Photosensitive composition

Abstract

To provide a photosensitive composition that can yield a cured product exhibiting superior breaking strength and toughness.SOLUTION: A photosensitive composition comprises a polyfunctional (meth)acrylate (A) represented by the general formula (1), a monofunctional (meth)acrylate (B) having an alicyclic structure, a monofunctional (meth)acrylate (C) having an aromatic structure, and a photopolymerization initiator (D). (In the formula, R1 and R3 are the same or different and each represent an organic group having 1 to 4 valences and containing no aromatic ring; R2 is a 2- to 4-valent organic group containing no aromatic ring; and X represents a structure represented by the general formula (2)).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a photosensitive composition, and more particularly to a photosensitive composition that can give a cured product having excellent breaking strength and toughness. [Background technology]

[0002] Photosensitive compositions that can react and cure with light are being considered for use in a variety of applications, such as various optical components, such as color filters, photoresists, inks, hard coats, and optical films used in liquid crystal display devices, as well as electrical and electronic devices, and resin compositions with excellent properties required for each application are being developed. In recent years, optical components, electrical and electronic devices, and the like have become smaller, thinner, and more energy-efficient, and this has led to demands for higher performance from the various components used. In order to meet such demands, research is being conducted on photosensitive compositions that can be used as materials for various components, etc.

[0003] Various photosensitive compositions have been proposed so far. For example, Patent Document 1 discloses an active energy ray-curable coating composition that is capable of forming a cured coating film that has excellent reactivity to active energy rays and excellent weather resistance and abrasion resistance, and that contains, based on 100 mass% of a radically polymerizable compound, 10 to 80 mass% of a specific mono- or polypentaerythritol poly(meth)acrylate compound modified with caprolactone, and 20 to 40 mass% of a urethane (meth)acrylate compound containing an isocyanurate skeleton.

[0004] Furthermore, for example, Patent Document 2 discloses a photosensitive resin composition containing a photopolymerizable compound containing at least one of a photopolymerizable monomer and a photopolymerizable oligomer, titanium oxide, and a polymerization initiator, the polymerization initiator containing an acylphosphine oxide-based polymerization initiator and a phenyl glyoxylate-based polymerization initiator. Furthermore, Patent Document 3 describes an active energy ray-curable coating resin composition containing a (meth)acrylate compound having a ring-opened structure of ε-caprolactone, and a phosphate ester compound having a hydrocarbon group with 8 or more carbon atoms and an ethylene oxide group.

[0005] Furthermore, for example, Patent Document 4 describes an active energy ray-curable composition that exhibits excellent mold releasability and water resistance after curing, and that contains a specific tetra- to hexafunctional (meth)acrylate, a bifunctional (meth)acrylate having an alicyclic skeleton, a tri- to hexafunctional (meth)acrylate having a specific divalent organic group in the molecule, and a specific photopolymerization initiator. Furthermore, Patent Document 5 describes a radically polymerizable ink composition that contains a monofunctional radically polymerizable unsaturated compound, a polyfunctional radically polymerizable unsaturated compound, a specific polymerization initiator, and a colorant. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-111810 [Patent Document 2] International Publication No. 2016 / 092718 [Patent Document 3] Japanese Patent Application Publication No. 2017-025217 [Patent Document 4] Japanese Patent Application Laid-Open No. 2019-94484 [Patent Document 5] Japanese Patent Application Laid-Open No. 2016-176043 Summary of the Invention [Problem to be solved by the invention]

[0007] When such a photosensitive composition is used to form a hard coat, an overcoat, an optical film, etc., it is desirable that the composition have high breaking strength and excellent toughness. However, with conventional photosensitive compositions, it has not been easy to obtain a cured product that is excellent in both breaking strength and toughness.

[0008] The present invention has been made in view of the above-mentioned circumstances, and has as its object to provide a photosensitive composition that can give a cured product having excellent breaking strength and toughness. [Means for solving the problem]

[0009] The present inventors have conducted extensive research into photosensitive compositions and have found that a cured product having excellent breaking strength and toughness can be obtained by containing a specific polyfunctional (meth)acrylate, a monofunctional (meth)acrylate having an alicyclic structure, a monofunctional (meth)acrylate having a specific aromatic structure, and a photopolymerization initiator, thereby completing the present invention.

[0010] That is, the present invention includes the following aspects. <1> A photosensitive composition comprising a polyfunctional (meth)acrylate (A) represented by the following general formula (1), a monofunctional (meth)acrylate (B) having an alicyclic structure, a monofunctional (meth)acrylate (C) having an aromatic structure represented by the following general formula (3), and a photopolymerization initiator (D).

[0011] [ka]

[0012] (In formula (1), R 1 and R 3 R are the same or different and represent a monovalent to tetravalent organic group not containing an aromatic ring. 2 represents a divalent to tetravalent organic group not containing an aromatic ring. X represents a structure represented by general formula (2). a and c are the same or different and represent an integer of 0 to 3, b represents an integer of 0 to 2, and m represents an integer of 0 to 6, and a+bm+c≧5 is satisfied. In formula (2), R 4 represents a hydrogen atom or a methyl group. 5 represents an alkylene group having 1 to 8 carbon atoms; d may be the same or different and represents an integer of 0 or 1; and n represents an integer of 1 to 3.

[0013] [ka]

[0014] (In formula (3), R 6 represents a hydrogen atom or a methyl group. 7 represents an alkylene group having 1 to 3 carbon atoms. 8 , R 9 and R 10 are the same or different and represent a hydrogen atom, an alkoxy group, or an alkyl group, an aryl group, an aralkyl group, or an aryloxy group, each of which may have a substituent. 8 , R 9 and R 10 At least one of R represents an alkoxy group, or an alkyl group, aryl group, aralkyl group, or aryloxy group, which may have a substituent. 8 and R 9 , or R 9 and R 10 may be bonded to each other to form an aromatic ring; e may be the same or different and represents an integer of 0 or 1; and f represents an integer of 1 to 3. <2> The photopolymerization initiator (D) is an acylphosphine oxide-based photopolymerization initiator. <1> The photosensitive composition according to claim 1. <3> The content of the polyfunctional (meth)acrylate (A) is 40 to 90% by mass in 100% by mass of the photosensitive composition. <1> or <2> The photosensitive composition according to claim 1. <4> The content of the monofunctional (meth)acrylate (C) having an aromatic structure is 4 to 30% by mass in 100% by mass of the photosensitive composition. <1> ~ <3> 1. The photosensitive composition according to any one of claims 1 to 9. <5> The content of the monofunctional (meth)acrylate (B) having an alicyclic structure is 5 to 30% by mass in 100% by mass of the photosensitive composition. <1> ~ <4> 1. The photosensitive composition according to any one of claims 1 to 9. <6> The content of the photopolymerization initiator (D) is 0.1 to 2% by mass in 100% by mass of the photosensitive composition. <1> ~ <5> 1. The photosensitive composition according to any one of claims 1 to 9. <7> The viscosity at 25°C is 100 mPa·s or more. <1> ~ <6> 1. The photosensitive composition according to any one of claims 1 to 9. <8> The photosensitive composition has a glass transition temperature of 10 to 60°C. <1> ~ <7> 1. The photosensitive composition according to any one of claims 1 to 9. [Effects of the Invention]

[0015] The photosensitive composition of the present invention can provide a cured product having excellent breaking strength and toughness, and is therefore suitable for various applications such as hard coats, optical films, microlenses, adhesives, overcoats, and insulating films. DETAILED DESCRIPTION OF THE INVENTION

[0016] The present invention will be described in detail below. In addition, a combination of two or more of the individual preferred embodiments of the present invention described below is also a preferred embodiment of the present invention. In addition, in this specification, "(meth)acrylate" means "acrylate and / or methacrylate", and "(meth)acrylic acid" means "acrylic acid and / or methacrylic acid".

[0017] The present invention is a photosensitive composition comprising a polyfunctional (meth)acrylate (A) represented by the above general formula (1), an alicyclic monofunctional (meth)acrylate (B), a monofunctional (meth)acrylate having an aromatic structure (C) represented by the above general formula (3), and a photopolymerization initiator (D).

[0018] The photosensitive composition of the present invention, having the above-described structure, can provide a cured product having excellent breaking strength and toughness. The reason why the photosensitive composition of the present invention can provide a cured product having excellent breaking strength and toughness is believed to be as follows: By including a long-chain polyfunctional (meth)acrylate, a flexible crosslinked structure can be formed during curing, thereby increasing the toughness of the cured product. Curing shrinkage can also be suppressed. Furthermore, by including a monofunctional (meth)acrylate having a specific aromatic structure and an alicyclic monofunctional (meth)acrylate, stacking interactions between molecules of the aromatic ring structure can be appropriately suppressed, resulting in a cured product with excellent toughness and without excessive strength. Each component contained in the photosensitive composition of the present invention will be described below.

[0019] (A) Polyfunctional (meth)acrylate The photosensitive composition of the present invention contains the polyfunctional (meth)acrylate (A) represented by the above general formula (1). In the above general formula (1), R 1 and R 3 R are the same or different and represent a monovalent to tetravalent organic group not containing an aromatic ring. 1 and R 3 The organic group represented by the formula (I) does not contain an aromatic ring, and therefore a highly flexible cured product can be obtained.

[0020] R 1 and R 3 Preferred examples of the organic group not containing an aromatic ring, represented by the formula (I), include an aliphatic hydrocarbon group or alicyclic hydrocarbon group which may have a substituent, or a group which contains an aliphatic hydrocarbon group or alicyclic hydrocarbon group which may have a substituent and at least one bond selected from the group consisting of -O-, -CO-, -COO-, -NH-, -S-, -SO-, and -SO-.

[0021] The aliphatic hydrocarbon group may be saturated or unsaturated, but is preferably a saturated aliphatic hydrocarbon group in terms of flexibility.

[0022] Specific examples of the monovalent aliphatic saturated hydrocarbon group include alkyl groups such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a t-amyl group, an octyl group, a 2-ethylhexyl group, a lauryl group, and a stearyl group.

[0023] The aliphatic hydrocarbon group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and even more preferably 1 to 10 carbon atoms, in view of good compatibility with other components.

[0024] Specific examples of the monovalent alicyclic hydrocarbon group include monocyclic hydrocarbon groups such as cycloalkyl groups, such as a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cyclooctyl group, a cyclododecyl group, a cyclobutenyl group, a cyclopentenyl group, and a cyclohexenyl group; and polycyclic hydrocarbon groups such as a dicyclopentanyl group, a dicyclopentenyl group, a tricyclodecanyl group, an adamantyl group, and an isobornyl group.

[0025] The alicyclic hydrocarbon group preferably has 6 to 20 carbon atoms, more preferably 6 to 15 carbon atoms, and even more preferably 6 to 10 carbon atoms, in terms of good compatibility with other components.

[0026] Divalent to tetravalent aliphatic hydrocarbon groups and alicyclic hydrocarbon groups include divalent to tetravalent groups obtained by further removing 1 to 3 hydrogen atoms from the above-mentioned monovalent aliphatic hydrocarbon groups and alicyclic hydrocarbon groups.

[0027] In the above aliphatic hydrocarbon group and alicyclic hydrocarbon group, at least one of the atoms constituting the hydrocarbon group may be substituted with an oxygen atom, a nitrogen atom, or a sulfur atom.

[0028] Examples of the substituent that the aliphatic hydrocarbon group and alicyclic hydrocarbon group may have include a hydroxyl group, a carboxyl group, an alkoxyl group, an alkyl group, a halogen atom, etc. It is preferable that the aliphatic hydrocarbon group and alicyclic hydrocarbon group have no substituent.

[0029] Examples of the group containing an aliphatic hydrocarbon group or alicyclic hydrocarbon group which may have a substituent and at least one bond selected from the group consisting of -O-, -CO-, -COO-, -NH2-, -S-, -SO- and -SO2- include -OR a1 -, -R a1 -O-, -(R a1 -O) p -R a2 -(p is an integer from 1 to 10), -SR a1 -, -SR a1 -S-, -SO-R a1 -, -R a1 -SO-R a2 -, -SO2-R a1 -, -R a1 -SO2-R a2 -(All R a1 and R a2 and are the same or different and represent the above-mentioned aliphatic hydrocarbon group or alicyclic hydrocarbon.) Among these, the above-mentioned optionally substituted aliphatic hydrocarbon group or alicyclic hydrocarbon group and a group containing -O- are preferred.

[0030] Among them, R 1 and R 3 The organic group represented by the formula (I) is preferably an aliphatic hydrocarbon group having 1 to 20 carbon atoms, more preferably an aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms, and even more preferably an aliphatic saturated hydrocarbon group having 1 to 10 carbon atoms, in view of good compatibility with other components.

[0031] R 1 and R 3 The organic group represented by the formula (I) is monovalent to tetravalent, but is preferably divalent to tetravalent, more preferably trivalent to tetravalent, in terms of flexibility.

[0032] R 2 R represents a divalent to tetravalent organic group that does not contain an aromatic ring. 2 The divalent to tetravalent organic group not containing an aromatic ring, represented by the formula (I), includes the above-mentioned R 1 and R 3Among the monovalent to tetravalent organic groups not containing an aromatic ring, which are represented by the following formula, groups similar to the divalent to tetravalent organic groups not containing an aromatic ring can be mentioned.

[0033] Among them, R 2 As the organic group represented by the formula (I), a group containing an aliphatic hydrocarbon group or an alicyclic hydrocarbon group which may have the above substituent and -O- is preferred in terms of flexibility.

[0034] R 2 The number of carbon atoms in the organic group represented by the formula (I) is preferably 2 to 20, more preferably 2 to 15, and even more preferably 2 to 12, in terms of good compatibility with other components.

[0035] [(XO) in the above general formula (1) a -R 1 ]-, for example, when a is 0, R 1 is a monovalent organic group, and when a is 1, R 1 is a divalent organic group, and when a is 2, R 1 is a trivalent organic group, and when a is 3, R 1 is a tetravalent organic group.

[0036] In the above general formula (1), -[R 3 -(OX) c ], for example, if c is 0, R 3 is a monovalent organic group, and when c is 1, R 3 is a divalent organic group, and when c is 2, R 3 is a trivalent organic group, and when c is 3, R 3 is a tetravalent organic group.

[0037] In the above general formula (1), m is preferably an integer of 0 to 6, and more preferably an integer of 0 to 3.

[0038] In the above general formula (1), a and c are the same or different and are an integer of 0 to 3, b is an integer of 0 to 2, and a+bm+c≧5 is satisfied. a and c may be the same or different and are more preferably integers of 1 to 3. b is more preferably an integer of 0 to 2. In the above general formula (1), it is more preferable that a+bm+c≧6 is satisfied, and it is even more preferable that 6≦a+bm+c≦8 is satisfied.

[0039] In the above general formula (1), X represents a structure represented by the above general formula (2). In the above general formula (2), R 4 represents a hydrogen atom or a methyl group. R 5 represents an alkylene group having 1 to 8 carbon atoms, preferably an alkylene group having 3 to 8 carbon atoms, and more preferably an alkylene group having 4 to 6 carbon atoms.

[0040] The polyfunctional (meth)acrylate (A) is preferably a compound represented by the following general formula (4).

[0041] [ka]

[0042] (In formula (4), Y represents a structure represented by general formula (5). In formula (5), R 11 represents a hydrogen atom or a methyl group. 12 represents an alkylene group having 1 to 8 carbon atoms; g is the same or different and represents an integer of 0 or 1; and h represents an integer of 1 to 3.

[0043] R 12 The number of carbon atoms in the alkylene group represented by the following formula is preferably 3 to 8, and more preferably 4 to 6, in terms of flexibility. In the above formula (5), g is preferably 1. In the above formula (5), h is preferably 1 to 3, and more preferably 2 or 3.

[0044] The polyfunctional (meth)acrylate (A) can be obtained, for example, by reacting raw material components containing a polyhydric aliphatic alcohol, a lactone compound, and (meth)acrylic acid by a known method.

[0045] Examples of the polyhydric aliphatic alcohol include trimethylolethane, ditrimethylolethane, trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, tripentaerythritol, and glycerin.

[0046] Examples of the lactone compound include β-propiolactone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, ε-caprolactone, enantholactone, caprylolactone, dodecanolactone, and compounds in which these lactones are substituted with one or more alkyl groups such as methyl groups.

[0047] The polyfunctional (meth)acrylate (A) can also be obtained, for example, by adding an alkylene oxide such as ethylene oxide to the polyhydric aliphatic alcohol and then reacting it with (meth)acrylic acid in a known manner.

[0048] The polyfunctional (meth)acrylate (A) may be a synthetic product, but commercially available products can also be used. Examples of commercially available polyfunctional (meth)acrylates include KAYARAD DPCA-60, DPCA-120, and KAYARAD DPEA-12 (all manufactured by Nippon Kayaku Co., Ltd.), and A-DPH-12E (manufactured by Shin-Nakamura Chemical Co., Ltd.).

[0049] The photosensitive composition of the present invention may contain only one type of the polyfunctional (meth)acrylate (A), or may contain two or more types.

[0050] The content of the polyfunctional (meth)acrylate (A) is more preferably 40 to 90 mass%, further preferably 40 to 80 mass%, and particularly preferably 45 to 70 mass%, based on 100 mass% of the photosensitive composition.

[0051] (B) Monofunctional (meth)acrylate having an alicyclic structure The monofunctional (meth)acrylate having an alicyclic structure is a monofunctional (meth)acrylate having an alicyclic hydrocarbon group and one (meth)acryloyl group in the molecule.

[0052] Examples of the alicyclic hydrocarbon group include monocyclic hydrocarbon groups such as cyclopropyl, cyclopentyl, cyclohexyl, cyclooctyl, cyclododecyl, cycloheptyl, cyclobutenyl, cyclopentenyl, and cyclohexenyl; and polycyclic hydrocarbon groups such as dicyclopentanyl, dicyclopentenyl, tricyclodecanyl, adamantyl, and isobornyl. Of these, polycyclic hydrocarbon groups are preferred because they can further improve the elastic recovery, hardness, and adhesion of the cured product of the photosensitive composition.

[0053] The alicyclic hydrocarbon group may be one in which at least one carbon atom constituting the alicyclic hydrocarbon group is substituted with an oxygen atom, a nitrogen atom, a sulfur atom, or the like, or one in which at least one hydrogen atom constituting the hydrocarbon group is substituted with a hydroxyl group, an alkyl group, an alkoxyl group, or the like.

[0054] The alicyclic hydrocarbon group preferably has 6 to 20 carbon atoms, more preferably 6 to 18 carbon atoms, even more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms, in terms of high strength.

[0055] The monofunctional (meth)acrylate (B) having an alicyclic structure preferably has a glass transition temperature (Tg) of 100° C. or higher in the form of a homopolymer. When a monofunctional (meth)acrylate (B) having an alicyclic structure and having a homopolymer glass transition temperature of 100°C or higher is used, heat resistance is improved, cure shrinkage can be prevented, and the adhesion of the cured product can be improved. The monofunctional (meth)acrylate (B) having an alicyclic structure more preferably has a homopolymer glass transition temperature (Tg) of 115° C. or higher. The upper limit of the glass transition temperature (Tg) of the homopolymer is not particularly limited, but is preferably 200° C. or lower in order to impart flexibility.

[0056] The glass transition temperature (Tg) of the homopolymer may be any of the values ​​described in POLYMER HANDBOOK (Polymer Handbook, 4th Edition, Wily Interscience, Chapter 6, page 200, etc.), J. Brandrup, EH Immergut, Polymer Handbook, 2nd Ed., J. Wiley, New York 1975, Photocuring Technology Data Book (Techno Net Books), etc.

[0057] Specific examples of the monofunctional (meth)acrylate (B) having an alicyclic structure include cyclohexyl (meth)acrylate, cyclohexylmethyl (meth)acrylate, isobornyl (meth)acrylate, 1-adamantyl (meth)acrylate, (3,4-epoxycyclohexyl)methyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, and tricyclodecanyl (meth)acrylate.

[0058] Among these, in terms of a high glass transition temperature and resistance to elimination of the alicyclic hydrocarbon, the monofunctional (meth)acrylate (B) having an alicyclic structure is preferably cyclohexyl (meth)acrylate, cyclohexylmethyl (meth)acrylate, isobornyl (meth)acrylate, 1-adamantyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, or tricyclodecanyl (meth)acrylate, more preferably cyclohexyl (meth)acrylate, cyclohexylmethyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, or dicyclopentenyl (meth)acrylate, and even more preferably isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, or dicyclopentanyl (meth)acrylate.

[0059] The photosensitive composition may contain only one type of the monofunctional (meth)acrylate (B) having an alicyclic structure, or may contain two or more types.

[0060] The content of the monofunctional (meth)acrylate (B) having an alicyclic structure is preferably 5 to 30 mass %, more preferably 10 to 25 mass %, and even more preferably 15 to 25 mass %, based on 100 mass % of the photosensitive composition, in terms of high strength.

[0061] (C) Monofunctional (meth)acrylate having an aromatic structure The monofunctional (meth)acrylate (C) having an aromatic structure is represented by the general formula (3).

[0062] In the above general formula (3), R 6 represents a hydrogen atom or a methyl group. 6 is preferably a hydrogen atom.

[0063] R 7 represents an alkylene group having 1 to 3 carbon atoms. 7is preferably an alkylene group having 1 to 2 carbon atoms.

[0064] R 8 , R 9 and R 10 are the same or different and represent a hydrogen atom, an alkoxy group, or an alkyl group, aryl group, aralkyl group or aryloxy group which may have a substituent.

[0065] R 8 , R 9 and R 10 The number of carbon atoms in the alkoxy group represented by the following formula is preferably 1 to 20, more preferably 1 to 15, and even more preferably 1 to 10, in terms of flexibility.

[0066] R 8 , R 9 and R 10 The alkyl group represented by the formula (I) may be linear or branched, but is preferably linear in terms of flexibility. The number of carbon atoms in the alkyl group is preferably 1 to 20, more preferably 2 to 15, and even more preferably 3 to 10, in terms of achieving both flexibility and sensitivity.

[0067] R 8 , R 9 and R 10 Examples of the aryl group represented by the formula (I) include a phenyl group, a naphthyl group, an anthryl group, etc. Among these, a phenyl group is preferred.

[0068] R 8 , R 9 and R 10 Examples of the aralkyl group represented by the formula (I) include a benzyl group and a 1-phenylethyl group. Of these, a benzyl group is preferred.

[0069] R 8 , R 9 and R 10 Examples of the aryloxy group represented by the formula (I) include a phenoxy group and a 1-naphthyloxy group. Of these, a phenoxy group is preferred.

[0070] R 8 , R 9 and R 10 The alkyl group, aryl group, aralkyl group and aryloxy group represented by the formula (I) may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group and an aryl group.

[0071] Among them, R 8 , R 9 and R 10 are preferably the same or different and represent a hydrogen atom, an alkyl group, a phenyl group, a benzyl group or a phenoxy group which may have a substituent.

[0072] R 8 and R 9 , or R 9 and R 10 may be bonded to each other to form an aromatic ring. The number of carbon atoms in the aromatic ring formed by the bond is preferably 4 to 15, more preferably 4 to 10, and even more preferably 4 to 8, in terms of high sensitivity.

[0073] In the above general formula (3), e represents an integer of 0 or 1, and e is preferably 0 in terms of high sensitivity.

[0074] In the above general formula (3), f represents an integer of 1 to 3, and f is preferably 1 in terms of high sensitivity.

[0075] The photosensitive composition may contain only one type of the monofunctional (meth)acrylate (C) having an aromatic structure, or may contain two or more types of the monofunctional (meth)acrylate (C).

[0076] The content of the monofunctional (meth)acrylate (C) having an aromatic structure is preferably 4 to 30 mass %, more preferably 10 to 30 mass %, and even more preferably 10 to 25 mass %, based on 100 mass % of the photosensitive composition, in terms of high toughness.

[0077] In the photosensitive composition, the mass ratio (B / C) of the monofunctional (meth)acrylate (B) having an alicyclic structure to the monofunctional (meth)acrylate (C) having an aromatic structure is preferably 1 / 3 to 3 / 1, more preferably 1 / 2 to 2 / 1, and even more preferably 1 / 1.5 to 1.5 / 1, in terms of high strength and high toughness.

[0078] (D) Photopolymerization initiator The photosensitive composition further contains a photopolymerization initiator (D). By containing the photopolymerization initiator, the photosensitive composition has good curability and can give a cured product with excellent breaking strength and toughness.

[0079] The photopolymerization initiator is not particularly limited, and any known photopolymerization initiator can be used. Among them, an acylphosphine oxide-based photopolymerization initiator is preferred in that it further improves the transmittance of the cured product.

[0080] Examples of the acylphosphine oxide photopolymerization initiator include monoacylphosphine oxide photopolymerization initiators such as 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 2,4,6-trimethylbenzoyl-ethyl-phenyl-phosphinate; bis-(2,6-dichlorobenzoyl)phenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, and bis-(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide. )-1-naphthylphosphine oxide, bis-(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and (2,5,6-trimethylbenzoyl)-2,4,4-trimethylpentylphosphine oxide, etc.

[0081] Among these, the acylphosphine oxide photopolymerization initiators are particularly preferred in terms of their high activity, including 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2,4,6-trimethylbenzoyl-ethyl-phenyl-phosphinate, bis-(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis-(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and (2,5,6-trimethylbenzoyl)-2,4,4-trimethylpentylphosphine oxide. Preferably, it is 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2,4,6-trimethylbenzoyl-ethyl-phenyl-phosphinate, bis-(2,6-dimethoxybenzoyl)phenylphosphine oxide, or bis-(2,4,6-trimethylbenzoyl)phenylphosphine oxide, more preferably, it is 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, or bis-(2,4,6-trimethylbenzoyl)phenylphosphine oxide, even more preferably.

[0082] The photosensitive composition may contain only one type of the photopolymerization initiator (D), or may contain two or more types.

[0083] The content of the photopolymerization initiator (D) is preferably 0.1 to 2 mass %, more preferably 0.1 to 1 mass %, and even more preferably 0.1 to 0.5 mass %, relative to 100 mass % of the photosensitive composition, in terms of high transmittance.

[0084] (E) Polymerization inhibitor The photosensitive composition of the present invention may further contain a polymerization inhibitor. By further containing a polymerization inhibitor, the storage stability of the photosensitive composition can be improved.

[0085] The polymerization inhibitor is not particularly limited, and known ones can be used, and examples thereof include benzoquinone, hydroquinones (e.g., hydroquinone, hydroquinone monomethyl ether, p-tert-butylhydroquinone, p-benzoquinone, etc.), phenols (e.g., 2,6-di-t-butyl-4-methylphenol, 6-t-butyl-2,4-dimethylphenol, 2,2'-methylenebis(4-methyl-6-t-butylphenol)), catechols (e.g., p-tert-butylcatechol, etc.), amines (e.g., N,N-diethylhydroxylamine, etc.), 1,1-diphenyl-2-picrylhydrazyl, tri-p-nitrophenylmethyl, phenothiazine, piperidine 1-oxyls (e.g., 2,2,6,6-tetramethylpiperidine 1-oxyl, etc.), and the like. Among these, benzoquinone, hydroquinones, phenols, amines, and piperidine 1-oxyls are preferred in terms of high solubility, benzoquinone, hydroquinones, phenols, and piperidine 1-oxyls are more preferred, and phenols and piperidine 1-oxyls are even more preferred.

[0086] The photosensitive composition may contain only one type of the polymerization inhibitor, or may contain two or more types of the polymerization inhibitor.

[0087] The content of the polymerization inhibitor is preferably 0.001 to 1 mass %, more preferably 0.005 to 0.5 mass %, and even more preferably 0.01 to 0.1 mass %, relative to 100 mass % of the photosensitive composition, in terms of high sensitivity.

[0088] (F) Other ingredients The photosensitive composition of the present invention may contain other components as needed in addition to the components described above. Examples of such other components include polymerizable compounds other than the (meth)acrylates described above; resins; solvents; colorants; dispersants; heat resistance improvers; leveling agents; development aids; inorganic fine particles such as silica fine particles; silane-based, aluminum-based, or titanium-based coupling agents; fillers; curing aids; plasticizers; UV absorbers; antioxidants; matting agents; antifoaming agents; antistatic agents; slip agents; surface modifiers; thixotropic agents; thixotropic aids; acid generators; photosensitizers; photoradical polymerization accelerators; surfactants; and the like. The photosensitive composition may contain only one of these components, or two or more of them. These components can be appropriately selected from known components and used. The amounts used can also be appropriately determined.

[0089] The photosensitive composition may contain a solvent, but is preferably substantially free of solvent, since there is a risk that the alicyclic monofunctional (meth)acrylate may also evaporate when the solvent is evaporated. The content of the solvent in the photosensitive composition is preferably 3% by mass or less, more preferably 2% by mass or less, and even more preferably 1% by mass or less, based on 100% by mass of the photosensitive composition.

[0090] The solvent may be any solvent commonly used in photosensitive compositions and may be selected appropriately depending on the purpose and application, without particular limitation. Examples include ethers such as tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, and diethylene glycol dimethyl ether; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; esters such as ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, and 3-methoxybutyl acetate; alcohols such as methanol, ethanol, isopropanol, n-butanol, ethylene glycol monomethyl ether, and propylene glycol monomethyl ether; aromatic hydrocarbons such as toluene, xylene, and ethylbenzene; various organic solvents such as chloroform; and dimethyl sulfoxide, as well as water. The photosensitive composition may contain one or more solvents.

[0091] The photosensitive composition may contain a colorant, but is preferably substantially free of a colorant, since this would reduce curability and transmittance. The content of the colorant in the photosensitive composition is preferably 3% by mass or less, more preferably 2% by mass or less, and even more preferably 1% by mass or less, based on 100% by mass of the photosensitive composition.

[0092] The colorant is not particularly limited, and examples thereof include known pigments and dyes that are commonly used as colorants.

[0093] The photosensitive composition may also contain an isocyanurate skeleton-containing urethane (meth)acrylate, but is preferably substantially free of an isocyanurate skeleton-containing urethane (meth)acrylate in order to prevent a decrease in transparency. The content of the isocyanurate skeleton-containing urethane (meth)acrylate in the photosensitive composition is preferably 3% by mass or less, more preferably 2% by mass or less, and even more preferably 1% by mass or less, based on 100% by mass of the photosensitive composition.

[0094] The photosensitive composition preferably has a viscosity of 100 mPa·s or more at 25°C. When the viscosity of the photosensitive composition is within the above range, the photosensitive composition can be applied to form a coating film. In terms of good film-forming properties, the viscosity of the photosensitive composition at 25°C is more preferably 100 to 1000 mPa·s, and even more preferably 100 to 500 mPa·s. The viscosity is measured at 25°C using a cone-plate type rotational viscometer (TVE22LT, manufactured by Toki Sangyo Co., Ltd.). The cone-plate uses a standard rotor (name: 1°34' x R=24) and the measurement is performed at a rotation speed of 1 to 5 rpm.

[0095] (Method for preparing photosensitive composition) The method for preparing the photosensitive composition of the present invention is not particularly limited, and any known method may be used, for example, a method in which the above-mentioned components are mixed and dispersed using a known mixer or disperser. The mixing and dispersion step is not particularly limited, and any known method may be used.

[0096] (Method for curing photosensitive composition) The method for curing the photosensitive composition of the present invention is not particularly limited, and any known method may be used. Examples of such a method include a method of applying the photosensitive composition to a substrate to form a coating film, and then irradiating the coating film with active energy rays to form a coating film, and a method of molding the photosensitive composition into a desired shape, and then irradiating the molded product with active energy rays to obtain a cured molded product. The coating method is not particularly limited, and examples thereof include known coating methods such as spin coating, slit coating, roll coating, and cast coating. The molding method is not particularly limited, and examples thereof include known molding methods such as injection molding, blow molding, extrusion molding, vacuum molding, compression molding, and press molding.

[0097] The active energy rays may be electron beams, ultraviolet rays, or visible light.The light source may be a thermionic emission gun, a field emission gun, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, a gallium lamp, a xenon lamp, a carbon arc lamp, an LED, or the like.

[0098] The amount of active energy radiation to be irradiated is not particularly limited and can be appropriately set depending on the purpose and use of the photosensitive composition, the amount of the photopolymerization initiator, etc., but is, for example, 10 to 10,000 mJ / cm 2 is preferred, and 20 to 9000 mJ / cm 2 More preferably, 30 to 8000 mJ / cm 2 is more preferred.

[0099] The curing method may also include a heating step, if necessary. For example, a heating step may be performed before, after, or both before and after the active energy ray irradiation step. For example, when the photosensitive composition contains a volatile component such as a solvent, a heating (drying) step may be performed to remove the volatile component. Furthermore, after the photosensitive composition is irradiated with the active energy ray, a heating step may be performed as a post-curing step. The heating conditions are not particularly limited and can be appropriately set from known methods depending on the purpose and use of the photosensitive composition. When the heating step is performed multiple times, the heating conditions for each step may be the same or different.

[0100] The cured product obtained by curing the photosensitive composition preferably has a glass transition temperature of 10 to 60°C. When the glass transition temperature is in the above range, the breaking strength and toughness are even better. In terms of flexibility, the glass transition temperature of the cured product is more preferably 15 to 60°C, and even more preferably 20 to 55°C. The glass transition temperature can be determined by measuring the temperature by the method described in the examples below.

[0101] (Application) The photosensitive composition of the present invention can provide a cured product having excellent breaking strength and toughness. The photosensitive composition also has excellent transparency. Therefore, the photosensitive composition can be suitably used in applications requiring excellent breaking strength, toughness, and transparency. The photosensitive composition can be suitably used, for example, in hard coats, overcoats, optical films, microlenses, insulating films, adhesives, sealants, and the like. [Example]

[0102] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "parts" means "parts by mass."

[0103] In the present examples, the evaluations were carried out by the following methods. (1) Viscosity The viscosity at 25°C was measured using a cone-plate type rotational viscometer (TVE22LT, manufactured by Toki Sangyo Co., Ltd.) with a standard cone-plate rotor (name: 1°34' x R=24) at a shear rate of 5 to 1 rpm.

[0104] (2) Transmittance The photosensitive composition was applied to a glass substrate using a bar coater (No. 50) to a film thickness of 100 μm. UV-LED irradiation (area-type irradiator manufactured by CCS Corporation) was used to apply the composition to the glass substrate at an illuminance of 100 mW / cm. 2 , exposure amount 6J / cm 2 Using a glass substrate as a blank, the transmittance of the cured coating film was measured with a spectrophotometer UV3100 (manufactured by Shimadzu Corporation) to determine the transmittance at 410 nm.

[0105] (3) Glass transition temperature (Tg) and storage modulus measurement The photosensitive composition was applied to a glass substrate using a bar coater (No. 50) to a film thickness of 100 μm. UV-LED irradiation (area-type irradiator manufactured by CCS Corporation) was used to apply the composition to the glass substrate at an illuminance of 100 mW / cm. 2 , exposure amount 6J / cm 2The film was exposed to light and cured. Strips 5 mm wide and 5 cm long were cut from the cured film. The storage modulus and tan δ of the cured film strips were measured using a dynamic viscoelasticity analyzer RSA-G2 (TA Instruments Japan) with a gap of 15 mm, at a temperature range of -50°C to 185°C (heating rate of 5°C / min), a frequency of 1 Hz, and a strain of 0.1%. The temperature at which the tan δ value reached its maximum was taken as Tg. The storage modulus and Tg temperatures at -20°C, 25°C, and 150°C are listed in Table 1.

[0106] (4) Breaking strength and elongation measurement The photosensitive composition was applied to a glass substrate using a bar coater (No. 50) to a film thickness of 100 μm. UV-LED irradiation (area-type irradiator manufactured by CCS Corporation) was used to apply the composition to the glass substrate at an illuminance of 100 mW / cm. 2 , exposure amount 6J / cm 2 The film was exposed to light and cured. Strips 5 mm wide and 6 cm long were cut from the cured film. A tensile test was carried out on these cured film strips using an Autograph AG-1kNNX (Shimadzu Corporation) at an initial gap of 30 mm and a speed of 10 mm / min until the strip broke. The breaking strength and elongation at break were calculated using the following formulas. Breaking strength (N / mm 2 ) = Test force at break (N) / Cross-sectional area of ​​strip (mm 2 ) Elongation at break (%) = 100 × sample elongation at break (mm) / initial gap (30 mm)

[0107] (Examples 1 to 9, Comparative Examples 1 to 7) Photosensitive compositions were prepared by mixing various polyfunctional monomers, monofunctional monomers, photopolymerization initiators, and polymerization inhibitors in a paint shaker to obtain the formulations (parts) shown in Table 1. The photosensitive compositions obtained were subjected to the above-mentioned evaluations. The results are shown in Table 1. The components shown in Table 1 are as follows:

[0108] (polyfunctional monomer) DPCA-60: KAYARAD DPCA-60, manufactured by Nippon Kayaku, polyacrylate of lactone-modified polyhydric aliphatic alcohol (lactone 6 mol added) DPCA-120: KAYARAD DPCA-120, manufactured by Nippon Kayaku Co., Ltd., polyacrylate of lactone-modified polyhydric aliphatic alcohol (12 mol lactone added) DPHA: Dipentaerythritol hexaacrylate, manufactured by Kyoeisha Chemical DCPA: Dicyclopentanyl diacrylate, manufactured by Kyoeisha Chemical A-9300: Ethoxylated isocyanuric acid triacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd. UX-5000: Hexafunctional urethane acrylate, manufactured by Nippon Kayaku

[0109] (monofunctional monomer) POBA: m-phenoxybenzyl acrylate NMT-A: Naphthyl methyl acrylate HRD-01: o-biphenyl ethoxy acrylate 513AS: Dicyclopentanyl methacrylate 2EHA: 2-ethylhexyl acrylate

[0110] (Photopolymerization initiator) TPO: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, acylphosphine oxide Irg819: Bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, acylphosphine oxide series Omni907: 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, an α-aminoalkylphenone OXE02: Ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime), N-oxime ester

[0111] (polymerization inhibitor) W400: Antage W400, manufactured by Kawaguchi Chemical Industry Co., Ltd., 2,2'-methylenebis(4-methyl-6-t-butylphenol) 4HTEMPO: 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl

[0112] [Table 1]

[0113] From Table 1, it can be seen that the photosensitive compositions of the examples give cured products that are excellent in all of breaking strength, toughness, and transparency. In addition, the photosensitive compositions of the examples give cured products that have a storage modulus at 25°C of 1 × 10 8 Pa or more than 2 x 10 9 It was confirmed that the fracture strength was less than 100 Pa, and that a good balance between fracture strength and toughness could be achieved.

Claims

1. A photosensitive composition comprising a polyfunctional (meth)acrylate (A) represented by the following general formula (1), a monofunctional (meth)acrylate (B) having an alicyclic structure, a monofunctional (meth)acrylate (C) having an aromatic structure represented by the following general formula (3), and a photopolymerization initiator (D): 【Chemical 1】 (In formula (1), R １ and R ３ R may be the same or different and represent a monovalent to tetravalent organic group not containing an aromatic ring. ２ represents a divalent to tetravalent organic group not containing an aromatic ring. X represents a structure represented by general formula (2). a and c are the same or different and represent an integer of 0 to 3, b represents an integer of 0 to 2, and m represents an integer of 0 to 6, and a+bm+c≧5 is satisfied. In formula (2), R ４ represents a hydrogen atom or a methyl group. ５ represents an alkylene group having 1 to 8 carbon atoms; d may be the same or different and represents an integer of 0 or 1; and n represents an integer of 1 to 3. 【Chemistry 2】 (In formula (3), R ６ represents a hydrogen atom or a methyl group. ７ represents an alkylene group having 1 to 3 carbon atoms. ８ , R ９ and R １０ are the same or different and represent a hydrogen atom, an alkoxy group, or an alkyl group, an aryl group, an aralkyl group, or an aryloxy group, each of which may have a substituent. ８ , R ９ and R １０ At least one of R represents an alkoxy group, or an alkyl group, aryl group, aralkyl group, or aryloxy group, which may have a substituent. ８ and R ９ , or R ９ and R １０ may be bonded to each other to form an aromatic ring; e may be the same or different and represents an integer of 0 or 1; and f represents an integer of 1 to 3.

2. 2. The photosensitive composition according to claim 1, wherein the photopolymerization initiator (D) is an acylphosphine oxide-based photopolymerization initiator.

3. 2. The photosensitive composition according to claim 1, wherein the content of the polyfunctional (meth)acrylate (A) is 40 to 90% by mass relative to 100% by mass of the photosensitive composition.

4. 2. The photosensitive composition according to claim 1, wherein the content of the monofunctional (meth)acrylate (C) having an aromatic structure is 4 to 30% by mass relative to 100% by mass of the photosensitive composition.

5. 2. The photosensitive composition according to claim 1, wherein the content of the monofunctional (meth)acrylate (B) having an alicyclic structure is 5 to 30% by mass relative to 100% by mass of the photosensitive composition.

6. 2. The photosensitive composition according to claim 1, wherein the content of the photopolymerization initiator (D) is 0.1 to 2% by mass based on 100% by mass of the photosensitive composition.

7. 2. The photosensitive composition according to claim 1, which has a viscosity at 25[deg.] C. of 100 mPa.s or more.

8. 2. The photosensitive composition according to claim 1, wherein the cured product obtained by curing the photosensitive composition has a glass transition temperature of 10 to 60°C.

Images