JP4504142B2 - Photoradical generator, photosensitive resin composition, and article - Google Patents

Description

The present invention was prepared using a radical generator comprising a compound having a molecular structure having an ethylenically unsaturated group together with a self-cleaving photoradical generation site, a photosensitive resin composition containing the same, and the resin composition. It relates to goods.
More specifically, the present invention, first of all, has a function as a photo radical initiator and a function as a polymerizable compound, and has a self-cleaving type high reaction potential (high sensitivity), but also initiates a photo radical. The present invention relates to a photoradical generator having a high ability to fix a cleavage portion of an agent in a matrix and excellent compatibility with a monomer component.

Secondly, the present invention contains the above radical generator, can reduce odor (outgas) at the time of exposure or post-baking, and is a volatile low-molecular decomposition product remaining in the product after curing, It is related with the photosensitive resin composition which can reduce especially an odor component.
Thirdly, the present invention relates to an article having high heat resistance and high stability, which is at least partially formed from a cured product of the photosensitive resin composition and has little deterioration due to heat.

Photosensitive resins that cure or change solubility upon irradiation with light such as ultraviolet rays are generally those with good solubility in the exposed area (positive type) and those with good solubility in the unexposed area (negative type). ). In the case of the negative type, since the photosensitive resin itself is cured and becomes insoluble by exposure, the photosensitive resin often remains on the substrate and becomes a part of the product as a functional film.
Negative-type photosensitive resins have been used initially in, for example, paints, printing inks, overcoat layers, adhesives, printing masters, etc., but in recent years, solder resists for wiring protection of printed wiring boards, interlayer insulating films, Applications have expanded to resists for forming color filter pixels, antireflection films, holograms, and the like.

  One of the commonly used negative photosensitive resins is a compound having one or more ethylenically unsaturated bonds, a photoradical initiator that generates radicals by light irradiation, and developability and coating as required. There is a resin composition in which a polymer compound that imparts film flexibility, an inorganic filler, a pigment, and the like are blended. When this composition is irradiated with light, a compound having an ethylenically unsaturated bond is bonded by a radical reaction, and is cured with a large molecular weight. During this curing reaction, the three-dimensional network structure is developed by a crosslinking reaction, whereby the hardness, strength, adhesion, solvent resistance, and heat resistance of the resulting cured product are improved.

  Photoradical initiators are generally classified into self-cleavage type (Type I) and non-degradable type (Type II) (Non-Patent Document 1). In the former case, like a benzoin ether compound, by absorbing light of a specific wavelength, the bond at the site corresponding to that wavelength is cleaved, and radicals are generated at each of the divided sites. The radical reaction begins. In the latter case, it is a radical generation mechanism that generates radicals without decomposing radical initiators when light of a specific wavelength is absorbed.For example, a hydrogen abstraction type represented by benzophenone absorbs electromagnetic waves of a specific wavelength. In the excited state, hydrogen is extracted from the surrounding hydrogen donor, and radicals are generated in each of the extracted hydrogen and the extracted hydrogen donor.

  In general, the self-cleavage type has good sensitivity and radical generation efficiency, but generates a low-molecular decomposition product when irradiated with light, which volatilizes in the work environment and causes odor, or re-coagulates after volatilization. There are problems that cause contamination and product defects, the low molecular decomposition products remain in the product and deteriorate the heat resistance and stability of the product, and the low molecular decomposition products are gradually released from the product.

  On the other hand, the hydrogen abstraction type does not cause problems such as the generation or residue of low molecular decomposition products derived from the initiator, but the hydrogen donor must exist in the vicinity of the excited initiator, and the energy for extracting hydrogen. Since the radical generation efficiency is determined by the size of the barrier, there is a problem that the sensitivity is relatively low.

To give a more realistic example, we face the problem of self-cleaving initiators in the following use situations.
As a first example, use in a solder resist or a colored resist can be mentioned. Solder resist used for the surface coating of printed wiring boards is mixed with organic pigments and fillers to provide heat resistance and flame retardancy. Color filter pixel forming resists contain pigments for color display. Have been mixed. Since these pigments are components that absorb light, in order to increase the sensitivity of the photosensitive resin, a self-cleavage type photo radical initiator is mainly used, and a large amount is expected in anticipation that it is not effectively used in radical reactions. Mixing. Here, the unreacted initiator, which was not cleaved even by irradiation, was lost due to the reaction in the solid phase due to the reaction in the solid phase even after radicalization by cleavage. There is a part to live.

  Therefore, since a large amount of initiator is used, a large amount of low-molecular decomposition products are generated at the time of light irradiation, and an odor is generated. In addition, in the cured product after exposure, a large amount of the residue derived from the initiator is present, of which the uncleavable photoradical initiator remains reactive after exposure, and thus alters the cured product. . In addition, the uncleavable photoradical initiator and the low-molecular decomposition product that has been cleaved but deactivated without being consumed by the radical reaction are not bonded to the crosslinked structure of the matrix, and are contained in the cured product as independent components. Exists and inhibits physical properties. Therefore, if the initiator-derived residue is left as it is, it will cause deterioration of light resistance, coloring and fading, peeling of the coating film and generation of cracks, etc., resulting in final products such as interlayer insulation films and solder resists for electronic parts, color This causes a decrease in the reliability of the filter pixel forming resist.

Since the self-cleaving type photo radical initiator has a strong sublimation property and decomposes by heat, it can be removed from the product by post-baking the product after exposure and development at a temperature of hundreds of degrees C. or more. However, a large amount of the sublimate derived from the initiator adheres to the heating device during post-baking, and it falls on the product obtained by curing, causing a product defect, which is a problem. In addition, there is a problem from the viewpoint of work safety because the decomposition product of the initiator is included in the atmosphere around the heating device.
It is possible to remove more radical initiator-derived residues by setting the post-baking conditions at a higher temperature and for a longer time, but because of volatilization from the solid, it is possible to completely remove it. Have difficulty. If conditions are stricter to remove more impurities derived from radical initiators, the conditions may cause product defects.

  As a second example, use in a resist for a release film can be mentioned. A photo-curing system similar to the solder resist is used for a resist for processing an electronic member used as a release film and a dry film resist. Although the resist for processing is finally peeled off and does not remain in the product, it is an initiator from the resist film in a chemical solution such as ferric chloride or cupric chloride used for processing in processing steps such as copper wiring formation. There was a problem that the residue of the origin was eluted and the life of the chemical solution was shortened.

  Further, as a third example, use in a coating material for a protective film can be mentioned. When a photosensitive resin is used as a paint for a protective film that protects the wallpaper of a building or the surface of a wall, reduction of solvent components and odor components from the entire building material is required from the viewpoint of measures against sick house syndrome. However, by using a highly volatile initiator, there was a problem that odor was generated even after the coating film was cured.

  As one of means for solving these problems, ESACURE KIP 150 (trade name) is commercially available from Nippon Shibel Hegner. This ESACURE KIP 150 has a structure in which a photoradical generation site is introduced into a side chain of a polymer skeleton. With such a structure, the photoradical generator has a plurality of radical generating sites in one molecule, so if one of the sites in the molecule is radicalized and bonded to the coating matrix, the same. Since unreacted radical generation sites in the molecule are also bonded to the matrix structure via the polymer skeleton, they do not volatilize during post-baking and do not move through the coating, reducing the reliability of the final product. There are few things.

  However, since ESACURE KIP 150 has a polymer skeleton and a relatively large molecular size, it is difficult to move in the photosensitive resin composition. Further, the sensitivity wavelength does not match the irradiation wavelength of the general-purpose light source. Therefore, the practical sensitivity in the resin composition is not so high, and there is a problem that the photoradical reactivity is difficult to increase.

  As another solution, LUNA 750 (trade name) is commercially available from Nippon Siebel Hegner. This LUNA750 introduces a functional group (side chain) with a large molecular weight into a self-cleaving type photoradical generation site having an α-aminoacetophenone skeleton, and converts the portion that is cleaved and released at the time of radical generation into a large molecule. It is possible to reduce the volatilization (outgas) of decomposition products. However, in this case, the volatilization temperature increases due to the increase in the molecular weight of the cleavage portion, and the gas does not easily gasify, and remains in the coating film as a decomposition product independent of the matrix structure of the coating film. For this reason, it cannot sufficiently cope with problems such as deterioration of product due to decomposition products, volatilization / elution of decomposition products, generation of odors, and the like, resulting in reduced reliability of final products such as coating films. In addition, when developing or washing an intermediate product or a final product, it is not possible to cope with a problem that a decomposition product derived from an initiator or an unreacted material is eluted into a developing solution or a washing solution.

Photo-curing technology, 39 pages, Technical Information Association, 2000

  The object of the present invention is to solve the above-mentioned problems of the self-cleaving photoradical generator. Specifically, the first object is to have the same sensitivity as that of a conventional self-cleaving initiator, and volatilization of low-molecular decomposition products from the resin composition or intermediate product during light irradiation or post-baking. It is an object of the present invention to provide a radical generator that can reduce generation of odor and odor and does not substantially leave a low-molecular decomposition product independent of the matrix of the cured product in the final product after photocuring.

In addition, the second object of the present invention is to contain the above radical generator, so that there is little volatilization or odor generation of low-molecular decomposition products during use, and low-molecular decomposition products remain in the final product after photocuring. It is providing the photosensitive resin composition.
Furthermore, the third object of the present invention is to provide an article having high heat resistance and high stability, which is at least partially formed using the photosensitive resin composition and hardly causes deterioration due to heat.

In order to solve the above problems, the photoradical generator provided by the present invention is characterized by comprising a compound (a1) represented by the following formula (1 ′) .

（ただし、式（１’）においてＲ ^１ は、水素原子又はメチル基で、Ｒ ^２ 及びＲ ^３ は、それぞれ水素原子である。Ｘ _１ は硫黄原子又は窒素原子でベンゾイル構造に結合している２価の基であり、Ｙは脂肪族３級アミン構造を持つ１価の基である。ｎは３〜１５の整数である。）
本発明の光ラジカル発生剤は、自己開裂型ラジカル発生剤としての機能と、硬化反応性化合物としての機能を兼ね備えている。
本発明の光ラジカル発生剤に光を照射すると、自己開裂型光ラジカル発生部位が開裂し、ラジカルを発生させる。この時に生成する断片は、エチレン性不飽和基を有しているので、当該エチレン性不飽和基の重合反応により硬化物のマトリックス構造に結合し、固定される。従って、硬化物のマトリックスから独立して存在する低分子分解物の生成量が少ない。

(In the formula (1 ′) , R ¹ is a hydrogen atom or a methyl group, and R ² and R ³ are each a hydrogen atom. X ₁ is a sulfur atom or a nitrogen atom that is bonded to the benzoyl structure 2. And Y is a monovalent group having an aliphatic tertiary amine structure, and n is an integer of 3 to 15. )
The photo radical generator of the present invention has a function as a self-cleaving radical generator and a function as a curing reactive compound.
When the photoradical generator of the present invention is irradiated with light, the self-cleaving photoradical generation site is cleaved to generate radicals. Since the fragment | piece produced | generated at this time has an ethylenically unsaturated group, it couple | bonds with the matrix structure of hardened | cured material by the polymerization reaction of the said ethylenically unsaturated group, and is fixed. Therefore, the amount of low-molecular decomposition products that exist independently from the matrix of the cured product is small.

As a result, the amount of low-molecular decomposition products that volatilize during light irradiation or post-baking is significantly reduced, and in particular, odor is reduced. The amount of decomposition products that re-solidify after volatilization and adhere to the manufacturing apparatus or product, or the amount of decomposition products that elute into the developer or cleaning solution, is significantly reduced. Furthermore, the amount of low-molecular decomposition products remaining after curing is reduced, and the heat resistance and stability of the final product are significantly improved.
In addition, the molecular size before the radical reaction of the photoradical generator of the present invention is much smaller than that of the polymer. Therefore, the compatibility with other components, such as a monomer component and a solvent, and solubility are high, and it can move around comparatively freely in the photosensitive resin composition. As a result, it has the same sensitivity as a conventional self-cleaving photoradical initiator.

Next, the photosensitive resin composition according to the present invention contains the photo radical generator according to the present invention as an essential component.
When the resin composition of the present invention is applied in a predetermined pattern or formed into a predetermined shape and then irradiated with light, a photoradical reaction is initiated, and various radical reactions such as radical polymerization proceed to cure and / or cure. Or it causes a change in solubility. In this radical reaction, the photoradical generator composed of the compound ( a1 ) acts as a self-cleaving radical generator and efficiently generates radicals, so that high sensitivity is obtained.

Further, at least one of the fragments generated by the cleavage of the compound ( a1 ) is bonded to the matrix of the cured product by the reaction of the ethylenically unsaturated group and becomes a part of the chemical structure. As a result, the amount of the low-molecular decomposition product derived from the radical generator is extremely small compared to the case where a conventional self-cleaving radical generator is used. Therefore, the amount of volatilization of low-molecular decomposition products is reduced during exposure and post-baking, and the odor is particularly reduced. In addition, the problem that the volatilized low-molecular decomposition product re-solidifies or elutes into the developer or the like is also improved.
Furthermore, since the amount of the low-molecular decomposition product remaining in the final product is small, there is an effect of high heat resistance and high stability. Therefore, the problem of reducing the reliability of the final product is also solved.

  The photosensitive resin composition as a pattern forming material, paint or printing ink, color filter, electronic component, interlayer insulating film, wiring coating film, optical member, optical circuit, optical circuit component, antireflection film When used as a material for forming holograms or building materials, there is an effect that products and films have high heat resistance and high stability. In addition, since no odor is generated during exposure, the working environment is improved.

The photo radical generator of the present invention can reduce the generation of low-molecular decomposition products while having a high self-cleavable reaction potential. According to the present invention, odor which is one of the problems of a self-cleaving radical generator can be reduced.
In particular, when the photo radical generator contains an aromatic component such as benzaldehyde, which is a cause of strong odor among odors, fixing the aromatic component to the matrix is extremely effective in reducing odor. Can be expensive.
Accordingly, the photoradical generator of the present invention is used as a photoradical generator for initiating and advancing radical reactions such as radical polymerization by excitation by irradiation with light.

Further, since the photo radical generator of the present invention has a function as a self-cleaving photo radical initiator and a function as a polymerizable compound, it is suitable as a curing reactive component having a photo radical initiating action itself. Used for.
Since the photosensitive resin composition of the present invention uses the photo radical generator of the present invention as an initiator, it has sufficient sensitivity for practical use, and uses a self-cleaving photo radical generator. There are few by-products of low molecular degradation products. In particular, the effect of reducing odor is great. In addition, since the amount of low-molecular decomposition products remaining in the final product is small, a highly reliable final product with high heat resistance and high stability can be obtained.

  The printed matter, color filter, electronic component, interlayer insulating film, wiring coating film, optical member, optical circuit, optical circuit component, antireflection film, hologram, or building material according to the present invention has high heat resistance and high stability. Since at least a part of the cured resin composition is formed, the product or film has high heat resistance and high stability, and therefore has a merit of high production yield.

  The present invention is described in detail below. The irradiation light used to cause the photoradical generation process in the present invention is visible and invisible which can radicalize the radical generation site of the photoradical initiator or cause the photosensitive resin composition to cause a radical reaction. This includes not only electromagnetic waves having a wavelength in the region, but also particle beams such as electron beams, and radiation or ionizing radiation that collectively refers to electromagnetic waves and particle beams. For curing the resin composition, an electromagnetic wave, an electron beam, ionizing radiation or the like having a wavelength of 2 μm or less is mainly used.

First, the photo radical generator according to the present invention will be described. The photoradical generator according to the present invention is characterized by comprising a compound (a) having one or more self-cleaving photoradical generation sites and one or more ethylenically unsaturated groups in one molecule.
The compound (a) has one or more self-cleaving photoradical generation sites and one or more ethylenically unsaturated groups in one molecule, and functions as a self-cleaving radical generator; It also functions as a curing reactive compound.

  In the present invention, the self-cleavable photoradical generation site of the photoradical generator is a site that absorbs light and excites and generates radicals with molecular structure decomposition (bond cleavage), that is, classified as Type I. It refers to the site that has a radical generation mechanism. Examples of self-cleaving photoradical generation sites include radical generation classified into Type I such as benzoin derivatives, benzyl ketal, α-acetoxyphenone, α-aminoacetophenone, acylphosphine oxide, titanocenes, O-acyloxime, etc. A structure in which a hydrogen atom at one or two or more positions to be bonded to an ethylenically unsaturated group is removed from a compound having a mechanism can be exemplified.

  In general, the self-cleaving photoradical initiator cleaves the molecular structure when generating radicals and generates a low-molecular decomposition product. As an example, an α-aminoacetophenone skeleton, which is known as a highly sensitive self-cleaving photoradical generation site, generates a benzoyl radical and an amino radical when it is excited by light to cause intramolecular cleavage. The polymerization reaction is expected to start when amino radicals or benzoyl radicals extract hydrogen from the reaction object (raw compound).

  In principle, each radical can bind to the end of the reaction product at the start of polymerization, but in reality, it generates hydrogen by extracting hydrogen from the surrounding molecules and deactivates itself in a cleaved state. It tends to be a decomposition product independent of polymer molecules. Low-molecular-weight decomposition products generated by cleavage of self-cleavable photoradical generation sites volatilize during light irradiation and post-bake to generate gas and odor, or re-solidify after volatilization and adhere to manufacturing equipment and products. Or, it does not volatilize and remains in the final product, causing problems such as loss of heat resistance and stability of the product.

  In particular, benzoyl radicals tend to extract hydrogen from surrounding molecules to form benzaldehyde and its analogs, and are difficult to bind to the surrounding matrix. Benzaldehyde and its analogs have a strong odor, which is a major cause of bad odor during light irradiation and post-baking, and it is difficult to volatilize completely during post-baking. It may also cause deterioration.

  In contrast to such a conventional self-cleaving photoradical initiator, the compound (a), which is a photoradical generator of the present invention, has an ethylenically unsaturated group in a portion that becomes a fragment by cleavage of the self-cleaving photoradical generation site. have. Therefore, when the photoradical reaction is initiated and advanced using the compound (a) as a photoradical initiator, the fragments generated by cleavage of the self-cleaving photoradical generation site are cured through an ethylenically unsaturated group. It is bonded to the matrix structure and fixed.

  As a result, the amount of low-molecular decomposition products that volatilize during light irradiation or post-baking is significantly reduced, and in particular, odor is reduced. The amount of decomposition products that re-solidify after volatilization and adhere to the manufacturing apparatus or product, or the amount of decomposition products that elute into the developer or cleaning solution, is significantly reduced. Furthermore, the amount of low-molecular decomposition products remaining after curing is reduced, and the heat resistance and stability of the final product are significantly improved.

  In addition, compound (a) has a considerable part of fragments generated by cleavage bonded to a polymerized or crosslinked matrix structure and becomes a part of a large molecule, but the molecular size before radical reaction is much smaller than that of a polymer. . Therefore, the compatibility with other components, such as a monomer component and a solvent, and solubility are high, and it can move around comparatively freely in the photosensitive resin composition. As a result, a resin composition having sensitivity equivalent to that of a conventional self-cleaving photoradical initiator and practically sufficient reactivity can be obtained.

  As the compound (a) having one or more self-cleaving photoradical generation sites and one or more ethylenically unsaturated groups in one molecule, for example, a compound (a1) represented by the following formula (1) Can be used.

(In the formula (1), R ¹ , R ² and R ³ are each independently a hydrogen atom, a halogen atom or a monovalent organic group. X is a divalent group and Y is 1) Valent group.)

  This compound (a1) has a self-cleaving photoradical generation site represented by-(C = O) -Y, and the bond is cleaved between the carbonyl carbon and the monovalent group Y, and Generate radicals. Among the generated radicals, when a fragment containing a benzoyl radical structure is deactivated to become benzaldehyde or an analog thereof having an independent molecular structure, it easily evaporates and causes a great odor. On the other hand, since the ethylenically unsaturated group of the compound (a1) is bonded to a portion that becomes a fragment containing a benzoyl radical structure by cleavage, benzaldehyde or a similar structure that causes a large odor is a cured product. It is bonded and fixed to the matrix structure. Therefore, in this case, the amount of low-molecular decomposition products with strong odor is extremely reduced, so that the effect of reducing odor is great.

R ¹ , R ² and R ³ present on the ethylenically unsaturated group of the compound (a1) are each independently a hydrogen atom, a halogen atom, or a saturated or unsaturated monovalent organic group. The monovalent organic group may contain a hetero atom other than C and / or a substituent. Preferred R ¹ , R ² and R ³ are each independently a hydrogen atom, a halogen atom, a saturated or unsaturated alkyl group, a saturated or unsaturated halogenated alkyl group, or a saturated or unsaturated hydroxyalkyl group, particularly Preferably, they are each independently a hydrogen atom, a halogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group. In particular, from the viewpoints of price, radical reaction rate, and final film physical properties, the ethylenically unsaturated group is a group in which R ¹ is a hydrogen atom, a halogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group. Most preferably, R ² and R ³ are each independently a hydrogen atom or a fluorine atom.

  Preferable examples of the ethylenically unsaturated group include acryloyl group, methacryloyl group, 2-trifluoromethylacryloyl group, and unsubstituted vinyl group.

  In the above formula (1), examples of the monovalent group Y contained in the self-cleaving type photoradical generation site include a structure containing an aliphatic ether or an aliphatic amine skeleton, and particularly an aliphatic tertiary amine structure. It is preferable that it has a group.

  In the formula (1), the chemical structure X connecting the ethylenically unsaturated group and the self-cleaving photoradical generation site may have any divalent or higher chemical structure, but typically 2 For example, a chemical structure represented by the following formula (2).

  In the divalent organic group represented by the above formula (2), X1 is a divalent organic group, X2 may be a bond capable of bonding to an ethylenically unsaturated group, and X3 is Any bond that can be bonded to the benzoyl structure may be used.

  The structure of the divalent organic group X1 is not particularly limited. Specifically, it is a linear, branched, or cyclic alkylene group, and preferably all have about 1 to 15 carbon atoms. However, these saturated alkylene groups have an aliphatic and / or aromatic cyclic site in the middle of the carbon skeleton, and / or ester bond, ether bond, thioether bond, amino bond, amide bond, urethane bond, urea bond Additional structures such as a bond, a thiocarbamate bond, a carbodiimide bond, or a carbonate bond may be contained alone or in combination of two or more. The divalent organic group X1 may be a polymer chain composed of a certain repeating unit such as a polycaprolactone structure.

  Specific examples of the structure X2 that can be bonded to an ethylenically unsaturated group include single bond, ester bond, ether bond, thioether bond, amino bond, amide bond, urethane bond, urea bond, thiocarbamate bond, carbodiimide bond, Although carbonate bond etc. are illustrated, if it is a well-known bivalent bond, it will not specifically limit.

  X2 is a single bond, an ester bond, an ether bond, a thioether bond, an amino bond, an amide bond, a urethane bond, a urea bond, a thiocarbamate bond, or in particular, in terms of price, availability, and ease of synthesis. Carbonate bonds are preferred.

  In addition, the structure X3 that can be bonded to the benzoyl structure can be the same structure as the structure X2, but the group that can adjust the absorption wavelength of the compound (a1) so that the irradiation wavelength has a lot of absorption. It is preferable that

  As a more specific compound belonging to the compound (a1) represented by the above formula (1), a compound (a3) represented by the following formula (3) can be exemplified.

(In the formula (3), R ¹ , R ² and R ³ are each independently a hydrogen atom, a halogen atom or a monovalent organic group. R ⁴ and R ⁵ are each independently hydrogen. An atom, an alkyl group having 1 to 15 carbon atoms (preferably 1 to 6 carbon atoms) R ⁶ and R ⁷ are each independently a monovalent organic group such as O, N, S, Si, etc. It may contain a heteroatom other than C, and R ⁶ and R ⁷ may combine to form a ring structure, X 1 is a divalent organic group, and X 2 and X 3 ′ are independent of each other. Divalent group.)

  In this compound (a3), S (sulfur) is bonded to the para-position of the benzoyl structure, and the carbonyl carbon of the benzoyl structure has a tertiary amine structure via a methylene group which may be alkyl-substituted. Has a combined structure. This structure has a high radical generating ability. In general, when a benzoyl radical containing S is deactivated and a benzaldehyde analog having an independent molecular structure is produced, it volatilizes and gives off a very strong odor. On the other hand, when the compound (a3) is used, even if the benzoyl radical is generated, the benzaldehyde analog containing S does not volatilize, so the odor is remarkably reduced.

  Moreover, since the amino radical produced | generated with a benzoyl radical has the high capability to start radical chain reaction, when this part can move around freely within a reaction system, especially high sensitivity is acquired. When the compound (a3) is used, since the amino radical portion has no ethylenically unsaturated bond, the amino radical can move freely in the photosensitive resin composition. Therefore, high sensitivity can be obtained.

  More specific examples of the compound belonging to the compound (a3) represented by the above formula (3) include a compound (a4) represented by the following formula (4).

(In the formula (4), R ^{1 to} R ⁷ are the same as those in the formula (3). N is an integer of 0 to 15, more preferably 0 to 8.)

  The tertiary amine structure portion of this compound (a4) has a morpholine skeleton. When the amino radical generated from this compound is finally deactivated, it becomes a morpholine having an independent molecular structure or its analog and volatilizes, but the morpholine has a weak odor compared to benzaldehydes. Therefore, the adverse effect on the work environment is small. In addition, since morpholines are highly volatile, they are easily removed from the product in the manufacturing process such as light irradiation and post-baking, and there is little residue. Therefore, a decomposition product having a morpholine skeleton is less likely to impair the heat resistance, stability, and reliability of the final product.

In order to improve the irradiation sensitivity of the compound (a) which is the photoradical generator of the present invention, it is desirable to have a chemical structure in which the radical generation site contained in the compound is excited by irradiation light and easily generates radicals. . For that purpose, a substituent (for example, R ^{4 to} R ⁷ ) or a linking structure (for example, X) contained in the compound (a) is selected to shift the absorption wavelength of light or change the extinction coefficient. Is considered effective.

  In order to obtain practical sensitivity, a part of the absorption wavelength of the compound (a) is emitted at any wavelength included in the exposure light source (irradiation light source) in the process by selecting the above-described substituents and linking structures. Preferably, the absorption maximum of the compound (a) is preferably within ± 20% of the value of the emission wavelength closest to the absorption maximum, and preferably within ± 10%. Further preferred.

Similarly, in terms of sensitivity, the molar extinction coefficient of the compound (a) is preferably 0.1 or more at any wavelength of light emitted from the exposure light source (irradiation light source) in the process. Here, the molar extinction coefficient ε is a relationship derived from Lambert-Beer's law and is expressed by the following equation.
A = εcb
A = absorbance b = optical path length in the sample (cm)
c = Concentration of solute (mol / L)

Normally, when the change in absorbance is recorded while changing the incident wavelength with a cell having the same optical path length using the same concentration solution, the absorbance changes depending on the wavelength, and the maximum molar absorption at the wavelength specific to the compound to be measured. The coefficient ε _MAX is shown. The molar extinction coefficient of the compound (a) at the exposure wavelength is 0.1 or more when the molar extinction coefficient when measured at any of the wavelengths employed when performing exposure using the compound (a) is 0. The maximum molar extinction coefficient ε _MAX does not mean 0.1 or more.

  In the case of a general high-pressure mercury lamp, there are three large light emissions of 365 nm (i-line), 405 nm (h-line), and 436 nm (g-line). It suffices if the compound (a) has an absorption maximum. In addition, when irradiation is performed with an F2 excimer laser (157 nm), an ArF excimer laser (193 nm), a KrF excimer laser (248 nm), etc., it is only necessary to have absorption near these wavelengths. Specifically, the absorption maximum near 365 nm is preferably in the range of 365 ± 73 nm, and more preferably in the range of 365 ± 37 nm.

  When the absorption wavelength overlaps with a region that overlaps at least one of the wavelengths 157 nm, 193 nm, 248 nm, 365 nm, 405 nm, and 436 nm, which are the main emission wavelengths of the above-described highly versatile exposure light source, the exposure wavelength is It is convenient to use, and it is particularly preferable that the molar extinction coefficient at the wavelength is 0.1 or more.

  Interpretation of the Ultraviolet Spectra of Natural Products (AIScott 1964) and identification methods by spectrum of organic compounds as a guideline on what substituents should be introduced to shift the absorption wavelength relative to the desired wavelength You can refer to the table described in the fifth edition (RMSilverstein 1993).

  When the photoradical generator of the present invention comprising the above compound (a) is used, fragments generated by cleavage of the self-cleaving photoradical generation site are bonded to the matrix structure of the cured product via the ethylenically unsaturated group. Therefore, the residue of highly volatile low-molecular decomposition products independent of the matrix structure is extremely small. Therefore, the stability of the finally obtained cured film is also improved, and deterioration of the light resistance of the coating film, coloring and fading, peeling of the coating film and cracking can be prevented.

From the viewpoint of heat resistance, the 5% weight loss temperature of the photoradical generator according to the present invention is preferably 50 ° C. or higher, more preferably 100 ° C. or higher, and particularly preferably 130 ° C. or higher. .
Here, the 5% weight reduction temperature is the time when the weight of the sample is reduced by 5% from the initial weight when the weight reduction is measured using a thermogravimetric analyzer in the same manner as in the examples of the present invention described later. Temperature. Similarly, the 10% weight reduction temperature is a temperature at which the sample weight is reduced by 10% from the initial weight.
The above-mentioned photoradical generator preferably has high solubility when blended in the resin composition from the viewpoint of improving the coating suitability, the transparency after curing, the sensitivity during exposure, and the like.

  From the viewpoint of coating suitability during coating, the photoradical generator is particularly preferably highly soluble in a solvent. Specifically, it is preferable that the solubility of the photoradical generator in the solvent to be used, particularly a general-purpose solvent described later, is 0.1% by weight or more.

  Also, even if the resin composition is transparently dissolved using a solvent, if the compatibility of the solids contained in the resin composition is low, it is deposited in the coating film while it is being dried. A thing is produced and sufficient transparency cannot be obtained. Therefore, when a highly transparent coating film or molded body is required as in an optical member, other solid components in the resin composition, particularly radical reactive compounds such as compounds having an ethylenically unsaturated group, It is preferable to use a photoradical generator having high compatibility. When high transparency is required, the total light transmittance (JIS K7105) is preferably 90% or more and 95% or more when the thickness of the coating film formed by curing the resin composition is 10 μm. More preferably.

  When the solubility of the photoradical generator in the radical reactive compound is high, the action as an initiator is improved, so that the sensitivity at the time of exposure is also excellent. From this point, when the solubility is evaluated using methyl acrylate as a representative monomer component, the saturation concentration of the photoradical generator with respect to methyl acrylate at 20 ° C. is preferably 0.01 mol / L or more. .

The solubility or compatibility of the photoradical generator is determined by taking into account the solvent to be dissolved or other solid components to be compatible, such as the substituents (for example, R ^{4 to} R ⁷ ) and the linked structure (for example, R ^{4 to} R ⁷ above). It can be improved by selecting X). For example, when a carboxyl group is selected as a substituent, it becomes easy to dissolve in water or an organic polar solvent, and when an ester is introduced, the solubility in a solvent or compound having an ester bond is improved.

  The compound (a) which is the photoradical generator of the present invention can be synthesized using various known methods. For example, a method of first synthesizing a compound having a self-cleaving photoradical generation site and then introducing an ethylenically unsaturated group into the compound, or a precursor that can be induced to the structure of the self-cleaving photoradical generation site First, an ethylenically unsaturated group is introduced, and then a method of inducing a part of the precursor to a self-cleaving type photoradical generation site is mentioned, but it is not particularly limited.

The method for synthesizing the compound represented by the above formula (a4) will be specifically illustrated below, but the present invention is not limited by the following method.
First, as a raw material, a self-cleaving radical generator having a substituent having an active hydrogen such as a hydroxyl group or an amino group is used. The ethylenically unsaturated group substitutes for the active hydrogen moiety. Although such a raw material compound is not particularly limited, for example, a compound obtained by modifying caprolactone at the benzophenone portion of α-aminoacetophenone can be used. As the caprolactone-modified moiety, one containing one to several caprolactones can be used. A commercial product of such a caprolactone-modified α-aminoacetophenone is LUNA750 (trade name: Nippon Siber Hegner Co., Ltd.).

  Next, the raw material compound and triethylamine are added to dehydrated tetrahydrofuran (THF) and stirred. Acrylic acid chloride is gradually added thereto until the spot of the raw material disappears by thin layer chromatography of the reaction solution, and subsequently stirred at room temperature for about 1 to 15 hours. The reaction solvent is not limited to the above tetrahydrofuran, and any solvent that dissolves the final product, such as an organic polar solvent, may be used. It is even better if the reaction solvent is dehydrated because the yield is improved.

After the stirring, the reaction solution is transferred to a separatory funnel, treated with 1N · HCl, and triethylamine is transferred to the aqueous layer. After separating into an aqueous layer and an oil layer, the oil layer is further treated with a saturated NaHCO ₃ solution, acrylic acid derived from unreacted acrylic acid chloride is moved to the aqueous layer, and the oil layer and the aqueous layer are separated. The separated oil layer is dehydrated with a suitable dehydrating agent such as magnesium sulfate and filtered. A product obtained by distilling off the solvent from the filtrate can be produced by column chromatography, recrystallization or the like to obtain the target product.

  The photo radical generator of the present invention thus obtained has a high self-cleavage type reaction potential (high sensitivity), and has a high ability to fix a fragment derived from a photo radical initiator in a matrix. Since it is excellent in solubility with components, it is used as a photo radical generator for initiating and advancing radical reactions such as radical polymerization by irradiating and exciting light. Further, since the photo radical generator of the present invention has a function as a self-cleaving photo radical initiator and a function as a polymerizable compound, it is suitable as a curing reactive component having a photo radical initiating action itself. Used for.

Next, the photosensitive resin composition according to the present invention (hereinafter simply referred to as “resin composition”) will be described.
The resin composition according to the present invention contains the above-mentioned photo radical generator as an essential component, and if necessary, a compound (b) having an ethylenically unsaturated group, a radical reactive compound other than the compound (b), Alternatively, a curing reactive compound other than the radical reactive compound, a high molecular weight binder component, a hydrogen donor, a radical generator other than the compound (a), or other components may be contained.

  When the resin composition according to the present invention is applied in a predetermined pattern or formed into a predetermined shape and then irradiated with light, a photoradical reaction is initiated, and radical polymerization, radical dimerization, radical crosslinking, etc. Various radical reactions proceed, causing changes in curing and / or solubility. In this radical reaction, the photoradical generator composed of the compound (a) acts as a self-cleaving radical generator and efficiently generates radicals, so that high sensitivity can be obtained. Further, since the compound (a) has at least one ethylenically unsaturated group, at least one of the fragments generated by cleavage is bonded to the matrix of the cured product by the reaction of the ethylenically unsaturated group, and its chemical structure Part of As a result, the amount of the low-molecular decomposition product derived from the radical generator is extremely small compared to the case of using a conventional self-cleaving radical generator. Therefore, the amount of volatilization of the low-molecular decomposition product is reduced during exposure and post-baking, the odor is reduced, and re-coagulation of the volatilized low-molecular decomposition product is also reduced. Moreover, since the molded object and coating film after hardening have few low molecular decomposition products which exist in the state independent of the matrix, there exists an effect of becoming high heat resistance and high stability. Therefore, the problem of reducing the reliability of the final product is also solved.

  Furthermore, since the photoradical generator composed of the compound (a) has an ethylenically unsaturated group and functions as a radical reactive compound, in the present invention, it is not necessary to mix other radical reactive compounds. A resin composition having photocurability can be prepared.

  Here, the term “crosslinking” refers to generation of a crosslinking bond, and the term “crosslinking” refers to a bond formed by bridging any two atoms among molecules composed of atoms bonded in a chain. In this case, the bond may be within the same molecule or between other molecules (Chemical Dictionary Tokyo Chemical Doujin p.1082). Here, “chain” includes an alicyclic ring structure.

  The compound (b) having an ethylenically unsaturated group has been heretofore widely used as a radically polymerizable curing reactive compound and has a wide range of applications, and is therefore preferably used in the present invention. As the compound (b), a compound having one or more ethylenically unsaturated bonds and a compound having another functional group together with at least one ethylenically unsaturated bond can be used. Ethylenically unsaturated group-containing compound, amide monomer, (meth) acrylate monomer, urethane (meth) acrylate oligomer, polyester (meth) acrylate oligomer, epoxy (meth) acrylate, hydroxyl group-containing (meth) acrylate, styrene An aromatic vinyl compound such as Here, (meth) acrylate means that either acrylate or methacrylate may be used.

Examples of the amide monomer include amide compounds such as N-vinylpyrrolidone, N-vinylcaprolactam, and acryloylmorpholine.
Examples of (meth) acrylate monomers include imide acrylates such as hexahydrophthalimidoethyl acrylate and succinimide ethyl acrylate; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-phenylpropyl Hydroxyalkyl (meth) acrylates such as acrylates; acrylates of alkylene oxide adducts of phenols such as phenoxyethyl (meth) acrylates and their halogen nucleus substitutions; mono- or di (meth) acrylates of ethylene glycol, methoxyethylene glycols Mono (meth) acrylate, tetraethylene glycol mono or di (meth) acrylate, tripropylene glycol mono or di (meth) acrylate, etc. Mono- or di (meth) acrylates of glycols; polyols such as trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate and pentaerythritol tetra (meth) acrylate, dipentaerythritol hexaacrylate and alkylene oxides thereof ( Examples include meth) acrylic ester, isocyanuric acid EO-modified di- or tri (meth) acrylate.

Examples of the urethane (meth) acrylate oligomer include a reaction product obtained by further reacting a hydroxyl group-containing (meth) acrylate with a reaction product of a polyol and an organic polyisocyanate.
Here, examples of the polyol include a low molecular weight polyol, polyethylene glycol, and polyester polyol, and examples of the low molecular weight polyol include ethylene glycol, propylene glycol, cyclohexanedimethanol, and 3-methyl-1,5-pentanediol. Examples of the polyether polyol include polyethylene glycol and polypropylene glycol. Examples of the polyester polyol include these low molecular weight polyols and / or polyether polyols, adipic acid, succinic acid, phthalic acid, hexahydrophthalic acid, and terephthalic acid. And a reaction product with an acid component such as a dibasic acid or an anhydride thereof.

  Examples of the organic polyisocyanate to be reacted with the polyol include tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate.

  As a polyester (meth) acrylate oligomer, the dehydration condensate of a polyester polyol and (meth) acrylic acid is mentioned. Examples of the polyester polyol include low molecular weight polyols such as ethylene glycol, polyethylene glycol, cyclohexanedimethanol, 3-methyl-1,5-pentanediol, propylene glycol, polypropylene glycol, 1,6-hexanediol and trimethylolpropane, and these And a reaction product from a polyol such as an alkylene oxide adduct and an acid component such as a dipic acid such as adipic acid, succinic acid, phthalic acid, hexahydrophthalic acid and terephthalic acid, or an anhydride thereof.

  Epoxy (meth) acrylate is obtained by addition reaction of unsaturated carboxylic acid such as (meth) acrylic acid to epoxy resin. Epoxy (meth) acrylate of bisphenol A type epoxy resin, epoxy of epoxy or cresol novolac type epoxy resin (Meth) acrylate, (meth) acrylic acid addition reactant of diglycidyl ether of polyether, and the like.

  The compound having an ethylenically unsaturated group preferably has 2 or more, particularly 3 or more ethylenically unsaturated bonds from the viewpoint of three-dimensional crosslinking of a radically polymerizable compound or a radically reactive compound other than radically polymerized.

In addition, when the resin composition is used as a resist for forming a pattern by exposure in applications such as an electronic member and a color filter, a compound having an ethylenically unsaturated group is used to improve the alkali developability of the resin composition. As (b), an alkali-soluble or hydrophilic functional group such as a carboxyl group, a phenolic hydroxyl group, a sulfonic acid group, or a hydroxyl group may be used.
In addition, the radical-reactive curable component such as compound (b) absorbs in the wavelength region where the irradiation wavelength and the absorption wavelength of the self-cleaving photoradical generation site overlap in order not to hinder the sensitivity of the resin composition to the irradiation light. It is preferable not to have.

In the photosensitive resin composition of the present invention, in order to adjust the film formability of the composition in an uncured state and the physical properties of the coated film after curing, a reaction method other than a polymer compound or radical reaction is used as a binder resin. A cured reactive compound may be blended.
As the binder resin, any known polymer compound or a curing reactive compound having a reaction form other than a radical reaction can be used according to the use of the resin composition. As the polymer compound, any of a non-reactive polymer and a polymer having a curable reactive group such as an ethylenically unsaturated group may be used.

  For example, organic polyisocyanates such as tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate; vinyl acetate, vinyl chloride, acrylate ester, methacrylate ester, etc. Polymers and copolymers of acrylic or vinyl compounds; styrene resins such as polystyrene; acetal resins such as formal resins and butyral resins; silicone resins; phenoxy resins; epoxy resins typified by bisphenol A type epoxy resins; polyurethanes, etc. Urethane resin; phenol resin; ketone resin; xylene resin; polyamide resin; polyimide resin; polyether resin; polyphenylene ether resin; Zole resin; Cyclic polyolefin resin; Polycarbonate resin; Polyester resin; Polyarylate resin; Polystyrene resin; Novolak resin; Cycloaliphatic polymer such as polycarbodiimide, polybenzimidazole, polynorbornene; Examples thereof include molecular compounds and curing reactive compounds.

  These polymer compounds or curing reactive compounds other than radical reactions may be used alone or in combination of two or more. The polymer compound as the binder component preferably has a weight average molecular weight of usually 3000 or more, depending on the use of the resin composition. In addition, if the molecular weight is too large, the solubility and processing characteristics are deteriorated. Therefore, the weight average molecular weight is usually preferably 10,000,000 or less.

  The amount of the photoradical generator of the present invention in the resin composition is required to obtain a sufficient radical generation amount in order to ensure a good curing rate and high crosslinking density and to improve the strength and glass transition temperature of the coating film. From this point, it is preferably 0.1% by weight or more of the total solid content of the resin composition. Furthermore, from the viewpoint of irradiation sensitivity and physical properties of the coating film, the amount of the photo radical generator is preferably 1% by weight or more of the total solid content of the resin composition. In addition, solid content of the photosensitive resin composition is all components other than a solvent, and a liquid monomer component is also contained in solid content.

  In order to obtain sufficient photocurability, the compound (b) having an ethylenically unsaturated group is preferably 1% by weight or more based on the entire solid content of the resin composition. In addition, the mixing ratio of the photo radical generator with respect to the compound (b) and other radical reactive compounds can be appropriately selected according to the type and amount of these radical reactive compounds or the use of the resin composition.

  When a binder resin such as a curable reactive compound other than a polymer or radical reaction is used, the content is preferably 1% by weight or more and 97% by weight or less based on the solid content of the entire resin composition. When there is more binder component resin than 97 weight%, the sclerosis | hardenability by light tends to fall.

  When the resin composition of the present invention is photocured, other photoradical generators may be used together with the compound (a) as necessary in order to promote the radical reaction. When other photoradical generators are used in combination, the other photoradical generators generate decomposition products, such as discoloration and physical properties of cured films, volatilization of decomposition products, stability of resin compositions, storage stability, etc. May cause problems. However, the combined use of compound (a) makes it possible to reduce the amount of other photoradical generators used, so that the above problems are less likely to occur than when only other photoradical generators are used. However, since the degree is light, the problem caused by the photo radical generator can be suppressed to a practically acceptable level while extracting sufficient radical reactivity.

  Other photo radical generators include, for example, benzoin such as benzoin, benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether and alkyl ethers thereof; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy 2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, etc. Anthraquinone, such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone and 2-amylanthraquinone; Thioxanthones such as dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone and 2,4-diisopropylpyroxanthone; ketals such as acetophenone dimethyl ketal and benzyldimethyl ketal; 2,4,6-trimethylbenzoyldiphenylphosphine oxide Monoacylphosphine oxides or bisacylphosphine oxides such as benzophenones such as benzophenone, and xanthones.

  These photo radical generators can be used alone or in combination with a photopolymerization initiation accelerator such as benzoic acid or amine. A preferable blending ratio of these photo radical generators is 0.1% by weight or more and 35% by weight or less, more preferably 1% by weight or more and 10% by weight or less based on the entire solid content of the resin composition.

In order to impart processing characteristics and various functionalities to the resin composition according to the present invention, various organic or inorganic low-molecular or high-molecular compounds may be blended. For example, dyes, surfactants, leveling agents, plasticizers, fine particles, sensitizers, and the like can be used. The fine particles include organic fine particles such as polystyrene and polytetrafluoroethylene, inorganic fine particles such as colloidal silica, carbon, and layered silicate, and the functions or forms include pigments, fillers, fibers, and the like.
The blending ratio of these optional components is preferably in the range of 0.1 wt% to 95 wt% with respect to the entire solid content of the resin composition. When the amount is less than 0.1% by weight, the effect of adding the additive is hardly exhibited, and when the amount exceeds 95% by weight, the characteristics of the resin composition are hardly reflected in the final product.

  When a large amount of a component that absorbs irradiation light is blended in the resin composition, light does not sufficiently reach the compound (a), which is a photoradical generator, and the sensitivity is lowered. Therefore, from the point of emphasizing the sensitivity of the resin composition, the transmittance of components other than the compound (a) in the wavelength region where the emission wavelength of the irradiation light source and the absorption wavelength of the compound (a) mixed in the resin composition overlap. Is preferably 20% or more.

  Moreover, you may dilute the resin composition which concerns on this invention to a suitable density | concentration using a solvent. As the solvent, various general-purpose solvents such as diethyl ether, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, and the like; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, Glycol monoethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether (so-called cellosolves); ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone, cyclopentanone, cyclohexanone; acetic acid Ethyl, butyl acetate, n acetate Propyl, i-propyl acetate, n-butyl acetate, i-butyl acetate, acetate esters of the above glycol monoethers (for example, methyl cellosolve acetate, ethyl cellosolve acetate), methoxypropyl acetate, ethoxypropyl acetate, dimethyl oxalate, lactic acid Esters such as methyl and ethyl lactate; alcohols such as ethanol, propanol, butanol, hexanol, cyclohexanol, ethylene glycol, diethylene glycol, and glycerin; methylene chloride, 1,1-dichloroethane, 1,2-dichloroethylene, 1-chloropropane, Halogenated hydrocarbons such as 1-chlorobutane, 1-chloropentane, chlorobenzene, bromobenzene, o-dichlorobenzene, m-dichlorobenzene; N, N-dimethylform Amides such as amide, N, N-dimethylacetamide; pyrrolidones such as N-methylpyrrolidone; lactones such as γ-butyrolactone; sulfoxides such as dimethyl sulfoxide; and other organic polar solvents, and the like. , Aromatic hydrocarbons such as benzene, toluene and xylene, and other organic nonpolar solvents. As the reactive diluent, a compound having a reactive group in the structure, such as an ethylenically unsaturated compound that is liquid at room temperature, may be used as a solvent. These solvents are used alone or in combination. In addition, these solvents may be used after filtering impurities by various known methods such as a filter having a pore size of about 0.05 μm to 0.2 μm.

  The resin composition may contain optional components such as a curing reactive compound such as the compound (b) having an ethylenically unsaturated group, a polymer binder component, and the like, as necessary, on the photo radical generator that is an essential component. The mixture can be prepared by mixing with stirring.

  The resin composition according to the present invention thus obtained is cured by irradiation with light, such as a pattern forming material (resist), a coating material, a printing ink, an adhesive, a filler, an electronic material, a molding material, and a three-dimensional modeling. It can be used in all known fields and products where materials that change or solubility change are used, but in particular, paints, printing inks, color filters, which require heat resistance and require high reliability. Suitable for forming electronic parts, interlayer insulating films, wiring coating films, optical members, optical circuits, optical circuit parts, antireflection films, holograms or building materials.

For example, in the case of a color filter, a pixel portion, a light shielding portion (black matrix) provided at the boundary of the pixel portion, a protective film, and a spacer for maintaining a cell gap are formed from a cured product of the photosensitive resin composition. can do.
In the case of an electronic component, for example, an underfill agent and a sealant for a semiconductor device can be exemplified.
As the interlayer insulating film, an interlayer insulating film for a build-up substrate that requires heat resistance and insulating reliability, an interlayer insulating film for a fuel cell, an insulating coating for automobile parts and household appliances, etc. It can be formed by a cured product.

Examples of the wiring protective film include a solder resist that is a wiring protective layer on the surface of the printed wiring board, and a surface coating of the electric wire.
In the case of an optical member, examples thereof include overcoats of various optical lenses, optical circuit components such as antireflection films, optical waveguides, and branching devices, relief-type and volume-type holograms, and the like.
In the case of building materials, wallpaper materials, wall materials, floor materials, and other skin materials with low volatile components, adhesive / adhesive materials, inks, and the like can be exemplified.
The printed matter, color filter, electronic component, interlayer insulating film, wiring coating film, optical member, optical circuit, optical circuit component, antireflection film, hologram, or building material according to the present invention has high heat resistance and high stability. Since at least a part of the cured resin composition is formed, it has high heat resistance and high stability, and therefore has a merit of high production yield.

Example 1
LUNA750 (trade name: Nippon Siebel Hegner Co., Ltd.) 5 g and 4-dimethylaminopyridine (DMAP) 12 which is a mixture of a benzophenone site of α-aminoacetophenone and a plurality of caprolactone modifications in a 500 ml eggplant type flask. 5 g and 300 ml of dried toluene were added and stirred. Thereto, 3 ml of acrylic acid chloride was added dropwise and stirred at room temperature for 1 hour. Thereafter, 1 ml of acrylic acid chloride was added dropwise every hour until the spot of the raw material disappeared by thin layer chromatography of the reaction solution. After completion of the reaction, the reaction solution was treated with distilled water and saturated aqueous sodium hydrogen carbonate solution in a separatory funnel, and then the organic solvent layer was dehydrated with magnesium sulfate, and the solvent was distilled off by a rotary evaporator. The reaction solution was purified by column chromatography to isolate Compound 1 represented by the following formula (5). This compound 1 has a structure in which a hexamer caprolactone modification site having an acryloyl group introduced at its terminal extends from the benzoyl group side of the radical generation site.

(Example 2)
In place of LUNA 750 of Example 1, the raw material compound A represented by the following formula (6) is a mixture having the same basic skeleton but different number of repeating units of caprolactone-modified sites, and mainly comprising the raw material compound A The product was reacted with acrylic acid chloride in the same manner as in Example 1 and purified to isolate compound 2 represented by the following formula (7). This compound 2 has a structure in which an acryloyl group is introduced at the terminal of the trimeric caprolactone modification site of the compound (A).

(Example 3)
In place of LUNA 750 of Example 1, a raw material compound B represented by the following formula (8) is a mixture having the same basic skeleton but different number of repeating units of caprolactone-modified sites, and mainly comprising the raw material compound B The product was reacted with acrylic acid chloride in the same manner as in Example 1, purified, and the compound 3 represented by the following formula (9) was isolated. This compound 3 has a structure in which an acryloyl group is introduced at the terminal of the trimeric caprolactone modification site of compound B.

Example 4
In place of LUNA 750 of Example 1, the raw material compound C represented by the following formula (10) is a mixture having the same basic skeleton but different number of repeating units of the caprolactone-modified site, and mainly comprising the raw material compound C The product was reacted with acrylic acid chloride in the same manner as in Example 1 and purified to isolate Compound 4 represented by the following formula (11). This compound 4 has a structure in which an acryloyl group is introduced at the end of the trimeric caprolactone modification site of compound C.

2. Evaluation test (1) Evaluation of heat resistance 5% by weight of Compound 1 at a heating rate of 10 ° C./min in a nitrogen atmosphere using a differential type differential thermal balance (product name: TG8120, manufactured by Rigaku Corporation) The decrease temperature was measured. As a comparative example, the same measurement was performed for LUNA750 (trade name, Nippon Shibel Hegner Co., Ltd.) and Irgacure 907 (trade name, manufactured by Ciba Specialty Chemicals). Both LUNA750 and Irgacure 907 are self-cleaving photoradical initiators. In particular, LUNA750 is a raw material for Compound 1, and has a structure in which the caprolactone modification site extends from the benzoyl group side of the radical generation site.

  Table 1 shows the 5% weight loss temperatures of Compound 1 and each comparative compound. Compound 1 was confirmed to have a significantly improved 5% weight loss temperature by introducing an acryloyl group as compared to LUNA750 and Irg907 having the same skeleton photopolymerization initiation site. From this result, it was found that by introducing an acryloyl group into the self-cleaving photoradical generator, the heat resistance is improved and the generation of volatile components by heating can be greatly reduced.

(2) Curability evaluation Using trifunctional pentaerythritol triacrylate (PETA) (trade name: M305, manufactured by Toagosei Co., Ltd.) as a polyfunctional monomer, compounds 1 to 4, LUNA 750 (trade name, Nippon Siber Hegner Co., Ltd.) )), And Irgacure 907 (trade name, manufactured by Ciba Specialty Chemicals) are mixed so that the photoradical generator site is 1/50 in molar ratio with respect to the double bond of the polyfunctional monomer, A THF solution was prepared. Each solution was spin-coated on a chromium-sputtered glass substrate to obtain a coating film. Moreover, the coating film of only the trifunctional acrylate which does not contain an initiator component was used as the blank.

While the coating film was exposed to UV, the amount of decrease in the peak at 810 cm ⁻¹ was recorded over time with an infrared spectrometer (product name: FTS6000, manufactured by BIO RAD), and how much the disappearance of the double bond progressed. I confirmed that I was doing. The atmosphere around the sample at the time of measurement was replaced with nitrogen. The UV exposure apparatus used was Ushio Electric's UV spot cure SP-III type (standard reflector type), and the UV lamp used was USH-255BY (Ushio Electric).

  Table 2 shows the results of observations regarding the compatibility with the trifunctional acrylate M305, the odor during exposure, the amount of reduction of double bonds (reaction rate) with respect to the exposure amount, and the coloring of the coating film.

From this result, it was found that, although Compound 1 had a slight reduction in reaction rate due to the introduction of acryloyl group as compared with LUNA 750, the reaction rate was rather improved as compared with Irgacure 907 and showed good sensitivity. The reaction rate is higher than that of Irgacure 907 having the same radical generating site because the caprolactone site, which is a side chain introduced into the skeleton of Compound 1 and LUNA 750, is a flexible skeleton. This is presumed to be due to the increased mobility and improved mobility of radicals and reactive groups.
Compounds 1 and 2 are suitable when the degree of coloration of the coating film is large but high sensitivity and high sensitivity is required. Compounds 3 and 4 are relatively low in sensitivity but have little coloration and high transparency. It is considered that it is suitable for applications that require high performance.

(3) Outgas test Compound 1 and pentaerythritol triacrylate (PETA) (trade name: M-305, manufactured by Toagosei Co., Ltd.), compound 1 double bond and PETA double bond in a molar ratio of 1/50 (= Compound 1 / PETA) was mixed at a ratio, and further diluted with chloroform so that the solid content was 20 wt%. (Photosensitive resin composition 1)
Moreover, the compound 2-4 was used instead of the compound 1, and the photosensitive resin compositions 2-4 were prepared with the same method.

The photosensitive resin compositions 1 to 4 are spin-coated on a glass substrate, heated on a hot plate at 50 ° C. for 1 minute, and then subjected to high pressure using a manual exposure apparatus (manufactured by Dainippon Screen Co., Ltd., MA-1200). An exposure of 2000 mJ / cm ^{2 in} terms of h-ray was performed with a mercury lamp to obtain a coating film having a thickness of 25 μm.
As a comparative example, a photosensitive resin composition was prepared in the same procedure for Irgacure 907, and a coating film was obtained.

Each glass substrate on which a coating film was formed was cut into a size of 1 cm × 1.5 cm, and the gas generated when heated at 250 ° C. for 1 hour was converted to GC-MS (QP-5000 manufactured by Shimadzu Corporation). And analyzed. Other measurement conditions are as follows.
Collection device: Japan Analytical Industry Co., Ltd. Curie Point Purge and Trap (JHS-100A type)
Heating conditions: 250 ° C x 60 min
Adsorbent: TENAX TA (2,6-Diphenyl-p-Phenylene Oxide) Weak polarity Collection temperature: -40 ° C (liquid nitrogen used for cooling)
Thermal decomposition temperature: 255 ° C x 30 s
Inlet temperature: 250 ° C
Column: 5% phenyl-95% dimethylsiloxane (PTE-5) slightly polar
Inner diameter: 0.25 μm Length: 30 m
Column temperature: 50 ° C. × 5 min (hold) −10 ° C./min (temperature rise) −320 ° C. × 3 min (hold)
Ionization method: Electron impact ionization method (EI method)
Detector: Quadrupole detector

As a result of the outgas test, a degradation product derived from the polyfunctional monomer M-305 was detected from any of the samples using the compounds 1 to 4 or Irgacure 907.
Further, as an outgas component derived from the initiator from the coating film using Compound 1, a compound having a morpholine skeleton was slightly detected, but a compound containing an aromatic ring was not detected. On the other hand, as an outgas component derived from the initiator from the coating film using Irgacure 907, in addition to a compound having a slight morpholine skeleton, a compound containing an aromatic ring such as benzaldehyde or acetophenone was detected.
For compounds 3 and 4, no aromatic compound was detected as an outgas component. For Compound 2, aromatic compounds were detected, but benzaldehyde and acetophenone were not detected.
From the above facts, it has been found that the compound of the present invention is effective in reducing components containing an aromatic ring that causes odor among the outgas derived from the initiator.

Claims (7)

The photoradical generator which consists of a compound (a1) represented by following formula (1 ') .

(In the formula (1 ′) , R ¹ is a hydrogen atom or a methyl group, and R ² and R ³ are each a hydrogen atom. X ₁ is a sulfur atom or a nitrogen atom that is bonded to the benzoyl structure 2. And Y is a monovalent group having an aliphatic tertiary amine structure, and n is an integer of 3 to 15. )   The photoradical generator according to claim 1, wherein the 5% weight loss temperature is 50 ° C or higher. A photosensitive resin composition comprising, as an essential component, at least one photoradical generator selected from the group consisting of the compound ( a1 ) according to claim 1 or 2. At least selected from the group consisting of a compound (b) having an ethylenically unsaturated group, a curing reactive compound other than the compound (b), a radical generator other than the compound ( a1 ), and a binder resin having a weight average molecular weight of 3000 or more. The photosensitive resin composition of Claim 3 which further contains one component.   The photosensitive resin composition according to claim 3, wherein the photosensitive resin composition is used as a pattern forming material.   The paint or printing ink, or a color filter, an electronic component, an interlayer insulating film, a wiring coating film, an optical member, an optical circuit, an optical circuit component, an antireflection film, a hologram or a building material, 4. The photosensitive resin composition according to 4.   A printed material, a color filter, an electronic component, an interlayer insulating film, a wiring coating film, an optical member, an optical circuit, light, which is at least partly formed by a cured product of the photosensitive resin composition according to claim 3 or 4. Articles that are either circuit components, antireflection films, holograms, or building materials.