JP5611770B2 - Novel white photosensitive resin composition and use thereof - Google Patents

Description

  Since this invention has photosensitivity, it can be finely processed, and the resulting cured film has excellent reflectance, excellent flexibility, excellent flame retardancy, low warpage of the substrate after curing, high temperature thermal history or The present invention relates to a white photosensitive resin composition, a resin film, an insulating film, and a printed wiring board with an insulating film with little change in reflectance and hue after light irradiation.

  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 insulating 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 an epoxy resin or the like is used. This photosensitive solder resist is excellent in electrical insulation reliability as an insulating material, but has mechanical properties such as flexibility. However, since the curing shrinkage is large, 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, a binder polymer, a polymerizable compound containing an ethylenically unsaturated group, a polymerization initiator, and a phosphine that are excellent in flame retardancy and plating resistance and can form a cured film having various properties required for a solder resist. A photosensitive resin composition containing an acid salt has been proposed (see, for example, Patent Document 1).

  On the other hand, light emitting diodes (LEDs) have recently been applied to backlights and lighting devices in liquid crystal displays such as portable devices, personal computers, and televisions because they can consume less power, have a longer life, and can be smaller, thinner, and lighter. The printed wiring board on which the LED chip is mounted is required to have high reflectivity in the photosensitive solder resist that is an insulating protective film of the printed wiring board in order to efficiently use the light from the LED chip. It has been.

  As such a high-reflectance solder resist, it has characteristics such as coating properties, photo-curing properties, developability, solder heat resistance, adhesion, and electrical insulation properties, and suppresses coloration due to deterioration and deterioration of reflectance over time. A solder resist composition having a high reflectance has been proposed (see, for example, Patent Document 2).

  In addition, when exposed to high temperatures during solder reflow or when irradiated with light, it is difficult to change color from white, and the reflectance is not easily lowered, and siloxane polymer, white filler, acid anhydride group or carboxyl group A resist material containing a resin having an unsaturated double bond has been proposed (see, for example, Patent Document 3).

JP 2009-294319 A JP 2007-322546 A International Publication No. 2009/090867

  In the above-mentioned patent documents, various methods for solving the problems of the photosensitive solder resist are proposed. However, although the photosensitive resin composition described in Patent Document 1 contains a phosphinate that is a phosphorus-containing compound, it is excellent in flame retardancy, plating resistance, solder heat resistance, HAST resistance, etc. There is a problem that the rate is low and the color change is large when exposed to high temperature or when irradiated with light. The solder resist composition described in Patent Document 2 contains a carboxyl group-containing resin that does not have an aromatic ring and a rutile-type titanium oxide, and thus has high reflectivity, and suppresses coloration due to deterioration and deterioration of reflectivity over time. However, since it has poor flame retardancy and flexibility and has a large shrinkage when cured, when used as an insulating protective film for flexible printed wiring boards, there is a problem of poor flame resistance and bending resistance and large warpage. . Since the resist material described in Patent Document 3 contains a siloxane polymer, a white filler, an acid anhydride group or a carboxyl group, and a resin having an unsaturated double bond, it is exposed to high temperatures during solder reflow. When it is used as an insulating protective film for flexible printed wiring boards, it is difficult to change its color from white when exposed to light or when irradiated with light. There are problems of contact failure due to bleed-out, as well as problems of poor flame resistance and breakage resistance and large warpage.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have at least (A) at least a hydroxyl group-containing (meth) acrylate ester and an alkyl (meth) acrylate that do not substantially contain a radical polymerizable group in the molecule. A hydroxyl group-containing resin obtained by copolymerizing an ester, (B) a carboxyl group-containing resin containing a radical polymerizable group in the molecule, (C) a radical polymerizable compound, and (D) an aromatic ring substantially in the molecule. A reactive group-containing compound having reactivity with a hydroxyl group not contained in (1), (E) a photopolymerization initiator, (F) rutile-type titanium oxide, (G) a phosphinate, and substantially containing a silicon-containing organic compound The white photosensitive resin composition is characterized in that it has photosensitivity and can be finely processed and developed with a dilute alkaline aqueous solution. Excellent sensitivity, flexibility, solder heat resistance, organic solvent resistance, flame resistance, low warpage of the substrate after curing, high temperature heat history, or low reflectance / hue change after light irradiation The knowledge which obtains a conductive resin composition, a resin film, an insulating film, and a printed wiring board with an insulating film was obtained, and based on these knowledge, this invention was achieved. The present invention can solve the above-described problems with a white photosensitive resin composition having the following novel configuration.

  That is, the invention of the present application is at least (A) a hydroxyl group obtained by copolymerizing at least a hydroxyl group-containing (meth) acrylic acid ester and a (meth) acrylic acid alkyl ester which do not substantially contain a radical polymerizable group in the molecule. -Containing resin, (B) a carboxyl group-containing resin containing a radically polymerizable group in the molecule, (C) a radically polymerizable compound, and (D) a reaction having reactivity with a hydroxyl group that does not substantially contain an aromatic ring in the molecule. White photosensitive resin characterized by containing a functional group-containing compound, (E) a photopolymerization initiator, (F) rutile-type titanium oxide, and (G) a phosphinic acid salt, and substantially free of a silicon-containing organic compound It is a composition.

  Moreover, in the white photosensitive resin composition concerning this invention, it is preferable that said (D) is an isocyanate resin which does not contain an aromatic ring substantially in a molecule | numerator.

  Moreover, in the white photosensitive resin composition concerning this invention, the said (D) is mix | blended so that it may become 1-100 weight part with respect to 100 weight part which totaled the said (A) and the said (B). It is preferable.

  Moreover, in the white photosensitive resin composition concerning this invention, the said (F) is 10 weight part with respect to 100 weight part which totaled the said (A), the said (B), the said (C), and the said (D). It is preferable that it is blended so as to be -150 parts by weight.

  Moreover, in the white photosensitive resin composition concerning this invention, said (G) is 1 with respect to 100 weight part which totaled said (A), said (B), said (C), and said (D). It is preferable that it is blended so as to be ˜50 parts by weight.

  Moreover, it is preferable that the white photosensitive resin composition concerning this invention contains at least 1 sort (s) chosen from the group which consists of (H) antioxidant, a ultraviolet absorber, and a light stabilizer further.

  Moreover, in the white photosensitive resin composition concerning this invention, said (H) is 0 with respect to 100 weight part which totaled said (A), said (B), said (C), and said (D). It is preferable that the amount is 0.001 to 1 part by weight.

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

  The insulating film according to the present invention is obtained by curing the resin film.

  The printed wiring board with an insulating film according to the present invention is obtained by coating the insulating film on the printed wiring board.

  As described above, the white photosensitive resin composition of the present invention has at least (A) at least a hydroxyl group-containing (meth) acrylate ester and an alkyl (meth) acrylate that do not substantially contain a radical polymerizable group in the molecule. A hydroxyl group-containing resin obtained by copolymerizing an ester, (B) a carboxyl group-containing resin containing a radical polymerizable group in the molecule, (C) a radical polymerizable compound, and (D) an aromatic ring substantially in the molecule. A reactive group-containing compound having reactivity with a hydroxyl group not contained in (1), (E) a photopolymerization initiator, (F) rutile-type titanium oxide, (G) a phosphinate, and substantially containing a silicon-containing organic compound Since the white photosensitive resin composition of the present invention has photosensitivity, it can be finely processed, and the resulting cured film has excellent reflectivity and high flexibility. , Excellent flame retardancy, warpage of the substrate after curing is small, less reflectance and hue changes after high-temperature heat history or light irradiation. Therefore, the photosensitive resin composition of the present invention can be used for protective films of various circuit boards and exhibits excellent effects.

Schematic diagram measuring the amount of warping of the film

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

(I) White photosensitive resin composition The white photosensitive resin composition of the present invention comprises at least (A) at least a hydroxyl group-containing (meth) acrylic acid ester and a (meta) group substantially free of radical polymerizable groups in the molecule. ) Hydroxyl group-containing resin obtained by copolymerizing alkyl acrylate, (B) carboxyl group-containing resin containing radical polymerizable group in molecule, (C) radical polymerizable compound, (D) aromatic in molecule A reactive group-containing compound having reactivity with a hydroxyl group substantially free of a ring, (E) a photopolymerization initiator, (F) rutile titanium oxide, (G) a phosphinate, and a silicon-containing organic compound It is a resin composition which does not contain substantially.

  In addition, substantially not containing the silicon-containing organic compound of the present invention means that the component (A), the component (B), the component (C), the component (D) and the component (E) contain a silicon-containing organic compound. In addition, other components blended in the white photosensitive resin composition of the present invention do not contain a silicon-containing organic compound. However, a silane coupling agent used for the purpose of surface treatment of an inorganic filler or the like may be contained.

  Here, although the present inventors discovered that the white photosensitive resin composition of this invention was excellent in various characteristics, it estimates that this may be based on the following reasons. That is, the hydroxyl group-containing resin obtained by copolymerizing at least a hydroxyl group-containing (meth) acrylic acid ester and a (meth) acrylic acid alkyl ester that does not substantially contain a radical polymerizable group in the molecule as the component (A). Since it has a hydroxyl group in the molecule, it becomes soluble in a developer typified by a dilute alkaline aqueous solution, and fine processing becomes possible by exposure and development. In addition, since the alkyl group derived from the (meth) acrylic acid alkyl ester functions as a flexible component and does not substantially contain a radical polymerizable group that is a photosensitive group in the molecule, crosslinking due to the reaction of the photosensitive group The density is not improved and the flexible component is not constrained. Therefore, the cured film obtained from the white photosensitive resin composition using this is excellent in flexibility.

  In addition, the carboxyl group-containing resin containing a radical polymerizable group in the molecule as the component (B) has a carboxyl group in the molecule and thus has excellent alkali developability, and has a radical polymerizable group and thus has excellent photosensitivity. Further, by combining with the component (A) which does not substantially contain a radical polymerizable group, the radical polymerizable group concentration can be adjusted to an optimum range. It is possible to achieve a high level of flexibility.

  Moreover, since the radically polymerizable compound which is (C) component is excellent in radical polymerizability, it becomes possible to adjust the distance between the crosslinking points of reaction of a radically polymerizable group to the optimal range.

  In addition, the reactive group-containing compound having reactivity with the hydroxyl group substantially not containing an aromatic ring in the molecule as the component (D) reacts with the hydroxyl group contained in the component (A) to form a crosslinked structure. The resulting cured film has excellent heat resistance and chemical resistance, and since it does not substantially contain an aromatic ring in the molecule, it is stable against energy such as heat and ultraviolet rays and is difficult to color.

  In addition, the rutile type titanium oxide which is the component (F) suppresses the photocatalytic activity of titanium oxide, so that when it is blended with the white photosensitive resin composition of the present invention, the resulting cured film is heat or ultraviolet light. It is stable against energy such as being difficult to be colored, and there is little change in reflectance and hue after high-temperature heat history or light irradiation. Furthermore, since it can be handled as a filler (filler), the glass transition temperature of the resulting cured film and the surface hardness of the cured coating film do not decrease, and sufficient reflectance can be obtained with a relatively low addition amount. Less change in reflectivity.

  Moreover, since the phosphinate which is (G) component can be handled as a filler (filler) when it mix | blends with the white photosensitive resin composition of this invention, it is a flame retardant component from the cured film obtained. No bleed-out occurs, the glass transition temperature and the surface hardness of the cured coating film do not decrease, and a cured film excellent in heat resistance and hydrolysis resistance is obtained. Furthermore, surprisingly, the white photosensitive resin composition of the present invention contains a filler component such as the component (F) or the component (G), but the cured film is not embrittled and is flexible. A cured film having excellent properties and breakage resistance can be obtained. This is because the radically polymerizable group is not substantially contained in the molecule of the component (A), so that the distance between the cross-linking points of the cured film is increased to form a flexible cross-linked structure, and the hydroxyl group contained in the component (A) It is speculated that the adhesive strength at the interface is improved because of its high affinity with phosphinates.

  In addition, since the white photosensitive resin composition of the present invention does not substantially contain a silicon-containing organic compound, no bleed-out of impurities derived from the silicon-containing organic compound from the resulting cured film occurs, so that the cured film is printed. When used as an insulating film for a wiring board, it does not cause contact failure and malfunction of mounted components due to bleed-out, and there is no concern about process contamination due to residual silicon-containing organic compounds in the processing process.

  Hereinafter, (A) a hydroxyl group-containing resin obtained by copolymerizing at least a hydroxyl group-containing (meth) acrylic acid ester and a (meth) acrylic acid alkyl ester substantially not containing radically polymerizable groups in the molecule, (B) molecule A carboxyl group-containing resin containing a radically polymerizable group therein, (C) a radically polymerizable compound, (D) a reactive group-containing compound having reactivity with a hydroxyl group substantially free of an aromatic ring in the molecule, (E ) Photopolymerization initiator, (F) rutile titanium oxide, (G) phosphinate, (H) antioxidant, UV absorber and light stabilizer, other components, and white photosensitive resin composition A method will be described.

<(A) Hydroxyl group-containing resin obtained by copolymerizing at least hydroxyl group-containing (meth) acrylic acid ester and (meth) acrylic acid alkyl ester substantially free of radical polymerizable groups in the molecule>
The hydroxyl group-containing resin obtained by copolymerizing at least a hydroxyl group-containing (meth) acrylic acid ester and a (meth) acrylic acid alkyl ester that does not substantially contain a radical polymerizable group in the molecule of the present invention (A) At least hydroxyl group-containing (meta) having substantially no radical polymerizable group in the molecule and having at least one hydroxyl group, and having a weight average molecular weight of 3,000 to 300,000 in terms of polyethylene glycol It is a polymer obtained by copolymerizing acrylic acid ester and (meth) acrylic acid alkyl ester.

  Here, the term “substantially free of radically polymerizable group in the molecule” means that the molecule may not contain any radically polymerizable group such as (meth) acryloyl group or vinyl group, and the effect of the present invention. If it is a range which does not impair expression of, you may contain. The range not impairing the expression of the effect of the present invention is that the value determined by measuring the radically polymerizable group in the molecule of the component (A) as an iodine value is less than 5. The iodine value is a value obtained by converting the amount of halogen bonded to 100 g of a sample into the number of g of iodine, and can be measured by a method defined in JIS K0070.

  The hydroxyl group content of the component (A) of the present invention can be measured as a hydroxyl value. Here, the hydroxyl value is the number of mg of potassium hydroxide required for acetylating the hydroxyl group contained in 1 g of the sample, and can be measured, for example, by the method defined in JIS K0070.

  The hydroxyl value of the component (A) used in the present invention is preferably 10 to 200 mgKOH / g, and more preferably 50 to 150 mgKOH / g. When the hydroxyl value is less than 10 mgKOH / g, the alkali developability of the white photosensitive resin composition may decrease, and when it exceeds 200 mgKOH / g, the hygroscopic property of the cured film increases and the electrical insulation reliability decreases. There is.

The molecular weight of the component (A) of the present invention can be measured, for example, by the following method.
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 alkali developability of the white photosensitive resin composition, the flexibility of the resulting cured film, and the chemical resistance are excellent. When the weight average molecular weight is 3,000 or less, flexibility and chemical resistance may be lowered. When the weight average molecular weight is 300,000 or more, alkali developability is lowered, and the white photosensitive resin composition Viscosity may increase.

  The hydroxyl group-containing (meth) acrylic acid ester used in the present invention is a compound having a hydroxyl group in the ester chain of (meth) acrylic acid ester. Here, (meth) acrylic acid means acrylic acid or methacrylic acid.

  Examples of the hydroxyl group-containing (meth) acrylic acid ester used in the present invention include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 1,4-cyclohexanedi Methanol mono (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, monohydroxyethyl (meth) acrylate phthalate, o-phenylphenol glycidyl ether (meth) acrylate, 3-chloro-2-hydroxypropyl ( (Meth) acrylates, and these may be used alone or in combination of two or more.

  The (meth) acrylic acid alkyl ester used in the present invention is a compound having an alkyl group having 1 to 20 carbon atoms in the ester chain of the (meth) acrylic acid ester. For example, methyl (meth) acrylate, (meth ) Ethyl acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, tertiary butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate , Nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, and the like, which can be used alone or in combination of two or more. Among these (meth) acrylic acid alkyl esters, in particular, the use of methyl (meth) acrylate, ethyl (meth) acrylate, and butyl (meth) acrylate is the flexibility of the cured film of the white photosensitive resin composition. It is preferable from the viewpoint of chemical resistance.

  The reaction for copolymerizing the hydroxyl group-containing (meth) acrylic acid ester and the (meth) acrylic acid alkyl ester can be advanced by generating a radical with a radical polymerization initiator, for example. Examples of the radical polymerization initiator include azo compounds such as azobisisobutyronitrile, azobis (2-methylbutyronitrile), 2,2′-azobis-2,4-dimethylvaleronitrile, t-butylhydro Organic peroxides such as peroxide, cumene hydroperoxide, benzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, persulfates such as potassium persulfate, sodium persulfate, ammonium persulfate, peracid number 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 above reaction can be carried out in the absence of a solvent. However, in order to control the reaction, it is desirable to carry out the reaction in an organic solvent system. For example, examples of the organic solvent include sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, N , N-dimethylformamide, formamide solvents such as N, N-diethylformamide, N, N-dimethylacetamide, acetamide solvents such as N, N-diethylacetamide, N-methyl-2-pyrrolidone, N-vinyl-2 Examples include pyrrolidone solvents such as -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, can also be used solvents ethers such as ethyl ether also ethylene glycol. Of these, symmetrical glycol diethers are preferably used because side reactions are unlikely to occur.

  The amount of solvent used in the reaction is preferably such that the solute weight concentration in the reaction solution, that is, the solution concentration is 5% to 90% by weight, and is 20% to 70% by weight. It is more preferable. 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.

<(B) Carboxyl group-containing resin containing a radical polymerizable group in the molecule>
The carboxyl group-containing resin containing a radically polymerizable group in the molecule (B) of the present invention is a weight average containing a radically polymerizable group and a carboxyl group in which a polymerization reaction proceeds by at least one radical polymerization initiator. A polymer having a molecular weight of 1,000 or more and 100,000 or less in terms of polyethylene glycol. Among them, a resin containing at least one unsaturated double bond and a carboxyl group in the molecule is preferable. Furthermore, the unsaturated double bond is preferably a (meth) acryloyl group or a vinyl group.

  The radically polymerizable group content of the component (B) of the present invention can be measured as an iodine value in the same manner as the component (A). The iodine value of the component (B) is preferably 10 to 200, more preferably 50 to 150. When the iodine value is less than 10, the photosensitivity of the white photosensitive resin composition may be lowered. When the iodine value is more than 200, the crosslinking density becomes high due to too many photosensitive groups, and the resulting cured film is flexible. May worsen and warpage may increase.

  The carboxyl group content of the component (B) of the present invention can be measured as an acid value. Here, the acid value is the number of mg of potassium hydroxide required to neutralize free fatty acid, resin acid and the like contained in 1 g of a sample. For example, the method defined in JIS K5601-2-1 Can be measured.

  The acid value of the component (B) of the present invention is preferably 50 to 200 mgKOH / g, and more preferably 50 to 150 mgKOH / g. When the acid value is less than 50 mgKOH / g, the alkali developability of the white photosensitive resin composition may be reduced. When the acid value is more than 200 mgKOH / g, the hygroscopic property of the cured film is increased and the electrical insulation reliability is reduced. There is.

  Moreover, it is preferable to control the weight average molecular weight within the above range because the white photosensitive resin composition has excellent alkali developability, flexibility of the resulting cured film, and chemical resistance. When the weight average molecular weight is 1,000 or less, flexibility and chemical resistance may be lowered. When the weight average molecular weight is 100,000 or more, alkali developability is lowered, and the white photosensitive resin composition Viscosity may increase.

  As the component (B) of the present invention, for example, an acid-modified vinyl ester resin, an acid addition product of an epoxy-modified (meth) acrylic resin, an acid addition product of a urethane-modified (meth) acrylic resin, a polyester-modified (meth) acrylic resin A carboxyl group-containing resin containing a radical polymerizable group in any molecule such as an acid adduct or an acid adduct of a (meth) acrylic acid-modified epoxy resin may be used. As the component (B), for example, trade names KAYARAD PCR-1169H, KAYARAD CCR-1159H, KAYARAD TCR-1310H, KAYARAD ZAR-1395H, KAYARAD ZFR-1401H, KAYARAD UXE-3000, manufactured by Nippon Kayaku Co., Ltd. Examples include trade names CYCLOMER ACA 200M, CYCLOMER ACA Z250, and CYCLOMER ACA Z300 manufactured by Cytec Corporation.

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

  Examples of the component (C) 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 dimethacrylate Acrylate, neopentyl glycol diacrylate, ethylene glycol diacrylate, pentaerythritol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol hexaacrylate, tetramethylol Lopan tetraacrylate, tetraethylene glycol diacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, ethylene glycol dimethacrylate, pentaerythritol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, dipentaerythritol hexa Methacrylate, tetramethylolpropane tetramethacrylate, tetraethylene glycol dimethacrylate, methoxydiethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, β-methacryloyloxyethyl hydrogen phthalate, β-methacryloyloxyethyl hydrogen succinate, 3-chloro-2-hydroxy Lopyl 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- (Methacryloxyethoxy) fe Nyl] 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-methacryloxy Propane, trimethylolpropane trimethacrylate, tetramethylolmethane triacrylate, tetramethylolmethane tetraacrylate, methoxydipropylene glycol methacrylate, methoxytriethyleneglycol Acrylate, nonylphenoxypolyethylene glycol acrylate, nonylphenoxypolypropylene glycol acrylate, 1-acryloyloxypropyl-2-phthalate, isostearyl acrylate, polyoxyethylene alkyl ether acrylate, nonylphenoxyethylene 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, tris Chlodecane 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 totimethylolpropane triacrylate, propoxylated tomethylolpropane triacrylate, isocyanuric acid tri (ethane acrylate), pentathritol tetraacrylate, ethoxylated pentathritol tetraacrylate, propoxylated pentas Ritolol tetraacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol polyacrylate, triallyl isocyanurate, glycidyl methacrylate, glycidyl allylate Tellurium, 1,3,5-triacryloylhexahydro-s-triazine, triallyl 1,3,5-benzenecarboxylate, triallylamine, triallyl citrate, triallyl phosphate, arborbital, 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′-isopropyl Redene diphenol diacrylate and the like are preferable, but not limited thereto. In particular, the repeating unit of EO (ethylene oxide) contained in one molecule of diacrylate or dimethacrylate is preferably in the range of 2-50, more preferably 2-40. By using the EO repeating unit in the range of 2 to 50, the solubility of the white photosensitive resin composition in an aqueous developer typified by an alkaline aqueous solution is improved, and the development time is shortened. Furthermore, stress hardly remains in the cured film obtained by curing the white photosensitive resin composition. For example, among printed wiring boards, when laminated on a flexible printed wiring board based on polyimide resin, the curling of the printed wiring board is difficult. It has the feature that can be suppressed.

  In particular, it is particularly preferable to increase the photosensitivity by using the EO-modified diacrylate or dimethacrylate together with a compound having three or more acryloyl groups or methacryloyl groups. For example, ethoxylated isocyanuric acid EO-modified triacrylate, ethoxy Isocyanuric acid EO-modified trimethacrylate, ethoxylated trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate Ethoxylated pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, ditrime Rollpropane tetraacrylate, ditrimethylolpropane tetraacrylate, propoxylated pentaerythritol tetraacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, 2,2,2-trisacryloyloxymethyl ethyl succinic acid, 2,2,2 -Trisacryloyloxymethylethylphthalic acid, propoxylated ditrimethylolpropane tetraacrylate, propoxylated dipentaerythritol hexaacrylate, ethoxylated isocyanuric acid triacrylate, ε-caprolactone modified tris- (2-acryloxyethyl) isocyanurate, caprolactone Modified ditrimethylolpropane tetraacrylate, the following general formula (1)

(Where a + b = 6 and n = 12.)
A compound represented by the following general formula (2)

(Where a + b = 4 and n = 4)
A compound represented by the following formula (3)

A compound represented by the following general formula (4)

(Where m = 1, a = 2, b = 4, or m = 1, a = 3, b = 3, or m = 1, a = 6, b = 0, or m = 2, a = 6 B = 0.)
A compound represented by the following general formula (5)

(Where a + b + c = 3.6)
A compound represented by the following formula (6)

A compound represented by the following general formula (7)

(Where m · a = 3, a + b = 3, where “m · a” is the product of m and a)
A compound represented by the formula is preferably used.

  In addition, hydroxyl groups in the molecular structure skeleton such as 2-hydroxy-3-phenoxypropyl acrylate, monohydroxyethyl acrylate phthalate, ω-carboxy-polycaprolactone monoacrylate, acrylic acid dimer, pentaerythritol tri and tetraacrylate, A compound having a carbonyl group is also preferably used.

  In addition, although it is also possible to use 1 type as (C) component, using 2 or more types together is preferable when improving the heat resistance of a cured film.

  The blending ratio of the component (A), the component (B), and the component (C) in the white photosensitive resin composition of the present invention is that of the component (B) and the component (C) with respect to 100 parts by weight of the component (A). It is preferable that the total is 50 to 150 parts by weight.

  When the total of the component (B) and the component (C) is less than the above range, the alkali resistance of the cured film after photocuring the white photosensitive resin composition is lowered, and the contrast when exposed and developed. May be difficult to attach. Moreover, when the sum total of (B) component and (C) component is more than the said range, the stickiness of the coating film obtained by apply | coating a white photosensitive resin composition on a base material and drying a solvent is obtained. Since it becomes large, productivity falls, and when a crosslinking density becomes high too much, a cured film may become weak and it will become easy to crack. For this reason, it is possible to set the resolution at the time of exposure / development to an optimal range by setting the value within the above range.

<(D) Reactive Group-Containing Compound Reactive with Hydroxyl Group that Does Not Contain Aromatic Ring in the Molecule>
The reactive group-containing compound having reactivity with a hydroxyl group that does not substantially contain an aromatic ring in the molecule of the present invention (D) does not substantially contain an aromatic ring in the molecule and reacts with at least one hydroxyl group. It is a compound containing a reactive group.

  Here, the phrase “substantially does not contain an aromatic ring in the molecule” may not contain an aromatic ring in the molecule at all, or may contain it as long as the effects of the present invention are not impaired. Good. The range that does not impair the expression of the effect of the present invention is that the value measured by using an unsaturated double bond derived from an aromatic ring in the molecule of component (D) as an iodine value is less than 5. The iodine value is a value obtained by converting the amount of halogen bonded to 100 g of a sample into the number of g of iodine, and can be measured by a method defined in JIS K0070.

  Examples of the component (D) include aliphatic diisocyanate compounds, aliphatic polyisocyanate compounds, alicyclic diisocyanate compounds, alicyclic polyisocyanate compounds, and block bodies of these isocyanate compounds. For example, Asahi Kasei Chemicals Corporation Company made Duranate 24A-100, TPA-100, THA-100, P-301-75E, 21S-75E, 18H-70B, MFA-75X, E-402-90T, E-405-80T, TSE-100, 17B-60PX, TPA-B80E, MF-B60X, E402-B80T etc. are mentioned, However, it is not limited to these. In particular, a resin having at least one isocyanate group in the molecule that does not substantially contain an aromatic ring in the molecule is preferable in terms of improving the flexibility of the cured film of the white photosensitive resin composition.

  The blending ratio of the component (D) in the white photosensitive resin composition of the present invention is 1 to 100 parts by weight with respect to 100 parts by weight of the sum of the components (A) and (B). Preferably it is.

  When the component (D) is less than the above range, the heat resistance and electrical insulation reliability of the cured film of the white photosensitive resin composition may be lowered, and the component (D) is more than the above range. In some cases, the cured film may become brittle and easily cracked due to the crosslinking density becoming too high.

<(E) Photopolymerization initiator>
The (E) 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. Examples of the component (E) include Mihiras 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, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether -Tell, benzoin isobutyl ether, 2-t-butylanthraquinone, 1,2-benzo-9,10-anthraquinone, methylanthraquinone, thioxanthone, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 1-hydroxycyclohexylphenyl Ketone, diacetylbenzyl, benzyldimethylketer , Benzyldiethylketal, 2 (2′-furylethylidene) -4,6-bis (trichloromethyl) -S-triazine, 2 [2 ′ (5 ″ -methylfuryl) 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-propan-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-cyclopentadiene-1 -Yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium, 1,2-octane ON, 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) etc. are mentioned. The photopolymerization initiator is preferably selected as appropriate, and one or more types are preferably mixed and used.

  The component (E) in the white photosensitive resin composition of the present invention may be blended so as to be 0.1 to 50 parts by weight with respect to a total of 100 parts by weight of the component (A) and the component (B). preferable.

  Since the photosensitivity of a white photosensitive resin composition improves by making it the said mixture ratio, it is preferable. When the component (E) is less than the above range, the reaction of the radical polymerizable group at the time of light irradiation hardly occurs, and the curing may be insufficient. Moreover, when there are more (E) components than the said range, adjustment of light irradiation amount becomes difficult and it may be in an overexposed state. Therefore, in order to advance the photocuring reaction efficiently, it is preferable to adjust within the above range.

<(F) Rutile type titanium oxide>
The (F) rutile type titanium oxide of the present invention is an oxide of titanium having a tetragonal crystal structure and is an inorganic compound represented by the composition formula TiO ₂ .

  The method for producing the component (F) in the present invention is not particularly limited. For example, the so-called sulfuric acid method in which a titanium sulfate solution is hydrolyzed and the resulting hydrous titanium oxide is baked, or titanium halide is vapor-phase oxidized. It can be produced by the so-called chlorine method. In addition, in the titanium oxide of the sulfuric acid method, for example, a metal such as zinc, potassium, aluminum, lithium, niobium, magnesium, or a compound such as phosphorus can be added as a baking treatment agent in the production process. In the case of the method titanium oxide, a compound such as aluminum or potassium may be added as a treating agent during the oxidation process of titanium tetrachloride in the production process. In particular, in the case of titanium oxide produced by the chlorine method, the reflectance and concealment of the cured film of the white photosensitive resin composition are good, and discoloration at high temperatures or light irradiation, and a decrease in reflectance are unlikely to occur. Is preferable.

  Specific examples of the component (F) include trade names TPEAKE R-550, R-580, R-630, R-670, R-680, R-780, R-780- manufactured by Ishihara Sangyo Co., Ltd. 2, R-820, R-830, R-850, R-855, R-930, R-980, CR-50, CR-50-2, CR-57, CR-58, CR-58-2, CR-60, CR-60-2, CR-63, CR-67, CR-Super70, CR-80, CR-85, CR-90, CR-90-2, CR-93, CR-95, CR- 953, CR-97, PF-736, PF-737, PF-742, PF-690, PF-691, PF-711, PF-739, PF-740, PC-3, S-305, CR-EL, PT-301, PT-401M, PT-501A PT-501R, trade names R-3L, R-5N, R-7E, R-11P, R-21, R-25, R-32, R-42, R-44, R manufactured by Sakai Chemical Industry Co., Ltd. -45M, R-62N, R-310, R-650, SR-1, D-918, GTR-100, FTR-700, TCR-52, trade names JR, JRNC, JR-301, manufactured by Teika Corporation JR-403, JR-405, JR-600A, JR-600E, JR-603, JR-605, JR-701, JR-800, JR-805, JR-806, JR-1000, MT-01, MT- 05, MT-10EX, MT-100S, MT-100TV, MT-100Z, MT-100AQ, MT-100WP, MT-100SA, MT-100HD, MT-150EX, MT-150W, M -300HD, MT-500B, MT-500SA, MT-500HD, MT-600B, MT-600SA, MT-700B, MT-700HD, trade names KR-310, KR-380, KR-380N manufactured by Titanium Industry Co., Ltd. And trade names TR-600, TR-700, TR-750, TR-840, TR-900 and the like manufactured by Fuji Titanium Industry Co., Ltd. are not limited thereto.

  (F) component in the white photosensitive resin composition of this invention is 10-150 weight part with respect to 100 weight part which totaled (A) component, (B) component, (C) component, and (D) component. It is preferable that it is mix | blended so that it may become.

  The blending ratio is preferable because the reflectance, shielding property, and whiteness of the white photosensitive resin composition are improved. When the component (F) is less than the above range, it may be difficult to obtain sufficient reflectance. Moreover, when there are more (F) components than the said range, the cured film of a white photosensitive resin composition becomes easy to become weak, and bending resistance may fall.

<(G) Phosphinate>
The (G) phosphinic acid salt of the present invention is a compound represented by the following general formula (8).

(In the formula, R ₁ and R ₂ 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 n.

  Examples of the component (G) include aluminum trisdiethylphosphinate, aluminum trismethylethylphosphinate, aluminum trisdiphenylphosphinate, zinc bisdiethylphosphinate, zinc bismethylethylphosphinate, zinc bisdiphenylphosphinate, bisdiethyl Examples thereof include titanyl phosphinate, titanyl bismethylethylphosphinate, titanyl bisdiphenylphosphinate, and 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 average particle size of the component (G) in the present invention is preferably 0.5 μm to 20 μm, more preferably 1.0 μm to 15 μm, and particularly preferably 1.0 μm to 10 μm.

  It is preferable to adjust the average particle size of the component (G) within the above range because the viscosity and viscosity of the white photosensitive resin composition can be adjusted within a range suitable for coating such as screen printing.

  When the average particle diameter of (G) component is smaller than the said range, the viscosity and viscosity of a white photosensitive resin composition increase, and it may be inferior to the bubble entrainment at the time of coating, and leveling property. Moreover, when the average particle diameter of (G) component is larger than the said range, the uniformity of (G) component which exists in the cured film of white photosensitive resin composition falls, and the external appearance of a cured film deteriorates. May be invited.

  In the present invention, the thermal decomposition starting temperature of the component (G) is preferably 280 ° C. or higher, more preferably 300 ° C. or higher, and particularly preferably 320 ° C. or higher. When the thermal decomposition starting temperature is lower than 280 ° C., when a cured film of the white photosensitive resin composition containing the component (G) is used as an insulating protective film of the printed wiring board, in the solder reflow process, about 260 ° C. When the cured film is exposed to a high temperature, the component (G) contained in the cured film releases a decomposition gas, which may cause swelling or peeling of the cured film surface.

  As the component (G) in the present invention, those subjected to surface treatment with a surface treatment agent can also be used. As the surface treatment agent, a silane coupling agent such as vinyl silane, epoxy silane, amino silane, or mercapto silane can be used.

  (G) component in the white photosensitive resin composition of this invention is 1-50 weight part with respect to 100 weight part which totaled (A) component, (B) component, (C) component, and (D) component. It is preferable that it is mix | blended so that it may become.

  By using the above blending ratio, sufficient flame retardancy is imparted to the white photosensitive resin composition, and the viscosity and viscosity of the photosensitive resin composition can be adjusted within a range suitable for coating such as screen printing. Therefore, it is preferable. When the component (G) is less than the above range, it may be difficult to obtain sufficient flame retardancy. Moreover, when there are more (G) components than the said range, the viscosity of a white photosensitive resin composition will become very high, and coating may become difficult. Moreover, the cured film of the white photosensitive resin composition tends to be brittle, and the folding resistance may be lowered.

<(H) Antioxidant, UV absorber and light stabilizer>
The present invention preferably further contains (H) at least one selected from the group consisting of an antioxidant, an ultraviolet absorber and a light stabilizer. By adding the component (H), it is possible to suppress the high temperature heat history of the cured film of the white photosensitive resin composition or the reflectance / hue change after light irradiation.

  The antioxidant of the present invention is a compound having a function of suppressing oxidation by heat, light, and other energy of a substance, a phenolic antioxidant having a radical scavenging action, an amine antioxidant, peroxide decomposition. Examples thereof include sulfur-based antioxidants and phosphorus-based antioxidants.

  The ultraviolet absorber of the present invention is a compound having a function of absorbing ultraviolet light and converting it to other energy, and a benzotriazole ultraviolet absorber, a triazine ultraviolet absorber, and a benzophenone ultraviolet absorber having a chain initiation inhibiting action. Etc.

  The light stabilizer of the present invention itself is a compound that hardly absorbs ultraviolet rays but has a function of stabilizing by efficiently capturing generated radicals, and examples thereof include hindered amine light stabilizers (HALS).

  (H) component in the white photosensitive resin composition of this invention is 0.001-1 with respect to 100 weight part which totaled (A) component, (B) component, (C) component, and (D) component. It is preferable that it is blended so as to be parts by weight.

  The blending ratio is preferable because the high-temperature heat history of the cured film of the white photosensitive resin composition or the reflectance / hue change after light irradiation can be suppressed. When the component (H) is less than the above range, it may be difficult to obtain a sufficient discoloration preventing effect. Moreover, when there are more (H) components than the said range, the photosensitivity of a white photosensitive resin composition may fall and hardening may become inadequate.

<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 white photosensitive resin composition of the present invention as necessary. As the filler, fine inorganic fillers such as silica, mica, talc, barium sulfate, wollastonite, and calcium carbonate, and fine organic polymer fillers may be contained. Moreover, as said antifoamer, an acrylic compound, a vinyl type compound, a butadiene type compound etc. can be contained, for example. Moreover, as said leveling agent, an acryl-type compound, a vinyl type compound, etc. can be contained, for example. Moreover, as said coloring agent, a phthalocyanine type compound, an azo type compound, carbon black etc. can be contained, for example. Moreover, as said adhesion assistant (it is also called adhesiveness imparting agent), a silane coupling agent, a triazole type compound, a tetrazole type compound, a triazine type compound, etc. can be contained. Moreover, as said polymerization inhibitor, hydroquinone, hydroquinone monomethyl ether, etc. can be contained, for example. Moreover, although the white photosensitive resin composition of this invention is excellent in a flame retardance since it contains a phosphinate, another flame retardant may be added in order to acquire a higher flame-retardant effect. Examples of flame retardants that can be added include phosphate ester compounds, halogen-containing compounds, metal hydroxides, and organic phosphorus compounds. The above various additives can be used alone or in combination of two or more. Moreover, it is desirable to select each content suitably.

<Mixing method of white photosensitive resin composition>
The white photosensitive resin composition of the present invention can be obtained by pulverizing and dispersing the components (A) to (H) 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 (F) component and the (G) component existing as fine particles is preferable.

  Examples of pulverizing and dispersing with a bead mill include the above components (A) to (H) 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 white 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 White Photosensitive Resin Composition Using the white photosensitive resin composition of the present invention directly or after preparing a white photosensitive resin composition solution, a cured film or a relief is as follows. A pattern can be formed. First, the white photosensitive resin composition or the white 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 white photosensitive resin composition of the present invention is 0.01 to 20% by weight, particularly preferably 0.02 to 10% by weight. . The temperature of the developer depends on the composition of the white 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. It is preferably used in the following.

  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 white photosensitive resin composition of the present invention is excellent in reflectance, flame retardancy, heat resistance, chemical resistance, electrical insulation reliability, flexibility, low warpage, and high temperature heat. Little change in reflectance and hue after history or light irradiation.

  Further, for example, the insulating film obtained from the white 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. . Therefore, the insulating film obtained from the white photosensitive resin composition is particularly suitable as an insulating material for flexible substrates for LED applications. 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 white photosensitive resin composition or the white photosensitive resin composition solution to the base-material surface, and drying. it can.

  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) Hydroxyl group-containing resin obtained by copolymerizing at least hydroxyl group-containing (meth) acrylic acid ester and (meth) acrylic acid alkyl ester substantially free of radical polymerizable groups in the molecule>
A reaction vessel equipped with a stirrer, thermometer, dropping funnel, and nitrogen introduction tube was charged with 100.0 g of methyltriglyme (= 1,2-bis (2-methoxyethoxy) ethane) as a solvent for polymerization, under a nitrogen stream. The temperature was raised to 80 ° C. with stirring. To this, 17.0 g (0.13 mol) of 2-hydroxyethyl methacrylate, 23.0 g (0.13 mol) of benzyl methacrylate, and 60.0 g (0.42) of butyl methacrylate were previously mixed at room temperature. Mol), 0.5 g of azobisisobutyronitrile as a radical polymerization initiator was added dropwise from a dropping funnel over a period of 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 further stirred for 2 hours while maintaining the temperature of the reaction solution at 90 ° C. to obtain a hydroxyl group-containing resin solution of the present invention. The resulting hydroxyl group-containing resin solution had a solid content concentration of 50%, a weight average molecular weight of 49,000, and a hydroxyl value of the solid content of 73 mgKOH / g. The solid content concentration, weight average molecular weight, and hydroxyl 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 150 ° C. × 1 hour.

<Weight average molecular weight>
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)

<Hydroxyl value>
The measurement was performed according to JIS K0070.

(Synthesis Example 2)
<(B) Carboxyl group-containing resin containing a radical polymerizable group in the molecule>
A reaction vessel equipped with a stirrer, thermometer, dropping funnel, and nitrogen introduction tube was charged with 100.0 g of methyltriglyme (= 1,2-bis (2-methoxyethoxy) ethane) as a solvent for polymerization, under a nitrogen stream. The temperature was raised to 80 ° C. with stirring. To this, 17.0 g (0.20 mol) of methacrylic acid, 23.0 g (0.13 mol) of benzyl methacrylate, 60.0 g (0.42 mol) of butyl methacrylate, previously mixed at room temperature, As a radical polymerization initiator, 0.5 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 further stirred for 2 hours while maintaining the temperature of the reaction solution at 90 ° C., and then cooled to room temperature. Next, the nitrogen inlet tube of the reaction vessel was replaced with an air inlet tube, charged with 8.5 g (0.06 mol) of glycidyl methacrylate, 0.5 g of dimethylbenzylamine and 0.1 g of hydroquinone monomethyl ether, and the reaction solution under an air stream The mixture was heated to 100 ° C. while stirring and stirred for 8 hours while maintaining the temperature at 100 ° C. to obtain a carboxyl group-containing resin solution containing a radical polymerizable group in the molecule of the present invention. The obtained carboxyl group-containing resin solution containing a radical polymerizable group in the molecule had a solid content concentration of 52%, a weight average molecular weight of 52,000, and a solid content acid value of 75 mgKOH / g. The solid content concentration and the weight average molecular weight were measured in the same manner as in Synthesis Example 1, and the acid value was measured according to JIS K5601-2-1.

(Examples 1-4)
<Preparation of white photosensitive resin composition>
Component (A) obtained in Synthesis Example 1, Component (B) obtained in Synthesis Example 2, (C) Radical polymerizable compound, (D) Reactivity with hydroxyl group substantially not containing an aromatic ring in the molecule A reactive group-containing compound having (E) a photopolymerization initiator, (F) a rutile-type titanium oxide, (G) a phosphinate, (H) an antioxidant and / or an ultraviolet absorber and / or a light stabilizer, Other components and the organic solvent were placed in a bead mill manufactured by AIMEX, and mixed and stirred at 760 rpm. Next, zirconia beads having a particle diameter of 1 mm were added so as to have a filling rate of 70%, and after stirring and dispersing at 1000 rpm, the zirconia beads were separated by filtration to obtain a white photosensitive resin composition solution of the present invention. The particle diameter of the fine particles in the white photosensitive resin composition was measured according to JIS K 5600-2-5. Table 1 shows the type of each constituent raw material and the blending amount of resin solids. In addition, 1,2-bis (2-methoxyethoxy) ethane which is an organic solvent in the table is the total amount including the amount used in Synthesis Example 1 and the amount used in the preparation. The following evaluation was carried out by completely defoaming the foam in the solution with a defoaming device.

<1> Product name of EO-modified isocyanuric acid triacrylate manufactured by Shin-Nakamura Chemical Co., Ltd. <2> Product name of EO-modified bisphenol A diacrylate manufactured by Shin-Nakamura Chemical Co., Ltd. <3> Hexamethylene diisocyanate block isocyanate manufactured by Asahi Kasei Chemicals Corporation Resin product name <4> BASF Japan Co., Ltd. photopolymerization initiator product name <5> Ishihara Sangyo Co., Ltd. rutile titanium oxide product name <6> Clariant Japan Co., Ltd. product name <7 > Product name of phenolic antioxidant manufactured by BASF Japan Ltd. <8> Product name of butadiene type antifoaming agent manufactured by Kyoeisha Chemical Co., Ltd.

<Preparation of coating film on polyimide film>
Using a Baker type applicator, the white photosensitive resin composition was cast and coated on a 25 μm polyimide film (manufactured by Kaneka Corporation: product name 25 NPI) to an area of 100 mm × 100 mm so that the final dry thickness was 20 μm. Then, 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 . Next, spray development was performed for 60 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 thoroughly washed with pure water, and then cured by heating in an oven at 150 ° C. for 60 minutes to prepare a cured film of a white 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 evaluation The surface of the cured film obtained by the same method as the above item <Creation of coating film on polyimide film> was observed and judged. 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) Adhesiveness of cured film The adhesive strength of the cured film obtained in the above item <Preparation of coating film on polyimide film> was evaluated by a cross-cut method according to JIS K 5600-5-6.
○: Classification 0 (the edges of the cuts are completely smooth, and there is no peeling to the eyes of any lattice).
(Triangle | delta): Classification 1 (The small peeling of the coating film in the crossing point of a cut. It is not clearly exceeding 5% that a crosscut part is influenced.).
X: Classification 2 (The coating film is peeled along the edge of the cut and / or at the intersection. It is clearly more than 5% but not more than 15% that is affected at the crosscut portion.)

(Iii) Solvent resistance The solvent resistance of the cured film obtained in the above item <Preparation of coating film on polyimide film> was evaluated. In the evaluation method, the film was dipped in methyl ethyl ketone at 25 ° C. for 15 minutes and then air-dried, 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.

(Iv) Folding resistance White photosensitive resin composition having a thickness of 20 μm on the surface of a 25 μm-thick polyimide film (Apical 25NPI 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 prepared. 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 placing, 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.
A: The cured film has no cracks after being bent five times.
Δ: The cured film has no cracks after being bent three times.
X: A crack occurs in the cured film at the first folding.

(V) Electrical insulation reliability Line width / space width on a flexible copper-laminated laminate (thickness of electrolytic copper foil 12 μm, polyimide film is Apical 25 NPI manufactured by Kaneka Corporation, and 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 white photosensitive resin composition having a thickness of 20 μm was prepared on a comb pattern by the same method as the above item <Preparation of coating film on polyimide film>, and a test piece was prepared. A 100 V direct current was applied to both terminals of the test piece in an environmental test machine at 85 ° C. and 85% RH, and changes in the insulation resistance value and occurrence of migration were observed.
○: A resistance value of 10 8 or more in 1000 hours after the start of the test, and no occurrence of migration or dendrite.
X: Migration, dendrite, etc. occurred in 1000 hours after the start of the test.

(Vi) Solder heat resistance A white photosensitive resin composition having a thickness of 20 μm on the surface of a 75 μm-thick polyimide film (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 prepared.

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.

(Vii) Warpage Curing of a white 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 in the above item <Preparation of coating film on polyimide film>. A film 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.

(Viii) Flame retardance According to the flammability test standard UL94VTM of plastic materials, the flammability test was conducted as follows. 25 μm-thick white photosensitive resin composition cured film laminated on both sides of a 25 μm-thick polyimide film (manufactured by Kaneka Corporation: trade name Apical 25 NPI) in the same manner as the above item <Preparation of coating film on polyimide film> A film was prepared. 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.

(Ix) Bleed-out The test piece after the electrical insulation reliability test was observed, and a minute bulge on the surface of the test piece, a bulge on the copper wiring, a seepage of an oily substance, and the like were observed.
○: No abnormalities such as swelling and bleeding on the surface of the test piece and the copper wiring in 1000 hours after the start of the test.
X: Abnormalities such as swelling and seepage appearing on the surface of the test piece and the copper wiring in 1000 hours after the start of the test.

(X) Initial reflectance The white photosensitive resin composition having a thickness of 20 μm on the surface of a 25 μm-thick polyimide film (Apical 25NPI manufactured by Kaneka Corporation) in the same manner as the above item <Preparation of coating film on polyimide film>. A cured film laminated film was prepared.
Using the obtained cured film laminated film, the initial reflectance of the white photosensitive resin composition cured film layer was measured by the following method, and the measured value at 450 nm was defined as the initial reflectance.
Equipment used: UV-visible spectrophotometer V-650 manufactured by JASCO Corporation
Measurement wavelength region: 300 to 800 nm
Standard white board: Spectralon TM manufactured by Labsphere

(Xi) Initial hue of white 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 in the above item <Preparation of coating film on polyimide film>. A cured film laminated film was produced.
L, a, b value of the white photosensitive resin composition cured film layer was measured with the following apparatus using the obtained cured film laminated film. L represents lightness, a represents reddishness, and b represents yellowishness.
Equipment used: Nippon Denshoku Industries Co., Ltd. Handy color difference meter NR-3000

(Xii) Change in reflectivity after high temperature heat history (x) The cured film laminated film used for the measurement of the initial reflectivity is reflowed once under the following conditions, and (x) the same method as the initial reflectivity measurement method The reflectance was measured at
Equipment used: IR combination conveyor type hot air reflow furnace FC220 manufactured by CIF
Reflow peak temperature: 260 ° C
Reflow peak time: 15 seconds The rate of change from the initial reflectance before the reflow treatment to the reflectance after the reflow treatment was calculated.
A: The rate of change in reflectance is less than 5%.
Δ: The reflectance change rate is 5% or more and less than 10%.
X: The rate of change in reflectance is 10% or more.

(Xiii) Hue change after high temperature heat history (xii) The cured film laminated film used for the initial hue measurement is reflowed once under the same conditions as (xii) Reflectance change after high temperature heat history. xi) L, a, and b values were measured by the same method as the initial hue measurement method.
○: L value is 80 or more, a value is less than 1, and b value is less than 1.
Δ: L value is 80 or more, a value is less than 2, and b value is less than 2.
X: L value is 80 or less, a value is 2 or more, b value is 2 or more.

(Xiv) Change in reflectance after light irradiation (x) The cured film laminated film used for the measurement of the initial reflectance was irradiated with 100 J / cm ² of UV under the following conditions, and (x) the same as the method for measuring the initial reflectance. The reflectance was measured by the method.
Equipment used: Conveyor type UV irradiator manufactured by Iwasaki Electric Co., Ltd. Output: 120 W / cm
Lamp: Metal halide lamp, 6 kW, 2 lamp irradiator: Cold mirror Condensation type The change rate from the initial reflectance before the light irradiation to the reflectance after the light irradiation was calculated.
A: The rate of change in reflectance is less than 5%.
Δ: The reflectance change rate is 5% or more and less than 10%.
X: The rate of change in reflectance is 10% or more.

(Xv) Hue change after light irradiation (xi) The cured film laminated film used for the initial hue measurement was irradiated with 100 J / cm ² of UV under the same conditions as (xiv) Reflectance change after light irradiation, (Xi) L, a, and b values were measured by the same method as the initial hue measurement method.
○: L value is 80 or more, a value is less than 1, and b value is less than 1.
Δ: L value is 80 or more, a value is less than 2, and b value is less than 2.
X: L value is 80 or less, a value is 2 or more, b value is 2 or more.

(Comparative Example 1)
It is a blending amount as a non-volatile content, and is an acrylic resin, which is a copolymer of methacrylic acid, methyl methacrylate, and butyl acrylate (methacrylic acid: methyl methacrylate: butyl acrylate = 17% by weight: 62% by weight: 21 % By weight) with a weight average molecular weight of 100,000, an acid value of 110 mg KOH / g, 30 parts by weight, a polyurethane compound (manufactured by Nippon Kayaku Co., Ltd., sample name UXE-3024, weight average molecular weight: 10,000), 40 parts by weight, bisphenol A poly 30 parts by weight of oxyethylene dimethacrylate (manufactured by Hitachi Chemical Co., Ltd., product name FA-321M), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 (manufactured by Ciba Japan Co., Ltd.) , Product name IRGACURE 369) 5 parts by weight, 1,7-bis (9-acrylic) Nil) heptane (manufactured by Asahi Denka Kogyo Co., Ltd., product name N-1717), 30 parts by weight of phosphinate (manufactured by Clariant Japan Co., Ltd., product name EXOLIT OP935, phosphorus content = 23 mass%), barium sulfate (Sakai Chemical Industry Co., Ltd., product name Variace B-30) 60 parts by weight, Block-type isocyanate (manufactured by Sumika Bayer Urethane Co., Ltd., product name Sumidur BL-3175) 30 parts by weight, yellow pigment (Pigment Yellow) 0.5 part by weight was mixed and mixed with methyl ethyl ketone as a diluent so that the nonvolatile content was 50% by mass, thereby obtaining a solution of a photosensitive resin composition. In addition, when using both FA-321M and OP-935, after mixing FA-321M and OP-935, the slurry obtained by carrying out the bead mill process was used. The particle size of OP-935 in the slurry was 80% by mass or more and 1 μm or less. The particle size distribution was measured using a particle size distribution meter (LS-230) manufactured by COULTER. The physical property values of this composition were evaluated in the same manner as in Examples 1 to 4. The results are listed in Table 2.

(Comparative Example 2)
In a 2 liter separable flask equipped with a stirrer, thermometer, reflux condenser, dropping funnel and nitrogen introducing tube, 900 g of diethylene glycol dimethyl ether as a solvent and t-butylperoxy 2-ethylhexanoate (Nippon Yushi) as a polymerization initiator 21.4 g of product name Perbutyl O) was added and heated to 90 ° C. After heating, 309.9 g of methacrylic acid, 116.4 g of methyl methacrylate, and 109.8 g of lactone-modified 2-hydroxyethyl methacrylate (product name Plaxel FM1 manufactured by Daicel Chemical Industries, Ltd.) were added as a polymerization initiator. (4-t-butylcyclohexyl) peroxydicarbonate (product name: Parroyl TCP, manufactured by Nippon Oil & Fats Co., Ltd.) was added dropwise over 3 hours together with 21.4 g, and further aged for 6 hours, whereby a carboxyl group-containing copolymer resin was obtained. Got. The reaction was performed under a nitrogen atmosphere. Next, 363.9 g of 3,4-epoxycyclohexylmethyl acrylate (product name: Cyclomer A200, manufactured by Daicel Chemical Industries, Ltd.), 3.6 g of dimethylbenzylamine as a ring-opening catalyst, and polymerization were obtained. As an inhibitor, 1.80 g of hydroquinone monomethyl ether was added, heated to 100 ° C., and stirred to carry out an epoxy ring-opening addition reaction. After 16 hours, a solution containing 53.8% by weight (nonvolatile content) of a carboxyl group-containing resin having no aromatic ring and having an acid value of solids of 108.9 mgKOH / g and a weight average molecular weight of 25,000 was obtained. . 186 parts by weight of this solution, 180 parts by weight of rutile type titanium oxide (Ishihara Sangyo Co., Ltd., product name Typaque R820), 19 parts by weight of triglycidyl isocyanurate (Nissan Chemical Co., Ltd., product name TEPIC-S), photopolymerization initiator ( Ciba Japan Co., Ltd. product name IRGACURE 907) 19 parts by weight, sensitizer (Nippon Kayaku Co., Ltd. product name KAYACURE DETX) 0.3 part by weight, dipentaerythritol hexaacrylate 15 parts by weight, silicone oil (Shin-Etsu Silicone Co., Ltd.) Company name, product name KS-66) 3 parts by weight were blended, stirred and dispersed with a three roll to obtain a solder resist composition. The physical property values of this composition were evaluated in the same manner as in Examples 1 to 4. The results are listed in Table 2.

(Comparative Example 3)
To a 1000 ml flask fitted with a condenser, 0.16 mol of 3- (glycidoxypropyl) trimethoxysilane, 0.24 mol of methyltrimethoxysilane, 0.6 mol of dimethyldimethoxysilane, and propylene glycol monomethyl ether acetate 87 4 ml was added to obtain a solution. Using a semicircular mechanical stirrer, an aqueous solution in which 0.28 g of potassium hydroxide was dissolved in 43.2 ml of water was slowly dropped while stirring the above solution. Thereafter, the solution was reacted at 50 ° C. for 3 hours with a mantle heater. Next, methanol and residual water produced by the condensation reaction with water were removed using an evaporator under the conditions of 2000 Pa pressure, 40 ° C. and 1 hour. Thereafter, the flask was left to reach room temperature to obtain a solution containing a siloxane polymer. The resulting solution containing the siloxane polymer had a solid content concentration of 50% by weight, the siloxane polymer had a weight average molecular weight of 5500, and an epoxy equivalent of 546. 72 parts by weight of this solution, 100 parts by weight of (meth) acrylic resin (product name Cyclomer P (ACA) Z300, manufactured by Daicel Chemical Industries, Ltd.) having a carboxyl group and an unsaturated double bond in the side chain, 10 parts by weight of pentaerythritol hexaacrylate, 120 parts by weight of rutile-type titanium oxide (Ishihara Sangyo Co., Ltd., product name TYPEKE CR-58) and 5% by weight of compound-type antifoaming agent (Shin-Etsu Silicone Co., Ltd., product name KS-69) And 9 parts by weight of a photopolymerization initiator (product name TPO manufactured by Nippon Shibel Hegner Co., Ltd.) were mixed for 2 minutes in a kneader (product name Nertaro SP-500 manufactured by Shinky Corporation), and then 3 Mixed with a roll. Then, resist material as a resin composition was obtained by defoaming the mixture for 3 minutes using SP-500. The physical property values of this composition were evaluated in the same manner as in Examples 1 to 4. The results are listed in Table 2.

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

Claims (10)

at least,
(A) A hydroxyl group-containing resin (a radical in the molecule), which is obtained by copolymerizing at least a hydroxyl group-containing (meth) acrylic acid ester and a (meth) acrylic acid alkyl ester , and contains substantially no radical polymerizable group in the molecule. “Containing substantially no polymerizable group” means that the radically polymerizable group is not contained in the molecule at all, or the value determined by measuring the radically polymerizable group in the molecule of the component (A) as an iodine value. Means less than 5.)
(B) a carboxyl group-containing resin containing a radical polymerizable group in the molecule;
(C) a radically polymerizable compound,
(D) A reactive group-containing compound that is reactive with a hydroxyl group that does not substantially contain an aromatic ring in the molecule . (If the molecule does not substantially contain an aromatic ring, does it contain no aromatic ring at all? Or (D) means that an unsaturated double bond derived from an aromatic ring in the molecule of the component is measured with an iodine value of less than 5) .
(E) a photopolymerization initiator,
(F) rutile type titanium oxide,
(G) containing a phosphinate,
White photosensitive resin composition characterized by containing substantially no silicon-containing organic compound (being substantially free of silicon-containing organic compound means that (A) component, (B) component, (C) component, The component (D) and the component (E) do not contain a silicon-containing organic compound, and other components blended in the white photosensitive resin composition do not contain a silicon-containing organic compound. A silane coupling agent used for the purpose of surface treatment of the inorganic filler may be contained, and the component (G) that has been surface-treated with the silane coupling agent can also be used. )   The white photosensitive resin composition according to claim 1, wherein the (D) is an isocyanate resin that does not substantially contain an aromatic ring in the molecule.   The said (D) is mix | blended so that it may become 1-100 weight part with respect to 100 weight part which totaled said (A) and said (B). White photosensitive resin composition.   Said (F) is mix | blended so that it may become 10-150 weight part with respect to 100 weight part which totaled said (A), said (B), said (C), and said (D). The white photosensitive resin composition of any one of Claims 1-3 characterized by the above-mentioned.   Said (G) is mix | blended so that it may become 1-50 weight part with respect to 100 weight part which totaled said (A), said (B), said (C), and said (D). The white photosensitive resin composition of any one of Claims 1-4 characterized by the above-mentioned.   Furthermore, it contains at least 1 sort (s) chosen from the group which consists of (H) antioxidant, a ultraviolet absorber, and a light stabilizer, The white photosensitive resin composition of any one of Claims 1-5 characterized by the above-mentioned. object.   Said (H) is mix | blended so that it may become 0.001-1 weight part with respect to 100 weight part which totaled said (A), said (B), said (C), and said (D). The white photosensitive resin composition according to claim 6.   The resin film obtained by apply | coating at least the white photosensitive resin composition of any one of Claims 1-7 to the base-material surface, and drying.   An insulating film obtained by curing the resin film according to claim 8.   The printed wiring board with an insulating film which coat | covered the insulating film of Claim 9 on the printed wiring board.

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