JP6652338B2 - Photocurable thermosetting resin composition, cured product thereof, and printed wiring board - Google Patents

Description

  The present invention relates to a photocurable thermosetting resin composition, a cured product thereof, and a printed wiring board. More specifically, the present invention relates to a photocurable thermosetting resin composition capable of lowering the dielectric constant and the dielectric loss tangent, a cured product thereof, and a printed wiring board.

  From the viewpoint of high precision and high density, a liquid alkali development type solder resist that forms an image by developing after exposure and heat-curing to form a coating film is used from the viewpoint of high precision and high density. Have been.

In recent years, in response to the miniaturization, high density, and high speed of printed wiring boards accompanying the lighter, thinner and smaller electronic devices and the higher capacity and higher speed, the permittivity in the high frequency band affects the transmission speed, especially for higher speeds. However, when the dielectric constant is high, the transmission speed is delayed and the signal waveform is disturbed, which makes it difficult to design a circuit corresponding to a high frequency. On the other hand, especially when the dielectric loss is large in the GHz band, the electric signal is attenuated, the battery consumption is increased, and the usable time of the electronic device is shortened. Therefore, it is required to reduce the dielectric constant and the dielectric loss tangent of the solder resist. ing.
Under such circumstances, a resin composition for a solder resist to which a specific component is added has been proposed in order to realize a low dielectric constant and a low dielectric loss tangent of the solder resist.

  For example, in Patent Literature 1, (A) a monomer unit derived from vinylbenzene and / or a derivative thereof, in order to obtain a resin composition for a solder resist having a low dielectric constant, and particularly having a small dielectric loss even in a high frequency band of 1 GHz or more, And / or a polymer comprising monomer units derived from vinyl naphthalene and / or a derivative thereof, (B) at least one selected from the group consisting of a cyanate ester resin, an oxetane ring-containing compound, a divinylbenzene compound and a (vinylphenyl) vinyl ether compound. There has been proposed a resin composition for a solder resist containing a compound of the type described above and (C) a cationic curing catalyst.

  Patent Document 2 discloses a circuit board for obtaining a composition for a solder resist which can be used for a substrate of a narrow pitch circuit and has good electrical characteristics such as high insulation and low dielectric constant and low dielectric loss. A thermosetting solder resist composition for forming a solder resist disposed thereon, which contains polysilsesquioxane having an aromatic group, and the formed solder resist has resolution by laser irradiation. There has been proposed a composition for a thermosetting solder resist characterized by the above.

JP 2004-354737 A JP 2010-34414 A

  In the solder resist compositions proposed so far, low dielectric constant and low dielectric loss tangent can be realized to some extent by adding specific components, etc. Today, there is a demand for further lowering the dielectric constant and the dielectric loss tangent in a high-frequency band while enabling alkali development.

Therefore, an object of the present invention is to provide a photocurable thermosetting resin composition, a cured product thereof, and a printed wiring board that can have a lower dielectric constant and a lower dielectric loss tangent than ever before.
Another object of the present invention is to provide a photocurable thermosetting resin composition capable of lowering the dielectric constant and the dielectric loss tangent than ever, while maintaining high solder heat resistance, and a cured product thereof. And a printed wiring board.

  The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have solved the above-mentioned problems by using a compound having an oxazoline group as a component of a composition containing a specific photosensitive resin containing a carboxyl group. It was found that the present invention was obtained, and the present invention was completed. In addition, by using a specific carboxyl group-containing photosensitive organic-inorganic hybrid resin varnish as a resin, even without using an epoxy resin that generates a hydroxyl group after thermosetting as a component of the composition, the solder heat resistance is highly maintained. On the other hand, they have further found that the dielectric constant and the dielectric loss tangent can be further reduced, and the present invention has been completed.

That is, the photocurable thermosetting resin composition of the present invention is obtained by reacting an unsaturated monocarboxylic acid (a2) with an epoxy group of a polyfunctional epoxy resin (a1), and reacting the reaction product with a polybasic. A photosensitive resin (A) containing a carboxyl group obtained by reacting an acid anhydride (a3);
A photopolymerization initiator (B);
A compound (C) having an oxazoline group capable of reacting with a carboxyl group of the photosensitive resin (A),
It is characterized by including.

  In the photocurable thermosetting resin composition of the present invention, the polyfunctional epoxy resin (a1) is preferably a dicyclopentadiene-type epoxy resin. Further, the unsaturated monocarboxylic acid (a2) is preferably (meth) acrylic acid. Further, the compound (C) having an oxazoline group is preferably a compound having at least one of styrene, acryl and derivatives thereof as a main skeleton.

  Further, in the photocurable thermosetting resin composition of the present invention, the photosensitive resin (A) includes at least one silane compound having a (meth) acryloyl group with respect to a hydroxyl group of the photosensitive resin (A). It is preferable that the varnish is a carboxyl group-containing photosensitive organic-inorganic hybrid resin varnish obtained by partially reacting a compound (D) obtained by hydrolyzing and condensing a silane compound containing the compound.

  Further, the cured product of the present invention is obtained by applying the photocurable thermosetting resin composition to a base material and photocuring it by irradiation with active energy rays.

  Furthermore, the printed wiring board of the present invention has a cured coating film obtained by applying the photocurable thermosetting resin composition on a substrate and forming a coating film by photocuring in a pattern. It is characterized by the following.

According to the present invention, it is possible to provide a photocurable thermosetting resin composition capable of lowering the dielectric constant and the dielectric loss tangent more than ever, a cured product thereof, and a printed wiring board.
Further, according to the present invention, by using a carboxyl group-containing photosensitive organic-inorganic hybrid resin varnish, a light capable of lowering the dielectric constant and the dielectric loss tangent more than before while maintaining a high solder heat resistance. A curable thermosetting resin composition, a cured product thereof, and a printed wiring board can also be provided.

4 is a graph showing a relationship between a dielectric constant and a dielectric loss tangent (tan δ) in Examples and Comparative Examples.

The photocurable thermosetting resin composition of the present invention (hereinafter, also referred to as “resin composition”) reacts an unsaturated monocarboxylic acid (a2) with an epoxy group of a polyfunctional epoxy resin (a1), Photosensitive resin (A) containing a carboxyl group obtained by reacting the reaction product with polybasic acid anhydride (a3) (hereinafter, also referred to as “photosensitive resin (A)”) and light A polymerization initiator (B) and a compound (C) having an oxazoline group capable of reacting with a carboxyl group of the photosensitive resin (A) (hereinafter, also referred to as “compound (C) having an oxazoline group”); including.
If the resin composition has a polar group such as a carboxyl group, since the polar group is also present in the cured coating film after heat curing, lowering the dielectric constant and lowering the dielectric loss tangent are difficult, In the present invention, a photosensitive resin (A) containing a carboxyl group obtained by reacting a polybasic acid anhydride (a3) and an oxazoline group capable of reacting with the carboxyl group of the photosensitive resin (A) are used. The compound (C) is blended with the compound (A) to reduce the number of carboxyl groups remaining in the resin composition at the time of heat curing, thereby making it possible to reduce the dielectric constant and the dielectric loss tangent even in a high frequency band.
Further, in the present invention, a carboxyl group-containing photosensitive organic-inorganic hybrid resin varnish (hereinafter, referred to as “organic-inorganic hybrid resin varnish”) obtained by partially hybridizing the carboxyl group-containing photosensitive resin (A). ) Can be maintained at a high level of solder heat resistance without using an epoxy resin, and a low dielectric constant and a low dielectric loss tangent can be obtained even in a high frequency band. Was.
Hereinafter, each component of the photocurable thermosetting resin composition of the present invention will be described in detail.

<Photosensitive resin containing carboxyl group (A)>
The photosensitive resin (A) containing a carboxyl group used in the photocurable thermosetting resin composition of the present invention reacts the unsaturated monocarboxylic acid (a2) with the epoxy group of the polyfunctional epoxy resin (a1). And reacting the reaction product with a polybasic acid anhydride (a3).
From the viewpoint of developability, the addition amount of the polybasic acid anhydride (a3) is preferably 50 to 100 mol%. When the addition amount of the polybasic acid anhydride (a3) is within the above range, the tackiness becomes good, which is preferable.

  Representative examples of the polyfunctional epoxy resin (a1) include dicyclopentadiene type epoxy resin, naphthalene type epoxy resin, cresol novolak type epoxy resin, phenol novolak type epoxy resin, and bisphenol A novolak type epoxy resin. Yes, it is possible to use a compound obtained by reacting epichlorohydrin with each resin according to a conventional method. From the viewpoint of lowering the dielectric constant and lowering the dielectric loss tangent, dicyclopentadiene-type epoxy resins are preferred.

  In the photosensitive resin (A), a reaction product generated by an esterification reaction between an epoxy group of the polyfunctional epoxy resin (a1) and a carboxyl group of the unsaturated monocarboxylic acid (a2) is reacted with a polybasic anhydride. Product (a3), and a large number of free carboxyl groups are added to the side chain of the backbone polymer produced by the former esterification reaction by the latter reaction. Becomes possible.

Examples of the unsaturated monocarboxylic acid (a2) include a reaction product of acrylic acid, methacrylic acid, cinnamic acid, a saturated or unsaturated dibasic acid anhydride and a (meth) acrylate having one hydroxyl group in one molecule. These can be used alone or in combination of two or more. From the viewpoint of photocurability, acrylic acid or methacrylic acid is preferable, and acrylic acid is more preferable.
In this specification, the term “(meth) acrylate” is a general term for acrylate, methacrylate and mixtures thereof, and the same applies to other similar expressions.

  Typical examples of the polybasic anhydride (a3) include maleic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, and methylhexahydroanhydride. Dibasic acid anhydrides such as phthalic acid, endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, chlorendic anhydride, methyltetrahydrophthalic anhydride; trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic acid Aromatic polycarboxylic anhydrides such as dianhydrides; and other concomitant examples of 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride Such polycarboxylic anhydride derivatives can be used.

<Photopolymerization initiator (B)>
The photocurable thermosetting resin composition of the present invention contains a photopolymerization initiator (B). As the photopolymerization initiator, one or more photopolymerization initiators selected from the following groups can be used.

  Examples of the photopolymerization initiator include benzoin and its alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether; acetophenone, 2,2-dimethoxy-1,2-diphenylethan-1-one, , 2-Dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenylketone, 2-methyl-1 [4- (methylthio) phenyl] -2 Acetophenones such as morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one; 2-methylanthraquinone, 2-ethylanthraquinone, 2-tercia Leave Le anthraquinone, 1-chloro anthraquinone, 2-anthraquinone such as amyl anthraquinone; like benzophenone or xanthone such as benzophenone; acetophenone dimethyl ketal, ketal such as benzil dimethyl ketal. The suitable range of the amount of the photopolymerization initiator as described above is preferably 1.0 to 20 parts by mass, more preferably 2.5 parts by mass, based on 100 parts by mass of the solid content of the photosensitive resin (A). It is a ratio that becomes 10 to 10 parts by mass.

<Compound (C) having an oxazoline group>
The photocurable thermosetting resin composition of the present invention contains a compound (C) having an oxazoline group capable of reacting with a carboxyl group of the photosensitive resin (A). In the present invention, by containing a compound having an oxazoline group, the carboxyl group remaining in the resin composition during thermal curing is reduced, and a low dielectric constant and a low dielectric loss tangent can be obtained even in a high frequency band.
As the compound having an oxazoline group, a compound having one or more oxazoline groups selected from the following groups can be used.

  The compound having an oxazoline group is not particularly limited as long as it has an oxazoline group capable of reacting with a carboxyl group of the photosensitive resin (A). Examples of the compound include 2-oxazoline and 2-amino-2-amine. Oxazoline, 2,2′-bis (2-oxazoline), 1,3-bis (4,5-dihydro-2-oxazolyl) benzene, 1,4-bis (4,5-dihydro-2-oxazolyl) benzene, 1,3,5-tris (4,5-dihydro-2-oxazolyl) benzene, 2,2 ′-(2,6-pyridinediyl) bis (4-isopropyl-2-oxazoline), 2,2 ′-( 2,6-pyridinediyl) bis (4-phenyl-2-oxazoline), 2-phenyl (2-oxazoline), 4,4-dimethyl-2-oxazoline, 2,2′-isopropyl Denbis (4-phenyl-2-oxazoline), 2-ethyl-2-oxazoline, 2,2′-isopropylidenebis (4-t-butyl-2-oxazoline), 2-isopropyl-2-oxazoline, 4-methoxy Methyl-2-methyl-5-phenyl-2-oxazoline, 2-methyl-2-oxazoline, 2,4,4-trimethyl-2-oxazoline, Nippon Shokubai's Epocross series K-1010E, K-2010E, K -1020E, K-2020E, K-1030E, K-2030E, WS-500, WS-700, RPS-1005, RAS-1005, and the like.

（式中、ｍ：ｎ＝１：１〜５０：１である。） The compound having an oxazoline group is preferably a compound having, as a main skeleton, at least one of styrene, acryl, and derivatives thereof, from the viewpoint of lowering the dielectric constant and lowering the dielectric loss tangent in a high-frequency band. And a compound having a structure represented by the following general formula (I) is more preferred.

(Where m: n = 1: 1 to 50: 1)

  The preferred range of the weight average molecular weight of the compound having an oxazoline group is from 10,000 to 300,000, more preferably from 50,000 to 200,000, from the viewpoint of tackiness and developability. When the weight average molecular weight is within the above range, tackiness, developability, and compatibility with the photosensitive material are improved. The weight average molecular weight can be measured by gel permeation chromatography.

  The preferred range of the amount of the compound having an oxazoline group as described above is 100 parts by mass of the solid content of the photosensitive resin (A) from the viewpoints of low dielectric constant and low dielectric loss tangent, developability and compatibility. Is preferably 5 to 50 parts by mass, more preferably 10 to 30 parts by mass.

(Carboxy group-containing photosensitive organic-inorganic hybrid resin varnish)
In the photocurable thermosetting resin composition of the present invention, from the viewpoint of lowering the dielectric constant, lowering the dielectric loss tangent, and the heat resistance of the solder, the photosensitive resin (A) has a hydroxyl group in the photosensitive resin (A). On the other hand, a carboxyl group-containing photosensitive organic-inorganic hybrid resin varnish obtained by partially reacting a compound (D) obtained by hydrolytic condensation reaction of a silane compound containing at least one silane compound having a (meth) acryloyl group is used. Preferably, there is.
Such organic-inorganic hybrid resin varnish is
The epoxy group of the polyfunctional epoxy resin (a1) is reacted with an unsaturated monocarboxylic acid (a2), and the reaction product is reacted with a polybasic anhydride (a3) to obtain a photosensitive compound containing a carboxyl group. Step (1) of obtaining a conductive resin (A),
It is obtained by subjecting a photosensitive resin (A) containing a carboxyl group, which is a reaction product of the above step (1), to a hydrolysis-condensation reaction with a silane compound containing at least one silane compound having a (meth) acryloyl group. The compound (D) is obtained by a production method that includes a step (2) of mixing or partially reacting the compound (D) in this order.

  First, the organic-inorganic hybrid resin varnish uses a polyfunctional epoxy resin (a1) as a starting material.

  In the step (1), the reaction product generated by the esterification reaction between the epoxy group of the polyfunctional epoxy resin (a1) and the carboxyl group of the unsaturated monocarboxylic acid (a2) is reacted with a polybasic acid anhydride ( a3) is reacted and a large number of free carboxyl groups are added to the side chain of the backbone polymer formed by the former esterification reaction by the latter reaction, so that development with an aqueous alkali solution is possible. Becomes

In the step (2), a silane compound containing at least one silane compound having a (meth) acryloyl group is hydrolyzed with respect to the photosensitive resin (A) having a carboxyl group, which is a reaction product of the step (1). In this step, the compound (D) obtained by the condensation reaction is mixed or partially reacted. In this step, for example, in the case of using an alkoxysilane compound having a (meth) acryloyl group, it is preferable to add about 1 equivalent of water to 3 equivalents of the alkoxysilane in the hydrolysis in the hydrolysis condensation reaction. The reason is that if the amount of water is less than this ratio, hydrolysis does not proceed sufficiently, and if it is too much, it is necessary to remove excess water from the system, and if water remains, condensation hardly proceeds, and the fluidity of the resin becomes poor. For they will be lost. In the hydrolysis in the above-mentioned hydrolysis-condensation reaction, the reaction proceeds with stirring at room temperature, but if the stirring time is short, sufficient hydrolysis does not take place, so that stirring is required for 30 minutes or more, preferably 3 hours or more. is there. On the other hand, the condensation reaction in the above-mentioned hydrolysis-condensation reaction partially occurs at room temperature at the same time as the hydrolysis, but the reaction can be carried out by raising the temperature to shorten the time. In the condensation reaction at a high temperature, since the acrylic component causes gelation, a reaction at 100 ° C. or lower is preferable.
In the present invention, the solder heat resistance can be improved to a high degree by partially hybridizing the carboxyl group-containing photosensitive resin (A) which is a reaction product of the step (1) in the step (2). A photocurable thermosetting resin composition capable of lowering the dielectric constant and the dielectric loss tangent more than before can be obtained while maintaining the composition.

In the present invention, a silane compound having at least a (meth) acryloyl group is used at the time of synthesizing the organic-inorganic hybrid resin varnish. Specific examples of such a silane compound having a (meth) acryloyl group include, for example, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, 3- (meth) And (3) alkoxysilane compounds having a (meth) acryloyl group, such as acryloxypropylmethyldimethoxysilane and 3- (meth) acryloxypropylmethyldiethoxysilane. These can be used alone or in combination of two or more. Among them, 3- (meth) acryloxypropyltrimethoxysilane is preferable from the viewpoint of photocurability and solder heat resistance.
As other silane compounds that can be used in combination with a silane compound having a (meth) acryloyl group, silane compounds generally known as a silane coupling agent can be used. For example, methyltrimethoxysilane, methyltrimethoxysilane, and the like can be used. Ethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, tetramethoxysilane, tetraethoxysilane and the like can be mentioned. Among them, dimethyldimethoxysilane is preferred because the dielectric constant can be reduced by increasing the hydrophobicity and decreasing the water absorption of the coating film.
When such another silane compound is used in combination with the silane compound having a (meth) acryloyl group, the mixing ratio is preferably silane compound having a (meth) acryloyl group: other silane compound = 1: 0 to 1: 1. When the mixing ratio is within the above range, a low dielectric constant can be achieved while maintaining high solder heat resistance.

  In the present specification, an organic-inorganic hybrid resin varnish is obtained by subjecting a photosensitive resin (A) having a carboxyl group and a silane compound containing at least one silane compound having a (meth) acryloyl group to a hydrolysis-condensation reaction. To obtain a mixture or a partial reaction product with the compound (D).

(Organic nitrogen compounds)
The photocurable thermosetting resin composition of the present invention may contain an organic nitrogen compound. Examples of the organic nitrogen compound include dicyandiamide, melamine and derivatives thereof. In the present invention, discoloration of the copper foil can be prevented by using this organic nitrogen compound. In particular, by adding melamine, yellowing and a decrease in reflectance of the coating film can be reduced even after a deterioration test in which the coating film is irradiated with UV or a thermal history is given.
Melamine is 2,4,6-triamino-1,3,5-triazine, and is mainly used as a raw material of melamine resin. By reacting melamine with formalin, methylol melamine can be obtained. By heating this using a catalyst, methylol melamine becomes a methylene bond, and a melamine resin can be produced. As a main production method of melamine, there is a method of reacting urea under the high pressure of ammonia. Melamine is industrially made by this process. As another method for producing melamine, melamine can also be synthesized from lime nitrogen, dicyandiamide, and hydrocyanic acid. Further, a melamine derivative such as methylol melamine may be used.
As melamine derivatives, there are monoacetylmelamine, diacetylmelamine, triacetylmelamine and the like, more specifically, stearic anhydride, palmitic anhydride, myristic anhydride, lauric anhydride, capric anhydride, Substitutes such as caprylic anhydride, butyric anhydride, acetic anhydride and the like are known. Salts, melamine-toluenesulfonic acid, and melamine-tetrahydrophthalic acid have been evaluated as solder resists.
The preferred compounding amount of such an organic nitrogen compound is 0.5 to 5% by mass, more preferably 1 to 2% by mass, based on 100% by mass of the solid content of the photosensitive resin (A). When the amount is 0.5% by mass or more, the effect is apparent, and when the amount is 5% by mass or less, storage stability, developability, water resistance of the coating film, and the like are improved.

  The photocurable thermosetting resin composition of the present invention may further contain, if necessary, a commonly used filler such as barium sulfate, silicon oxide, talc, clay, and calcium carbonate, phthalocyanine blue, phthalocyanine green, and titanium oxide. , Known additives such as colorants such as carbon black, defoamers, adhesion promoters or leveling agents, or known and conventional polymerizations such as hydroquinone, hydroquinone monomethyl ether, pyrogallol, tertiary butyl catechol, and phenothiazine Inhibitors may be added.

  The photocurable thermosetting resin composition of the present invention is, for example, applied to the entire surface by a screen printing method, a roll coater method, or a curtain coater method on a substrate for a printed wiring board, and the active energy rays are passed through a resist pattern film. After irradiating and curing the required portion, the unexposed portion is dissolved with an aqueous alkali solution and then cured by heating, so that a desired solder resist film can be formed.

  As the aqueous alkali solution used for the development, an aqueous alkali solution such as potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, and amines can be used. Further, as an irradiation light source for photocuring, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a metal halide lamp, or the like is appropriate. In addition, a laser beam or the like can also be used as an active light beam for exposure.

  Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. In the following, “parts” and “%” are all based on mass unless otherwise specified.

[Synthesis Example 1 (Synthesis of Resin 1 by Step (1))]
104 g of dicyclopentadiene type epoxy resin (HP-7200 manufactured by DIC) was weighed and placed in a 500 cc three-neck separable flask, and 104 g of diethylene glycol monoethyl ether acetate was added thereto and dissolved by heating. Thereafter, 31.7 g (1.1 equivalent) of acrylic acid, 0.10 g of phenothiazine and 0.15 g of tetramethylammonium chloride were added, and the mixture was refluxed at 105 ° C. while blowing air at a rate of 0.5 L / min to prevent gelation. Stirring was performed for 8 hours. Further, 36.5 g of tetrahydrophthalic anhydride (0.6 equivalent to the hydroxyl group) was added, and the mixture was stirred at 100 ° C. for 4 hours to obtain Resin 1. Resin 1 obtained by synthesis was liquid at room temperature, had a nonvolatile content of 66%, an acid value of 47.5 mKOH / g, and an addition amount of an acid anhydride to a hydroxyl group of 60 mol%.

[Synthesis Example 2 (Synthesis of Resin 2 by Step (1))]
Resin 2 was obtained in the same manner as in Synthesis Example 1, except that 36.5 g of tetrahydrophthalic anhydride (0.6 equivalent to the hydroxyl group) was changed to 60.8 g (1.0 equivalent to the hydroxyl group). . Resin 2 obtained by synthesis was liquid at ordinary temperature, had a nonvolatile content of 69%, an acid value of 81 mKOH / g, and an addition amount of an acid anhydride to a hydroxyl group of 100 mol%.

[Synthesis Example 3 (Synthesis of Resin 3 by Step (1))]
108 g of cresol novolak type epoxy resin (manufactured by DIC, N-695) was weighed and placed in a 500 cc three-neck separable flask, and 135 g of diethylene glycol monoethyl ether acetate was added thereto and dissolved by heating. Thereafter, 39.6 g (1.1 equivalents) of acrylic acid, 0.10 g of phenothiazine and 0.15 g of tetramethylammonium chloride are added, and the mixture is refluxed at 105 ° C. while blowing air at 0.5 L / min to prevent gelation. Stirring was performed for 8 hours. Further, 45.6 g of tetrahydrophthalic anhydride (0.6 equivalent to the hydroxyl group) was added, and the mixture was stirred at 100 ° C. for 4 hours to obtain Resin 3. Resin 3 obtained by synthesis was liquid at normal temperature, had a nonvolatile content of 60%, an acid value of 58 mKOH / g, and an addition amount of an acid anhydride to a hydroxyl group of 60 mol%.

[Synthesis Example 4 (Synthesis of Organic-Inorganic Hybrid Resin Varnish A-1 by Step (2))]
In a 500 cc three-neck separable flask, 18.7 g of 3-acryloxypropyltrimethoxysilane (KBM-5103, Shin-Etsu Chemical Co., Ltd.), 9.6 g of dimethyldimethoxysilane (KBM-22, Shin-Etsu Chemical Co., Ltd.), and 2.83 g of distilled water Then, 0.28 g of dibutyltin dilaurate was weighed, replaced with nitrogen, and stirred at room temperature for 130 rpm for 3 hours.
Next, 42.3 g of the resin 1 (addition product of acrylate anhydride of dicyclopentadiene-type epoxy resin) obtained in Synthesis Example 1 was added, and the mixture was refluxed for 1 hour at 80 ° C. while blowing air at a rate of 0.5 L / min. Stirred. Thereafter, the system was switched from the reflux system to a system for recovering alcohol as a by-product, and further stirred and heated at 80 ° C. for 1 hour to obtain a mixture of Resin 1 and an organic-inorganic hybrid acrylic oligomer. This mixture is referred to as an organic-inorganic hybrid resin varnish A-1.

[Synthesis Example 5 (Synthesis of Organic-Inorganic Hybrid Resin Varnish A-2 by Step (2))]
In a 500 cc three-neck separable flask, 28.3 g of 3-acryloxypropyltrimethoxysilane (KBM-5103 manufactured by Shin-Etsu Chemical Co., Ltd.), 2.83 g of distilled water, and 0.28 g of dibutyltin dilaurate are weighed, replaced with nitrogen, and then cooled to room temperature. At 130 rpm for 3 hours.
Next, 41.1 g of the resin 2 (acrylate anhydride anhydride adduct of dicyclopentadiene-type epoxy resin) obtained in Synthesis Example 2 was added, and the mixture was refluxed at 80 ° C. for 1 hour while blowing air at a rate of 0.5 L / min. Stirred. Thereafter, the system was switched from the reflux system to a system for recovering alcohol as a by-product, and further stirred and heated at 80 ° C. for 1 hour to obtain a mixture of the resin 2 and the organic-inorganic hybrid acrylic oligomer. This mixture is referred to as an organic-inorganic hybrid resin varnish A-2.

[Synthesis Example 6 (Synthesis of Organic-Inorganic Hybrid Resin Varnish A-3 by Step (2))]
Synthesis Example 5 except that 41.1 g of Resin 2 (addition product of acrylate anhydride of dicyclopentadiene type epoxy resin) was changed to 43.3 g of Resin 1 (addition product of acrylate anhydride of epoxy resin of dicyclopentadiene type). In the same manner as in 1, a mixture of Resin 1 and an organic-inorganic hybrid acrylic oligomer was obtained. This mixture is referred to as an organic-inorganic hybrid resin varnish A-3.

<Preparation of photocurable thermosetting resin compositions of Examples 1 to 4 and Comparative Examples 1 to 6>
According to the composition shown in the following table, each component was blended, and preliminarily mixed with a stirrer, then dispersed and kneaded with a three-roll mill manufactured by Inoue Seisakusho Co., Ltd. to prepare a photocurable thermosetting resin composition. . The blending amounts in the table indicate parts by mass.

＊１：シラン化合物の質量比はＫＢＭ−５１０３：ＫＢＭ−２２＝１：１、感光性樹脂固形分５０質量部
＊２：シラン化合物はＫＢＭ−５１０３のみ含む、感光性樹脂固形分５０質量部
＊３：シラン化合物はＫＢＭ−５１０３のみ含む、感光性樹脂固形分５０質量部
＊４：酸無水物の付加量６０モル％、感光性樹脂固形分５０質量部
＊５：酸無水物の付加量６０モル％、感光性樹脂固形分６６質量部
＊６：１００質量部のクレゾールノボラック型エポキシ樹脂（ＤＩＣ社製Ｎ−６９５）を５０質量部のカルビトールアセテートで溶解したワニス、固形分２０質量部
＊７：１００質量部のジシクロペンタジエン型エポキシ樹脂（ＤＩＣ社製ＨＰ−７２００）を３３．３質量部のカルビトールアセテートで溶解したワニス、固形分２０質量部
＊８：１００質量部のオキサゾリン基を有する化合物（日本触媒社製エポクロスＲＰＳ−１００５）を１００質量部のカルビトールアセテートで溶解したワニス、固形分１０質量部、オキサゾリン基を有する化合物の重量平均分子量（Ｍｗ）約１６０，０００
＊９：ジペンタエリスリトールヘキサアクリレート（日本化薬社製）
＊１０：光重合開始剤、２−ベンジル−２−ジメチルアミノ−１−（４−モルホリノフェニル）−ブタン−１−オン（ＢＡＳＦジャパン社製）
＊１１：硫酸バリウム（堺化学工業社製）
＊１２：有機窒素化合物
＊１３：消泡剤（信越化学工業社製）

* 1: The mass ratio of the silane compound is KBM-5103: KBM-22 = 1: 1, and the photosensitive resin solid content is 50 parts by mass. * 2: The silane compound contains only KBM-5103, and the photosensitive resin solid content is 50 parts by mass. 3: The silane compound contains only KBM-5103, 50 parts by mass of solid content of photosensitive resin * 4: 60 mol% of added amount of acid anhydride, 50 parts by mass of solid content of photosensitive resin * 5: 60 parts by mass of added acid anhydride Molar%, photosensitive resin solid content 66 parts by mass * 6: Varnish prepared by dissolving 100 parts by mass of cresol novolac type epoxy resin (DIC N-695) with 50 parts by mass of carbitol acetate, solid content 20 parts by mass * 7: A varnish obtained by dissolving 100 parts by mass of a dicyclopentadiene-type epoxy resin (HP-7200 manufactured by DIC) with 33.3 parts by mass of carbitol acetate, 20 parts by mass of solid content * 8 A varnish prepared by dissolving 100 parts by mass of a compound having an oxazoline group (Epocross RPS-1005 manufactured by Nippon Shokubai Co., Ltd.) with 100 parts by mass of carbitol acetate, a solid content of 10 parts by mass, and a weight average molecular weight (Mw) of the compound having an oxazoline group. About 160,000
* 9: Dipentaerythritol hexaacrylate (Nippon Kayaku Co., Ltd.)
* 10: Photopolymerization initiator, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one (manufactured by BASF Japan)
* 11: Barium sulfate (made by Sakai Chemical Industry Co., Ltd.)
* 12: Organic nitrogen compound * 13: Antifoaming agent (Shin-Etsu Chemical Co., Ltd.)

  About each photocurable thermosetting resin composition of the said Examples 1-4 and Comparative Examples 1-6, the following items were tested and evaluated. Table 2 shows the results of each evaluation. The method of the evaluation test is shown below.

<Sensitivity>
The photocurable thermosetting resin composition obtained in each of Examples 1 to 4 and Comparative Examples 1 to 6 was applied to the entire surface of a copper foil of a glass epoxy substrate by screen printing. It dried at 30 degreeC and 30 minutes. On these substrates, Kodak No. 2 step tablet, exposed at 250 mJ / cm ² or 800 mJ / cm ² , developed with 1% by mass aqueous solution of Na ₂ CO ₃ at a spray pressure of 0.2 MPa for 1 minute, and the number of steps where the coating film was completely left Was evaluated.

<Solder heat resistance>
The photocurable thermosetting resin composition obtained in each of Examples 1 to 4 and Comparative Examples 1 to 6 was applied to the entire surface of a printed wiring board on which a circuit was formed by screen printing, and was applied in a hot air circulation drying oven. It dried at 30 degreeC and 30 minutes. A negative film on which a solder resist pattern was drawn was applied to these substrates, exposed under an exposure condition of an exposure amount of 800 mJ / cm ² , and developed for 1 minute with a 1% by mass aqueous solution of Na ₂ CO ₃ at a spray pressure of 0.2 MPa. A resist pattern was formed. This substrate was thermally cured at 150 ° C. for 60 minutes to prepare an evaluation substrate.
The evaluation substrate was coated with a rosin-based flux and immersed in a solder bath set at 260 ° C. in advance for 10 seconds or 30 seconds. After the flux dipped in the solder-immersed substrate was washed with isopropyl alcohol, a peel test was performed using a cellophane adhesive tape, and the swelling, peeling, and discoloration of the resist layer were evaluated according to the following criteria.
：: no change observed at all △: slight change in color change etc. ×: swelling or peeling of resist layer

<Dielectric constant, dielectric loss tangent>
The photocurable thermosetting resin compositions obtained in Examples 1 to 4 and Comparative Examples 1 to 6 were respectively coated on the mirror surface of a copper foil by screen printing using a 100 Mesh tetron bias plate. Drying was performed for 15 minutes in a hot-air circulation drying oven, and after natural cooling to room temperature, re-printing was performed again. After drying for 15 minutes, third printing was performed. After performing the final drying for 20 minutes, using an opening mask of 1.7 mm × 100 mm, exposure was performed with an exposure machine HMW-680GW of a metal halide lamp manufactured by Oak Manufacturing Co. under an exposure condition of 800 mJ / cm ² , and 1 mass% Na _{2 was used.} Development was performed for 2 minutes with a developer manufactured by Tokyo Kakoki using an aqueous solution of CO ₃ , and post-curing was performed at 150 ° C. for 1 hour, and then peeled off from the copper foil to prepare a cured coating film for evaluation.
The dielectric constant and the dielectric loss tangent (tan δ) were measured using a network analyzer E-507 manufactured by Keysight Technologies, Inc. using a cavity resonator (5 GHz) manufactured by Kanto Electronics Application Development Co., Ltd. Table 2 and FIG. 1 show average values of three measurements of the same sample having the same dielectric constant and dielectric loss tangent (tan δ).

Claims (6)

Photosensitive resin containing mosquitoes carboxyl group and (A),
A photopolymerization initiator (B);
A compound (C) having an oxazoline group capable of reacting with a carboxyl group of the photosensitive resin (A),
A photocurable thermosetting resin composition containing
The photosensitive resin (A) containing a carboxyl group reacts an unsaturated monocarboxylic acid (a2) with an epoxy group of a polyfunctional epoxy resin (a1), and the reaction product is reacted with a polybasic acid anhydride. A compound obtained by subjecting a reaction product obtained by reacting the product (a3) to a hydrolysis-condensation reaction with a silane compound containing at least one alkoxysilane compound having a (meth) acryloyl group with respect to a hydroxyl group of the reaction product ( A photocurable thermosetting resin composition, which is a carboxyl group-containing photosensitive organic-inorganic hybrid resin varnish obtained by reacting D) and partially hybridizing.   The photocurable thermosetting resin composition according to claim 1, wherein the polyfunctional epoxy resin (a1) is a dicyclopentadiene type epoxy resin.   The photocurable thermosetting resin composition according to claim 1 or 2, wherein the unsaturated monocarboxylic acid (a2) is (meth) acrylic acid.   The photocurable thermosetting resin composition according to any one of claims 1 to 3, wherein the compound (C) having an oxazoline group is a compound having at least one of styrene, acryl, and derivatives thereof as a main skeleton. object.   A cured product obtained by applying the photocurable thermosetting resin composition according to any one of claims 1 to 4 to a substrate and photocuring by irradiation with active energy rays.   A cured film obtained by applying a photocurable thermosetting resin composition according to any one of claims 1 to 4 on a substrate and forming a film by photocuring in a pattern. A printed wiring board characterized by the following.

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