the product and A liquid photosensitive resin composition of a reaction product such as a polybasic acid (for example, refer to Patent Document 3).

Patent Document 1: Japanese Unexamined Patent Publication No. 7-207211

Patent Document 2: JP-A-8-134390

Patent Document 3: Japanese Unexamined Patent Publication No. 9-5997

Contents of the invention

However, the present inventors have studied in detail conventional liquid FPC ink compositions and photosensitive resin compositions headed by the materials described in the above-mentioned patent documents, and found that when the weight-average molecular weight of the modified epoxy resin contained is less than Or when it is equal to 10000, the coating property is lacking. That is, the inventors of the present invention have found that when a coating film of these compositions is formed on FPC or the like, the coating film becomes sticky and there is a problem that workability falls.

In addition, the present inventors also found that when the weight average molecular weight of the modified epoxy resin contained in these compositions is greater than or equal to 50,000, the storage stability of the resist film finally obtained by using these compositions will decrease. Furthermore, usually, after the photosensitive resin composition is applied on a printed circuit board and partially cured, it is developed with a dilute alkaline aqueous solution to remove the uncured part. When the alkali aqueous solution is used for developing treatment, if the weight average molecular weight of the modified epoxy resin is greater than or equal to 50,000, the uncured part cannot be sufficiently peeled off and removed.

Therefore, the present invention is carried out in view of the above-mentioned circumstances, and the purpose is to provide a modified epoxy resin capable of preparing a photosensitive resin composition, a production method thereof, and a photosensitive resin composition. It satisfies the characteristics (especially sensitivity, resolution, filmability, solder heat resistance, plating resistance, and flexibility) required for permanent masks formed on film-like substrates such as FPC cover films. In addition, another object of the present invention is to provide a photosensitive element having such a photosensitive resin composition.

As a result of intensive studies to achieve the above object, the present inventors found that the above object can be achieved by including a modified epoxy resin having a specific structure in the photosensitive resin composition, and completed the present invention.

That is, the modified epoxy resin of the present invention is characterized by having a repeating unit represented by the following general formula (1).

In formula (1), R ¹ represents a divalent organic group as a diglycidyl ether type epoxy compound residue, R ² represents a divalent organic group as a dibasic acid residue, R ³ represents a hydrogen atom or the following In the group represented by the general formula (2), n represents an integer greater than or equal to 1. In formula (2), R ⁴ represents an acid anhydride residue. In this specification, the so-called "modified epoxy resin" refers to a resin obtained by modifying an epoxy compound (epoxy resin), whether or not the "modified epoxy resin" itself has an epoxy group (glycidol) basis) is irrelevant.

In addition, the "diglycidyl ether type epoxy compound" means a compound represented by the following general formula (4). Here R ⁵ represents a divalent organic group.

This modified epoxy resin can be represented by the following general formula (3), for example.

In formula (3), R ¹ represents a divalent organic group as a diglycidyl ether type epoxy compound residue, R ² represents a divalent organic group as a dibasic acid residue, R ³ represents a hydrogen atom or the above-mentioned In the group represented by the general formula (2), n represents an integer of 1 or more.

In addition, the modified epoxy resin of the present invention is obtained by the following method for producing a modified epoxy resin, which includes: obtaining an intermediate product through a polymerization reaction of a diglycidyl ether type epoxy compound and a dibasic acid The first process; the second process of adding acid anhydride to the intermediate product.

Such a modified epoxy resin has an ester-type chain bond, and since the entire molecule tends to have a chain structure, it is considered that gelation tends to be difficult to occur. Therefore, a photosensitive element having a photosensitive resin composition layer formed from a photosensitive resin composition containing such a modified epoxy resin, when using it to form a resist film, can perform well using a dilute aqueous alkali solution. development.

In the modified epoxy resin obtained as described above, the dibasic acid is a modified epoxy resin obtained by using a dicarboxylic acid, and has a chain structure formed by an ester bond formed by the reaction of a carboxyl group and a glycidyl group in the molecule. Resin is preferable since it tends to realize excellent alkali developability.

The modified epoxy resin having such a structure may have at least one carboxyl group, and preferably has a weight average molecular weight of 10,000 to 70,000. Thereby, the coating film property, dilute alkali aqueous solution developability, etc. of the photosensitive resin composition containing this modified epoxy resin tend to improve further.

In addition, the modified epoxy resin preferably has an acid value of 70 to 200 mgKOH/g. Thereby, the galvanic insulation, chemical resistance, plating resistance, etc. of the cured film of the photosensitive resin composition containing this modified epoxy resin tend to improve further.

Furthermore, the manufacturing method of the modified epoxy resin of the present invention is characterized in that it includes the following two processes: the first process of obtaining an intermediate product through the polymerization reaction of a diglycidyl ether type epoxy compound and a dibasic acid; The second process of adding an acid anhydride to the product to obtain a modified epoxy resin. The modified epoxy resin produced in this way can form a chain structure due to ester bonds, a network structure due to ether bonds, and a network structure due to ester bonds in the molecule, so that alkali developability can be adjusted.

In this case, it is preferable to use a dicarboxylic acid as the dibasic acid from the viewpoint that the above-mentioned effect tends to be further exerted.

In the method for producing an epoxy resin, it is preferable to use a tertiary amine having a pKa of 9.0 or less as a polymerization catalyst. Thereby, the dilute alkali aqueous solution developability of the resist film formed using this resin tends to improve. Here, "Ka" represents an acid dissociation constant, and "pKa" represents a numerical value defined as pKa=-log(Ka).

In addition, the present invention provides a photosensitive resin characterized by containing (A) the above-mentioned modified epoxy resin, (B) a photopolymerizable compound having at least one ethylenically unsaturated group in the molecule, and (C) a photopolymerization initiator. combination.

The photosensitive resin composition can fully satisfy the characteristics required for a permanent mask formed on a film-like base material such as a cover film of an FPC (especially the sensitivity) by including the above-mentioned (A) to (C) as essential components. , resolution, coating film, solder heat resistance, plating resistance, flexibility), as a result, while improving the characteristics of the photosensitive element, it is possible to efficiently produce high-resolution, high-density printed circuit boards.

In addition, the photosensitive resin composition of the present invention preferably further contains a component (D) obtained by copolymerizing (a) a (meth)acrylate monomer and a monomer having a predetermined functional group (I). (b) a resin having an unsaturated group obtained by polymerizing a compound having a predetermined functional group (II) and an unsaturated group through a reaction between the functional group (I) and the functional group (II).

By further containing the said (D)component, the flexibility of a photosensitive resin composition can be improved more. And it tends to obtain the plating resistance of this photosensitive resin composition more reliably.

Here, the functional group (I) is preferably at least one selected from the group consisting of a hydroxyl group, a carboxyl group, an epoxy group, and an isocyanate group.

Furthermore, the monomer having the functional group (I) is preferably obtained from 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, phenyl shrink Glyceryl ether (meth)acrylate, (meth)acrylic acid, itaconic acid, β-(meth)acryloyloxyethyl hydrosuccinate, glycidyl (meth)acrylate, (meth)allyl At least one selected from the group consisting of glycidyl ether, vinyl isocyanate, (meth)acryl isocyanate and 2-(meth)acryloxyethyl isocyanate.

In addition, the functional group (II) is preferably at least one selected from the group consisting of an aldehyde group, a hydroxyl group, an ethyleneamino group, a carboxyl group, an epoxy group, and an isocyanate group.

Furthermore, (b) the unsaturated group of the compound having a predetermined functional group (II) and an unsaturated group is preferably a vinyl group, an isopropenyl group, a (meth)allyl group, and a (meth)acryloyl group. At least one selected from the group.

In addition, the combination of the functional group (I) and the functional group (II) is preferably selected from the group consisting of hydroxyl and isocyanate, hydroxyl and epoxy, hydroxyl and aldehyde, hydroxyl and carboxyl, hydroxyl and ethyleneamino, carboxyl and epoxy, One or more combinations selected from the group consisting of carboxyl group and hydroxyl group, isocyanate group and hydroxyl group, and epoxy group and carboxyl group.

Furthermore, it is preferable that (D) the resin which has an unsaturated group has a glass transition temperature of -10-60 degreeC, a weight average molecular weight of 10000-200000, and an acid value of 50-150 mgKOH/g. Thereby, the galvanic insulation, chemical resistance, plating resistance, etc. of the cured film of a photosensitive resin composition tend to improve further.

Moreover, when the photosensitive resin composition of this invention contains (D) component, it is preferable that said (A) component is represented by the following general formula (3) from a viewpoint which can obtain the said effect of this invention more easily and reliably. modified epoxy resin.

In formula (3), R ¹ represents a divalent organic group as a diglycidyl ether type epoxy compound residue, R ² represents a divalent organic group as a dibasic acid residue, R ³ represents a hydrogen atom or the above-mentioned In the group represented by the general formula (2), n represents an integer of 1 or more.

In addition, the above-mentioned photosensitive resin composition of the present invention can be used to form a flexible cured resin on a film-like substrate. Therefore, for example, by curing the photosensitive resin composition and using it as a permanent mask for FPC, even if the FPC is bent, the permanent mask can be prevented from being destroyed.

Furthermore, the present invention provides a photosensitive element characterized by having a support, and a photosensitive resin composition layer formed on the support and composed of the above-mentioned photosensitive resin composition.

If such a photosensitive element is used, it is excellent in all of developability, high resolution, solder heat resistance, plating resistance, and flexibility, and thus high-resolution, high-density printed wiring boards can be efficiently produced.

According to the present invention, it is possible to provide a modified epoxy resin capable of preparing a photosensitive resin composition, a method for producing the same, and a photosensitive resin composition. Properties required for permanent masks on film substrates (especially sensitivity, resolution, coating properties, solder heat resistance, plating resistance, flexibility). Moreover, this invention can also provide the photosensitive element which has such a photosensitive resin composition.

Description of drawings

FIG. 1 is a graph showing the IR spectrum of a modified epoxy resin obtained in Examples.

Detailed ways

Next, preferred embodiments of the present invention will be described in detail.

Here, (meth)acrylic acid in the present invention refers to acrylic acid and its corresponding methacrylic acid, (meth)acrylate refers to acrylate and its corresponding methacrylate, (meth)acryloyl refers to acrylic The acyl group and its corresponding methacryloyl group, and the (meth)acryloyloxy group refer to an acryloyloxy group and its corresponding methacryloyloxy group.

The modified epoxy resin of the present invention has a repeating unit represented by the following general formula (1).

In formula (1), R ¹ represents a diglycidyl ether type epoxy compound residue, R ² represents a dibasic acid residue, R ³ represents a hydrogen atom or a group represented by the following general formula (2), n represents An integer greater than or equal to 1.

In formula (2), R ⁴ represents an acid anhydride residue. Examples of such modified epoxy resins include those represented by the following general formula (3).

The weight-average molecular weight (Mw) of the modified epoxy resin can be measured by gel permeation chromatography (GPC) (in terms of standard polystyrene). According to this measurement method, the Mw of the epoxy resin is preferably from 10,000 to 70,000, more preferably from 25,000 to 60,000, and still more preferably from 30,000 to 50000.

Here, in the above-mentioned structural formula of the modified epoxy resin represented by the general formula (1), the upper limit of n can be appropriately changed according to the types of residues of R ¹ , R ² , R ³ and R ⁴ , but preferably The upper limit is defined as a value of n whose weight average molecular weight is 70,000.

The acid value of the above-mentioned modified epoxy resin can be measured by the following method. First, accurately weigh about 1 g of the modified epoxy resin solution of the present invention, then add 30 g of acetone to the resin solution to evenly dissolve the resin solution. Next, an appropriate amount of indicator phenolphthalein was added to this solution, and titration was performed using a 0.1 N KOH aqueous solution. Then, the acid value is calculated according to the following general formula (5) according to the titration result.

A=10×Vf×56.1/(Wp×I) (5)

In the formula, A represents the acid value (mgKOH/g), V represents the titration (mL) of phenolphthalein, W represents the weight (g) of the modified epoxy resin solution, and I represents the non-volatile components of the modified epoxy resin solution The ratio (mass %).

According to this measurement method, the acid value of the modified epoxy resin is preferably 70 from the viewpoint of the dilute alkali aqueous solution developability and the galvanic insulation of the obtained cured film, chemical resistance and plating resistance. ~200 mgKOH/g, more preferably 80~180 mgKOH/g, even more preferably 90~160 mgKOH/g.

Next, a method for producing the above-mentioned modified epoxy resin will be described.

The manufacture method of the modified epoxy resin comprises the following two steps: the first step of obtaining an intermediate product through the polymerization reaction of a diglycidyl ether type epoxy compound having two glycidyl groups in one molecule and a dibasic acid; The second step of obtaining the above-mentioned modified epoxy resin by adding an acid anhydride to the intermediate product.

Here, the diglycidyl ether-type epoxy compound residue represented by R ¹ in the general formula (1) is a portion other than the glycidyl group in the structure of the diglycidyl ether-type epoxy compound. In addition, the dibasic acid residue represented by R ² in the above general formula (1) is a part other than the dibasic acid functional group in the structure of the dibasic acid compound.

(first process)

In the first step, the diglycidyl ether type epoxy compound used as a raw material is not particularly limited, but preferably further has one or more phenoxy groups in one molecule, and more preferably has two or more phenoxy groups in one molecule. Two or more phenoxy groups.

Examples of the diglycidyl ether type epoxy compound include bisphenol A type epoxy resins such as bisphenol A diglycidyl ether, bisphenol F type epoxy resins such as bisphenol F diglycidyl ether, bisphenol S di Bisphenol S-type epoxy resins such as glycidyl ether, bisphenol-type epoxy resins such as bisphenol diglycidyl ether, bis-xylenol-type epoxy resins such as bis-xylenol diglycidyl ether, hydrogenated bisphenol A Hydrogenated bisphenol A epoxy resins such as glycidyl ether, and their dibasic acid-modified diglycidyl ether epoxy resins. Among them, bisphenol A type epoxy resin is preferable because it is excellent in heat resistance and chemical resistance, and relatively does not shrink due to curing. These may be used alone or in combination of two or more.

As these compounds, commercially available products can be used. For example, examples of bisphenol A diglycidyl ether include Epicoat 828, Epicoat 1001, and Epicoat 1002 (all manufactured by Japan Epoxy Resin Co., Ltd., trade names) and the like. Examples of bisphenol F diglycidyl ether include Epicoat 807 (manufactured by Japan Epoxy Resin Co., Ltd., trade name), and examples of bisphenol S diglycidyl ether include EBPS-200 (manufactured by Nippon Kayaku Co., Ltd. , trade name) and Epicron EXA-1514 (manufactured by Dainippon Ink & Chemicals Co., Ltd., trade name) and the like. In addition, examples of bisphenol diglycidyl ether include YL-6121 (manufactured by Japan Epoxy Resin Co., Ltd., trade name) and the like, and examples of bis-xylenol diglycidyl ether include YX-4000 (Japan Epoxy Resin Co., Ltd. Company system, product name), etc. Furthermore, examples of hydrogenated bisphenol A diglycidyl ether include ST-2004 and ST-2007 (both manufactured by Tohto Chemical Co., Ltd., trade names), etc., as the above-mentioned dibasic acid-modified diglycidyl ether type ring Examples of the oxygen resin include ST-5100 and ST-5080 (both manufactured by Tohto Kasei Co., Ltd., trade names) and the like.

The epoxy equivalent of these diglycidyl ether type epoxy compounds (the gram weight of the compound containing 1 equivalent of epoxy group) can be measured according to JIS K 7236 "Calculation method of epoxy equivalent of epoxy resin". According to this measurement method, the epoxy equivalent of the epoxy compound is preferably 160-3300, more preferably 180-980, from the viewpoint of the dilute alkali aqueous solution developability.

As the dibasic acid compound, dicarboxylic acids are preferable, and specifically, for example, maleic acid, succinic acid, phthalic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, hexahydrophthalic acid, formic acid, Base hexahydrophthalic acid, methyl methyl tetrahydrophthalic acid, methyl methyl tetrahydrophthalic acid, etc. Among these dibasic acids, tetrahydrophthalic acid is more preferable. These acids may be used alone or in combination of two or more.

The polymerization reaction in the first step can be carried out according to a conventional method. The mixing ratio of the diglycidyl ether type epoxy compound and the dibasic acid is considered from the viewpoint of the molecular weight of the modified epoxy resin, the viewpoint of the dilute alkali aqueous solution developability, the viewpoint of storage stability, and the viewpoint of coating film property. The functional group equivalent ratio (carboxyl group/epoxy group) is preferably 1.03 to 1.30.

As a catalyst used for the polymerization reaction in a 1st process, a phosphine, an alkali metal compound, an amine, etc. are mentioned, for example. Specifically, for example, phosphines such as tributylphosphine and triphenylphosphine; alkali metal compounds such as sodium hydroxide and potassium hydroxide; triethanolamine, N,N'-dimethylpiperazine, triethylamine, Amines such as tri-n-propylamine, hexamethylenetetramine, pyridine, and tetramethylammonium bromide. These may be used alone or in combination of two or more.

Among them, as the catalyst used in the polymerization reaction in the first step, a tertiary amine having a pKa of 9.0 or less is preferable, and a tertiary amine having a pKa of 7.3 or less is more preferable. By using such a catalyst, finally, a modified epoxy resin represented by the above general formula (1) can be selectively synthesized. In addition, among the above-mentioned specific catalysts, it is preferable to use phosphine from the viewpoint of preventing gelation caused by the bond type (ether network structure and/or ester network structure) in the obtained modified epoxy resin. species, substances other than alkali metal compounds, or substances that are tertiary amines and have a pKa of 9.0 or less.

The intermediate product produced by the polymerization reaction in the above-mentioned first step can form in its molecule a chain structure brought about by an ester bond formed by the reaction of a carboxyl group and a glycidyl ether group, and a chain structure by a reaction of a hydroxyl group and a glycidyl ether group. The network structure due to the generated ether bond and the network structure caused by the ester bond generated by the reaction of the hydroxyl group and the carboxyl group. When the obtained intermediate product has a network structure due to ether bonds and a network structure due to ester bonds in many of these structures in the molecule, it is considered that the whole tends to form a three-dimensional structure. Therefore, the intermediate product and the modified epoxy resin obtained after the second step described later tend to be gelled, so the uncured portion of the resist film formed by using this resin tends to be cured even when dilute alkali is used. It will not be removed by developing with an aqueous solution.

On the other hand, the intermediate product synthesized using the above-mentioned catalyst is further subjected to the second process using it to obtain a chain-shaped compound having a large number of ester bonds in the molecule headed by the substance represented by the general formula (1). Since the modified epoxy resin has a chain structure and has a chain structure as a whole, it is considered that gelation tends to be difficult to occur. Accordingly, the uncured portion of the resist film formed by using such a modified epoxy resin can be easily removed by development using a dilute alkaline aqueous solution.

The use amount of the relevant catalyst is preferably from the viewpoint of the polymerization reaction rate and the heat resistance and galvanic insulation of the cured film obtained from the photosensitive resin composition, relative to the diglycidyl ether type epoxy compound and 100 mass parts of total amounts of dibasic acids are 1-10 mass parts.

The reaction temperature in the first step is preferably 100 to 150° C. from the viewpoint of the polymerization reaction rate and the prevention of side reactions.

(second process)

In the second step, a modified epoxy resin is produced by reacting the intermediate product produced in the first process with an acid anhydride.

Here, the acid anhydride residue represented by R ⁴ in the above-mentioned general formula (2) is a part except the acid anhydride functional group in the structure of the acid anhydride compound.

Examples of the acid anhydride compound include maleic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylhexahydrophthalic anhydride, Dibasic acid anhydrides such as hydrophthalic anhydride, methyl methylene tetrahydrophthalic anhydride, chlorobacterial anhydride, methyltetrahydrophthalic anhydride, etc.; aromatics such as trimellitic anhydride, pyromellitic anhydride, and benzophenone tetracarboxylic anhydride Polycarboxylic acid anhydrides; In addition, polycarboxylic acid anhydrides such as 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydrides accompanying them can also be mentioned. A polycarboxylic acid anhydride derivative, etc.

Among these, dibasic acid anhydrides are preferably used, and dicarboxylic acid anhydrides are more preferably used. These may be used alone or in combination of two or more.

The amount of acid anhydride added is determined by the functional group equivalent ratio (acid anhydride group in the added acid anhydride/in the first step) from the viewpoint of the developability of dilute alkaline aqueous solution and the heat resistance and galvanic insulation of the cured film finally obtained. Hydroxyl group of the produced intermediate product) is preferably 0.6 to 1.3.

The reaction temperature in the second step is preferably 80 to 130° C. from the viewpoint of the reaction rate and prevention of side reactions.

According to the production method including the first step and the second step as described above, a modified epoxy resin having a repeating unit represented by the above general formula (1), for example, represented by the above general formula (3), can be produced.

In addition, in the production method of this modified epoxy resin, an appropriate amount of solvent is usually used. Specifically, for example, ketone compounds such as methyl isobutyl ketone, cyclohexanone or methylcyclohexanone; aromatic hydrocarbon compounds such as toluene, xylene or tetramethylbenzene; cellosolve, methyl cellosolve , butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether or triethylene glycol monoethyl ether and other glycol ether compounds; ester compounds such as acetate compounds of glycol ether compounds; alcohol compounds such as ethylene glycol or propylene glycol; or petroleum-based solvents such as petroleum ether, naphtha, hydrogenated naphtha, or solvent naphtha.

The modified epoxy resin of the present invention thus obtained can be used, for example, contained in a photosensitive resin composition. This photosensitive resin composition contains (B) a photopolymerizable compound having at least one ethylenically unsaturated group in the molecule, (C) in addition to the above-mentioned modified epoxy resin (referred to as (A) component). Photopolymerization initiator.

Examples of the photopolymerizable compound having at least one ethylenically unsaturated group in the molecule (hereinafter simply referred to as "photopolymerizable compound") of the component (B) include bisphenol A-based (meth)acrylate compounds. ; Compounds obtained by reacting polyhydric alcohols with α, β-unsaturated carboxylic acids; Compounds obtained by reacting glycidyl-containing compounds with α, β-unsaturated carboxylic acids; (meth)acrylic acid having urethane bonds Urethane monomers or urethane oligomers such as ester compounds, in addition, nonylphenoxy polyethylene oxide acrylate, γ-chloro-β-hydroxypropyl-β'-(methyl Base) phthalic acid-based compounds such as acryloyloxyethyl phthalate, β-hydroxyalkyl-β'-(meth)acryloyloxyalkyl phthalate, etc.; (meth)acrylic acid Alkyl ester, EO modified nonylphenol (meth)acrylate, etc. These may be used alone or in combination of two or more.

Examples of bisphenol A-based (meth)acrylate compounds include 2,2-bis(4-((meth)acryloyloxypolyethoxy)phenyl)propane, 2,2-bis(4 -((meth)acryloyloxypolypropoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxypolybutoxy)phenyl)propane, and 2,2-bis (4-((meth)acryloyloxypolyethoxypolypropoxy)phenyl)propane and the like.

Examples of 2,2-bis(4-((meth)acryloyloxypolyethoxy)phenyl)propane include 2,2-bis(4-((meth)acryloyloxydiethoxy yl)phenyl)propane, 2,2-bis(4-((meth)acryloyloxytriethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxytetraethoxy Ethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxypentaethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyl Oxyhexaethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxyheptaethoxy)phenyl)propane, 2,2-bis(4-((methyl) Acryloyloxy octaethoxy) phenyl) propane, 2,2-bis(4-((meth)acryloyloxy nonaethoxy)phenyl)propane, 2,2-bis(4-((methyl) base) acryloyloxydecaethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxydecaethoxy)phenyl)propane, 2,2-bis(4- ((Meth)acryloyloxydodecethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxytridecethoxy)phenyl)propane, 2,2- Bis(4-((meth)acryloyloxytetradecethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxypentadecaethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxyhexadecylethoxy)phenyl)propane, etc., 2,2-bis(4-(methacryloyloxypentaethoxy)phenyl) As propane, commercial product BPE-1300 (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., brand name) can be used. These may be used alone or in combination of two or more.

Examples of 2,2-bis(4-((meth)acryloyloxypolypropoxy)phenyl)propane include 2,2-bis(4-((meth)acryloyloxydipropoxy) )phenyl)propane, 2,2-bis(4-((meth)acryloyloxytripropoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxytetrapropane Oxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxypentapropoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxy Hexapropoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxyheptapropoxy)phenyl)propane, 2,2-bis(4-((meth)propene Acyloxy octapropoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxynonapropoxy)phenyl)propane, 2,2-bis(4-((methyl) )acryloyloxydecapropoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxyundecapropoxy)phenyl)propane, 2,2-bis(4-( (Meth)acryloyloxydodecylpropoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxytridecylpropoxy)phenyl)propane, 2,2-bis (4-((meth)acryloyloxytetradecylpropoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxypentadecapropoxy)phenyl)propane, 2 , 2-bis(4-((meth)acryloxyhexadecylpropoxy)phenyl)propane, etc. These may be used alone or in combination of two or more.

Examples of 2,2-bis(4-((meth)acryloyloxypolyethoxypolypropoxy)phenyl)propane include 2,2-bis(4-((meth)acryloyloxy Diethoxyoctapropoxy)phenyl)propane, 2,2-bis(4-((meth)acryloxytetraethoxytetrapropoxy)phenyl)propane, and 2,2-bis (4-((meth)acryloyloxyhexaethoxyhexapropoxy)phenyl)propane and the like. These may be used alone or in combination of two or more.

Examples of the compound obtained by reacting a polyhydric alcohol with an α,β-unsaturated carboxylic acid include compounds using (meth)acrylic acid as the α,β-unsaturated carboxylic acid. Specifically, polyethylene glycol di(meth)acrylate having 2 to 14 ethylene groups, polypropylene glycol di(meth)acrylate having 2 to 14 propylene groups, ethylene glycol di(meth)acrylate having 2 to 14 ethylene groups, Polypropylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, EO modified trimethylolpropane tri(meth)acrylate, PO modified trimethylolpropane tri(meth)acrylate, EO·PO modified trimethylolpropane tri(meth)acrylate, Tetramethylolmethane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and the like. These may be used alone or in combination of two or more.

Here, "EO" means "ethylene oxide", and "PO" means "propylene oxide". In addition, "EO modification" refers to a block structure having an ethylene oxide unit (-CH ₂ -CH ₂ -O-), and "PO modification" refers to a block structure having a propylene oxide unit (-CH ₂ -CH( CH ₃ )-O-) block structure.

Examples of compounds obtained by reacting a glycidyl group-containing compound with an α,β-unsaturated carboxylic acid include compounds using (meth)acrylic acid or the like as the α,β-unsaturated carboxylic acid. Specifically, trimethylolpropane triglycidyl ether tri(meth)acrylate, 2,2-bis(4-((meth)acryloyloxy-2-hydroxy-propoxy) Benzene etc.

Examples of urethane monomers include (meth)acrylic monomers having an OH group at the β position, isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, 1, Addition reaction products of diisocyanate compounds such as 6-hexamethylene diisocyanate; tris((meth)acryloyloxytetraethylene glycol isocyanate) hexamethylene isocyanurate, EO modified urethane di( Meth)acrylate and EO or PO modified urethane di(meth)acrylate, etc.

Furthermore, examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, Esters etc.

These (B) components may be used individually by 1 type, and may use 2 or more types together.

Examples of the photopolymerization initiator of the component (C) include benzophenone, N,N'-tetramethyl-4,4'-diaminobenzophenone, 2-benzyl-2-dimethylamino- 1-(4-morpholinophenyl)-butanone-1,2-methyl-1-[4-(thiomethyl)phenyl]-2-morpholino-acetone-1 and other aromatic ketones quinones such as alkyl anthraquinones; benzoin ether compounds such as benzoin alkyl ethers; benzoin compounds such as benzoin and alkylbenzoin; benzyl derivatives such as benzyl dimethyl ketal; 2,4,5-triaryl imidazole dimer; 9-phenylacridine, 1,7-bis(9,9'-acridyl)heptane and other acridine derivatives; N-phenylglycine, N - Phenylglycine derivatives; coumarin-based compounds, etc. These may be used alone or in combination of two or more.

The content of the component (A) in the photosensitive resin composition is preferably relative to (A) Component and (B) The total amount of 100 mass parts of components is 30-70 mass parts, More preferably, it is 45-55 mass parts.

It is preferable that content of (B) component is 10-70 mass parts with respect to 100 mass parts of total amounts of (A) component and (B) component, More preferably, it is 35-55 mass parts. If the content is less than 10 parts by mass, the sensitivity tends to be insufficient, and when it exceeds 70 parts by mass, the photocured product tends to become brittle.

The content of component (C) is preferably 0.1 to 20 parts by mass, more preferably 0.2 parts by mass, based on 100 parts by mass of the total amount of components (A) and (B) from the viewpoint of sensitivity and solder heat resistance. ~10 parts by mass.

In addition, the photosensitive resin composition of the present invention preferably further contains a component (D) obtained by copolymerizing (a) a (meth)acrylate monomer and a monomer having a predetermined functional group (I). (b) a resin having an unsaturated group obtained by polymerizing a compound having a predetermined functional group (II) and an unsaturated group through the reaction of the functional group (I) and the functional group (II). Here, the resin of (a) is an acrylic resin, and the resin of (D) component is an acrylic resin which has an unsaturated group.

The glass transition temperature (Tg) of the resin which has an unsaturated group as (D) component is -10-60 degreeC, More preferably, it is 10-45 degreeC. By adjusting the glass transition temperature of the resin having an unsaturated group in this temperature range, the flexibility of the cured film obtained from the photosensitive resin composition of the present invention can be improved, and at the same time, the cured film can be formed on the FPC. The curvature of FPC at the time of filming tends to be small, and the stickiness of the coating film of this photosensitive resin composition also tends to be suppressed.

(D) The weight average molecular weight (Mw) of the resin which has an unsaturated group which is a component can be measured by GPC (in terms of standard polystyrene). According to this measurement method, the Mw of the resin having an unsaturated group is preferably 10,000 to 200,000, more preferably 30,000 to 100,000 from the viewpoint of coating film properties (less stickiness) and dilute alkaline aqueous solution developability.

The acid value of the resin having an unsaturated group as the component (D) is preferably It is 50-150 mgKOH/g, More preferably, it is 70-110 mgKOH/g.

Examples of (meth)acrylate monomers that are copolymerized components for obtaining the above (a) acrylic resin include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate ester, isobutyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, (meth)acrylic acid 2-Ethylhexyl, decyl (meth)acrylate, lauryl (meth)acrylate, etc. These may be used alone or in combination of two or more.

In addition, in addition to the above-mentioned (meth)acrylate monomers, styrene-based monomers such as styrene, vinyl toluene, and α-methylstyrene; (meth)acrylonitrile; (meth)acrylamide can also be used. ; Vinyl acetate, etc. These may be used alone or in combination of two or more.

As the monomer having the functional group (I) of the copolymerization component when obtaining the above-mentioned (a) acrylic resin, there can be mentioned an unsaturated group that can be copolymerized with the (meth)acrylate monomer, and at least one functional group ( I) monomer.

As a functional group (I), a hydroxyl group, a carboxyl group, an epoxy group, an isocyanate group etc. are mentioned, for example, Among them, a hydroxyl group and a carboxyl group are preferable.

As a monomer having a hydroxyl group, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, phenyl glycidyl ether ( Meth)acrylate, etc. As a monomer which has a carboxyl group, (meth)acrylic acid, itaconic acid, (beta)-(meth)acryloyloxyethyl hydrosuccinate etc. are mentioned, for example. As a monomer which has an epoxy group, glycidyl (meth)acrylate, glycidyl (meth)acrylate, etc. are mentioned, for example. As a monomer which has an isocyanate group, vinyl isocyanate, (meth)acrylic acid isocyanate, 2-(meth)acryloyloxyethyl isocyanate etc. are mentioned, for example. These may be used alone or in combination of two or more.

Examples of compounds having a functional group (II) and an unsaturated group in (b) above include, for example, vinyl, isopropenyl, (meth)allyl, (meth)acryloyl and other unsaturated groups. , and a compound having at least one functional group (II) capable of reacting with the functional group (I).

The above-mentioned functional group (II) can be appropriately selected according to the type of functional group (I) so as to be able to react (bond) with the functional group (I). For example, when the functional group (I) is a hydroxyl group, examples of the functional group (II) include an isocyanate group, an epoxy group, an aldehyde group, a carboxyl group, and an ethyleneamino group. Moreover, when a functional group (I) is a carboxyl group, an epoxy group, a hydroxyl group, etc. are mentioned as a functional group (II), for example. In addition, when the functional group (I) is an isocyanate group, a hydroxyl group etc. are mentioned as a functional group (II), for example. In addition, when the functional group (I) is an epoxy group, examples of the functional group (II) include a carboxyl group and the like.

Examples of (b) compounds having a functional group (II) and an unsaturated group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxypropyl (meth)acrylate, Hydroxybutyl ester, phenyl glycidyl ether (meth)acrylate and other monomers with hydroxyl groups; (meth)acrylic acid, itaconic acid, β-(meth)acryloyloxyethyl hydrogen succinate, etc. monomers; monomers with epoxy groups such as glycidyl (meth)acrylate and (meth)allyl glycidyl ether; vinyl isocyanate, (meth)acryl isocyanate, 2-(methyl) Monomers with isocyanate groups such as acryloyloxyethyl isocyanate; monomers with aldehyde groups such as (meth)acrolein; 2-(1-aziridinyl)ethyl(meth)acrylate, 4-( 1-Aziridinyl)butyl (meth)acrylate and other monomers having an ethylene amino group. These compounds having a functional group (II) and an unsaturated group may be used alone or in combination of two or more.

When the above-mentioned photosensitive resin composition further contains (D) component, the content of (A) component in the photosensitive resin composition, prevents bleeding from the end face of the photosensitive film that has photosensitive resin composition layer From the viewpoint of development and solder heat resistance, preferably 30 to 60 parts by mass, more preferably 40 to 50 parts by mass.

It is preferable that content of (B)component is 10-70 mass parts with respect to 100 mass parts of total amounts of (A) component, (B) component, and (D)component, More preferably, it is 35-55 mass parts. When this content is less than 10 parts by mass, the sensitivity tends to be insufficient, and when it exceeds 70 parts by mass, the photocured product of the photosensitive resin composition tends to become brittle.

It is preferable that content of (D)component is 1-20 mass parts with respect to 100 mass parts of total amounts of (A) component, (B) component, and (D)component, More preferably, it is 5-15 mass parts. When the content is less than 1 part by mass, flexibility, solder heat resistance, or plating resistance tends to be insufficient, and when it exceeds 20 parts by mass, the coating film of the photosensitive resin composition tends to become sticky easily. Moreover, the elongation of the cured film of a photosensitive resin composition tends to increase so that there is much content of (D)component, and tensile modulus of elasticity and tensile strength tend to fall.

The content of the component (C) is preferably 0.1 to 20 parts by mass relative to 100 parts by mass of the total amount of the components (A), (B) and (D) from the viewpoint of sensitivity and solder heat resistance. , More preferably 0.2 to 10 parts by mass.

In addition, the photosensitive resin composition may contain thermosetting components such as melamine resin or isocyanate block, dyes such as malachite green, photochromic agents such as tribromophenyl sulfone or leuco crystal violet, thermal color-forming agents, etc., if necessary. Inhibitors, plasticizers such as p-tolylsulfonamide, organic pigments such as phthalocyanine and azo such as phthalocyanine green or phthalocyanine blue, or inorganic pigments such as titanium dioxide, silica, alumina, talc, calcium carbonate or barium sulfate, etc. Fillers, defoamers, flame retardants, stabilizers, adhesion imparting agents, leveling agents, antioxidants, fragrances or imaging agents, etc. composed of inorganic pigments, the content of which is relative to (A) component and (B The total amount of 100 mass parts of ) component is 0.01-20 mass parts, respectively. Moreover, when the photosensitive resin composition further contains (D)component, it is preferable to contain 0.01-20 mass parts each with respect to 100 mass parts of total amounts of (A) component, (B) component, and (D)component. These may be used alone or in combination of two or more. Moreover, polymer components other than (A) component, such as an acrylic-type copolymer, and (D) component can also be used together.

Furthermore, the photosensitive resin composition can be dissolved in methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N,N-dimethylformamide, propylene glycol mono In a solvent such as methyl ether or a mixed solvent thereof, it is applied as a solution having a solid content of about 30 to 70% by mass.

Next, the photosensitive element of the present invention will be described.

The photosensitive element of the present invention has a support and a photosensitive resin composition layer made of the photosensitive resin composition of the present invention formed on the support. The photosensitive resin composition layer may further have a protective film covering the photosensitive resin composition layer.

Preferably, the photosensitive resin composition of the present invention is dissolved in the above-mentioned solvent or mixed solvent to prepare a solution having a solid content of about 30 to 70% by mass, and then the solution is applied to a support to form a photosensitive resin composition. layer. The thickness of the photosensitive resin composition layer varies depending on the application, but is preferably 10 to 100 μm, more preferably 20 to 60 μm, as a thickness after removing the solvent by heating and/or blowing hot air and drying. If the thickness is less than 10 μm, it tends to be difficult to coat industrially; if it exceeds 100 μm, the above-mentioned effects brought about by the present invention tend to decrease, and in particular, flexibility and resolution tend to decrease.

Examples of the support that the photosensitive element has include heat-resistant and solvent-resistant polymer films such as polyethylene terephthalate, polypropylene, polyethylene, and polyester.

The thickness of the support is preferably 5 to 100 μm, more preferably 10 to 30 μm. If the thickness is less than 5 μm, the support tends to be easily broken when the support is peeled off before development; and if it exceeds 100 μm, the resolution and flexibility tend to decrease.

A photosensitive element consisting of two layers of a support and a photosensitive resin composition layer as described above or a photosensitive element consisting of three layers of a support and a photosensitive resin composition layer and a protective film, for example, can be directly stored, or It can also be stored in the form of a roll wound on a core with the protective film interposed therebetween.

The method for forming a resist pattern using the photosensitive element of the present invention includes, if necessary: a removal step of removing the protective film from the above-mentioned photosensitive element; The lamination process of laminating on the substrate for circuit formation; the exposure process of irradiating active light to a predetermined part of the photosensitive resin composition layer through the support as needed to form a photocured part on the photosensitive resin composition layer; removing The development process of the photosensitive resin composition layer other than a photocuring part. Here, the circuit-forming substrate refers to a substrate having an insulating layer and a conductor layer (copper, copper alloy, nickel, chromium, iron, stainless steel, or other iron alloy, preferably copper, copper alloy, or iron alloy) formed on the insulating layer.

As a lamination process in the lamination process after the removal process which removes a protective film as needed, the method of laminating|stacking by pressure-bonding to the board|substrate for circuit formation etc. are mentioned, heating a photosensitive resin composition layer. The atmosphere involved in lamination is not particularly limited, but lamination under reduced pressure is preferred from the viewpoint of adhesion and adhesion. The laminated surface is usually the surface of the conductor layer of the circuit-forming substrate, but may be a surface other than the conductor layer. The heating temperature of the photosensitive resin composition layer is preferably 70-130° C., the crimping pressure is preferably about 0.1-1.0 MPa, and the ambient air pressure is preferably less than or equal to 4000 Pa, but these conditions are not particularly limited. In addition, if the photosensitive resin composition layer is heated to 70 to 130°C as described above, it is not necessary to preheat the circuit-forming substrate, but in order to further improve the laminarity, the circuit-forming substrate may also be pre-heated. heat treatment.

After the lamination is completed in this way, a predetermined portion of the photosensitive resin composition layer may be irradiated with active light in an exposure step to form a photocured portion. As a method of forming a photocured portion, a method of irradiating active light in an image form through a negative or positive mask pattern called an artwork can be mentioned. At this time, when the support present on the photosensitive resin composition layer is transparent, active light can be irradiated directly, but if it is not transparent, the photosensitive resin composition layer is irradiated with active light after the support is removed.

As the light source of active light, known light sources can be used, such as carbon arc lamps, mercury vapor lamps, ultra-high pressure mercury lamps, high pressure mercury lamps, xenon lamps and other light sources capable of effectively emitting ultraviolet rays. In addition, a light source capable of efficiently emitting visible light, such as a photographic floodlight or a sun lamp, may be used.

Next, after exposure, when there is a support body on the photosensitive resin composition layer, after removing the support body, in the development process, the photosensitive resin composition layer other than the photocured part can be removed by wet development, dry development, etc. Development is performed to form a resist pattern. In the case of wet development, development is performed by known methods such as spraying, shaking dipping, brushing, and scraping using a developer corresponding to the photosensitive resin composition, such as an alkaline aqueous solution, an aqueous developer, or an organic solvent. As the developer, a safe, stable, and easy-to-handle developer is used, for example, a dilute sodium carbonate solution (1 to 5 mass % aqueous solution) at 20 to 50° C. can be used.

The resist pattern obtained by the above-mentioned formation method is preferably used for forming a flexible cured resin on a film-like base material, and is more preferably used as a permanent mask formed on a film-like base material. For example, when used as a cover film for FPC, after the above-mentioned development process is completed, it is preferable to irradiate ultraviolet rays or heat with a high-pressure mercury lamp for the purpose of improving the solder heat resistance and chemical resistance of the FPC cover film. When irradiating ultraviolet rays, the irradiation dose can be adjusted as necessary, and irradiation can be performed at an irradiation dose of about 0.2 to 10 J/cm ² , for example. When irradiating ultraviolet rays, it is not necessary to preheat the resist pattern in advance, but in order to further improve solder heat resistance, chemical resistance, etc., the resist pattern can be preheated at 60 to 150°C. Moreover, when heating a resist pattern, it is preferable to carry out in the range of about 100-170 degreeC, and the range of about 15-90 minutes. Furthermore, ultraviolet irradiation and heating may be performed at the same time, or one may be performed first, and then the other may be performed.

Since this cover film also serves as a protective film for wiring after soldering to the substrate, it has excellent flexibility, insulation, etc., and can be effectively used as a permanent mask for FPC.

Such a substrate having a resist pattern (cover film) is subsequently mounted with components such as LSI (for example, by soldering), and then mounted on electronic equipment such as a camera.

Example

Hereinafter, the present invention will be described in further detail based on examples, but the present invention is not limited to these examples.

(A) Component modified epoxy resin was prepared by the following method. First, in a flask equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen gas inlet tube, bisphenol A type epoxy resin (ェピコート 1001, manufactured by Japan Epoxy Resin Co., Ltd., epoxy equivalent 479g/eq, trade name ) 182.7 parts by mass, 64.0 parts by mass of cyclohexanone, and 30.0 parts by mass of toluene were stirred while blowing nitrogen gas in a state heated to 130° C., and the moisture contained in the dehydration epoxy resin was refluxed. Next, 34.9 parts by mass of tetrahydrophthalic acid (manufactured by Nippon Chemical Co., Ltd.) and 3.6 parts by mass of dimethyl-p-toluidine (manufactured by Samsung Chemical Co., Ltd.) were added thereto, and the mixture was kept at 140° C. for 4 hours. Then, 108.0 parts by mass of tetrahydrophthalic anhydride (manufactured by Shin-Nippon Rika Co., Ltd.) was added, and it was heat-retained at 120 degreeC for 3 hours, and (A) component modified epoxy resin was obtained. Then, this modified epoxy resin was diluted with 127.0 parts of methyl ethyl ketone. The obtained modified epoxy resin had a weight average molecular weight of 49000, a solid content of 57.0%, and an acid value of 133 mgKOH/g. In addition, the IR spectrum of the obtained modified epoxy resin is shown in FIG. 1 . Here, the IR spectrum was measured using "FTS135" (manufactured by Deji Tebo Japan Co., Ltd.).

In addition, the weight average molecular weight (measured by gel permeation chromatography (GPC), the value converted using the calibration curve of standard polystyrene) of a modified epoxy resin was measured on the following conditions.

(GPC conditions)

Pump: Hitachi L-6000 [manufactured by Hitachi, Ltd.]

Detector: Hitachi L-4000 UV [manufactured by Hitachi, Ltd.]

Column: Gelpack GL-S300MDT-5 (two pieces) (manufactured by Hitachi Chemical Industries, Ltd., brand name)

Column size: 8mmφ×300mm

Eluent: DMF/THF=1/1+phosphoric acid 0.06M+lithium bromide 0.06M

Sample concentration: 5mg/1mL

Injection volume: 5μL

Pressure: 35kgf/ ^cm2

Flow: 1.0mL/min

Next, the constituent material polyurethane resin of (B) component was prepared by the following method. First, after introducing air into a flask with a stirrer, a reflux condenser, a thermometer, and a nitrogen inlet tube, add polycarbonate diol (Praccel CD205PL, manufactured by Daicel Chemical Industry Co., Ltd., weight average molecular weight 500, trade name) 196.8 mass 58.3 parts by mass of dimethylolbutyric acid (manufactured by Mitsubishi Chemical Corporation), 37.6 parts by mass of diethylene glycol (manufactured by Nisso Maruzen Chemical Co., Ltd.), 1,4-cyclohexanedimethanol monoacrylate (manufactured by Mitsubishi Chemical Corporation) 148.1 parts by mass, 0.55 parts by mass of p-methoxyphenol (manufactured by Wako Pure Chemical Industries, Ltd.), 0.55 parts by mass of dibutyltin laurate (manufactured by Tokyo Fine Chemical Co., Ltd., L101), and 110.2 parts by mass of methyl ethyl ketone The temperature was raised to 65°C while stirring under air flow.

Next, 305.9 parts by mass of trimethylhexamethylene diisocyanate (VESTANAT TMDI, manufactured by Heyles Japan Co., Ltd., trade name) was added to the dropping funnel, and the temperature of the reaction vessel was kept at 65±3°C for 3 hours. Evenly added dropwise to the reaction vessel. After finishing the dropwise addition, the dropping funnel was cleaned with 76.5 parts by mass of methyl ethyl ketone, and the cleaning solution was directly put into the reaction container. After further maintaining the temperature with stirring for 2 hours, the temperature of the reaction vessel was raised to 75°C.

Then, continue stirring and incubating at 75±3° C. until the disappearance of the peak of the infrared absorption spectrum showing the isocyanate group can be confirmed using an infrared spectrophotometer. After raising the temperature to 75° C., the peak of the infrared absorption spectrum due to the isocyanate group disappears in about 6 to 8 hours. After confirming that the peak disappeared, the temperature of the reaction container was lowered to 60°C, 9.3 parts by mass of methanol was added, and the mixture was kept at 60±3°C for 30 minutes. Then, 56.4 parts by mass of methyl ethyl ketone was added to obtain a transparent solution containing a polyurethane resin. Set it to Resin (2). The polyurethane resin had a solid content of 75.6%, an acid value of 22.2 mgKOH/g, and a viscosity of 1810 mPa·s.

Examples 1-4 and Comparative Examples 1-3

First, each component shown in Table 1 was mixed according to the mixing ratio (mass basis) of the solid content shown, and the photosensitive resin composition solution was obtained. Here, in the table, resin (1) is a 65% by mass carbitol acetate/solvent naphtha solution of acid-modified bisphenol A epoxy acrylate (ZAR-1035, manufactured by Nippon Kayaku Co., Ltd., commercial product name). In addition, resin (3) is bisphenol A polyoxyethylene dimethacrylate (BPE-10, manufactured by Shin-Nakamura Chemical Industry Co., Ltd., brand name), and component (C) is 2-benzyl-2-dimethylamino -1-(4-morpholinophenyl)-butanone-1 (I-369, manufactured by Ciba Specialty Chemicals Co., Ltd., trade name), BL3175 is an isocyanurate with hexamethylene diisocyanate as the base isocyanate A 75% by mass methyl ethyl ketone solution of a methyl ethyl ketone oxime block of an ester body (BL3175, manufactured by Sumika Bayeruretan Co., Ltd., trade name).

Table 1

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Comparative example 1 Comparative example 2 Comparative example 3 (A) Ingredients 100 100 100 100 90 80 70 - - - Resin (1) - - - - - - - 100 100 100 (D) Ingredients - - - - 10 20 30 - - - (B) Component Resin (2) Resin (3) 5342 6742 6733 5748 5748 5748 5748 5342 6742 6733 (C) Ingredients 3 3 3 3 3 3 3 3 3 3 Others BL3175 Phthalocyanine blue methyl ethyl ketone 200.235 200.235 200.235 200.235 200.235 200.235 200.235 200.235 200.235 200.235

Note: The values in Table 1 are the mixing ratios of the solid components of each component. (Except methyl ethyl ketone.)

In addition, the mark "-" in the table|surface shows that a corresponding component is not contained.

Embodiment 5-7

Each component shown in Table 1 was mixed in the shown solid content mixing ratio (mass basis), and the photosensitive resin composition solution was obtained. Among them, the component (D) in the table is 40% by mass of methyl ethyl ketone/propylene glycol monomethyl ketone with Tg of 12°C, weight average molecular weight of 50,000, and acid value of 90 mgKOH/g, an acrylic resin having an unsaturated group. Ether solution (manufactured by Shin-Nakamura Chemical Industry Co., Ltd., trade name "AP-29M"). In addition, resin (2), resin (3), and (C) component are the same as above. Here, the weight average molecular weight of the obtained photosensitive resin composition was measured on the said GPC conditions.

Next, these photosensitive resin composition solutions were uniformly coated on a polyethylene terephthalate film (G2-16, manufactured by Teijin Corporation, trade name) as a support layer with a thickness of 16 μm to form a photosensitive resin composition. The resin composition layer was dried at 100° C. for about 10 minutes using a hot air convection dryer. The film thickness of the photosensitive resin composition layer after drying was 25 micrometers.

Next, a polyethylene film (NF-13, manufactured by Tamapoli Co., Ltd., trade name) was attached as a protective film on the surface of the photosensitive resin composition layer opposite to the side in contact with the support layer to obtain a photosensitive element.

Next, the copper surface of a substrate for a flexible printed circuit board (F30VC1, manufactured by Nikkan Industries Co., Ltd., trade name) on which a copper foil with a thickness of 18 μm was laminated on a polyimide base material was polished with an abrasive brush, washed with water, and dried. Using a continuous vacuum laminator (HLM-V570, manufactured by Hitachi Chemical Industry Co., Ltd., trade name) on the substrate for this flexible printed circuit board, the temperature at the heating contact end is 100°C, the lamination speed is 0.5m/min, and the air pressure is less than or The resulting photosensitive element was laminated while peeling off the polyethylene film under the conditions of 4000 Pa and a pressure bonding pressure of 0.3 MPa to obtain a laminate for evaluation.

[Evaluation of Sensitivity]

On the obtained above-mentioned laminated body for evaluation, a photographic tool having a Stouffer 21-level exposure scale was attached as a negative film, and a HMW-201GX type exposure machine manufactured by ォククイライイExposure was performed with energy at which the residual order became 8.0. Next, it was left still at normal temperature for 1 hour, and after peeling off the PET film, it sprayed 1 mass % sodium carbonate aqueous solution of 30 degreeC for 60 seconds, developed, and heated (dried) at 80 degreeC for 10 minutes. As a numerical value for evaluating the sensitivity, the energy described above was used. The lower the value, the higher the sensitivity. The results are shown in Table 2.

[Evaluation of resolution]

Attach a photographic tool with a Stouffer 21-level exposure scale and a photographic tool with a circuit pattern with a line width/space width of 30/30 to 200/200 (unit: μm) as a negative for resolution evaluation, and adhere to the evaluation layer On the integrated body, use the above-mentioned exposure machine to perform exposure with the energy that can make the residual level of the Stouffer 21-level exposure scale become 8.0. Next, it was left still at normal temperature for 1 hour, and after peeling off the PET film, it sprayed 1 mass % sodium carbonate aqueous solution of 30 degreeC for 60 seconds, developed, and heated (dried) at 80 degreeC for 10 minutes. Here, the resolution is evaluated based on the minimum value (unit: μm) of the space width between the line widths of the rectangular resist shape obtained by the development process. The smaller the value, the higher the resolution. The results are shown in Table 2.

[Evaluation of Coating Properties]

The obtained laminate for evaluation was not exposed, the polyethylene terephthalate on the laminate was peeled off, a finger was lightly pressed on the surface of the coating film, and the stickiness to the finger was evaluated according to the following criteria. That is, the case where stickiness was not felt or hardly felt was rated as "A", and the case where stickiness was felt was rated as "B". The results are shown in Table 2.

Furthermore, on the obtained laminated body for evaluation, a photographic tool having a Stouffer 21-step exposure ruler and a photographic tool having a circuit pattern as a negative film for reliability evaluation of the cover film were attached, and the above-mentioned exposure machine was used to enable Exposure was carried out at an energy of 8.0 with the remaining steps of the Stouffer 21-step exposure scale. Next, let stand at room temperature for 1 hour, peel off the polyethylene terephthalate on the laminate, spray develop with the same developing solution and developing conditions as in the sensitivity evaluation, and heat (dry) at 80°C. )10 minutes. Next, ultraviolet irradiation was performed at an energy of 1 J/cm ² using an ultraviolet irradiation device manufactured by Oak Seisakusho Co., Ltd., and heat treatment was performed at 160° C. for 60 minutes to obtain an FPC for evaluation on which a cover film was formed.

[Evaluation of solder heat resistance]

A rosin-based flux (MH-820V, manufactured by Tamura Kaken Co., Ltd., trade name) was applied to the FPC for evaluation obtained as described above, and then immersed in a solder bath at 260° C. for 30 seconds to perform a soldering process.

The occurrence of cracks in the cover film on the FPC subjected to solder plating in this way, and the degree of lift and peeling of the cover film from the substrate were observed visually, and evaluated according to the following criteria. That is, the case where no cracks were observed in the cover film and the case where the cover film was not lifted or peeled off was rated as "A", and the case where either of them was seen was rated as "B". The results are shown in Table 2.

[plating resistance]

The obtained FPC for evaluation was immersed in a plating bath at 85° C. containing an electroless nickel plating solution (Melpure NI-865T, manufactured by Meltex Corporation, trade name) for 15 minutes, and then immersed in an electroless gold plating solution (Melpure AU-601 (manufactured by Meltex Corporation, trade name) was dipped in a 90° C. plating tank for 10 minutes to perform plating treatment.

The occurrence of cracks in the cover film on the FPC thus subjected to electroless nickel plating and gold plating, and the degree of warping and peeling of the cover film from the substrate were observed visually, and evaluated according to the following criteria. That is, the case where no cracks were observed in the cover film and the case where the cover film was not lifted or peeled off was rated as "A", and the case where either of them was seen was rated as "B". The results are shown in Table 2.

[Evaluation of folding resistance (flexibility)]

The obtained FPC for evaluation was bent at 180° with a curler, and the occurrence of cracks in the cover film at this time was visually observed, and evaluated according to the following criteria. That is, the case where cracks were not seen in the coating film was rated as "A", and the case where cracks were seen was rated as "B". The results are shown in Table 2.

[Evaluation of Tensile Elastic Modulus, Tensile Strength, and Elongation]

Tensile elastic modulus, tensile strength, and elongation are measured based on JIS K 7127 "Tensile test methods for plastic films and sheets". The results are shown in Table 2.

Table 2

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Comparative example 1 Comparative example 2 Comparative example 3 Sensitivity (mJ/cm²) 170 170 190 170 200 200 200 150 150 150 Resolution (μm) 50 50 60 50 50 50 50 40 40 50 Coating properties A A A A A A A B B B Solder heat resistance A A A A A A A A A A Resistance to electroless gold plating A A A A A A A A A A Folding resistance (flexibility) A A A A A A A B B B Tensile modulus of elasticity (GPa) - - - 1.35 1.22 1.08 0.97 - - - Tensile strength (MPa) - - - 41.9 40.4 36.1 31.1 - - - Elongation(%) - - - 4.2 5.9 6.7 7.8 - - -

Note: The symbol "-" in Table 2 means that it has not been evaluated or measured.

As can be seen from Table 2, the laminates using the photosensitive resin compositions of Examples 1 to 7 were very excellent in sensitivity, resolution, and coating properties. In addition, it was confirmed that the FPC obtained by using these laminates is very excellent in flexibility. Furthermore, it turned out that FPC using the photosensitive resin composition of Examples 5-7 containing (D)component is more excellent in plating resistance.

Industrial Utilization Possibility

According to the present invention, it is possible to provide a modified epoxy resin capable of preparing a photosensitive resin composition, a method for producing the same, and a photosensitive resin composition. Properties required for permanent masks on film substrates (especially sensitivity, resolution, coating properties, solder heat resistance, plating resistance, flexibility). Moreover, this invention can also provide the photosensitive element which has such a photosensitive resin composition.

Claims (12)

1. photosensitive polymer combination, it contains:

(A) having the represented repeating unit of following general formula (1), weight-average molecular weight is 10000～70000 modified epoxy,

In the formula (1), R ¹Expression is as the divalent organic group of diglycidyl ether-type epoxy compounds residue, R ²Expression is as the divalent organic group of diprotic acid residue, R ³Expression hydrogen atom or the represented group of following general formula (2), n represents the integer more than or equal to 1,

In the formula (2), R ⁴Expression acid anhydrides residue;

(B) comprise and have dihydroxyphenyl propane system (methyl) acrylic compound and have (methyl) acrylic compound of ammonia ester bond, have the optical polymerism compound of at least one alkene class unsaturated group at intramolecularly; With

(C) Photoepolymerizationinitiater initiater.

2. the described photosensitive polymer combination of claim 1, described (A) composition are with following general formula (3) expression, and it is that weight-average molecular weight is 10000～70000 modified epoxy,

In the formula (3), R ¹Expression is as the divalent organic group of diglycidyl ether-type epoxy compounds residue, R ²Expression is as the divalent organic group of diprotic acid residue, R ³Expression hydrogen atom or the represented group of following general formula (2), n represents the integer more than or equal to 1,

In the formula (2), R ⁴Expression acid anhydrides residue.

3. claim 1 or 2 described photosensitive polymer combinations, described modified epoxy has the acid number of 70～200mgKOH/g.

4. claim 1 or 2 described photosensitive polymer combinations, described modified epoxy is manufactured by the following method and obtains, and described manufacture method comprises: first operation that obtains intermediate product by diglycidyl ether-type epoxy compounds and diprotic acid polyreaction; Second operation to described intermediate product addition acid anhydrides; In described first operation, have the tertiary amine that is less than or equal to 9.0 pKa by use and carry out described polyreaction as catalyzer.

5. the described photosensitive polymer combination of claim 4, described diprotic acid uses dicarboxylic acid.

6. the described photosensitive polymer combination of claim 4, functional group's equivalence ratio of the epoxy group(ing) of the carboxyl of described dicarboxylic acid and described diglycidyl ether-type epoxy compounds is 1.03～1.30.

7. the described photosensitive polymer combination of claim 1, further containing (D) composition, should (D) composition be to make (a) copolymerization (methyl) acrylate monomer and have the monomer of specified functional groups (I) and the resin, (b) that obtain have the compound resin with unsaturated group that polymerization obtains by the reaction of described functional group (I) and described functional group (II) of specified functional groups (II) and unsaturated group;

Described functional group (I) is at least a for what select from the group of being made up of hydroxyl, carboxyl, epoxy group(ing) and isocyanate group;

Described functional group (II) is at least a for what select from the group of being made up of aldehyde radical, hydroxyl, ethylidene imino-, carboxyl, epoxy group(ing) and isocyanate group;

Described unsaturated group is at least a for what select from the group of being made up of vinyl, pseudoallyl, (methyl) allyl group and (methyl) acryl;

The combination of one or more that being combined as of described functional group (I) and described functional group (II) selected from the group of being made up of hydroxyl and isocyanate group, hydroxyl and epoxy group(ing), hydroxyl and aldehyde radical, hydroxyl and carboxyl, hydroxyl and ethylidene imino-, carboxyl and epoxy group(ing), carboxyl and hydroxyl, isocyanate group and hydroxyl and epoxy group(ing) and carboxyl.

8. the described photosensitive polymer combination of claim 7, described monomer with functional group (I) is for from by (methyl) vinylformic acid 2-hydroxy methacrylate, (methyl) vinylformic acid 2-hydroxy propyl ester, (methyl) vinylformic acid 4-hydroxyl butyl ester, phenyl glycidyl ether (methyl) acrylate, (methyl) vinylformic acid, methylene-succinic acid, β-(methyl) acrylyl oxy-ethyl hydrogen succinate ester, (methyl) glycidyl acrylate, (methyl) glycidyl allyl ether, vinyl isocyanate, that selects in the group that (methyl) propenyl isocyanic ester and 2-(methyl) acrylyl oxy-ethyl isocyanic ester are formed is at least a.

9. claim 7 or 8 described photosensitive polymer combinations, the glass transition temp that described (D) has the resin of unsaturated group is-10～60 ℃, and weight-average molecular weight is 10000～200000, and acid number is 50～150mgKOH/g.

10. claim 1 or 2 described photosensitive polymer combinations form the purposes of pliability cured resin on membranaceous base material.

11. claim 1 or the 2 described photosensitive polymer combinations purposes in the permanent mask that forms flexible printed circuit board.

12. photosensitive element, it has support and is formed on the photosensitive polymer combination layer that is formed by claim 1 or 2 described photosensitive polymer combinations on this support.