JP2014071325A - Novel photosensitive resin composition and use of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin composition which has excellent tackiness after dried and photosensitivity, thereby, which can be micro-processed, which gives a cured film having excellent flexibility, flame retardancy and reliability of electric insulation, and which reduces warpage of a substrate after cured, and to provide a resin film, a cured film and a printed wiring board with a cured film.SOLUTION: The photosensitive resin composition comprises at least (A) a binder polymer, (B) crosslinked polymer particles encapsulating a flame retardant, (C) a radical polymerizable compound, and (D) a photopolymerization initiator.

Description

  This invention is excellent in tackiness after drying and can be finely processed because it has photosensitivity, and the resulting cured film is excellent in flexibility, flame retardancy, and electrical insulation reliability, and the warped substrate after curing. The present invention relates to a small photosensitive resin composition, a resin film, a cured film, and a printed wiring board with a cured film.

  Polyimide resins are widely used in electrical and electronic applications because of their excellent heat resistance, electrical insulation reliability, chemical resistance, and mechanical properties. For example, it is used to form insulating films and protective coatings on semiconductor devices, base materials such as flexible circuit boards and integrated circuits, surface protective materials, and further, interlayer cured films and protective films for fine circuits. .

  In particular, when used as a surface protection material for a flexible circuit board, a coverlay film obtained by applying an adhesive to a molded body such as a polyimide film has been used. When bonding this coverlay film on a flexible circuit board, there is a method in which an opening is provided in advance by a method such as punching in a terminal portion of a circuit or a joint portion with a component, and after aligning, a method of thermocompression bonding by a hot press or the like is used. It is common.

  However, it is difficult to provide a high-accuracy opening in a thin coverlay film, and since the alignment at the time of lamination is often performed manually, the positional accuracy is poor and the workability of the lamination is also poor. The cost was high.

  On the other hand, a solder resist or the like may be used as a surface protection material for a circuit board. In particular, a solder resist having a photosensitive function is preferably used when fine processing is required. As this photosensitive solder resist, a photosensitive resin composition mainly composed of acid-modified epoxy acrylate, epoxy resin, or the like is used. This photosensitive solder resist is excellent in electrical insulation reliability as an insulating material, but is bent. Therefore, when it is laminated on a thin and flexible circuit board such as a flexible circuit board, the warpage of the board becomes large and it is difficult to use it for a flexible circuit board. Further, the flame retardancy is poor, and when a flame retardant is added for the purpose of imparting flame retardancy, there are problems such as deterioration in physical properties and contact failure due to bleeding out from the cured film and process contamination.

  As this photosensitive solder resist, various proposals that can exhibit flexibility and flame retardancy have been made.

  For example, there has been proposed a photosensitive resin composition capable of ensuring sufficient flame retardancy without using a halogen-based flame retardant and capable of obtaining a cured product having a sufficient elongation (for example, patents). Reference 1).

  On the other hand, one of the important characteristics when carrying out the photosensitive solder resist processing is that the coating film surface tackiness (tackiness) after applying the coating film and drying the solvent is good. This prevents the photomask from sticking to the coating film when it is irradiated with UV light by placing a photomask necessary for fine pattern formation on the surface of the coating film. This is an important characteristic for preventing the circuit boards from sticking to each other when the boards are stacked.

  As a method of improving the tack-free property after drying the coating film of this photosensitive solder resist, a technique of adding an inorganic filler to provide unevenness on the coating film surface is used, but the cured film is brittle because the inorganic filler is hard. Thus, there were problems such as generation of cracks and peeling from the substrate.

  Therefore, a high-performance photocurable liquid solder resist ink composition has been proposed that is highly sensitive and excellent in tack-free and developability of the coating film, and does not cause adhesion degradation or peeling due to cracking or volume shrinkage. (For example, refer to Patent Document 2).

JP 2008-134484 A Japanese Patent Laid-Open No. 9-137109

  In the above-mentioned patent documents, various methods for solving the problems of the photosensitive solder resist are proposed. However, since the photosensitive resin composition described in Patent Document 1 uses a filler-type flame retardant having a high phosphorus content, it can impart flame retardancy with a small addition amount, and has a sufficient elongation rate. However, since the adhesiveness between the flame retardant and the resin constituting the matrix is inferior, there is a problem that the crack is the starting point and the flexibility to withstand repeated bending is insufficient. The solder resist ink composition described in Patent Document 2 is excellent in tackiness after drying the coating film due to dispersion of polymer fine particles having a glass transition temperature of 20 ° C. or less, and is caused by generation of cracks and volume shrinkage. Although the deterioration of adhesion or peeling is suppressed, when used as an insulating protective film of a flexible printed wiring board, there is a problem that bending resistance and flame retardancy are poor and warpage is large.

  As a result of diligent research to solve the above-mentioned problems, the present inventors have found that at least (A) a binder polymer, (B) a crosslinked polymer particle containing a flame retardant, (C) a radical polymerizable compound, and (D) photopolymerization. From the photosensitive resin composition characterized by containing an initiator, it is excellent in tackiness after drying and has photosensitivity so that it can be finely processed, and the resulting cured film is flexible, flame retardant, electric Obtained knowledge to obtain a photosensitive resin composition, a resin film, a cured film, and a printed wiring board with a cured film having excellent insulation reliability and small warping of the substrate after curing, and based on these findings, reached the present invention. It is a thing. This invention can solve the said subject with the photosensitive resin composition of the following novel structures.

  That is, the present invention contains at least (A) a binder polymer, (B) a crosslinked polymer particle containing a flame retardant therein, (C) a radical polymerizable compound, and (D) a photopolymerization initiator. It is a photosensitive resin composition.

  Moreover, in the photosensitive resin composition concerning this invention, it is preferable that the said (B) crosslinked polymer particle has a urethane bond in a molecule | numerator.

  In the photosensitive resin composition according to the present invention, the flame retardant is at least one selected from the group consisting of (b1) phosphinates, (b2) metal hydroxides, and (b3) melamine compounds. It is preferable.

  Moreover, in the photosensitive resin composition concerning this invention, it is preferable to contain (E) thermosetting resin further.

  In the photosensitive resin composition according to the present invention, the (A) binder polymer has at least one selected from the group consisting of (a1) urethane bond, (a2) carboxyl group, and (a3) imide group. Is preferred.

  Moreover, in the photosensitive resin composition concerning this invention, it is preferable that the average particle diameter of the said (B) crosslinked polymer particle is 1-20 micrometers.

  Moreover, in the photosensitive resin composition concerning this invention, it is preferable that the compounding quantity of the said (B) crosslinked polymer particle is 50-200 weight part with respect to 100 weight part of (A) binder polymer.

  Moreover, the resin film concerning this invention is obtained by drying, after apply | coating the said photosensitive resin composition to the base-material surface.

  Moreover, the cured film concerning this invention is obtained by hardening the said resin film.

  Moreover, the printed wiring board with a cured film concerning this invention is the said cured film coat | covered with a printed wiring board.

  As described above, the photosensitive resin composition of the present invention comprises at least (A) a binder polymer, (B) a crosslinked polymer particle containing a flame retardant, (C) a radical polymerizable compound, and (D) photopolymerization initiation. Since it has a composition containing an agent, it has excellent tackiness after drying, and can be finely processed because it has photosensitivity, and the resulting cured film is excellent in flexibility, flame retardancy, and electrical insulation reliability, The warpage of the substrate after curing is small. Therefore, the photosensitive resin composition of the present invention can be used for protective films of various circuit boards and exhibits excellent effects.

It is the schematic diagram which has measured the curvature amount of the film.

  Hereinafter, the present invention will be described in detail in the order of (I) the photosensitive resin composition and (II) the method of using the photosensitive resin composition.

(I) Photosensitive resin composition The photosensitive resin composition of the present invention includes at least (A) a binder polymer, (B) crosslinked polymer particles containing a flame retardant therein, (C) a radical polymerizable compound, (D ) A photosensitive resin composition containing a photopolymerization initiator.

  Here, although the present inventors discovered that the photosensitive resin composition of this invention was excellent in various characteristics, it estimates that this may be based on the following reasons. That is, since the (B) crosslinked polymer particle plays a role of providing unevenness on the coating film surface, it has the effect of suppressing stickiness after the photosensitive resin composition containing the component (B) is applied to a substrate and dried. The obtained tackiness is excellent. In addition, by using the flame retardant in a form in which the crosslinked polymer particles are included, the crosslinked polymer particles become non-thermoplastic, and the flame retardant is not discharged outside the crosslinked polymer particles due to external stimuli such as temperature and pressure. It is possible to prevent deterioration of insulation reliability and process contamination due to bleed out. In addition, by using a flame retardant incorporated in the interior of the crosslinked polymer particles, strong adhesiveness is obtained at the interface with the resin constituting the matrix of the cured film obtained from the photosensitive resin composition, and bending is repeated. Flexibility that can withstand is developed, and it is excellent in folding resistance. Furthermore, surprisingly, in general, when a flame retardant is used in the photosensitive resin composition, when developing with an alkaline aqueous solution when forming a fine opening using a coating film obtained from the photosensitive resin composition, The flame retardant on the surface of the paint film elutes into the developer to form fine voids on the surface. After that, water and various chemicals used when processing the printed wiring board enter the paint film, and after the electrical insulation reliability test However, it is possible to suppress the elution of the flame retardant during development by using the flame retardant in the form of the crosslinked polymer particles. Will be very good.

  (A) binder polymer, (B) crosslinked polymer particles containing a flame retardant therein, (C) radical polymerizable compound, (D) photopolymerization initiator, (E) thermosetting resin, other components, and The method for mixing the photosensitive resin composition will be described.

<(A) Binder polymer>
The (A) binder polymer of the present invention is a polymer that is soluble in an organic solvent and has a weight average molecular weight of 1,000 or more and 1,000,000 or less in terms of polyethylene glycol.

  Examples of the organic solvent include, but are not limited to, sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, N, N-dimethylformamide, formamide solvents such as N, N-diethylformamide, N, N-dimethylacetamide, Examples thereof include acetamide solvents such as N, N-diethylacetamide, pyrrolidone solvents such as N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone, hexamethylphosphoramide, and γ-butyrolactone. Further, if necessary, these organic polar solvents can be used in combination with an aromatic hydrocarbon such as xylene or toluene.

  Furthermore, for example, methyl monoglyme (1,2-dimethoxyethane), methyldiglyme (bis (2-methoxyether) ether), methyltriglyme (1,2-bis (2-methoxyethoxy) ethane), methyltetraglyme (Bis [2- (2-methoxyethoxyethyl)] ether), ethyl monoglyme (1,2-diethoxyethane), ethyldiglyme (bis (2-ethoxyethyl) ether), butyldiglyme (bis (2 Symmetric glycol diethers such as -butoxyethyl) ether), methyl acetate, ethyl acetate, isopropyl acetate, n-propyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether Cetate (aka carbitol acetate, 2- (2-butoxyethoxy) ethyl acetate)), diethylene glycol monobutyl ether acetate, 3-methoxybutyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, dipropylene glycol methyl ether Acetates such as acetate, propylene glycol diacetate, 1,3-butylene glycol diacetate, dipropylene glycol methyl ether, tripropylene glycol methyl ether, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripylene glycol n Propyl ether, propylene glycol phenyl ether, dipropylene glycol dimethyl ether, 1,3-dioxolane, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, ethers such solvents such as ethyl ether also ethylene glycol.

  The solubility of the organic solvent, which is an index that becomes soluble in the organic solvent, can be measured as parts by weight of the base polymer dissolved in 100 parts by weight of the organic solvent, and is soluble in 100 parts by weight of the organic solvent. If the weight part of the base polymer is 5 parts by weight or more, it can be made soluble in an organic solvent. The organic solvent solubility measurement method is not particularly limited. For example, 5 parts by weight of the base polymer is added to 100 parts by weight of the organic solvent, stirred at 40 ° C. for 1 hour, cooled to room temperature, and left for 24 hours or longer. It can be measured by a method for confirming that the solution is uniform without generation of insoluble matter or precipitates.

  The weight average molecular weight of the component (A) of the present invention can be measured, for example, by the following method.

(Weight average molecular weight measurement)
Equipment used: Tosoh HLC-8220GPC equivalent column: Tosoh TSK gel Super AWM-H (6.0 mm ID x 15 cm) x 2 guard columns: Tosoh TSK guard column Super AW-H
Eluent: 30 mM LiBr + 20 mM H3PO4 in DMF
Flow rate: 0.6 mL / min
Column temperature: 40 ° C
Detection conditions: RI: Polarity (+), response (0.5 sec)
Sample concentration: about 5 mg / mL
Standard product: PEG (polyethylene glycol)

  Controlling the weight average molecular weight within the above range is preferable because the resulting cured film has excellent flexibility and chemical resistance. When the weight average molecular weight is 1,000 or less, flexibility and chemical resistance may decrease, and when the weight average molecular weight is 1,000,000 or more, the viscosity of the photosensitive resin composition may increase. is there.

  The component (A) of the present invention is not particularly limited. For example, polyurethane resin, poly (meth) acrylic resin, polyvinyl resin, polystyrene resin, polyethylene resin, polypropylene resin, polyimide resin, polyamide resin, for example. Resin, polyacetal resin, polycarbonate resin, polyester resin, polyphenylene ether resin, polyphenylene sulfide resin, polyether sulfone resin, polyether ether ketone resin, and the like. These may be used alone or in combination of two or more. Can be used in combination. Among these, a resin containing a urethane bond in the molecule (a1) is preferred because the cured film obtained from the photosensitive resin composition is improved in flexibility and breakage resistance and less warped. Moreover, when it is (a2) resin containing a carboxyl group, since the adhesiveness of the cured film obtained from the photosensitive resin composition and a base material improves, it is preferable. Moreover, (a3) When it is resin containing an imide group, since the heat resistance of a cured film obtained from the photosensitive resin composition, a flame retardance, and electrical insulation reliability improve, it is preferable. Furthermore, in the case of containing two or three of the above (a1) resin containing a urethane bond, (a2) a resin containing a carboxyl group, and (a3) a resin containing an imide group, their synergistic effect Is preferable because a cured film excellent in various properties can be obtained.

<(A1) Resin containing urethane bond>
The resin containing a urethane bond (a1) of the present invention contains a repeating unit containing at least one urethane bond in the molecule and has a weight average molecular weight of 1,000 or more in terms of polyethylene glycol, 1, 000,000 or less polymer.

  The resin (a1) containing a urethane bond of the present invention can be obtained by any reaction. For example, the following general formula (1)

(Wherein R ₁ represents a divalent organic group)
A diol compound represented by the following general formula (2)

(Wherein X ₁ represents a divalent organic group)
By reacting the diisocyanate compound represented by the following general formula (3)

(Wherein R ₁ and X ₁ each independently represent a divalent organic group, and n represents an integer of 1 or more)
It is obtained as a structure containing a repeating unit containing a urethane bond represented by

  The diol compound of the present invention is not particularly limited as long as it has the above structure. For example, ethylene glycol, diethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, neo Pentyl glycol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decane Polyoxya such as diol, alkylene diol such as 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and a random copolymer of tetramethylene glycol and neopentyl glycol Ring-opening addition reaction of lactones such as xylene diol, polyester diol obtained by reacting polyhydric alcohol and polybasic acid, polycarbonate diol having carbonate skeleton, γ-butyllactone, ε-caprolactone, δ-valerolactone Polycaprolactone diol, bisphenol A, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, hydrogenated bisphenol A, ethylene oxide adduct of hydrogenated bisphenol A, propylene oxide addition of hydrogenated bisphenol A The thing etc. are mentioned, These can be used individually or in combination of 2 or more types.

  In particular, when long-chain diols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyoxyalkylene diol, polyester diol, polycarbonate diol, polycaprolactone diol, etc. are used, the elastic modulus of the cured film is lowered and the flexibility is low. It is preferable at the point which is excellent in curvature.

  The diisocyanate compound of the present invention is not particularly limited as long as it has the above structure. For example, diphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2'- or 4,3 '-Or 5,2'- or 5,3'- or 6,2'- or 6,3'-dimethyldiphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4, 2'- or 4,3'- or 5,2'- or 5,3'- or 6,2'- or 6,3'-diethyldiphenylmethane-2,4'-diisocyanate, 3,2'- or 3 , 3'- or 4,2'- or 4,3'- or 5,2'- or 5,3'- or 6,2'- or 6,3'-dimethoxydiphenylmethane-2,4'-diisocyanate, Diphenylmethane-4,4'-diisocyanate, diph Nylmethane-3,3'-diisocyanate, diphenylmethane-3,4'-diisocyanate, diphenylether-4,4'-diisocyanate, benzophenone-4,4'-diisocyanate, diphenylsulfone-4,4'-diisocyanate, tolylene-2, 4-diisocyanate, tolylene-2,6-diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, naphthalene-2,6-diisocyanate, 4,4 '-[2,2-bis (4-phenoxyphenyl) propane Aromatic diisocyanates such as diisocyanates, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate Compounds, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, aliphatic diisocyanate compounds such lysine diisocyanate, etc. These can be used alone or in combinations of two or more.

  In particular, when an alicyclic diisocyanate and an aliphatic diisocyanate compound are used, it is preferable in that the cured film has excellent flexibility.

  In the method for synthesizing a resin containing a urethane bond according to the present invention, the ratio of the number of hydroxyl groups to the number of isocyanate groups in the blending amount of the diol compound and the diisocyanate compound is isocyanate group / hydroxyl group = 0.5 or more and 2.0 or less. It mix | blends so that it may be obtained by making it react in a solvent-free or organic solvent.

  Moreover, when using 2 or more types of diol compounds, reaction with a diisocyanate compound may be performed after mixing 2 or more types of diol compounds, or each diol compound and diisocyanate compound may be made to react separately. Good. Moreover, after making a diol compound and a diisocyanate compound react, you may make the obtained terminal isocyanate compound react with another diol compound, and also make this react with a diisocyanate compound. The same applies when two or more types of diisocyanate compounds are used. In this way, a resin containing a urethane bond in a desired molecule can be produced.

  The reaction temperature between the diol compound and the diisocyanate compound is preferably 40 to 160 ° C, and more preferably 60 to 150 ° C. If it is less than 40 ° C., the reaction time becomes too long. If it exceeds 160 ° C., a three-dimensional reaction occurs during the reaction and gelation tends to occur. The reaction time can be appropriately selected depending on the scale of the batch and the reaction conditions employed. If necessary, the reaction may be performed in the presence of a catalyst such as a tertiary amine, an alkali metal, an alkaline earth metal, a metal such as tin, zinc, titanium, cobalt, or a metalloid compound.

  The above reaction can be carried out without solvent, but it is desirable to carry out the reaction in an organic solvent system in order to control the reaction. Although the organic solvent used here is not specifically limited, For example, what was illustrated above can be used.

  The amount of the organic solvent used in the reaction is desirably such that the solute weight concentration in the reaction solution, that is, the solution concentration is 5 wt% or more and 90 wt% or less. The solute weight concentration in the reaction solution is more preferably 10 wt% or more and 80 wt% or less. When the solution concentration is 5% or less, the polymerization reaction hardly occurs and the reaction rate is lowered, and a desired structural substance may not be obtained.

  The resin (a1) containing a urethane bond of the present invention may further contain at least one organic group selected from the group consisting of a (meth) acryloyl group, a carboxyl group, and an imide group. The (meth) acryloyl group is an acryloyl group and / or a methacryloyl group. When the (meth) acryloyl group is contained, the photosensitivity of the photosensitive resin composition is improved, so that it is cured by ultraviolet irradiation in a short time. It becomes possible to make it. Moreover, when it contains a carboxyl group, the solubility of the photosensitive resin composition in a developing solution of a dilute alkaline aqueous solution is improved, so that a fine pattern can be formed by developing in a short time. In addition, when it contains an imide group, the heat resistance of the photosensitive resin composition and the electrical insulation reliability under high temperature and high humidity conditions are improved. A wiring board is obtained.

  Here, the resin containing the (meth) acryloyl group and containing the (a1) urethane bond can be obtained by any reaction. For example, in addition to the diol compound and the diisocyanate compound, the following general formula (4) )

(In the formula, R ₂ represents an m + 1 valent organic group, R ₃ represents hydrogen or an alkyl group, and m represents an integer of 1 to 3)
And / or a compound containing at least one (meth) acryloyl group and / or the following general formula (5)

(Wherein X ₂ represents an l + 1 valent organic group, X ₃ represents hydrogen or an alkyl group, and l represents an integer of 1 to 3)
It is obtained by reacting a compound containing an isocyanate group represented by the formula (1) and at least one (meth) acryloyl group.

  The compound containing a hydroxyl group and at least one (meth) acryloyl group of the present invention is not particularly limited as long as it has the above structure. For example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2-hydroxy-1-acryloxy-3-methacryloxypropane, o-phenylphenol glycidyl ether (meth) acrylate, polyethylene glycol mono (Meth) acrylate, pentaerythritol tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate di (meth) acrylate, 1,4-cyclohexanedimethanol mono (meth) acrylate, 4-hy Roxyphenyl (meth) acrylate, 2- (4-hydroxyphenyl) ethyl (meth) acrylate, N-methylol acrylamide, 3,5-dimethyl-4-hydroxybenzyl acrylamide, etc. may be mentioned, and these may be used alone or in combination of two or more. Can be used in combination.

  The compound containing an isocyanate group and at least one (meth) acryloyl group of the present invention is not particularly limited as long as it has the above structure. For example, 2- (meth) acryloyloxyethyl isocyanate, 1,1- (bisacryloyl) And oxymethyl) ethyl isocyanate, 2- (2-methacryloyloxyethyloxy) ethyl isocyanate, and the like. These can be used alone or in combination of two or more.

  In addition, the resin containing a carboxyl group-containing (a1) urethane bond can be obtained by any reaction. For example, in addition to the diol compound and the diisocyanate compound, the following general formula (6)

(Wherein R ₄ represents a trivalent organic group)
It can be obtained by reacting a compound containing two hydroxyl groups and one carboxyl group.

  The compound containing two hydroxyl groups and one carboxyl group of the present invention is not particularly limited as long as it has the above structure. For example, 2,2-bis (hydroxymethyl) propionic acid, 2,2-bis (2- Hydroxyethyl) propionic acid, 2,2-bis (3-hydroxymepropyl) propionic acid, 2,3-dihydroxy-2-methylpropionic acid, 2,2-bis (hydroxymethyl) butanoic acid, 2,2-bis (2-hydroxyethyl) butanoic acid, 2,2-bis (3-hydroxypropyl) butanoic acid, 2,3-dihydroxybutanoic acid, 2,4-dihydroxy-3,3-dimethylbutanoic acid, 2,3-dihydroxy Hexadecanoic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxy Benzoic acid, 3,4-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, etc. These can be used alone or in combinations of two or more.

  In particular, when a compound containing two aliphatic hydroxyl groups and one carboxyl group is used, it is preferable in terms of excellent photosensitivity of the photosensitive resin composition.

  The resin containing an imide group (a1) and containing a urethane bond can be obtained by any reaction. For example, in addition to a diol compound and a diisocyanate compound, the following general formula (7)

(Wherein Y represents a tetravalent organic group)
It is obtained by reacting a tetracarboxylic dianhydride represented by

  The tetracarboxylic dianhydride of the present invention is not particularly limited as long as it has the above structure. For example, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, pyromellitic dianhydride, 3 , 3 ′, 4,4′-oxydiphthalic dianhydride, 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride, 2,2-bis (4-hydroxyphenyl) Propane dibenzoate-3,3 ′, 4,4′-tetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride, 3,3 ′, 4,4′- Biphenyltetracarboxylic dianhydride, 2,3,3 ′, 4-biphenyltetracarboxylic dianhydride, 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1 , 2-Dicarboxylic Tetracarboxylic acid dianhydride anhydrides, etc. These can be used alone or in combinations of two or more.

<(A2) Resin containing carboxyl group>
The resin containing a carboxyl group (a2) of the present invention contains at least one carboxyl group in the molecule and has a weight average molecular weight of 1,000 or more and 1,000,000 or less in terms of polyethylene glycol. It is a polymer.

  The resin containing a carboxyl group (a2) of the present invention can be obtained by any reaction. For example, the same method as the method for obtaining a resin containing a carboxyl group (a1) containing a urethane bond Is obtained.

  In addition to the above method, it can be obtained by reacting (meth) acrylic acid with a (meth) acrylic ester derivative. Here, (meth) acrylic acid is acrylic acid and / or methacrylic acid, and (meth) acrylic acid ester derivative is an acrylic acid ester derivative and / or methacrylic acid ester derivative.

  The reaction of (meth) acrylic acid and (meth) acrylic ester of the present invention can be carried out by any method. For example, (meth) acrylic acid and / or (meth) acrylic ester derivatives are used as solvents. It can be obtained by reacting in the presence of a radical polymerization initiator.

  The (meth) acrylic acid ester derivative of the present invention is not particularly limited. For example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, (meth ) Tertiary butyl acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate , Stearyl (meth) acrylate, benzyl (meth) acrylate, and the like, and these can be used alone or in combination of two or more. Among these (meth) acrylic acid ester derivatives, it is particularly preferable to use methyl (meth) acrylate, ethyl (meth) acrylate, and butyl (meth) acrylate to improve the flexibility and resistance of the cured film of the photosensitive resin composition. It is preferable from the viewpoint of chemical properties.

  Examples of the radical polymerization initiator include azo compounds such as azobisisobutyronitrile, azobis (2-methylbutyronitrile), 2,2′-azobis-2,4-dimethylvaleronitrile, t- Organic peroxides such as butyl hydroperoxide, cumene hydroperoxide, benzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, persulfates such as potassium persulfate, sodium persulfate, ammonium persulfate, Acid value hydrogen etc. are mentioned, These can be used individually or in combination of 2 or more types.

  The amount of the radical polymerization initiator used is preferably 0.001 to 5 parts by weight and more preferably 0.01 to 1 part by weight with respect to 100 parts by weight of the monomer used. When the amount is less than 0.001 part by weight, the reaction hardly proceeds, and when the amount is more than 5 parts by weight, the molecular weight may be lowered.

  The amount of solvent used in the above reaction is preferably such that the solute weight concentration in the reaction solution, that is, the solution concentration is 5 wt% or more and 90 wt% or less, and is 20 wt% or more and 70 wt% or less. More preferably. When the solution concentration is less than 5%, the polymerization reaction is difficult to occur and the reaction rate is lowered, and a desired structural substance may not be obtained. When the solution concentration is more than 90% by weight, the reaction solution has a high viscosity. And the reaction may be non-uniform.

  The reaction temperature is preferably 20 to 120 ° C, and more preferably 50 to 100 ° C. When the temperature is lower than 20 ° C., the reaction time becomes too long, and when it exceeds 120 ° C., gelation due to rapid progress of reaction or three-dimensional crosslinking accompanying side reaction may be caused. The reaction time can be appropriately selected depending on the scale of the batch and the reaction conditions employed.

  In addition, a method of reacting a polyvalent carboxylic acid compound with a functional group-containing resin such as a hydroxyl group, an isocyanate group, an amino group, or an epoxy group can also be mentioned.

<(A3) Resin containing imide group>
The resin containing (a3) imide group of the present invention contains a repeating unit containing at least one imide group in the molecule, and the weight average molecular weight is 1,000 or more in terms of polyethylene glycol, 1, 000,000 or less polymer.

  The resin containing the (a3) imide group of the present invention can be obtained by any reaction. For example, the same method as the method for obtaining the resin containing the (a1) urethane bond containing the imide group Is obtained.

  In addition to the above method, the tetracarboxylic dianhydride represented by the above general formula (7) and the following general formula (8)

(Wherein Z represents a divalent organic group)
It can be obtained by reacting the diamino compound represented by

  The tetracarboxylic dianhydride of the present invention is not particularly limited as long as it has the above structure. For example, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, pyromellitic dianhydride, 3 , 3 ′, 4,4′-oxydiphthalic dianhydride, 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride, 2,2-bis (4-hydroxyphenyl) Propane dibenzoate-3,3 ′, 4,4′-tetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride, 3,3 ′, 4,4′- Biphenyltetracarboxylic dianhydride, 2,3,3 ′, 4-biphenyltetracarboxylic dianhydride, 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1 , 2-Dicarboxylic Tetracarboxylic acid dianhydride anhydrides, etc. These can be used alone or in combinations of two or more.

  The diamino compound of the present invention is not particularly limited as long as it has the above structure. For example, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, bis (3- Aminophenyl) sulfide, (3-aminophenyl) (4-aminophenyl) sulfide, bis (4-aminophenyl) sulfide, bis (3-aminophenyl) sulfoxide, (3-aminophenyl) (4-aminophenyl) sulfoxide Bis (4-aminophenyl) sulfoxide, bis (3-aminophenyl) sulfone, (3-aminophenyl) (4-aminophenyl) sulfone, bis (4-aminophenyl) sulfone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, 3,3 -Diaminobenzophenone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3,4'-diamino Diphenyl ether, bis [4- (3-aminophenoxy) phenyl] sulfoxide, bis [4- (aminophenoxy) phenyl] sulfoxide, (4-aminophenoxyphenyl) (3-aminophenoxyphenyl) phenyl] sulfoxide, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, (4-aminophenoxyphenyl) (3-aminophenoxyphenyl) phenyl] sulfone, bis [4- (3-aminophenyl) Noxy) phenyl] sulfide, bis [4- (aminophenoxy) phenyl] sulfide, (4-aminophenoxyphenyl) (3-aminophenoxyphenyl) phenyl] sulfide, 3,3′-diaminobenzanilide, 3,4′- Diaminobenzanilide, 4,4′-diaminobenzanilide, bis [4- (3-aminophenoxy) phenyl] methane, bis [4- (4-aminophenoxy) phenyl] methane, [4- (4-aminophenoxyphenyl) )] [4- (3-Aminophenoxyphenyl)] methane, 1,1-bis [4- (3-aminophenoxy) phenyl] ethane, 1,1-bis [4- (4-aminophenoxy) phenyl] ethane , 1,1- [4- (4-aminophenoxyphenyl)] [4- (3-aminophenoxyphenyl)] ethane 1,2-bis [4- (3-aminophenoxy) phenyl] ethane, 1,2-bis [4- (4-aminophenoxy) phenyl] ethane, 1,2- [4- (4-aminophenoxyphenyl) ] [4- (3-aminophenoxyphenyl)] ethane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2- [4- (4-aminophenoxyphenyl)] [4- (3-aminophenoxyphenyl)] propane, 2,2-bis [3- (3-aminophenoxy) phenyl] -1,1,1 , 3,3,3-hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 2,2- [4 -(4-aminophenoxy) Phenyl)] [4- (3-aminophenoxyphenyl)]-1,1,1,3,3,3-hexafluoropropane, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis ( 3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 4,4 '-Bis (3-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] ketone, bis [4- (3-aminophenoxy) phenyl ] Ether, bis [4- (4-aminophenoxy) phenyl] ether, polytetramethylene oxide-di-p-aminobenzoate, poly (tetramethyl Lene / 3-methyltetramethylene ether) glycol bis (4-aminobenzoate), trimethylene-bis (4-aminobenzoate), p-phenylene-bis (4-aminobenzoate), m-phenylene-bis (4-aminobenzoate) ), Bisphenol A-bis (4-aminobenzoate), 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, 3,3'-diamino-4,4'-di Carboxybiphenyl, 4,4′-diamino-3,3′-dicarboxybiphenyl, 4,4′-diamino-2,2′-dicarboxybiphenyl, [bis (4-amino-2-carboxy) phenyl] methane, [Bis (4-amino-3-carboxy) phenyl] methane, [Bis (3-amino-4-carboxy) phenyl] methane, [Bis (3-amino-5- Carboxy) phenyl] methane, 2,2-bis [3-amino-4-carboxyphenyl] propane, 2,2-bis [4-amino-3-carboxyphenyl] propane, 2,2-bis [3-amino- 4-carboxyphenyl] hexafluoropropane, 2,2-bis [4-amino-3-carboxyphenyl] hexafluoropropane, 3,3′-diamino-4,4′-dicarboxydiphenyl ether, 4,4′-diamino 3,3′-dicarboxydiphenyl ether, 4,4′-diamino-2,2′-dicarboxydiphenyl ether, 3,3′-diamino-4,4′-dicarboxydiphenyl sulfone, 4,4′-diamino- 3,3′-dicarboxydiphenyl sulfone, 4,4′-diamino-2,2′-dicarboxydiphenyl sulfone, 2, Diaminophenols such as 3-diaminophenol, 2,4-diaminophenol, 2,5-diaminophenol, 3,5-diaminophenol, 3,3′-diamino-4,4′-dihydroxybiphenyl, 4,4 ′ -Hydroxybiphenyl such as diamino-3,3'-dihydroxybiphenyl, 4,4'-diamino-2,2'-dihydroxybiphenyl, 4,4'-diamino-2,2 ', 5,5'-tetrahydroxybiphenyl Compounds, dihydroxy such as 3,3′-diamino-4,4′-dihydroxydiphenylmethane, 4,4′-diamino-3,3′-dihydroxydiphenylmethane, 4,4′-diamino-2,2′-dihydroxydiphenylmethane Diphenylmethanes, 2,2-bis [3-amino-4-hydroxyphenyl] propane, , 2-bis [4-amino-3-hydroxyphenyl] propane, bis [hydroxyphenyl] propanes, 2,2-bis [3-amino-4-hydroxyphenyl] hexafluoropropane, 2,2-bis [ Bis [hyhydroxyphenyl] hexafluoropropanes such as 3-amino-4-hydroxyphenyl] hexafluoropropane, 3,3′-diamino-4,4′-dihydroxydiphenyl ether, 4,4′-diamino-3,3 Hydroxydiphenyl ethers such as' -dihydroxydiphenyl ether, 4,4'-diamino-2,2'-dihydroxydiphenyl ether, 3,3'-diamino-4,4'-dihydroxydiphenylsulfone, 4,4'-diamino-3, 3′-dihydroxydiphenylsulfone, 4,4′-diamino-2,2 ′ Dihydroxydiphenyl sulfones such as dihydroxydiphenyl sulfone, 3,3′-diamino-4,4′-dihydroxydiphenyl sulfide, 4,4′-diamino-3,3′-dihydroxydiphenyl sulfide, 4,4′-diamino-2 Dihydroxydiphenyl sulfides such as 2,2'-dihydroxydiphenyl sulfide, 3,3'-diamino-4,4'-dihydroxydiphenyl sulfoxide, 4,4'-diamino-3,3'-dihydroxydiphenyl sulfoxide, 4,4 ' -Dihydroxydiphenyl sulfoxides such as diamino-2,2'-dihydroxydiphenyl sulfoxide, bis [(hydroxyphenyl) phenyl] alkanes such as 2,2-bis [4- (4-amino-3-hydroxyphenoxy) phenyl] propane Conversion Bis (hydroxyphenoxy) biphenyl compounds such as 4,4′-bis (4-amino-3-hydroxyphenoxy) biphenyl, 2,2-bis [4- (4-amino-3-hydroxyphenoxy) ) Bis [(hydroxyphenoxy) phenyl] sulfone compounds such as phenyl] sulfone, 4,4′-diamino-3,3′-dihydroxydiphenylmethane, 4,4′-diamino-2,2′-dihydroxydiphenylmethane, 2 Bis (hydroxyphenoxy) biphenyl compounds such as 2,4'-bis [3-amino-4-carboxyphenyl] propane, 4,4'-bis (4-amino-3-hydroxyphenoxy) biphenyl, etc. Can be used alone or in combination of two or more.

  The reaction between the tetracarboxylic anhydride and the diamino compound can be performed by any method, and for example, can be performed by the following method.

  Method 1: A polyamino acid solution is prepared by adding and reacting a diamino compound in a solution in which tetracarboxylic dianhydride is dispersed or dissolved in an organic solvent. At this time, the total addition amount of the diamino compound is added so as to be a ratio of 0.50 to 1.50 mol with respect to 1 mol of tetracarboxylic dianhydride. After the reaction between the tetracarboxylic dianhydride and the diamino compound is completed, the resulting polyamic acid solution is heated to 100 ° C. or higher and 300 ° C. or lower, more preferably 150 ° C. or higher and 250 ° C. or lower to perform imidization.

  Method 2: A polyamic acid solution is prepared in the same manner as in Method 1 above. Add an imidization catalyst (preferably tertiary amines such as pyridine, picoline, isoquinoline, trimethylamine, triethylamine, tributylamine, etc.) and a dehydrating agent (acetic anhydride, etc.) to this polyamic acid solution at 60 ° C or higher. The imidization is carried out by heating to 180 ° C. or lower.

  Method 3: A polyamic acid solution is prepared in the same manner as in Method 1 above. The polyamic acid solution is placed in a vacuum oven heated to 100 ° C. or more and 250 ° C. or less, and imidation is performed by drawing a vacuum while heating and drying.

<(B) Crosslinked polymer particles containing flame retardant therein>
The crosslinked polymer particles containing the flame retardant (B) of the present invention in the interior contains at least one flame retardant inside and has at least one crosslinked structure in the molecule, and an average particle size of 1 to 1 100 μm polymer particles.

  The flame retardant of the present invention is a compound having an effect of suppressing combustion of organic matter when mixed with organic matter, and is not particularly limited, but is a halogen flame retardant which is a compound containing chlorine or bromine atoms in the molecule, Phosphorus flame retardants that are compounds containing phosphorus atoms in the molecule, nitrogen flame retardants that are compounds containing nitrogen atoms in the molecule, inorganic flame retardants such as metal hydroxides and metal salts, etc. These can be used alone or in combination of two or more. In particular, in the case of phosphorus-based flame retardants, nitrogen-based flame retardants, metal hydroxides, and metal salts that do not contain chlorine or bromine atoms in the molecule, fine openings are formed using a coating obtained from a photosensitive resin composition This is preferable because elution of the flame retardant during development by the aqueous alkali solution during the development can be further suppressed, and the electrical insulation reliability is excellent and the appearance change after the test can be suppressed.

  The flame retardant of the present invention is not particularly limited. For example, in the case of at least one selected from the group consisting of (b1) phosphinates, (b2) metal hydroxides, and (b3) melamine compounds, a photosensitive resin The flame retardancy of the cured film obtained from the composition is improved, the electrical insulation reliability is excellent, and the warpage of the cured film is reduced, which is preferable.

  The (b1) phosphinate of the present invention is a compound represented by the following general formula (9).

(In the formula, R ₅ and R ₆ each independently represent a linear or branched alkyl group having 1 to 6 carbon atoms or an aryl group, and M represents Mg, Ca, Al, Sb, Sn, Ge, Ti. , Fe, Zr, Zn, Ce, Bi, Sr, Mn, Li, Na, and K represent metals selected from the group consisting of at least one of t.

  The phosphinic acid salt of the present invention is not particularly limited as long as it has the above structure. For example, aluminum trisdiethylphosphinate, aluminum trismethylethylphosphinate, aluminum trisdiphenylphosphinate, zinc bisdiethylphosphinate, bismethylethylphosphine Examples thereof include zinc oxide, zinc bisdiphenylphosphinate, titanyl bisdiethylphosphinate, titanyl bismethylethylphosphinate, titanyl bisdiphenylphosphinate, and the like. These can be used alone or in combination of two or more. Of these, aluminum trisdiethylphosphinate and aluminum trismethylethylphosphinate are particularly preferable because high flame retardancy can be obtained.

  The (b2) metal hydroxide of the present invention is not particularly limited as long as it is a metal compound that does not substantially dissolve in water and / or an organic solvent and contains crystal water. For example, aluminum hydroxide, hydroxide Examples thereof include magnesium, zirconium hydroxide, zinc hexahydroxide, zinc borate 3.5 hydrate, calcium aluminate hydrate, and the like. These can be used alone or in combination of two or more.

  The (b3) melamine compound of the present invention is not particularly limited as long as it does not substantially dissolve in water and / or an organic solvent and contains a melamine structure. For example, melamine polyphosphate, melamine cyanurate, nitrilotrismethylene Examples include melamine phosphonate adducts and melamine oligomer condensates, which can be used alone or in combination of two or more.

  The inclusion of the flame retardant of the present invention is a state in which at least a part of the flame retardant is included in the crosslinked polymer particles, and only a part of the flame retardant is included even if the entire flame retardant is included. May be. Here, in general, the state in which the flame retardant is included in the polymer particles includes the state in which the hollow microparticles are included in the inner pores by means of immersion treatment, reduced pressure / pressure immersion treatment, or the like, and the thermoplastic resin is polymerized. In this case, the inclusion substance is suspended and emulsified together with the monomer and polymerized to form fine particles, and the inclusion substance is included by melt mixing and pulverizing with the thermoplastic resin. In any case, the flame retardant contained by external stimuli such as heat and pressure is discharged outside the polymer particles. For this reason, when used in a photosensitive resin composition, physical properties such as process contamination and electrical insulation reliability due to bleeding out may be caused. The state in which the flame retardant of the present invention is included is non-thermoplastic because the polymer particle has a cross-linked structure. Therefore, the flame retardant is included in the polymer particle in a state different from the above, and is discharged to the outside by an external stimulus. Not. Therefore, when used in the photosensitive resin composition, there is no occurrence of bleed-out and excellent flame retardancy, flexibility, and electrical insulation reliability.

  The crosslinked polymer particles of the present invention are not particularly limited. For example, when the crosslinked polymer particles have a urethane bond in the molecule, it is preferable because flexibility is improved.

  Although the manufacturing method of (B) component of this invention is not specifically limited, For example, a flame retardant component, a polyol component, and a polyisocyanate component are thrown into water, each component is disperse | distributed and reacted, and a flame retardant in water There is a method of preparing a polymer particle by preparing a suspension in which crosslinked polymer particles containing therein are dispersed, then separating the liquid from the obtained suspension and drying and solidifying. Here, in order to make (B) component into a crosslinked structure, it is necessary to use at least one trifunctional or higher functional polyol and / or polyisocyanate.

  The amount of the flame retardant component added is preferably 10 to 500 parts by weight, more preferably 20 to 200 parts by weight based on 100 parts by weight of the total of the polyol component and the polyisocyanate component. The flame retardancy of the resulting cured film is improved. When the amount of the flame retardant component is less than 10 parts by weight, the flame retardancy may be inferior. When the amount of the flame retardant component is more than 500 parts by weight, the flame retardant component is difficult to be included in the crosslinked polymer particles, and the flexibility to withstand repeated bending is poor. There is a case.

  Although it does not specifically limit as a polyol component of this invention, For example, ethylene glycol, diethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 3 -Methyl-1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1, Polyoxyalkylene dimers such as alkylene diols such as 4-cyclohexanediol and 1,4-cyclohexanedimethanol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and random copolymers of tetramethylene glycol and neopentyl glycol A ring-opening addition reaction of lactones such as polyol, polyester diol obtained by reacting polyhydric alcohol and polybasic acid, polycarbonate diol having carbonate skeleton, γ-butyllactone, ε-caprolactone, δ-valerolactone, etc. Polycaprolactone diol, bisphenol A, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, hydrogenated bisphenol A, ethylene oxide adduct of hydrogenated bisphenol A, propylene oxide adduct of hydrogenated bisphenol A Diols such as glycerin, trimethylolpropane, trifunctional polyols such as 1,2,6-hexanetriol, tetrafunctional polyols such as pentaerythritol, hexafunctional polyols such as dipentaerythritol, etc. The recited, and these may be used alone or in combinations of two or more.

  As the polyisocyanate component of the present invention, when only a diol is used as the polyol component, it is necessary to use a tri- or higher functional polyisocyanate to obtain a crosslinked structure. The trifunctional or higher functional polyisocyanate is not particularly limited, and for example, isocyanurate type, biuret type, and adduct type polyisocyanates can be used alone or in combination of two or more. Examples of the isocyanurate type polyisocyanate include trade name Duranate TPA-100 and THA-100 manufactured by Asahi Kasei Chemicals Corporation. Examples of biuret type polyfunctional polyisocyanate include trade name Duranate 24A manufactured by Asahi Kasei Chemicals Corporation. −100, 22A-75PX, and examples of the adduct-type polyfunctional polyisocyanate include trade names Duranate P-301-75E and E-402-90T manufactured by Asahi Kasei Chemicals Corporation. In addition to the polyisocyanate, the diisocyanate compound mentioned above for the resin containing a urethane bond (a1) can be used in combination.

  The content of the component (B) of the present invention is preferably 50 to 200 parts by weight, more preferably 70 to 150 parts by weight with respect to 100 parts by weight of the component (A), and the effect on the surface of the obtained cured film. As a result, it is possible to form irregularities on the surface and has excellent tackiness. The filling effect of the component (B) is obtained, so the warpage of the cured film is reduced, and the flexibility to withstand repeated bending by improving the stress relaxation effect and fracture toughness. Will improve. When the amount of the component (B) is less than 50 parts by weight, it may be inferior in tack-free property or flexibility to withstand repeated bending, and when it is more than 200 parts by weight, it is applied when the photosensitive resin composition solution is applied. In some cases, the appearance deteriorates due to foaming or insufficient leveling of the coating film during coating.

  The average particle size of the component (B) of the present invention is preferably 1 to 50 μm, more preferably 1 to 20 μm, so that the coating property of the photosensitive resin composition, the smoothness of the cured film, and the electrical insulation reliability are achieved. Is preferable because it is excellent.

  The average particle diameter of the component (B) of the present invention can be measured, for example, as a volume-based median diameter (particle diameter with respect to an integrated distribution value of 50%) by the following method.

(Average particle size measurement)
Equipment used: LA-950V2 or equivalent manufactured by Horiba, Ltd. Measurement method: Laser diffraction / scattering method

  The fact that the flame retardant that is substantially insoluble in water and / or organic solvent of the present invention is included in the interior of the crosslinked polymer particles means that, for example, polymer fine particles obtained with a scanning electron microscope are observed by the following method. This can be confirmed.

(Scanning electron microscope)
Equipment used: Hitachi High-Technologies Corporation S-3000N equivalent Observation conditions: Acceleration voltage 15 kV
Magnification: 1000 times

<(C) Radical polymerizable compound>
The (C) radical polymerizable compound of the present invention is a compound containing in the molecule at least one radical polymerizable group that undergoes a polymerization reaction by a radical polymerization initiator. Among these, the radical polymerizable group is preferably an unsaturated double bond. Furthermore, the unsaturated double bond is preferably a (meth) acryloyl group or a vinyl group.

  Examples of the (C) radical polymerizable compound include bisphenol F EO modified (n = 2 to 50) diacrylate, bisphenol A EO modified (n = 2 to 50) diacrylate, and bisphenol S EO modified (n = 2 to 50). ) Diacrylate, bisphenol F EO modified (n = 2-50) dimethacrylate, bisphenol A EO modified (n = 2-50) dimethacrylate, bisphenol S EO modified (n = 2-50) dimethacrylate, 1,6- Hexanediol diacrylate, neopentyl glycol diacrylate, ethylene glycol diacrylate, pentaerythritol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol hexaacrylate, Lamethylolpropane tetraacrylate, tetraethylene glycol diacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, ethylene glycol dimethacrylate, pentaerythritol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, dipenta Erythritol hexamethacrylate, tetramethylolpropane tetramethacrylate, tetraethylene glycol dimethacrylate, methoxydiethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, β-methacryloyloxyethyl hydrogen phthalate, β-methacryloyloxyethyl hydrogen succinate, 3-chloro- -Hydroxypropyl methacrylate, stearyl methacrylate, phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, phenoxy polyethylene glycol acrylate, β-acryloyloxyethyl hydrogen succinate, lauryl acrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene Glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2-hydroxy-1,3-dimethacryloxypropane, 2,2- Bis [4- (methacryloxy Ethoxy) phenyl] propane, 2,2-bis [4- (methacryloxy / diethoxy) phenyl] propane, 2,2-bis [4- (methacryloxy / polyethoxy) phenyl] propane, polyethylene glycol diacrylate, tripropylene glycol diacrylate , Polypropylene glycol diacrylate, 2,2-bis [4- (acryloxydiethoxy) phenyl] propane, 2,2-bis [4- (acryloxypolyethoxy) phenyl] propane, 2-hydroxy-1-acryloxy-3- Methacryloxypropane, trimethylolpropane trimethacrylate, tetramethylolmethane triacrylate, tetramethylolmethane tetraacrylate, methoxydipropylene glycol methacrylate, methoxytrie Lenglycol acrylate, nonyl phenoxy polyethylene glycol acrylate, nonyl phenoxy polypropylene glycol acrylate, 1-acryloyloxypropyl-2-phthalate, isostearyl acrylate, polyoxyethylene alkyl ether acrylate, nonyl phenoxy ethylene glycol acrylate, polypropylene glycol dimethacrylate, 1, 4-butanediol dimethacrylate, 3-methyl-1,5-pentanediol dimethacrylate, 1,6-mexanediol dimethacrylate, 1,9-nonanediol methacrylate, 2,4-diethyl-1,5-pentanediol Dimethacrylate, 1,4-cyclohexanedimethanol dimethacrylate, dipropylene glycol diacrylate , Tricyclodecane dimethanol diacrylate, 2,2-hydrogenated bis [4- (acryloxy polyethoxy) phenyl] propane, 2,2-bis [4- (acryloxy polypropoxy) phenyl] propane, 2,4 -Diethyl-1,5-pentanediol diacrylate, ethoxylated tomethylolpropane triacrylate, propoxylated tomethylolpropane triacrylate, isocyanuric acid tri (ethane acrylate), pentathritol tetraacrylate, ethoxylated pentathritol tetraacrylate, Propoxylated pentathritol tetraacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol polyacrylate, triallyl isocyanurate, glycidyl methacrylate, glycine Diallyl ether, 1,3,5-triacryloylhexahydro-s-triazine, triallyl 1,3,5-benzenecarboxylate, triallylamine, triallyl citrate, triallyl phosphate, alloverbital, diallylamine, diallyldimethylsilane , Diallyl disulfide, diallyl ether, zalyl sialate, diallyl isophthalate, diallyl terephthalate, 1,3-dialyloxy-2-propanol, diallyl sulfide diallyl maleate, 4,4′-isopropylidene diphenol dimethacrylate, 4,4 ′ -An isopropylidene diphenol diacrylate etc. can be mentioned, These can be used individually or in combination of 2 or more types. In particular, when one containing 2 to 50 mol of EO (ethylene oxide) repeating units contained in one molecule of diacrylate or dimethacrylate is used, an aqueous development represented by an alkaline aqueous solution of the photosensitive resin composition is used. This is preferable because the solubility in the solution is improved and the development time is shortened.

  In addition to the above radical polymerizable compound, for example, an acid-modified epoxy acrylate obtained by reacting an epoxy compound with an unsaturated monocarboxylic acid and further adding a saturated or unsaturated polyvalent carboxylic acid anhydride, Urethane acrylate, which is a polymer of a diol compound having an ethylenically unsaturated group and / or a carboxyl group, and a diisocyanate compound, (meth) acrylic acid and (meth) acrylic acid having a carboxyl group and a copolymerizable double bond Radicals such as acrylated acrylates obtained by obtaining a copolymer with an ester, etc., and reacting a part of the carboxyl group in the side chain with an epoxy group of a compound having a (meth) acrylic group such as glycidyl methacrylate and an epoxy group A polymerizable group-containing resin can also be used. Examples of the epoxy acrylate include ZFR series, ZAR series, ZCR series, CCR series, and PCR series manufactured by Nippon Kayaku Co., Ltd., and urethane acrylates include, for example, UXE series manufactured by Nippon Kayaku Co., Ltd. Can be mentioned. Examples of the acrylated acrylate include Cyclomer ACA series manufactured by Daicel Cytec Co., Ltd.

<(D) Photopolymerization initiator>
The (D) photopolymerization initiator of the present invention is a compound that is activated by energy such as UV and initiates / promotes a reaction of a radical polymerizable group.

  The component (D) of the present invention is not particularly limited as long as it has the above structure. For example, Michler's ketone, 4,4′-bis (diethylamino) benzophenone, 4,4 ′, 4 ″ -tris (dimethylamino) ) Triphenylmethane, 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-diimidazole, acetophenone, benzoin, 2-methylbenzoin, benzoinmethyl ester -Tell, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2-t-butylanthraquinone, 1,2-benzo-9,10-anthraquinone, methylanthraquinone, thioxanthone, 2,4-diethyl Thioxanthone, 2-isopropylthioxanthone, 1-hydroxycyclohexyl phenyl keto , Diacetylbenzyl, benzyldimethylketal, benzyldiethylketal, 2 (2′-furylethylidene) -4,6-bis (trichloromethyl) -S-triazine, 2 [2 ′ (5 ″ -methyl) Furyl) ethylidene] -4,6-bis (trichloromethyl) -S-triazine, 2 (p-methoxyphenyl) -4,6-bis (trichloromethyl) -S-triazine, 2,6-di (p-azidobenzal) ) -4-methylcyclohexanone, 4,4'-diazidochalcone, di (tetraalkylammonium) -4,4'-diazidostilbene-2,2'-disulfonate, 2,2-dimethoxy-1,2 -Diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propane 1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-methyl-1- [4- (methylthio) phenyl]- 2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane-1, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, Bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 2-hydroxy-2-methyl-1-phenyl- Propane-1-ketone, bis (n5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pi 1-yl) -phenyl) titanium, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], iododium, (4-methylphenyl) [ 4- (2-methylpropyl) phenyl] -hexafluorophosphate (1-), ethyl-4-dimethylaminobenzoate, 2-ethylhexyl-4-dimethylaminobenzoate, ethanone, 1- [9-ethyl-6- ( 2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxyome) and the like, and these can be used alone or in combination of two or more.

<(E) Thermosetting resin>
The (E) thermosetting resin of the present invention is a compound containing at least one thermosetting organic group in the molecule. The use of the component (E) is preferable because heat resistance can be imparted to the cured film.

  The component (E) of the present invention is not particularly limited as long as it has the above structure. For example, epoxy resin, oxetane resin, phenol resin, isocyanate resin, block isocyanate resin, bismaleimide resin, bisallyl nadiimide resin, polyester resin (For example, unsaturated polyester resin), diallyl phthalate resin, silicon resin, vinyl ester resin, melamine resin, polybismaleimide triazine resin (BT resin), cyanate resin (for example, cyanate ester resin), urea resin, guanamine resin, sulfoamide Resins, aniline resins, polyurea resins, thiourethane resins, polyazomethine resins, episulfide resins, ene-thiol resins, benzoxazine resins, copolymer resins thereof, modified resins obtained by modifying these resins, or these Mixtures of resins with each other or other resins and the like.

  The component (E) of the present invention is capable of imparting heat resistance to the cured film, especially when using an epoxy resin among the above thermosetting resins, and also imparting adhesion to conductors such as metal foil and circuit boards. This is preferable because it can be performed.

  The epoxy resin is a compound containing at least one epoxy group in the molecule and is not particularly limited. For example, as the bisphenol A type epoxy resin, trade names jER828, jER1001, and jER1002 manufactured by Japan Epoxy Resin Co., Ltd. Adeka Resin EP-4100E, Adeka Resin EP-4300E manufactured by ADEKA Co., Ltd., Trade Names RE-310S and RE-410S manufactured by Nippon Kayaku Co., Ltd., and Epicron 840S, Epicron 850S and Epicron 1050 manufactured by DIC Corporation. , Epicron 7050, Etoto YD-115, Etototo YD-127, Etototo YD-128, manufactured by Toto Kasei Co., Ltd. 806, jER807, trade names Adeka Resin EP-4901E, Adeka Resin EP-4930, Adeka Resin EP-4950 manufactured by ADEKA Corporation, trade names RE-303S, RE-304S, RE-403S, RE-404S manufactured by Nippon Kayaku Co., Ltd. DIC Corporation's trade name Epicron 830, Epicron 835, Toto Kasei Co., Ltd. trade names Epototo YDF-170, Epototo YDF-175S, Epototo YDF-2001, and bisphenol S type epoxy resin are manufactured by DIC Corporation. Trade name Epicron EXA-1514 and hydrogenated bisphenol A type epoxy resin include trade names jERYX8000, jERYX8034, jERYL7170, and ADEKA trade names ADEKA manufactured by Japan Epoxy Resin Co., Ltd. Jin EP-4080E, DIC Corporation trade name Epicron EXA-7015, Toto Kasei Co., Ltd. trade name Epototo YD-3000, Epototo YD-4000D, biphenyl type epoxy resin, Japan Epoxy Resin Corporation product Names jERYX4000, jERYL6121H, jERYL6640, jERYL6677, trade names NC-3000 and NC-3000H manufactured by Nippon Kayaku Co., Ltd. Epoxy resins include DIC Corporation's trade names Epicron HP-4032, Epicron HP-4700, Epicron HP-4200, and Nippon Kayaku Co., Ltd. trade names NC-700. As a 0L, phenol novolac type epoxy resin, trade names jER152 and jER154 manufactured by Japan Epoxy Resin Co., Ltd., trade names EPPN-201-L manufactured by Nippon Kayaku Co., Ltd., and trade name Epicron N-740 manufactured by DIC Corporation, Epicron N-770, trade name Epototo YDPN-638 manufactured by Toto Kasei Co., Ltd., cresol novolac type epoxy resin, trade names EOCN-1020, EOCN-102S, EOCN-103S, EOCN-104S manufactured by Nippon Kayaku Co., Ltd. DIC Corporation's product names Epicron N-660, Epicron N-670, Epicron N-680, Epicron N-695, Trisphenolmethane type epoxy resin, trade names EPPN-501H manufactured by Nippon Kayaku Co., Ltd., EPPN-501HY, E As PN-502H, dicyclopentadiene type epoxy resin, trade name XD-1000 manufactured by Nippon Kayaku Co., Ltd., trade name Epicron HP-7200 manufactured by DIC Corporation, and as epoxy type resin, Japan Epoxy Resin Co., Ltd. Product names jER604, jER630 manufactured by Toto Kasei Co., Ltd., Epototo YH-434, Epototo YH-434L, Mitsubishi Gas Chemical Co., Ltd. trade names TETRAD-X, TERRAD-C, and flexible epoxy resins Trade names jER871, jER872, jERYL7175, jERYL7217, DIC Corporation's trade name Epicron EXA-4850 manufactured by Japan Epoxy Resin Co., Ltd., and urethane-modified epoxy resins are trade names Adeka Resin EPU-6 manufactured by ADEKA Corporation. Adeka Resin EPU-73, Adeka Resin EPU-78-11, and rubber-modified epoxy resins are trade names of Adeka Resin EPR-4023, Adeka Resin EPR-4026, Adeka Resin EPR-1309, and Chelate-modified Epoxy Resins ADEKA brand names Adeka Resin EP-49-10, Adeka Resin EP-49-20, and heterocyclic ring-containing epoxy resins include the brand name TEPIC made by Nissan Chemical Co., Ltd. These may be used alone or in combination of two or more. Can be used in combination.

  Although it does not specifically limit as a hardening | curing agent of the said thermosetting resin in the photosensitive resin composition of this invention, For example, phenol resins, such as a phenol novolak resin, a cresol novolak resin, a naphthalene type phenol resin, an amino resin, and a urea resin , Melamine, dicyandiamide and the like, and these can be used alone or in combination of two or more.

  Further, the curing accelerator is not particularly limited, but for example, phosphine compounds such as triphenylphosphine; amine compounds such as tertiary amine, trimethanolamine, triethanolamine and tetraethanolamine; 1,8- Borate compounds such as diaza-bicyclo [5,4,0] -7-undecenium tetraphenylborate, imidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-un Imidazoles such as decylimidazole, 1-benzyl-2-methylimidazole, 2-heptadecylimidazole, 2-isopropylimidazole, 2,4-dimethylimidazole, 2-phenyl-4-methylimidazole; 2-methylimidazoline, 2- Ethyl imidazoline, 2 Imidazolines such as isopropylimidazoline, 2-phenylimidazoline, 2-undecylimidazoline, 2,4-dimethylimidazoline, 2-phenyl-4-methylimidazoline; 2,4-diamino-6- [2′-methylimidazolyl- ( 1 ′)]-ethyl-s-triazine, 2,4-diamino-6- [2′-undecylimidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6- [2 ′ Examples include azine-based imidazoles such as -ethyl-4'-methylimidazolyl- (1 ')]-ethyl-s-triazine, and these can be used alone or in combination of two or more.

<Other ingredients>
Various additives such as a filler, an adhesion assistant, an antifoaming agent, a leveling agent, a colorant, and a polymerization inhibitor can be further added to the photosensitive resin composition of the present invention as necessary.

  Examples of the filler include fine inorganic fillers such as silica, mica, talc, barium sulfate, wollastonite, and calcium carbonate.

  Examples of the adhesion assistant (also referred to as adhesion-imparting agent) include silane coupling agents, triazole compounds, tetrazole compounds, and triazine compounds.

  Examples of the antifoaming agent include acrylic compounds, vinyl compounds, butadiene compounds, and the like.

  Examples of the leveling agent include acrylic compounds and vinyl compounds.

  Examples of the colorant include phthalocyanine compounds, azo compounds, and carbon black.

  Examples of the polymerization inhibitor include hydroquinone and hydroquinone monomethyl ether.

  The photosensitive resin composition of the present invention may contain a flame retardant in order to obtain a higher flame retardant effect. As the flame retardant, for example, a halogen-containing compound, a phosphorus compound, a metal hydroxide, a melamine compound, or the like can be added. The above various additives can be used alone or in combination of two or more.

<Method for mixing photosensitive resin composition>
The photosensitive resin composition of the present invention can be obtained by pulverizing and dispersing the components (A) to (E) and other components and mixing them. The pulverizing / dispersing method is not particularly limited, and for example, it is performed using a general kneading apparatus such as a bead mill, a ball mill, or a three roll. Among these, in particular, when pulverized / dispersed using a bead mill and confused, the particle size distribution of the component (B) present as fine particles is preferably uniform.

  Examples of pulverizing and dispersing with a bead mill include the above components (A) to (E) and other components, and optionally mixed with a solvent, mixed with beads, and stirred with a predetermined device to cut off. By applying, fine particles can be pulverized and dispersed to be mixed. As the kind of beads, zirconia, zircon, glass, titania, etc. are used, and beads suitable for the target particle size and application may be used. The bead particle size is not particularly limited as long as it is suitable for the target particle size. The stirring speed (peripheral speed) varies depending on the apparatus, but stirring may be performed within a range of 100 to 3000 rpm. If the speed increases, the temperature rises. Therefore, by appropriately flowing cooling water or refrigerant, the temperature rise is suppressed. Just do it. If a desired particle diameter is obtained, beads can be separated by filtration to obtain the photosensitive resin composition of the present invention. The particle diameter of the fine particles can be measured by a method using a gauge defined in JIS K 5600-2-5. Moreover, if a particle size distribution measuring apparatus is used, an average particle diameter, a particle diameter, and a particle size distribution can be measured.

(II) Method of using photosensitive resin composition Using the photosensitive resin composition of the present invention directly or after preparing a photosensitive resin composition solution, a cured film or a relief pattern is formed as follows. can do. First, the photosensitive resin composition or the photosensitive resin composition solution is applied to a substrate and dried to remove the organic solvent. The substrate can be applied by screen printing, curtain roll, river roll, spray coating, spin coating using a spinner, or the like. Drying of the coating film (preferably thickness: 5 to 100 μm, particularly 10 to 100 μm) is performed at 120 ° C. or less, preferably 40 to 100 ° C.

  Next, after drying, a negative photomask is placed on the dried coating film and irradiated with actinic rays such as ultraviolet rays, visible rays, and electron beams. Next, the relief pattern can be obtained by washing out the unexposed portion with a developer using various methods such as shower, paddle, immersion, or ultrasonic wave. Since the time until the pattern is exposed varies depending on the spraying pressure and flow rate of the developing device and the temperature of the etching solution, it is desirable to find the optimum device conditions as appropriate.

  As the developer, an alkaline aqueous solution is preferably used. This developer may contain a water-soluble organic solvent such as methanol, ethanol, n-propanol, isopropanol, or N-methyl-2-pyrrolidone. Examples of the alkaline compound that gives the alkaline aqueous solution include hydroxides, carbonates, hydrogen carbonates, amine compounds, and the like of alkali metals, alkaline earth metals, or ammonium ions, and specifically sodium hydroxide. , Potassium hydroxide, ammonium hydroxide, sodium carbonate, potassium carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetraisopropylammonium Hydroxide, N-methyldiethanolamine, N-ethyldiethanolamine, N, N-dimethylethanolamine, triethanolamine, triisopropanolamine, triiso Etc. can be mentioned Ropiruamin, aqueous solution with compounds of other long as it exhibits basicity can also be naturally used. The concentration of the alkaline compound that can be suitably used in the development step of the photosensitive resin composition of the present invention is preferably 0.01 to 20% by weight, particularly preferably 0.02 to 10% by weight. Further, the temperature of the developer depends on the composition of the photosensitive resin composition and the composition of the alkali developer, and is generally 0 ° C. or higher and 80 ° C. or lower, more generally 10 ° C. or higher and 60 ° C. or lower. Is preferably used.

  The relief pattern formed by the development process is rinsed to remove unnecessary residues. Examples of the rinsing liquid include water and acidic aqueous solutions.

  Next, heat treatment is performed on the obtained relief pattern. By carrying out heat treatment to react the reactive groups remaining in the molecular structure, a cured film having high heat resistance can be obtained. The thickness of the cured film is determined in consideration of the wiring thickness and the like, but is preferably about 2 to 50 μm. The final curing temperature at this time is desired to be able to be cured by heating at a low temperature for the purpose of preventing oxidation of the wiring and the like and not reducing the adhesion between the wiring and the substrate.

  The curing temperature at this time is preferably 100 ° C. or higher and 250 ° C. or lower, more preferably 120 ° C. or higher and 200 ° C. or lower, and particularly preferably 130 ° C. or higher and 180 ° C. or lower. If the final heating temperature is high, the wiring is oxidatively deteriorated, which is not desirable.

  The cured film formed from the photosensitive resin composition of the present invention is excellent in flexibility, flame retardancy, and electrical insulation reliability, and the warpage of the substrate after curing is small.

  In addition, for example, the insulating film obtained from the photosensitive resin composition preferably has a thickness of about 2 to 50 μm and a resolution of at least 10 μm after photocuring, particularly a resolution of about 10 to 1000 μm. For this reason, the insulating film obtained from the photosensitive resin composition is particularly suitable as an insulating material for a flexible substrate. Furthermore, it is used for various photo-curing wiring coating protective agents, photosensitive heat-resistant adhesives, electric wire / cable insulation coatings, and the like.

  In addition, this invention can provide the same insulating material even if it uses the resin film obtained by apply | coating the said photosensitive resin composition or the photosensitive resin composition solution to the base-material surface, and drying.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

(Synthesis Example 1)
<(A) Binder polymer 1>
Into a reaction vessel equipped with a stirrer, a thermometer, and a nitrogen introduction tube, 30.00 g of methyltriglyme (= 1,2-bis (2-methoxyethoxy) ethane) was charged as a polymerization solvent, and this was mixed with norbornene diisocyanate 10 .31 g (0.050 mol) was charged and dissolved by heating to 80 ° C. with stirring under a nitrogen stream. To this solution, polycarbonate diol 50.00 g (0.025 mol) (manufactured by Asahi Kasei Corporation, product name PCDL T5652, weight average molecular weight 2000) and 2,2-bis (hydroxymethyl) butanoic acid 3.70 g (0.025 Mol) in 30.00 g of methyltriglyme was added over 1 hour. This solution was reacted by heating and stirring at 80 ° C. for 5 hours. By performing the above reaction, a resin solution containing a urethane bond and a carboxyl group in the molecule was obtained. The obtained resin solution had a solid content concentration of 52%, a weight average molecular weight of 5,600, and a solid content acid value of 22 mgKOH / g. The solid content concentration, weight average molecular weight, and acid value were measured by the following methods.

<Concentration of solid content>
The measurement was performed according to JIS K 5601-1-2. The drying conditions were 170 ° C. × 1 hour.

<Weight average molecular weight>
Measurement was performed under the following conditions.
Equipment used: Tosoh HLC-8220GPC equivalent column: Tosoh TSK gel Super AWM-H (6.0 mm ID x 15 cm) x 2 guard columns: Tosoh TSK guard column Super AW-H
Eluent: 30 mM LiBr + 20 mM H3PO4 in DMF
Flow rate: 0.6 mL / min
Column temperature: 40 ° C
Detection conditions: RI: Polarity (+), response (0.5 sec)
Sample concentration: about 5 mg / mL
Standard product: PEG (polyethylene glycol)

<Acid value>
Measurement was performed according to JIS K 5601-2-1.

(Synthesis Example 2)
<(A) Binder polymer 2>
A reaction vessel equipped with a stirrer, thermometer, dropping funnel, and nitrogen introduction tube was charged with 100.00 g of methyltriglyme (= 1,2-bis (2-methoxyethoxy) ethane) as a polymerization solvent under a nitrogen stream. The temperature was raised to 80 ° C. with stirring. To this, 12.00 g (0.14 mol) of methacrylic acid, 28.00 g (0.16 mol) of benzyl methacrylate, 60.00 g (0.42 mol) of butyl methacrylate, previously mixed at room temperature, As a radical polymerization initiator, 0.50 g of azobisisobutyronitrile was added dropwise from a dropping funnel over 3 hours while keeping the temperature at 80 ° C. After completion of the dropwise addition, the reaction solution was heated to 90 ° C. while stirring, and the reaction solution was further stirred for 2 hours while maintaining the temperature of the reaction solution at 90 ° C. for reaction. By performing the above reaction, a resin solution containing a carboxyl group in the molecule was obtained. The resulting resin solution had a solid content concentration of 50%, a weight average molecular weight of 48,000, and a solid content acid value of 78 mgKOH / g. The solid content concentration, weight average molecular weight, and acid value were measured in the same manner as in Synthesis Example 1.

(Synthesis Example 3)
<(A) Binder polymer 3>
Into a reaction vessel equipped with a stirrer, a thermometer, and a nitrogen introduction tube, 35.00 g of methyltriglyme (= 1,2-bis (2-methoxyethoxy) ethane) was charged as a polymerization solvent, and this was mixed with norbornene diisocyanate 10 .31 g (0.050 mol) was charged and dissolved by heating to 80 ° C. with stirring under a nitrogen stream. A solution obtained by dissolving 50.00 g (0.025 mol) of polycarbonate diol (product name: PCDL T5652; weight average molecular weight 2000) in 35.00 g of methyltriglyme was added to this solution over 1 hour. This solution was heated and stirred at 80 ° C. for 2 hours. After completion of the reaction, 15.51 g (0.050 mol) of 3,3 ′, 4,4′-oxydiphthalic dianhydride (hereinafter referred to as ODPA) was added to the above reaction solution. After the addition, the mixture was heated to 190 ° C. and reacted for 1 hour. The solution was cooled to 80 ° C. and 3.60 g (0.200 mol) of pure water was added. After the addition, the temperature was raised to 110 ° C. and heated to reflux for 5 hours. By performing the above reaction, a resin solution containing a urethane bond, a carboxyl group and an imide group in the molecule was obtained. The obtained resin solution had a solid content concentration of 53%, a weight average molecular weight of 9,200, and a solid content acid value of 86 mgKOH / g. The solid content concentration, weight average molecular weight, and acid value were measured in the same manner as in Synthesis Example 1.

(Synthesis Example 4)
<(B) Crosslinked polymer particles 1 containing a flame retardant therein>
In a 2 L separable flask equipped with a stirrer, a thermometer, a dropping funnel, and a nitrogen introduction tube, 600.00 g of ion-exchanged water and 150.00 g of phosphinate as a flame retardant that does not substantially dissolve in water and / or an organic solvent (Clariant A product name Exolit OP-935) manufactured by Japan Co., Ltd. was charged, and the temperature was raised to 60 ° C. with stirring under a nitrogen stream. Polycarbonate diol 94.00 g (manufactured by Asahi Kasei Chemicals Corporation, product name PCDL T5652, weight average molecular weight 2000), hexamethylene diisocyanate-based isocyanurate type polyisocyanate 56.00 g (Asahi Kasei Chemicals) previously mixed at room temperature. Manufactured by Co., Ltd., product name Duranate TPA-100, NCO content: 23.1 wt%), 50.00 g of methyl ethyl ketone as a solvent, and 0.0015 g of dibutyltin dilaurate as a polymerization catalyst in a state kept at 60 ° C. It dropped from the dropping funnel over 2 hours. After completion of the dropwise addition, the reaction solution was stirred and reacted at 60 ° C. for 4 hours. Next, the reaction solution was cooled to room temperature, and after separating the solid, it was washed with ion-exchanged water three times and dried at 70 ° C. for 20 hours to obtain crosslinked polymer particles. The average particle diameter of the obtained crosslinked polymer particles was 6 μm. Moreover, it was confirmed by observing the obtained polymer fine particle with a scanning electron microscope that the phosphinate was encapsulated inside the crosslinked polymer particles. In addition, the scanning electron microscope and the average particle diameter were measured by the following method.

<Scanning electron microscope>
Equipment used: Hitachi High-Technologies Corporation S-3000N equivalent Observation conditions: Acceleration voltage 15 kV
Magnification: 1000 times

<Average particle size>
Equipment used: LA-950V2 manufactured by Horiba, Ltd.
Measurement method: Laser diffraction / scattering type

(Synthesis Example 5)
<(B) Crosslinked polymer particles 2 containing a flame retardant therein>
In place of the phosphinate used in Synthesis Example 4, synthesis was performed in the same manner as in Synthesis Example 5 using metal hydroxide (Navaltech, boehmite type aluminum hydroxide, product name: APYRAL AOH60). The average particle diameter of the obtained crosslinked polymer particles was 6 μm. Moreover, it was confirmed by observing the obtained polymer fine particle with a scanning electron microscope that the metal hydroxide was encapsulated inside the crosslinked polymer particle. The scanning electron microscope and the average particle diameter were measured by the same method as in Synthesis Example 4.

(Synthesis Example 6)
<(B) Crosslinked polymer particle 3 including flame retardant therein>
It replaced with the phosphinic acid salt used in the synthesis example 4, and synthesize | combined by the method similar to the synthesis example 5 using the melamine type compound (the BASF Japan Co., Ltd. product, melamine cyanurate, product name MELAPUR MC). The average particle diameter of the obtained crosslinked polymer particles was 6 μm. Moreover, it was confirmed by observing the obtained polymer fine particle with a scanning electron microscope that the melamine compound was encapsulated inside the crosslinked polymer particles. The scanning electron microscope and the average particle diameter were measured by the same method as in Synthesis Example 4.

(Examples 1-7 and Comparative Example 1)
<Preparation of photosensitive resin composition>
(A) Binder polymer obtained in Synthesis Examples 1-3, (B) Crosslinked polymer particles containing flame retardants obtained in Synthesis Examples 4-6, (C) Radical polymerizable compound, (D) Light A polymerization initiator, (E) a thermosetting resin, other components, and an organic solvent were added to prepare a photosensitive resin composition. Table 1 shows the blending amount of each constituent raw material in the resin solid content and the kind of the raw material. In addition, 1,2-bis (2-methoxyethoxy) ethane which is a solvent in the table is the total amount of the solvent including the solvent contained in the synthesized resin solution. The photosensitive resin composition was first mixed with a general stirring device with a stirring blade, and then passed twice with a three-roll mill to obtain a uniform solution. When the particle diameter was measured with a grindometer, all were 10 μm or less. The following evaluation was carried out by completely defoaming the foam in the solution with a defoaming device.

<1> Product name FANCYL FA-321M of radically polymerizable compound (EO-modified bisphenol A dimethacrylate) manufactured by Hitachi Chemical Co., Ltd.
<2> Nippon Kayaku Co., Ltd. product name, radically polymerizable compound (carboxyl group and photosensitive group-containing resin, solid content concentration 65%, solid content acid value 98 mgKOH / g), product name KAYARAD UXE-3000
<3> Product name IRGACURE369 of photopolymerization initiator manufactured by BASF Japan Ltd.
<4> Product name TEPIC-SP of Nissan Chemical Co., Ltd. epoxy resin (triglycidyl isocyanurate)
<5> Product name of butadiene type antifoaming agent manufactured by Kyoeisha Chemical Co., Ltd. Floren AC-2000
<6> Clariant Japan Co., Ltd. product name of phosphinate EXOLIT OP-935

<Preparation of coating film on polyimide film>
The above photosensitive resin composition was cast and applied to an area of 100 mm × 100 mm on a 25 μm polyimide film (manufactured by Kaneka Co., Ltd .: trade name 25 NPI) using a Baker type applicator so that the final dry thickness was 20 μm. After drying at 80 ° C. for 20 minutes, exposure was performed by irradiating with an ultraviolet ray having an accumulated exposure amount of 300 mJ / cm ² . Subsequently, spray development was performed for 90 seconds at a discharge pressure of 1.0 kgf / mm ² using a solution obtained by heating a 1.0 wt% sodium carbonate aqueous solution to 30 ° C. After development, the film was sufficiently washed with pure water, and then cured by heating in an oven at 150 ° C. for 30 minutes to prepare a cured film of the photosensitive resin composition on the polyimide film.

<Evaluation of cured film>
The obtained cured film was evaluated for the following items. The evaluation results are shown in Table 2.

(I) Photosensitivity The surface of the cured film obtained by the same method as the above item <Creation of a coating film on a polyimide film> was observed and determined. However, the exposure was performed by placing a negative photomask of line width / space width = 100 μm / 100 μm.
◯: A photosensitive pattern having a line width / space width = 100/100 μm can be drawn on the polyimide film surface without noticeable line thickness or development residue.
X: A line width / space width = 100/100 μm photosensitive pattern is not drawn on the polyimide film surface.

(Ii) Tackiness Using the Baker applicator, the photosensitive resin composition is formed into an area of 100 mm × 100 mm so that the final dry thickness is 20 μm on a 25 μm polyimide film (manufactured by Kaneka Corporation: trade name 25 NPI). The film was cast and applied, and dried at 80 ° C. for 20 minutes to produce a solvent-dried coating film. The method for evaluating the tack-free property of the coating film is to cut out the film with the coating film after drying the solvent into 50 mm x 30 mm strips, and the coating film surfaces overlap each other with the coating film on the inside. After applying a load of 300 g for 3 seconds, the load was removed and the state when the coating film surface was peeled off was observed.
○: There is no sticking between the coating films, and no sticking marks remain on the coating film.
(Triangle | delta): The coating films stick a little and the sticking trace remains in the coating film.
X: The coating films adhered completely and cannot be peeled off.

(Iii) Folding resistance of the photosensitive resin composition having a thickness of 20 μm on the surface of a polyimide film having a thickness of 25 μm (Apical 25NPI manufactured by Kaneka Corporation) in the same manner as described above in <Preparation of coating film on polyimide film>. A cured film laminated film was produced. The evaluation method of the bending resistance of the cured film laminated film is that the cured film laminated film is cut into 50 mm × 10 mm strips, bent at 180 ° at 25 mm with the cured film on the outside, and a load of 5 kg is applied to the bent portion for 3 seconds. After loading, the load was removed, and the apex of the bent portion was observed with a microscope. After microscopic observation, the bent portion was opened, and a 5 kg load was again applied for 3 seconds, and then the load was removed to completely open the cured film laminated film. The above operation was repeated, and the number of occurrences of cracks in the bent portion was defined as the number of bending times. The folding resistance is preferably 5 times or more.

(Iv) Electrical insulation reliability Line width / space width on a flexible copper-clad laminate (thickness of electrolytic copper foil 12 μm, polyimide film is Apical 25 NPI manufactured by Kaneka Co., Ltd., copper foil is bonded with polyimide adhesive) = 100 μm / 100 μm comb-shaped pattern was prepared, immersed in a 10% by volume sulfuric acid aqueous solution for 1 minute, washed with pure water, and subjected to a copper foil surface treatment. Thereafter, a cured film of a photosensitive resin composition having a thickness of 20 μm was prepared on the comb pattern by the same method as the above item <Preparation of coating film on polyimide film>, and a test piece was prepared. A DC voltage of 100 V was applied to both terminals of the test piece in an environmental test machine at 85 ° C. and 85% RH, and the insulation resistance value after 1000 hours was measured. The resistance value is preferably 1 × 10 ⁸ or more. Further, after 1000 hours, appearance changes such as migration and dendrite were visually observed.
○: No change in appearance such as migration and dendrite after 1000 hours.
Δ: Some change in appearance such as migration and dendrite after 1000 hours.
X: Appearance changes such as migration and dendrite noticeably after 1000 hours.

(V) Solder heat resistance of a photosensitive resin composition having a thickness of 20 μm on the surface of a polyimide film having a thickness of 75 μm (Apical 75NPI manufactured by Kaneka Corporation) in the same manner as in the above item <Preparation of coating film on polyimide film>. A cured film laminated film was produced.
The obtained cured film laminated film was floated so that the surface coated with the cured film of the photosensitive resin composition was in contact with the solder bath completely dissolved at 260 ° C., and then pulled up 10 seconds later. The operation was performed three times, and the state of the film surface was observed.
○: There is no abnormality in the coating film.
X: Abnormality such as swelling or peeling occurs in the coating film.

(Vi) Warpage Cured film of photosensitive resin composition having a thickness of 20 μm on the surface of a polyimide film having a thickness of 25 μm (Apical 25 NPI manufactured by Kaneka Corporation) in the same manner as the above item <Preparation of coating film on polyimide film>. A laminated film was produced.
The obtained cured film laminated film was cut into an area of 50 mm × 50 mm and placed on a smooth table so that the coating film was on the upper surface, and the warp height of the film edge was measured. A schematic diagram of the measurement site is shown in FIG. The smaller the amount of warpage on the polyimide film surface, the smaller the stress on the surface of the printed wiring board and the lower the amount of warping of the printed wiring board. The warp amount is preferably 5 mm or less. In addition, when rounding cylindrically, it was set as x.

(Vii) Flame retardancy In accordance with the flammability test standard UL94VTM of plastic materials, the flammability test was performed as follows. In the same manner as the above item <Preparation of coating film on polyimide film>, a 25 μm-thick polyimide film (manufactured by Kaneka Corporation: trade name Apical 25 NPI) is coated with a 20 μm-thick photosensitive resin composition cured film laminated film. Was made. Cut out the sample prepared above into dimensions: 50 mm width x 200 mm length x 75 μm thickness (including the thickness of the polyimide film), put a marked line in the 125 mm part, round it into a cylinder with a diameter of about 13 mm, and above the marked line PI tape was affixed so that there was no gap in the overlapping part (75 mm) and the upper part, and 20 cylinders for flammability test were prepared. Of these, 10 were treated at (1) 23 ° C./50% relative humidity / 48 hours, and the remaining 10 were treated at (2) 70 ° C. for 168 hours and then cooled in a desiccator containing anhydrous calcium chloride for 4 hours or more. The upper part of these samples is clamped and fixed vertically, and a burner flame is brought close to the lower part of the sample for 3 seconds to ignite. After 3 seconds, move the burner flame away and measure how many seconds after the sample flame or burning disappears.
○: For each condition ((1), (2)), the flame and combustion stopped within 10 seconds on average (average of 10) after the flame of the burner was moved away from the sample, and self-extinguishment within 10 seconds at maximum However, it has not burned to the rating line.
×: Even one sample does not extinguish within 10 seconds, or the flame rises above the rating line and burns.

DESCRIPTION OF SYMBOLS 1 Polyimide film which laminated the photosensitive resin composition 2 Warpage amount 3 Smooth stand

Claims (10)

A photosensitive resin composition comprising at least (A) a binder polymer (B) a crosslinked polymer particle containing a flame retardant therein (C) a radical polymerizable compound (D) a photopolymerization initiator.   The photosensitive resin composition according to claim 1, wherein the (B) crosslinked polymer particles have a urethane bond in the molecule. The photosensitive resin composition according to claim 1, wherein the flame retardant is at least one selected from the group consisting of the following (b1) to (b3).
(B1) Phosphinate (b2) Metal hydroxide (b3) Melamine compound   Furthermore, (E) thermosetting resin is contained, The photosensitive resin composition of any one of Claims 1-3 characterized by the above-mentioned. The said (A) binder polymer has at least 1 sort (s) chosen from the group which consists of following (a1)-(a3), The photosensitive resin composition of any one of Claims 1-4 characterized by the above-mentioned. .
(A1) Urethane bond (a2) Carboxyl group (a3) Imido group   The photosensitive resin composition according to any one of claims 1 to 5, wherein the average particle diameter of the (B) crosslinked polymer particles is 1 to 20 µm.   The blending amount of the (B) crosslinked polymer particles is 50 to 200 parts by weight with respect to 100 parts by weight of the (A) binder polymer. Resin composition.   The resin film obtained by apply | coating the photosensitive resin composition of any one of Claims 1-7 to the base-material surface, and drying.   A cured film obtained by curing the resin film according to claim 8.   A printed wiring board with a cured film, wherein the cured film according to claim 9 is coated on the printed wiring board.

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