JP6502121B2 - Method for suppressing yellowing of optical member, optical member and adhesive - Google Patents

Description

  The present invention relates to a method of suppressing yellowing of an optical member even by heat treatment, an optical member whose yellowing is suppressed by this method, and an adhesive or pressure-sensitive adhesive useful for obtaining the optical member.

  Materials having a fluorene skeleton are excellent in optical properties such as high refractive index and low birefringence, and are known to be used in optical material applications and the like. As a representative example of the compound to be used, a multifunctional (meth) acrylate having a fluorene skeleton (for example, 9,9-bis (4- (2-acryloyloxyethoxy) phenyl) fluorene etc.) and the like are proposed. Such compounds are used as an optical member, an adhesive, an ink material, a coating agent, etc. However, yellowing caused by the influence of heat or the like in the use environment or in the manufacturing process is a problem. In particular, in applications to optical materials, etc., it often causes fatal defects as a product, and therefore, improvement in thermal yellowing resistance is required.

  International Publication WO 2013/022065 (Patent Document 1) discloses a multifunctional (meth) acrylate having a 9,9-bis (polyalkoxyaryl) fluorene skeleton. The cured product of this compound achieves both high refractive index and scratch resistance, and in the curable composition, it can achieve both handling and curability. However, no mention is made of thermotropic yellowing.

  JP-A-2012-224845 (Patent Document 2) discloses a fluorene compound (A) having a polymerizable unsaturated bond, and a non-fluorene having at least one functional group selected from a hydroxyl group and a carboxyl group. Curable compositions comprising a system (meth) acrylic monomer (B) are described, in the examples 9,9-bis (4- (2-acryloyloxyethoxy) phenyl) fluorene (BPEFA) and pentaerythritol tritriol The heat-resistant yellowing of a cured product of a curable composition containing an acrylate (PETA) is described. However, in such a cured product, although the improvement of the heat resistant yellowing can be seen, the non-fluorene (meth) acrylic monomer (B) having a predetermined functional group is 65 to 85% of all (meth) acrylic monomer components. The refractive index improvement effect derived from the fluorene skeleton was not high, probably because it was introduced in a relatively large amount of 80 mol%. Further, Comparative Example 1 describes heat resistant yellowing in a cured product of BPEFA alone, and describes that the heat resistant yellowing is low under severe conditions of 150 ° C. In addition, although the compound which has a 9,9-bis (polyalkoxy aryl) fluorene structure as a fluorene compound (A) is illustrated by patent document 2, it is not described in the Example. Also, no mention is made of the use as an adhesive.

  Further, JP 2009-235147 A (Patent Document 3) is a molded product obtained by curing a curable resin containing an aromatic ring or a resin composition thereof in a fluid state while applying a magnetic field and / or an electric field, It is disclosed that coloring is suppressed and it has high transparency. In the examples, a cured product obtained by thermally curing 9,9-bis (phenoxyethanol) fluorene glycidyl ether (BPEFG) and diethylenetriamine in a magnetic field is described. In this embodiment, although a transparent film is obtained, it is necessary to apply a magnetic field and / or an electric field, which restricts the form of the molded body. In addition, in Comparative Example 1, it was confirmed that a cured product of BPEFG and diethylenetriamine was prepared without applying a magnetic field and turned yellow. Although Patent Document 3 exemplifies a compound having a 9,9-bis (polyalkoxyaryl) fluorene skeleton as a compound containing an aromatic ring, the compound is not described in the Examples and is used as an adhesive. There is no mention about. Furthermore, none of the documents describes that the light transmission loss of the optical member obtained by bonding is reduced.

International Publication WO 2013/022065 (Paragraphs [0009]-[0011], Example) JP, 2012-224845, A (claim 1, paragraph [0003], Examples 1-4, comparative example 1) JP, 2009-235147, A (paragraph [0009], Example 1, comparative example 1)

  Therefore, an object of the present invention is to provide a method capable of suppressing yellowing of an optical member even by heat treatment, an optical member thereof, and an adhesive or pressure-sensitive adhesive (optically transparent adhesive or pressure-sensitive adhesive) used in the method. It is to do.

  Another object of the present invention is a method for reducing loss of light transmitted through an optical member while suppressing yellowing of the optical member, the optical member, and an adhesive or pressure-sensitive adhesive used in the method Agent or adhesive).

  As a result of intensive studies to achieve the above-mentioned problems, the inventors of the present invention have found that even when heat treatment is carried out, heat resistance yellowing occurs when the transparent member is bonded with a polymerizable compound having a 9,9-bis (polyalkoxyaryl) fluorene skeleton. It finds out that it is excellent and completes the present invention.

  That is, in the method for suppressing yellowing of the present invention, at least one of the bonding step of bonding a substrate, at least one of which is transparent, and the adherend with an adhesive or a pressure-sensitive adhesive Heat treatment is performed to suppress yellowing of the obtained optical member. In such a method, a heat or photo-curable adhesive containing a fluorene compound represented by the following formula (1) or a pressure-sensitive adhesive containing a polymer of the fluorene compound is used as the adhesive or the adhesive. Suppress yellowing of

(Wherein, Z ¹ and Z ² are each an aromatic hydrocarbon ring, R ^2a and R ^2b are each an alkylene group, m 1 and m 2 are each integers of 2 or more, n 1 and n 2 are each integers of 1 or more, R ^3a and R ^3b is a substituent inert to the reaction, p1 and p2 each is an integer of 0 or more, R ^4a and R ^4b each is a substituent inert to the reaction, q1 and q2 each is an integer from 0 to 4, X ¹ And X ² each represents the following formula (2) or the following formula (3)

(In the formula, R ¹ represents a hydrogen atom or a methyl group, respectively). )

The compounds in the above-mentioned formula (1) are those wherein Z ¹ and Z ² are each a C _6-24 aromatic hydrocarbon ring (for example, an aromatic hydrocarbon ring selected from a benzene ring, a naphthalene ring or a biphenyl ring), R ^2a and R ^2b are each _{C 2-4} alkylene group _{(e.g., C 2-3} alkylene group), m1 and m2 are each 3 or more (e.g., 4 or more) integer, 1 to 3 n1 and n2 are each (e.g., 1 2), R ^3a and R ^3b each represent an alkyl group (eg, methyl group), p 1 and p 2 each represent an integer of 0 to 2 (eg, 0 or 1), q 1 and q 2 each represent 0, X ¹ and X 2 ² may be a group represented by the formula (2).

  The adhesive may be a photocurable adhesive, and the heat treatment may be performed at 100 to 200 ° C.

  The transparent member of at least one of the substrate and the adherend may be a ceramic substrate (for example, a transparent ceramic substrate such as a sapphire glass substrate) or an optical film.

  The refractive index (25 ° C., wavelength 589 nm) of the adhesive layer or adhesive layer after the adhesion step may be 1.46 to 1.76.

  Further, the present invention also includes an optical member or a bonded body (for example, a component member of a touch panel display) whose yellowing is suppressed by the method for suppressing yellowing. Furthermore, in the present invention, it is an adhesive or a pressure-sensitive adhesive for use in the method for suppressing yellowing, which comprises a heat- or photo-curable adhesive containing the fluorene compound represented by the above formula (1) The adhesive which contains the polymer of the fluorene compound represented by 1) is also included.

  In the present specification, “(meth) acrylate” means both acrylate and methacrylate.

  In the present invention, since the adhesive or pressure-sensitive adhesive contains a specific fluorene compound, at least one of the bonding step of bonding the substrate and the adherend and the post-processing step subsequent to the bonding step includes heat treatment. However, yellowing of the obtained optical member can be suppressed. Therefore, an optical member in which yellowing is suppressed by the above method can also be obtained. In addition, since the adhesive or the adhesive contains a specific fluorene compound, the refractive index of the adhesive layer or the adhesive layer can be easily adjusted to the same refractive index as the transparent member, and the loss of light passing through the obtained optical member can be reduced. And heat resistant yellowing can be compatible.

[Adhesive or pressure sensitive adhesive]
The adhesive or pressure-sensitive adhesive contains a polyfunctional fluorene compound (hereinafter sometimes referred to as a fluorene compound) having a 9,9-bis (polyalkoxyaryl) fluorene skeleton or a polymer thereof. Such an adhesive or pressure-sensitive adhesive is highly transparent and may form an optical clear adhesive or pressure-sensitive adhesive (Optical Clear Resin (OCR) or Optical Clear Adhesive (OCA)).

[Fluorene compound]
The representative fluorene compound may be a compound represented by the following formula (1).

(Wherein, Z ¹ and Z ² are each an aromatic hydrocarbon ring, R ^2a and R ^2b are each an alkylene group, m 1 and m 2 are each integers of 2 or more, n 1 and n 2 are each integers of 1 or more, R ^3a and R ^3b is a substituent inert to the reaction, p1 and p2 each is an integer of 0 or more, R ^4a and R ^4b each is a substituent inert to the reaction, q1 and q2 each is an integer from 0 to 4, X ¹ And X ² each represents the following formula (2) or the following formula (3)

(In the formula, R ¹ represents a hydrogen atom or a methyl group, respectively). )

In the above formula (1), examples of the aromatic hydrocarbon ring represented by the rings Z ¹ and Z ² include a monocyclic aromatic hydrocarbon ring such as a benzene ring, a polycyclic aromatic hydrocarbon ring and the like The polycyclic aromatic hydrocarbon ring includes a fused polycyclic aromatic hydrocarbon ring, a ring-aggregated aromatic hydrocarbon ring and the like.

As the fused polycyclic aromatic hydrocarbon ring, for example, a fused bicyclic arene ring (for example, a fused bicyclic C _10-16 arene ring such as naphthalene), a fused tricyclic arene ring (for example, anthracene, phenanthrene) And the like, and fused di- to tetra-cyclic arene rings and the like. As a preferable fused polycyclic aromatic hydrocarbon ring, a naphthalene ring, an anthracene ring and the like can be mentioned, and in particular, a naphthalene ring is preferable.

As the ring-aggregated aromatic hydrocarbon ring, biarene ring, for example, bi-C _6-12 arene ring such as biphenyl ring, binaphthyl ring, phenyl naphthalene ring (1-phenyl naphthalene ring, 2-phenyl naphthalene ring, etc.), terarene ring For example, a ter C _6-12 arene ring such as a terphenylene ring can be exemplified. Preferred ring-aggregated aromatic hydrocarbon rings include bi-C _6-10 arene rings, in particular biphenyl rings.

Preferred rings Z ¹ and Z ² include C _6-24 arene rings (eg, C _6-14 arene rings, in particular, benzene ring, naphthalene ring and biphenyl ring). The two rings Z ¹ and Z ² may be the same or different rings.

In the above formula (1), the groups X ¹ and X ² are groups represented by the above formula (2) or (3), and an acryloyl group in which the group R ¹ in the above formula (2) is a hydrogen atom, well group R ¹ is even methacryloyl group is a methyl group, or a glycidyl group group R ¹ in formula (3) is a hydrogen atom, the group R ¹ was 2-methyl glycidyl groups with a methyl group May be Preferred groups X ¹ and X ² include groups represented by the above formula (2) ((meth) acryloyl group). The groups X ¹ and X ² may be identical to or different from each other. When the number of substitutions n1 and n2 is 2 or more, the groups X ¹ or X ² bonded to the same ring Z ¹ or Z ² through the polyalkoxy group may be the same or different from each other Good.

In the above formula (1), examples of the alkylene group represented by the groups R ^2a and R ^2b include a linear or branched alkylene group. As a linear alkylene group, for example, a C _2-6 alkylene group such as ethylene group, trimethylene group, tetramethylene group, pentamethylene group, preferably a C _2-4 alkylene group, more preferably a C _2-3 alkylene group, In particular, an ethylene group can be exemplified. Examples of branched alkylene groups include C _3-6 alkylene groups such as propylene group, 1,2-butanediyl group, and 1,3-butanediyl group, preferably C _3-4 alkylene groups, particularly propylene group. Preferred groups ^R2a and ^R2b are _C2-4 alkylene groups, in particular _C2-3 alkylene groups. When the number of repeating units m1 and m2 is 2 or more, the groups R ^2a and R ^2b may be composed of the same or different types of alkylene groups. The groups R ^2a and R ^2b may also be constituted by the same or different types of alkylene groups.

The repeating unit numbers m1 and m2 of the groups OR ^2a and OR ^2b may each be an integer of 2 or more, and may be, for example, about 2 to 20 (for example, 2 to 15), preferably 3 or more It may be an integer (for example, an integer of 3 to 10), more preferably an integer of 4 or more (for example, an integer of 4 to 8), and particularly an integer of 4 to 7 (for example, 4 to 6). In addition, when m1 and m2 each is an integer of 5 to 15, preferably an integer of 7 to 13, and more preferably an integer of 8 to 12, tackiness is easily developed, and can be suitably used as an adhesive. M1 and m2 may be the same or different.

  In addition, the sum (m1 + m2) of m1 and m2 is 4 to 40 (eg, arithmetic average or arithmetic average) with respect to the entire fluorene compound (molecular assembly of fluorene compound represented by the formula (1)). 4 to 30), preferably 4 to 20 (e.g. 6 to 18), more preferably 4 to 18 (e.g. 8 to 16), especially 6 to 14 (e.g. 8 to 12) It may be When used as a pressure-sensitive adhesive, it may be about 10 to 30, preferably 14 to 28, and more preferably about 15 to 24. When the above m1 or m2 (or m1 + m2) is too large, there is a possibility that the properties such as the refractive index and the heat yellowing resistance may be deteriorated. On the other hand, if it is too small, the viscosity of the fluorene compound may be increased, and the handling property may be reduced. The number of repeating units of the average (arithmetic average or arithmetic average) can be measured by a conventional method, and the measurement method is not particularly limited, but can be easily calculated by, for example, the method described in Patent Document 1.

In the formula (1), the n1 and n2, respectively may be a integer of 1 or more, depending on the ring ^{Z 1} and ^{Z 2,} for example, be selected from 1-9 the range of about, for example, 1-7 integer Preferably, it may be an integer of 1 to 5, more preferably an integer of 1 to 3 (for example, an integer of 1 to 2), particularly 1. Note that n1 and n2 may be the same or different.

In the formula (1), group _{^{[-O- (R 2a O) m1}} -X 1] and _{^{[-O- (R 2b O) m2}} -X 2] , when n1 or n2 is 1, ring ^{Z 1} And Z ² can be substituted at appropriate positions. For example, when the rings Z ¹ and Z ² are benzene rings, they are often substituted at the 2-, 3-, 4-position (in particular, the 3-position or 4-position) of the phenyl group. When Z ¹ and Z ² are a naphthalene ring, they are often at positions 5 to 8 of the naphthyl group, and 1,5-, 2,5-, 1,6-, 2,6-positions. For example, it may be a relation such as 1, 5-position or 2, 6-position (in particular, 2, 6-position relation). When Rings Z ¹ and Z ² are a ring assembly arene ring, the substitution position is not particularly limited. For example, the arene ring bound to 9-position of fluorene or an arene ring adjacent to this arene ring is substituted May be For example, when the rings Z ¹ and Z ² are biphenyl rings, the 3- or 4-position of the biphenyl rings Z ¹ and Z ² is often bonded to the 9-position of fluorene, for example, 3 Arbitrary substitution positions such as 5-position, 3,6-position, 3,3'-position, 3,4'-position, 4,2-position, 4,3'-position, 4,4'-position, etc. 3,5-, 3,6-position, 3,4'-position, 4,2-position, 4,4'-position, more preferably 3,6-position. And may be substituted at the 4, 2-position substitution positions. Even when n1 or n2 is 2 or more, it can be substituted in a suitable position on the ring ^{Z 1} and ^{Z 2.} The substitution position is not particularly limited, but at least one is often substituted at the position exemplified when n1 or n2 is 1.

In the formula (1), as the substituent R ^3a and R ^3b inert to the reaction, a halogen atom (eg, fluorine atom, chlorine atom, bromine atom, iodine atom), alkyl group (methyl group, ethyl group) And linear or branched C _1-10 alkyl groups such as propyl, isopropyl, n-butyl, s-butyl and t-butyl groups, preferably linear or branched C _1-6 Alkyl group, more preferably linear or branched C _1-4 alkyl group etc., cycloalkyl group (C _5-10 cycloalkyl group such as cyclopentyl group, cyclohexyl group etc.), aryl group [phenyl group , alkylphenyl group (methylphenyl (tolyl) group, dimethylphenyl (xylyl) group), a biphenyl group, a _{C 6-12} aryl group such as a naphthyl group, aralkyl Group (benzyl group, such as _{C 6-10} aryl _{-C 1-4} alkyl group such as a phenethyl group), an alkoxy group (e.g., methoxy group, an ethoxy group, a propoxy group, n- butoxy group, isobutoxy group, t-butoxy group etc.) straight chain or branched chain C _1-10 alkoxy group such as, cycloalkoxy group (e.g., a C _5-10 cycloalkyloxy group such as cyclohexyloxy group cyclohexylene), an aryloxy group (e.g., phenoxy group etc. (C _6-10 aryloxy group etc.), aralkyloxy group (eg C _6-10 aryl-C _1-4 alkyloxy group such as benzyloxy group etc.), alkylthio group (eg methylthio group, ethylthio group, propylthio group) Group, C _1-10 alkylthio group such as n-butylthio group, t-butylthio group, etc.), cyclic Roarukiruchio group (e.g., a _{C 5-10} cycloalkylthio groups such as cyclohexylthio group cyclohexylene), an arylthio group (e.g., a _{C 6-10} arylthio group such as thiophenoxy group), aralkylthio group (e.g., benzylthio etc. C _6-10 aryl-C _1-4 alkylthio group etc.), acyl group (eg C _1-6 acyl group such as acetyl group etc.), nitro group, cyano group, dialkylamino group (eg dimethylamino group etc.) such as di-C _1-4 alkylamino group), dialkyl carbonyl amino group (e.g., di-C _1-4 alkyl, such as di-acetylamino group - carbonyl amino group), and others.

Among these groups R ^3a and R ^3b , representatively, halogen atoms, alkyl groups, aryl groups, alkoxy groups, acyl groups, nitro groups, cyano groups, substituted amino groups and the like can be mentioned. Preferred groups R ^3a and R ^3b include alkyl groups (such as linear or branched C _1-6 alkyl groups such as methyl group), aryl groups, and alkoxy groups (such as linear or branched groups such as methoxy group) Particularly preferred is an alkyl group (eg, a methyl group) such as a C _1-4 alkoxy group). When the groups R ^3a and R ^3b are aryl groups, the groups R ^3a and R ^3b may together with the rings Z ¹ and Z ² form the above-mentioned ring assembly arene ring. The types of the groups R ^3a and R ^3b may be the same or different, and in the case where p 1 and p 2 are 2 or more, the types of the groups R ^3a and R ^{3b in} the same ring Z ¹ and Z ² are , May be the same or different.

The number of substitutions p1 and p2 can be appropriately selected according to the rings Z ¹ and Z ² and, for example, 0 to 8, preferably 0 to 4 (eg, 0 to 2), more preferably 0 or 1 (eg, 0) It may be In particular, when p is 1, the rings Z ¹ and Z ² may be a benzene ring, a naphthalene ring or a biphenyl ring, and R ^3a and R ^3b may be a methyl group. Incidentally, the substitution position of group ^{R 3a} and ^{R 3b} are not particularly limited, on the ring ^{Z 1} and ^{Z 2,} the group _{^{[- (OR 2a) m1 -OH}} ] and _{^{[- (OR 2b) m2 -OH}} ] Except for the position to be substituted.

In the above formula (1), as the groups R ^4a and R ^4b , a cyano group, a halogen atom (eg, fluorine atom, chlorine atom, bromine atom etc.), an alkyl group (eg, methyl group, ethyl group, propyl group, isopropyl group) , butyl group, _{C 1-6} alkyl group), such as t- butyl group, an aryl group (e.g., _{C 6-10} aryl group such as phenyl group) and the like. Among these groups R ^4a and R ^4b , a C _1-4 alkyl group (in particular, a methyl group) is preferable. The groups R ^4a and R ^4b may be the same or different, and when the substitution numbers q 1 and q 2 are 2 or more, each of the groups R ^4a and R ^4b is on the corresponding benzene ring in the fluorene structure , May be the same or different.

The substitution numbers q1 and q2 can be selected from the integers of 0 to 4, preferably 0 to 1, particularly 0. The substitution numbers q1 and q2 may be identical to or different from each other. Also, the substitution position of the groups R ^4a and R ^4b is not particularly limited, and examples thereof include the 2-position to the 7-position of the fluorene ring (such as 2-position, 7-position, 2- and 7-position) It is also good.

The compound represented by the formula (1) is a compound (hereinafter referred to as a fluorene (meth) acrylate compound) in which the groups X ¹ and X ² are a group represented by the formula (2) ((meth) acryloyl group) a) it can be divided into groups X ¹ and X ² are the formula (3) a group represented by (a glycidyl group or compound is 2-methyl glycidyl group) (hereinafter, referred to as fluorene epoxy compound) and.

(Fluorene (meth) acrylate compound)
Representative fluorene (meth) acrylate compounds include 9,9-bis ((meth) acryloyloxypolyalkoxyphenyl) fluorenes, 9,9-bis ((meth) acryloyloxypolyalkoxynaphthyl) fluorenes, etc. .

As the 9,9-bis ((meth) acryloyloxypolyalkoxyphenyl) fluorenes, in the above formula (1), the rings Z ¹ and Z ² are substituted or unsubstituted benzene rings, and R ^2a and R ^2b are linear Cyclic or branched _C2-4 alkylene group, compounds wherein m1 and m2 are 2 and q1 and q2 are each 0, for example, (A1) 9,9-bis [4- (2- (2- (meth)) 9,9-Bis ((meth) acryloyloxy C such as acryloyloxyethoxy) ethoxy) phenyl] fluorene, 9,9-bis [4- (2- (2- (meth) acryloyloxypropoxy) propoxy) phenyl] fluorene and the like _2-4 alkoxy C _2-4 alkoxyphenyl) fluorene, (A2) 9,9-bis [4- (2- (2- (meth) acryloyloxyethoxy) eth X) -3-Methylphenyl] fluorene, 9,9-bis (4- (2- (2- (meth) acryloyloxyethoxy) ethoxy) -3-isopropylphenyl) fluorene, 9,9-bis (4- ( 2- (2- (Meth) acryloyloxyethoxy) ethoxy) -3-isobutylphenyl) fluorene, 9,9-bis (4- (2- (2- (meth) acryloyloxyethoxy) ethoxy) -3-t- Butylphenyl) fluorene, 9,9-bis [4- (2- (2- (meth) acryloyloxyethoxy) ethoxy) -3,5-dimethylphenyl] fluorene, 9,9-bis (4- (2- (2- (2- (2- (meth) acryloyloxyethoxy) ethoxy)) 9,9-Bis ((meth) acryloyl) such as 2- (meth) acryloyloxyethoxy) ethoxy) -5-t-butyl-2-methylphenyl) fluorene Shi _{C 2-4} alkoxy _{C 2-4} alkoxy - (mono or _{di) C 1-4} alkyl phenyl) fluorene, (A3) 9,9-bis (4- (2- (2- (meth) acryloyloxy ethoxy) 9,9-bis ((meth) acryloyloxy _C2-4 alkoxy _C2-4 alkoxy- _C5-10 cycloalkylphenyl) fluorene such as ethoxy) -3-cyclohexylphenyl) fluorene, (A4) 9,9- Bis [4- (2- (2- (meth) acryloyloxyethoxy) ethoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (2- (2- (meth) acryloyloxypropoxy) propoxy) -3-phenyl phenyl] fluorene such as 9,9-bis ((meth) acryloyloxy _{C 2-4} alkoxy _{C 2-4} alkoxy Ci-C _6-10 arylphenyl) fluorene and the like; rings Z ¹ and Z ² are substituted or unsubstituted benzene rings, R ^2a and R ^2b are linear or branched C _2-4 alkylene groups, m 1 and m 2 In the compounds (A1) to (A4) in which m1 and m2 are 3 to 10, for example, 9,9-bis ((meth) Acryloyloxy _C2-4 alkoxy _C2-4 alkoxy _C2-4 alkoxy phenyl) fluorene, 9,9-bis ((meth) acryloyloxy _C2-4 alkoxy _C2-4 alkoxy _C2-4 alkoxy- (mono) Or di) C _1-4 alkylphenyl) fluorene, 9,9-bis ((meth) acryloyloxy C _2-4 alkoxy C _2-4 alkoxy C _2-4 al Coxy-C _5-10 cycloalkylphenyl) fluorene, 9, 9-bis ((meth) acryloyloxy C _2-4 alkoxy C _2-4 alkoxy C _2-4 alkoxy C _6-10 arylphenyl) fluorene and the like Be

As 9,9-bis ((meth) acryloyloxy polyalkoxynaphthyl) fluorenes, for example, rings Z ¹ and Z ² are substituted or unsubstituted naphthalene rings, and R ^2a and R ^2b are linear or branched. Compounds wherein the _C2-4 alkylene group, m1 and m2 are 2, and q1 and q2 are each 0, for example (A5) 9,9-bis [6- (2- (2- (meth) acryloyloxyethoxy) ethoxy ) -2-Naphthyl] fluorene, 9,9-bis [5- (2- (2- (meth) acryloyloxyethoxy) ethoxy) -1-naphthyl] fluorene, 9,9-bis [6- (2- (2- (2-) 9,9-Bis ((meth) acryloyloxy C _2-4 alkoxy C _2-4 alkoxy such as 2- (meth) acryloyloxypropoxy) propoxy) -2-naphthyl] fluorene Xynaphthyl) fluorene and the like; rings Z ¹ and Z ² are substituted or unsubstituted naphthalene rings, R ^2a and R ^2b are linear or branched C _2-4 alkylene groups, m 1 and m 2 are 3 to 10, q 1 and Compounds in which q2 is 0, ie, compounds in which m1 and m2 are 3 to 10 in the above compound (A5), for example, 9,9-bis ((meth) acryloyloxy C _2-4 alkoxy C _2-4 And alkoxy C _2-4 alkoxynaphthyl) fluorene and the like.

  These fluorene (meth) acrylate compounds can be used alone or in combination of two or more.

Commercially available products may be used as the fluorene compounds having these (meth) acryloyl groups, and conventional methods (for example, corresponding fulles in which X ¹ and X ² are hydrogen atoms in the above formula (1)) A method of reacting an orangeol compound with (meth) acrylic acid or an ester-forming derivative thereof (eg, (meth) acrylic acid lower alkyl ester, (meth) acrylic acid halide, (meth) acrylic anhydride, etc.) ) May be used.

Preferred fluorene (meth) acrylate compounds are 9,9-bis ((meth) acryloyloxypoly C such as 9,9-bis (4- (2- (2- (meth) acryloyloxyethoxy) ethoxy) phenyl) fluorene 9,9-bis (C _1-4 ) such as _2-4 alkoxyphenyl) fluorene, 9,9-bis (4- (2- (2- (meth) acryloyloxyethoxy) ethoxy) -3-methylphenyl) fluorene alkyl - (meth) acryloyloxy poly _{C 2-4} alkoxyphenyl) fluorene, 9,9-bis (4- (2- (2- (meth) acryloyloxy) ethoxy) -3-phenylphenyl) of fluorene 9 , 9-Bis ((meth) acryloyloxypoly C _2-4 alkoxy-phenylphenyl) fluorene, 9, 9-Bis (5- (2- (2- (meth) acryloyloxyethoxy) ethoxy) -1-naphthyl) fluorene, 9,9-bis (6- (2- (2- (meth) acryloyloxyethoxy) ethoxy ) -2-naphthyl) 9,9-bis fluorene [(meth) acryloyloxy poly _{C 2-4} alkoxy naphthyl] fluorene and the like.

(Fluorene epoxy compound)
Representative fluorene epoxy compounds include 9,9-bis (glycidyloxypolyalkoxyphenyl) fluorenes, 9,9-bis (glycidyloxypolyalkoxynaphthyl) fluorenes, and the like.

As the 9,9-bis (glycidyloxy polyalkoxyphenyl) fluorenes, in the formula (1), the rings Z ¹ and Z ² are substituted or unsubstituted benzene rings, and R ^2a and R ^2b are linear or branched. A chain _C2-4 alkylene group, a compound wherein m1 and m2 are 2 and q1 and q2 are each 0, for example, (B1) 9,9-bis [4- (2- (2-glycidyloxyethoxy) ethoxy) 9,9-bis (glycidyloxy _C2-4 alkoxy _C2-4 alkoxy phenyl) fluorene such as phenyl] fluorene, 9, 9-bis [4- (2- (2- glycidyloxy propoxy) propoxy) phenyl] fluorene and the like , (B2) 9,9-bis [4- (2- (2-glycidyloxyethoxy) ethoxy) -3-methylphenyl] fluorene, 9,9-bi (4- (2- (2-glycidyloxyethoxy) ethoxy) -3-isopropylphenyl) fluorene, 9,9-bis (4- (2- (2-glycidyloxyethoxy) ethoxy) -3-isobutylphenyl) Fluorene, 9,9-bis (4- (2- (2-glycidyloxyethoxy) ethoxy) -3-t-butylphenyl) fluorene, 9,9-bis [4- (2- (2-glycidyloxyethoxy)) 9,9 9- such as (ethoxy) -3,5-dimethylphenyl] fluorene, 9,9-bis (4- (2- (2-glycidyloxyethoxy) ethoxy) -5-t-butyl-2-methylphenyl) fluorene - bis (glycidyloxy _{C 2-4} alkoxy _{C 2-4} alkoxy - (mono or _{di) C 1-4} alkyl phenyl) fluorene, (B3) 9, 9 Bis (4- (2- (2-glycidyloxy) ethoxy) -3-cyclohexyl phenyl) 9,9-bis fluorene (glycidyloxy _{C 2-4} alkoxy _{C 2-4} alkoxy _{-C 5-10} cycloalkyl Phenyl) fluorene, (B4) 9,9-bis [4- (2- (2-glycidyloxyethoxy) ethoxy) -3-phenylphenyl] fluorene, 9,9-bis [4- (2- (2-glycidyl) such oxy propoxy) propoxy) -3-phenyl phenyl] 9,9-bis fluorene (glycidyloxy _{C 2-4} alkoxy _{C 2-4} alkoxy _{-C 6-10} aryl phenyl) fluorene; ring ^{Z 1} and ^{Z 2} is Substituted or unsubstituted benzene ring, R ^2a and R ^2b are linear or branched C _2-4 alkylene groups, m 1 and And m2 is 3 to 10, and q1 and q2 are 0, that is, compounds in which m1 and m2 are 3 to 10 in the above compounds (B1) to (B4), for example, 9,9-bis (glycidyloxy) C _2-4 alkoxy _{C 2-4} alkoxy _{C 2-4} alkoxyphenyl) fluorene, 9,9-bis (glycidyloxy _{C 2-4} alkoxy _{C 2-4} alkoxy _{C 2-4} alkoxy - (mono or di) _{C 1 -4-} alkylphenyl) fluorene, 9,9-bis (glycidyloxy _C2-4 alkoxy _C2-4 alkoxy _C2-4 alkoxy- _C5-10 cycloalkylphenyl) fluorene, 9,9-bis (glycidyloxy C) _2-4 alkoxy _C2-4 alkoxy _C2-4 alkoxy-C6-10 _arylphenyl ) fluorene and the like.

As 9,9-bis (glycidyloxy polyalkoxynaphthyl) fluorenes, for example, ring Z ¹ and Z ² are substituted or unsubstituted naphthalene ring, and R ^2a and R ^2b are linear or branched C ₂ -C _{2. 4} Compounds in which the alkylene group, m1 and m2 are 2, and q1 and q2 are each 0, such as (B5) 9,9-bis [6- (2- (2-glycidyloxyethoxy) ethoxy) -2-naphthyl] Fluorene, 9,9-bis [5- (2- (2-glycidyloxyethoxy) ethoxy) -1-naphthyl] fluorene, 9,9-bis [6- (2- (2-glycidyloxypropoxy) propoxy)- 2-naphthyl] fluorene such as 9,9-bis (glycidyloxy _{C 2-4} alkoxy _{C 2-4} alkoxy naphthyl) fluorene; ring ^{Z 1} and ^{Z 2} are location Or unsubstituted naphthalene ^{ring, R 2a} and ^{R 2b} is linear or branched _{C 2-4} alkylene group, m1 and m2 is 3-10, Compound q1 and q2 are each 0, i.e., the compound ( B5) includes compounds in which m1 and m2 are 3 to 10, such as 9,9-bis (glycidyloxy _C2-4 alkoxy _C2-4 alkoxy _C2-4 alkoxy naphthyl) fluorene and the like.

  These fluorene epoxy compounds can be used alone or in combination of two or more.

Commercially available products may be used as these fluorene epoxy compounds, and a conventional method (for example, a corresponding fluorenzole compound in which the groups X ¹ and X ² in the formula (1) are hydrogen atoms, Halomethyl oxirane compounds [eg, epihalohydrin (eg, epichlorohydrin (chloromethyl oxirane), epibromohydrin (bromomethyl oxirane), etc.), 1-halomethyl-2-methyl oxirane (eg, 1-chloromethyl-2 (Methyl oxirane etc.) and the like, etc.) may be used.

Preferred fluorene epoxy compound, 9,9-bis (4- (2- (2-glycidyloxy) ethoxy) phenyl) fluorene such as 9,9-bis (glycidyloxy poly _{C 2-4} alkoxyphenyl) fluorene, 9 9,9-bis (C _1-4 alkyl-glycidyloxy poly C _2-4 alkoxyphenyl) such as 9, 9-bis (4- (2- (2-glycidyl oxyethoxy) ethoxy) -3-methylphenyl) fluorene 9,9-Bis (glycidyloxypoly _C2-4 alkoxy-phenylphenyl) fluorenes such as fluorene, 9,9-bis (4- (2- (2-glycidyloxyethoxy) ethoxy) -3-phenylphenyl) fluorene 9,9-bis (5- (2- (2-glycidyloxyethoxy) ethoxy) -1-naphth Chill) fluorene, 9,9-bis (6- (2- (2-glycidyloxy) ethoxy) -2-naphthyl) 9,9-bis fluorene [glycidyloxy poly _{C 2-4} alkoxy naphthyl] fluorene, In particular, 9,9-bis (4-((meth) acryloyloxy (tetra to octa) ethoxy) phenyl) fluorene, 9,9-bis (6-((meth) acryloyloxy (tetra to octa) ethoxy) -2-) Naphthyl) fluorene, 9,9-bis (4- (glycidyloxy (tetra to octa) ethoxy) phenyl) fluorene, 9,9-bis (6- (glycidyloxy (tetra to octa) ethoxy) -2-naphthyl) fluorene It is. In the above exemplification, a compound in which a glycidyl group is replaced by a 2-methyl glycidyl group can be similarly used.

  Adhesives (for example, OCR) used in the present invention are roughly classified into acrylic adhesive compositions containing a fluorene (meth) acrylate compound and epoxy adhesive compositions containing a fluorene epoxy compound.

[Acryl-based adhesive composition]
The acrylic adhesive composition may be composed of a fluorene (meth) acrylate compound alone, and other polymerizable (meth) acrylates (monofunctional (meth) acrylates, polyfunctionals) as long as the thermal yellowing resistance is not impaired. It may contain other polymerizable components such as (meth) acrylates). As another polymerizable (meth) acrylate, polyfunctional (meth) acrylate is preferable.

As polyfunctional (meth) acrylates, difunctional (meth) acrylates [for example, C _2-10 alkylene glycol di (meth) acrylates such as ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, diethylene glycol Polyalkylene glycol di (meth) acrylates such as di (meth) acrylate, di (meth) acrylate of bisphenol A (or its alkylene oxide adduct), trifunctional or higher (meth) acrylates [eg, trimethylolpropane tritriol Triols or tetraols such as (meth) acrylates, pentaerythritol tri (meth) acrylates, pentaerythritol tetra (meth) acrylates or tri or tetra (meth) acrylates of tetraols], urethane (meth) a Crylates, epoxy (meth) acrylates, polyester (meth) acrylates, (meth) acrylates having a fluorene skeleton which does not belong to the above formula (1) [eg, 9,9-bis [4- (2- (meth) acryloyl) Oxyethoxy) phenyl] fluorene etc.] and the like. These monofunctional and polyfunctional (meth) acrylates can be used alone or in combination of two or more.

  The ratio of the fluorene (meth) acrylate compound to another polymerizable (meth) acrylate (monofunctional (meth) acrylate, polyfunctional (meth) acrylate) is the former / the latter (weight ratio) = 30/70 to It may be selected from the range of about 100/0, and may be, for example, about 50/50 to 95/5, preferably about 60/40 to 90/10 (for example, 70/30 to 85/15). If the proportion of the fluorene (meth) acrylate compound is too small, there is a possibility that the improvement effect of heat resistant yellowing may not be sufficiently obtained.

  The acrylic adhesive composition may contain a polymerization initiator. The polymerization initiator may be a thermal polymerization initiator (heat radical generator) or a photopolymerization initiator (photo radical generator).

  As a thermal polymerization initiator, organic peroxides (dialkyl peroxides (eg, di-t-butyl peroxide etc.), diacyl peroxides (eg, lauroyl peroxide, benzoyl peroxide etc.), peracids (or Peracid esters) (eg, t-butyl hydroperoxide, cumene hydroperoxide, t-butyl peracetate etc.) ketone peroxides, peroxycarbonates, peroxyketals], azo compounds [eg 2, Examples include azonitrile compounds such as 2'-azobis (isobutyronitrile), azoamide compounds, azoamidine compounds, and the like. These thermal polymerization initiators can be used alone or in combination of two or more.

  Examples of the photopolymerization initiator include benzoins (benzoin, benzoin alkyl ethers such as benzoin ethyl ether, etc.), acetophenones (acetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, etc.), Aminoacetophenones {2-methyl-1- [4- (methylthio) phenyl] -2-morpholinoaminopropanone-1 etc.}, anthraquinones (anthraquinone, 2-methylanthraquinone etc.), thioxanthones (2,4-dimethylone) Thioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, etc., ketals (acetophenone dimethyl ketal, benzyl dimethyl ketal, etc.), benzophenones (benzophenone, etc.), xanthones, etc. can be exemplified. You may use these photoinitiators individually or in combination of 2 or more types.

  The amount of the polymerization initiator (heat or photopolymerization initiator) used is 0.1 to 15 parts by weight based on 100 parts by weight of the total of (meth) acrylate components (fluorene (meth) acrylate compounds and other (meth) acrylates) The amount may be about 0.5 to 10 parts by weight (eg, 1 to 8 parts by weight), and more preferably about 2 to 5 parts by weight.

  The photoinitiator may be combined with a photosensitizer. Photosensitizers include tertiary amines {eg, trialkylamines, trialkanolamines (such as triethanolamine), ethyl N, N-dimethylaminobenzoate [ethyl p- (dimethylamino) benzoate, etc.] 4, alkylaminobenzoic acid alkyl esters such as amyl N, N-dimethylaminobenzoic acid [such as p- (dimethylamino) benzoic acid amyl acid], bis (dialkylamino) benzophenones such as 4,4-bis (diethylamino) benzophenone, Conventional photosensitizers such as dialkylamino benzophenones such as-(dimethylamino) benzophenone etc. and the like can be mentioned. These photosensitizers may be used alone or in combination of two or more.

  The amount of the photosensitizer used may be about 1 to 200 parts by weight, preferably 5 to 150 parts by weight, and more preferably about 10 to 100 parts by weight, with respect to 100 parts by weight of the polymerization initiator.

  The acrylic adhesive composition may contain a solvent, if necessary. The solvent is not particularly limited, and examples thereof include hydrocarbons (aliphatic hydrocarbons such as hexane, heptane and cyclohexane, or alicyclic hydrocarbons, aromatic hydrocarbons such as toluene and xylene, etc.), halogenation Hydrocarbons (methylene chloride, chloroform, carbon tetrachloride etc.), ethers (dialkyl ethers such as diethyl ether, cyclic ethers such as tetrahydrofuran), ketones (acetone, methyl ethyl ketone etc.), sulfoxides (dimethyl sulfoxide etc.) And nitriles (eg, acetonitrile etc.), esters (eg, ethyl acetate etc.), cellosolves (eg, methyl cellosolve etc.), carbitols (eg, methyl carbitol etc.) and the like. These solvents may be used alone or in combination of two or more.

  The amount of the solvent used can be selected from the range of about 0 to 10000 parts by weight, for example, 100 parts by weight with respect to 100 parts by weight of the total of (meth) acrylate components (fluorene (meth) acrylate compounds and other (meth) acrylates) It may be about 2000 parts by weight, preferably about 500 to 1000 parts by weight.

  Furthermore, acrylic adhesive compositions can be prepared using conventional additives, such as stabilizers (heat stabilizers, antioxidants, ultraviolet absorbers, etc.), fillers, antistatic agents, flame retardants, surfactants, plasticizers. , Tackifiers, protective colloids, thickeners, anti-aging agents, antifoaming agents, etc. may be included. These additives may be used alone or in combination of two or more.

[Epoxy adhesive composition]
The epoxy adhesive composition may be configured by combining a fluorene epoxy compound and a curing agent, and includes other components such as another epoxy compound (or epoxy resin) as long as the heat yellowing resistance is not impaired. It may be.

As another epoxy compound (or epoxy resin), for example, glycidyl ether type epoxy resin [for example, bisphenol type epoxy resin (for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, bisphenol S type] Epoxy resin, brominated bisphenol A type epoxy resin, biphenol type epoxy resin, etc .; Phenol type epoxy resin (eg phenol novolac type epoxy resin, cresol novolac type epoxy resin, phenol type glycidyl ether such as brominated phenol novolac type epoxy resin Brominated epoxy resin; glycol type epoxy resin (for example, bisphenols (such as bisphenol A) or an alkylene oxide adduct of a hydrogenated product thereof Reactants with pichlorohydrin etc.); Diglycidyl ethers of alicyclic diols (eg, 1,4-cyclohexanedimethanol diglycidyl ether etc.), dicyclopentadiene type epoxy resins, cycloaliphatic epoxy resins (eg, vinylcyclohexene) Epoxy resin having an alicyclic skeleton such as dioxide, dicyclopentadiene oxide, alicyclic diepoxy acetal, aliphatic cyclic diepoxy adipate, aliphatic cyclic diepoxy carboxylate etc .; poly (glycidyloxy phenyl) alkane ( for example, 1,1,2,2-tetrakis (4-glycidyloxy-phenyl) ethane, 1,1,1-tris tri- or tetra _{(glycidyloxyphenyl)} such as (glycidyloxy) methane _{C 1-4} a Epoxy resins having a naphthalene skeleton (for example, di (glycidyloxy) naphthalene such as 2,6-di (glycidyloxy) naphthalene, 2,2′-diglycidyl oxybinaphthalene, bis (2-glycidyloxynaphthyl) ) Diglycidyloxynaphthalenes such as bis (glycidyloxynaphthyl) C _1-6 alkanes such as methane, bis [2,7-di (glycidyloxy) naphthyl] methane, etc., epoxy resins having a xanthene skeleton (eg, 9) Glycidyl ether having a condensed ring skeleton such as -phenyl-2,7-diglycidyloxy-1,3,4,5,6,8-hexamethylxanthene etc., etc.], glycidyl amine type epoxy resin (eg tetraglycidyl) Diaminodiphenylmethane, triglycidyl para aminopheno Glycidyl ester type epoxy resin (eg, aromatic dicarboxylic acid (phthalic acid etc.) or its hydrogenated product (tetrahydrophthalic acid, hexahydrophthalic acid etc.) with epichlorohydrin, dimer acid Glycidyl esters and the like), epoxy compounds having a fluorene skeleton (fluorene-based epoxy resins) [for example, fluorenes not belonging to the category of the above formula (1) having a phenolic hydroxyl group such as bisphenoxyethanol fluoric glycidyl ether and bisphenol fluorocarbon glycidyl ether Polyglycidyl ether etc.], nitrogen-containing epoxy compounds (eg, triglycidyl isocyanurate, epoxy resin having hydantoin skeleton, N, N-diglycidyl-4-glycidyloxyaniline etc.), peracetic acid Type epoxy compound, and a silicon-containing epoxy compound.

  The ratio of the fluorene epoxy compound to the other epoxy compound (or epoxy resin) can be selected from the range of about 30/70 to 100/0, for example 50/50 to 95/5. , Preferably about 60/40 to 90/10 (e.g. 70/30 to 85/15). When the proportion of the fluorene epoxy compound is too small, there is a possibility that the improvement effect of heat resistant yellowing may not be sufficiently obtained.

  Examples of curing agents for epoxy resins include amine curing agents [particularly, primary amines, for example, linear aliphatic amines (for example, linear aliphatic polyamines such as ethylene diamine, hexamethylene diamine, diethylene triamine, triethylene tetramine, etc. And the like, cyclic aliphatic amines (eg, mensene diamine, isophorone diamine, bis (4-amino-3-methylcyclohexyl) methane, 3,9-bis (3-aminopropyl) -2,4,8,10). Monocyclic aliphatic polyamines such as tetraoxaspiro [5.5] undecane; crosslinked cyclic polyamines such as norbornane diamine etc., araliphatic polyamines such as xylylene diamine etc., aromatic amines (eg meta) Phenylenediamine etc.], polyaminoamide curing agent, acid anhydride Hardeners (for example, aliphatic acid anhydrides such as dodecenyl succinic anhydride; alicyclic acid anhydrides such as tetrahydrophthalic anhydride; aromatic acid anhydrides such as phthalic anhydride); phenol resin Hardeners (for example, novolac resin etc.) and the like can be mentioned. These curing agents may be used alone or in combination of two or more.

  The proportion of the curing agent is 0.5 to 3.0 equivalents of the functional group of the curing agent, preferably 0.7 to 1 equivalent of epoxy groups of the entire epoxy resin component (fluorene epoxy compound and other epoxy compounds). It may be adjusted to be 1.5 equivalents, more preferably 0.8 to 1.2 equivalents.

  The epoxy adhesive composition may also contain a curing accelerator. As the curing accelerator, for example, amines [eg, tertiary amines (eg, triethylamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris (dimethylaminomethyl) phenol, 1,8-diazamicyclo [5 .4.0] undecene-1, etc.), imidazoles (eg, alkylimidazoles such as 2-methylimidazole; arylimidazoles such as 2-phenylimidazole, etc.) and derivatives thereof (eg, phenol salts, phenol novolac salts, carbonates) , Salts of formates, etc.], alkali metal or alkaline earth metal alkoxides, phosphines, amide compounds (eg, dimer acid polyamide etc.), Lewis acid complex compounds (eg, boron trifluoride ethylamine complex etc.), sulfur Compound [e.g., polysulfide, mercaptan compound (thiol compound), etc.], boron compounds (e.g., phenyl dichloroborane), condensable organic metal compound (e.g., an organic titanium compound, an organoaluminum compound) and the like. These curing accelerators can be used alone or in combination of two or more.

  The proportion (addition amount) of the curing accelerator is, for example, 0.01 to 30 parts by weight, preferably 1 to 20 parts by weight, based on 100 parts by weight of the total of the epoxy compound components (fluorene epoxy compound and other epoxy compounds). More preferably, it may be about 5 to 10 parts by weight.

The epoxy adhesive composition may contain a photopolymerization initiator (cationic polymerization initiator, photoacid generator). Examples of the photopolymerization initiator include onium salts of Bronsted acid [for example, aromatic diazonium salts such as 4-chlorobenzenediazonium hexafluorophosphate; and aromatic sulfonium salts such as triphenylsulfonium triflate (or trifluoromethanesulfonate). An aromatic iodonium salt such as bis (4-t-butylphenyl) iodonium hexafluorophosphate etc., an iron aromatic compound salt of Br ブ レ ン nsted acid [eg, (η ⁶ -isopropylbenzene) (η ⁵ -cyclopentadienyl); And the like, etc.) and the like. These photopolymerization initiators can be used alone or in combination of two or more. The proportion of the photopolymerization initiator to be used is about 0.1 to 10 parts by weight, preferably about 0.5 to 5 parts by weight with respect to 100 parts by weight of the whole epoxy resin component (fluorene epoxy compound and other epoxy compounds) It may be.

  The epoxy adhesive composition may also contain a solvent. It does not specifically limit as a solvent, The solvent etc. which were illustrated in the said acrylic adhesive composition are mentioned. These solvents may be used alone or in combination of two or more.

  The amount of the solvent used can be selected from the range of about 0 to 10000 parts by weight, for example, 100 to 2000 parts by weight, preferably about 100 parts by weight with respect to 100 parts by weight of the total of epoxy compound components (fluorene epoxy compound and other epoxy compounds). It may be about 200 to 1000 parts by weight.

  Furthermore, the epoxy adhesive may contain conventional additives, such as the additives exemplified in the above-mentioned acrylic adhesive composition. These additives may be used alone or in combination of two or more.

  In addition, the acrylic adhesive composition and the epoxy adhesive composition are a thermosetting adhesive containing a thermal polymerization initiator or a curing agent in the composition, and a photocurable adhesive containing a photopolymerization initiator. It can be classified into In the present invention, since the fluorene compound represented by the above formula (1) can exhibit adhesiveness in a cured product, it is possible to use OCA as an adhesive instead of the adhesive (for example, OCR), You may adhere | attach an adherend.

[Composition of adhesive]
The pressure-sensitive adhesive (or pressure-sensitive adhesive layer) contains at least a polymer of the fluorene compound, and the fluorene compound may be the fluorene epoxy compound, but from the viewpoint of adhesiveness, the fluorene (meth) acrylate compound Is preferred. The polymer of the fluorene compound may be a homopolymer of the fluorene (meth) acrylate compound, but if necessary, a polymerizable monomer that exhibits adhesiveness upon curing, for example, an acrylic ester ( For example, copolymers with ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate and the like may be used. The proportion of the fluorene compound to the total monomers in the polymer can be selected from the range of about 30 to 100% by weight, for example, 50 to 95% by weight, preferably 60 to 90% by weight (eg, 70 to 85% by weight) It may be an extent.

  In addition, if necessary, an elastomer component (for example, natural rubber, styrene-butadiene copolymer rubber (SBR), polyisobutylene, silicone rubber, etc.) may be contained, and a polymer containing the above-mentioned fluorene compound as a structural unit The ratio to the elastomer component can be selected from the range of about 30/70 to 100/0, for example, 50/50 to 95/5, preferably 60/40 to 90/10 (eg, for example). 70/30 to 85/15).

  Furthermore, other additives may be included as long as the effects of the present invention are not impaired. As an additive, a tackifier, a softener (plasticizer), an antiaging agent, a filler etc. are mentioned, for example. The content of the additive is, for example, 0 to 20 parts by weight, preferably 2 to 15 parts by weight, and more preferably 4 to 4 parts by weight, based on 100 parts by weight of the total of the polymer containing the fluorene compound in the constituent unit and the elastomer component. It may be about 10 parts by weight.

  Among the thermosetting adhesive, the photocurable adhesive, and the pressure-sensitive adhesive, a photocurable adhesive is preferable from the viewpoint of productivity and the like.

[Substrate, adherend]
In the present invention, the substrate and the adherend may be rigid (or hard) or flexible. The substrate is a hard substrate, for example, a ceramic substrate (for example, a glass (for example, a glass (for example, silicate glass such as quartz glass or borosilicate glass) substrate), an alumina substrate (for example, a sapphire glass substrate), a silicon substrate) , Metal substrates (for example, copper substrates, aluminum substrates, silver substrates, etc.), plastic substrates (for example, polymethyl methacrylate substrates, polyolefin substrates, polycarbonate substrates (for example, bisphenol A type polycarbonate substrates, etc.), polyester substrates (for example, polyethylene terephthalate) And the like). In addition, the substrate may be a flexible substrate, for example, a thin film metal substrate such as a metal foil, a plastic film substrate (such as an optical film substrate), or the like. As a preferable substrate, for example, a ceramic substrate [for example, a transparent conductive film laminated glass substrate, a cover glass (for example, a surface cover glass such as a display device), etc.], a light guide plate, a flexible printed wiring board and the like can be exemplified.

  In addition, an ITO (indium tin oxide) transparent conductive film, a hard coat layer, a light scattering layer, an antiglare layer, an antireflective layer, a low refractive index layer, an anti-Newton ring, for at least one member of the substrate and the adherend A functional layer such as a layer, an electrical insulating layer, or a semiconductor layer may be formed.

  The adherend may also be a hard adherend or a flexible adherend. As a hard adherend, a sheet in which a functional layer is laminated on the above-mentioned ceramic substrate, metal substrate, plastic substrate and the like can be exemplified. As a flexible adherend, for example, an optical film (for example, a protective film (for example, a protective film such as a display device)), a hard coat film, a polarizing film, a reflective film, an antireflection film, an antiglare film, a partial reflection film Partially transmitting film, interference filter film, color filter film, hologram film, diffraction grating film, anti-Newton ring film, prism sheet, etc. can be exemplified.

  In the present invention, at least one member of the substrate and the adherend may be a transparent member, and the other member may be an opaque or translucent member. In a preferred embodiment, the members of both the substrate and the adherend may be transparent members. More specifically, a combination of a ceramic substrate and an optical film may be used.

  In the method of the present invention, the step of bonding the substrate and the adherend with an adhesive, and the bonded body or optical member (referred to as primary optical member) obtained in the bonding step are post-processed to obtain an optical member (secondary And a step of obtaining an optical member), and heat treatment is performed in at least one of the bonding step and the post-processing step to suppress yellowing of the obtained primary and secondary optical members.

Bonding process
The bonding step (or bonding method) may include a heat treatment of heating and bonding the adhesive or the adhesive in the process of bonding the substrate and the adherend. The bonding step is typically performed in three steps, that is, a coating step of applying (or sticking) an adhesive or a pressure-sensitive adhesive to a substrate and / or an adherend, and bonding to bond the substrate and the adherend And a curing step of curing and bonding the adhesive. In addition, when it adhere | attaches with an adhesive, it is not necessary to harden. The temperature of the heat treatment can be appropriately selected according to the purpose of heating, the adhesive or the pressure-sensitive adhesive composition, and is, for example, about 50 to 250 ° C., preferably 100 to 200 ° C., and more preferably about 120 to 180 ° C. It is also good.

(Coating process)
In the coating step, the adhesive or the pressure-sensitive adhesive is applied (or pasted) to at least one of the substrate and the adherend. In general, the substrate may be coated (or pasted). The adhesive or pressure-sensitive adhesive may be applied (or pasted) to all or part of the adhesive surface of the substrate and / or the adherend. The coating method is not particularly limited, and may be a conventional method, for example, a method using a coater such as a flow coater, a roll coater, a knife coater, a gravure coater, a spin coater, a hot melt applicator, and the like.

  The thickness of the adhesive layer or adhesive layer formed of the adhesive or the adhesive can be selected from the range of about 0.1 to 5000 μm (for example, 1 to 1000 μm), for example, about 10 to 300 μm, preferably about 50 to 200 μm. May be

  In the application step, the adhesive or the adhesive may be heat treated. In particular, in the case of using a photocurable adhesive, for example, in the case of a solventless adhesive, the viscosity of the adhesive decreases under heating, and a hot melt system is used in order to improve the handling during application. The adhesive may then be applied with a reduced viscosity. The temperature of the heat treatment may be, for example, about 50 to 150 ° C, preferably about 70 to 120 ° C, and more preferably about 80 to 100 ° C. When the adhesive composition contains a solvent, the solvent may be removed by heat treatment after application. The temperature of the heat treatment may be, for example, about 50 to 150 ° C, preferably about 60 to 120 ° C, and more preferably about 70 to 100 ° C.

  The coating step may be performed in the air atmosphere (in air) or an inert gas atmosphere (for example, a nitrogen atmosphere, a rare gas atmosphere such as argon, etc.). In order to suppress yellowing, it is preferable to carry out heat treatment in a non-oxygen atmosphere (for example, the above-mentioned inert gas atmosphere etc.), but in the present invention, thermal yellowing can be effectively prevented. May be

  The coating process may be performed under atmospheric pressure. The heat treatment may also be performed in the atmosphere and under the pressure.

(Bonding process)
After the application step, the substrate and the adherend can be bonded in a desired positional relationship.

  In the bonding step, pressure may be applied to the bonding surface using a roller / roll or the like for bonding, or bonding may be performed by the weight of the base material or the adherend. The pressure applied to the bonding surface is not particularly limited, and can be selected, for example, from the range of about 0.01 to 10 MPa, preferably about 0.05 to 5.0 MPa, and more preferably about 0.1 to 1.0 MPa It is also good.

  Note that the bonding step may be performed while heat treating an adhesive or a pressure-sensitive adhesive. The heat treatment can suppress the mixing / generation of air bubbles, so that the substrate and the adherend can be in close contact with each other, and even if air bubbles are generated, they are easily removed. The temperature of the heat treatment may be, for example, about 50 to 150 ° C, preferably about 70 to 120 ° C, and more preferably about 80 to 100 ° C. In addition, when the adhesive or the adhesive contains volatile components such as a solvent and a small amount of water, it may be dried (or removed) by heat treatment. The temperature of the heat treatment may be, for example, about 50 to 150 ° C, preferably about 60 to 120 ° C, and more preferably about 70 to 100 ° C.

  The bonding step may also be performed in an air atmosphere or an inert gas atmosphere (for example, a nitrogen atmosphere, a rare gas atmosphere such as argon, or the like).

  The bonding step may be performed under atmospheric pressure, under reduced pressure (or under vacuum, for example, about 1 to 3000 Pa, preferably about 10 to 1000 Pa, more preferably about 100 to 500 Pa) or under pressure (for example, 0.03) It may be carried out at about -3 MPa, preferably about 0.05 to 2 MPa, and more preferably about 0.1 to 1 MPa. In particular, when performed under reduced pressure, air bubbles in the adhesive or pressure-sensitive adhesive can be removed, and mixing of air bubbles can be suppressed. The pressure (and heating temperature) may be adjusted as appropriate. For example, the substrate and the adherend are attached to each other while preventing removal of bubbles and generation of bubbles under reduced pressure (and under heating), and then an autoclave or the like The bubbles may be removed under pressure (and under heat). The heat treatment may also be performed in the atmosphere and under pressure.

(Curing process)
In the curing step, active energy is applied to cure the adhesive to bond the substrate and the adherend. As the active energy, thermal energy and / or light energy (ultraviolet light, X-ray, etc.) can be used, and can be appropriately selected according to the type of adhesive.

  When thermal energy is used, the adhesive can be cured by heat treatment, and the temperature of the heat treatment is, for example, about 50 to 250 ° C., preferably 60 to 150 ° C., and more preferably about 70 to 120 ° C. May be The heating time may be, for example, about 5 minutes to 12 hours, preferably about 10 minutes to 8 hours, and more preferably about 30 minutes to 4 hours.

When the adhesive is cured by light irradiation (for example, ultraviolet irradiation), the light irradiation energy amount can be appropriately selected according to the application, and is, for example, 50 to 10000 mJ / cm ² , preferably 70 to 8000 mJ / cm ² , More preferably, it may be about 100 to 5000 mJ / cm ² (for example, 500 to 3000 mJ / cm ² ).

  In addition, also when it hardens | cures by light irradiation, in order to improve adhesiveness and reactivity, you may heat-process before and / or after light irradiation. The temperature of the heat treatment may be, for example, about 50 to 250 ° C., preferably 60 to 120 ° C., and more preferably about 70 to 100 ° C.

  The curing step (or heat treatment) may be performed in an air atmosphere or an inert gas atmosphere (for example, a nitrogen atmosphere, a rare gas atmosphere such as argon, or the like).

  The curing step (or heat treatment) may be performed under atmospheric pressure or under reduced pressure (or under vacuum, for example, 1 to 3000 Pa, preferably 10 to 1000 Pa, and more preferably about 100 to 500 Pa). .

  In addition, the active energy may be irradiated in a plurality of times to form a temporary cured state in the middle. Since the viscosity can be adjusted by the pre-cured state, dripping can be suppressed.

  By such a method, a bonded body or an optical member in which the substrate and the adherend are bonded can be obtained. The obtained bonded body or optical member is excellent in heat yellowing resistance and can maintain high light transmittance. As a conjugate or an optical member, typically, for example, a display device (for example, touch panel display, electronic paper, LCD (liquid crystal display), PDP (plasma display), VFD (vacuum fluorescent display), SED (surface conduction electron) It may be a component such as a light emitting element display), an FED (field emission display), an NED (nano emissive display), an organic EL (electroluminescence) display, and the like.

[Post-processing process]
In the method of the present invention, the primary optical member does not necessarily have to be heat-treated in the bonding step, and usually the heat-treatment is often accompanied in the post-processing step. The heat treatment in the post-processing step may be carried out by, for example, baking treatment, evaporation treatment (including thin film formation treatment by PVD or CVD such as sputtering) including evaporation under heating and vacuum heating, pattern formation treatment under heating, cutting, etc. Processing that generates heat (such as semiconductor processing), processing that adheres the primary optical member to other members (such as the housing of a display device, a case, etc.) by heating (such as the thermosetting adhesive of the present invention; epoxy system An adhesive agent, a process of bonding with a thermosetting adhesive such as a urethane adhesive, and the like may be used. The temperature of the heat treatment can be appropriately selected according to the post-processing step, and may be, for example, about 50 to 250 ° C., preferably about 100 to 200 ° C., and more preferably about 120 to 180 ° C. Further, the heat treatment may be performed in an air atmosphere (in air) or an inert gas atmosphere (for example, a nitrogen atmosphere, a rare gas atmosphere such as argon, or the like). Although heat treatment is preferably performed in a non-oxygen atmosphere (for example, the above-mentioned inert gas atmosphere etc.) in order to suppress yellowing, in the present invention, thermal yellowing is performed even if heat treatment is performed in air. It can be effectively prevented.

[Characteristics of adhesive cured product or adhesive (adhesive layer or adhesive layer)]
The cured adhesive or adhesive (i.e., adhesive layer or adhesive layer) used in the present invention has the following characteristics.

  The difference in light transmittance (temperature 25 ° C., wavelength 400 nm, thickness 2.5 mm) before and after heating for 5 hours at 180 ° C. of the cured adhesive or adhesive is, for example, 0.1 to 20.0% (for example, 1) 0 to 20.0%), preferably 3.0 to 18.0% (eg, 5.0 to 15.0%), more preferably 8.0 to 12.0% ( For example, it may be about 10.0 to 12.0%.

  The Shore C hardness (measurement method according to ASTM D 2240) of the cured adhesive or adhesive can be selected, for example, from the range of about 30 to 80 (eg, 40 to 80), preferably 50 to 78 (eg, 60 to 60). 78), and more preferably about 65 to 75 (e.g. 70 to 75). If the Shore C hardness is too high, the elasticity may be reduced and the impact resistance of the adhesive layer or the adhesive layer may be reduced.

  The refractive index of the cured adhesive or adhesive at 25 ° C. and wavelength 589 nm can be selected from the range of about 1.35 to 1.90, for example, 1.40 to 1.85, preferably 1.43 to 1. It may be about .80, more preferably about 1.45 to 1.80. In particular, it is close to the refractive index of the ceramic substrate (for example, glass substrate: approximately 1.46, sapphire glass substrate: approximately 1.76, etc.) in the range of 1.46 to 1.76, so primary or secondary optical The loss of light transmitted through the member can be significantly reduced. Since the adhesive cured product or the adhesive contains the above-mentioned fluorene compound, it has a high refractive index, and the refractive index of the ceramic substrate is adjusted by adjusting the ratio with other components (for example, a copolymer component, an additive, etc.) It is easy to get close. Therefore, the optical member obtained can be compatible with heat-resistant yellowing and light loss reduction.

  The light transmittance and the Shore C hardness can be measured by the method described in the examples, and the refractive index can be measured using an Abbe refractometer (for example, Atago Co., Ltd., multi-wavelength Abbe refractometer DR-M2 according to JIS K7142). The refractive index at a temperature of 25 ° C. and 589 nm can be measured using a circulating constant temperature water bath 60-C3 or the like.

  The present invention will be described in more detail based on examples given below, but the present invention is not limited by these examples. The evaluation method is shown below.

(Heat resistant yellowing)
The sample with a thickness of 2.5 mm was heated at 180 ° C. for 5 hours, and the light transmittance was measured at a temperature of 25 ° C. and a wavelength of 400 nm using an ultraviolet-visible absorptiometer (UV-3600 manufactured by Shimadzu Corporation) The difference between before and after heating was calculated.

(Shore C hardness)
The measurement was performed according to ASTM D2240 using a sample of 2.5 mm in thickness.

Example 1
As a polyfunctional fluorene compound having a 9,9-bis (polyalkoxyaryl) fluorene skeleton, 9,9-bis (4-acryloyloxypolyethoxyphenyl) fluorene, that is, in the above formula (1), ring Z ¹ and A compound wherein Z ² is a benzene ring, groups X ¹ and X ² are an acryloyl group, group R ² is an ethylene group, m 1 + m 2 = 11, n 1 = n 2 = 1 and p 1 = p 2 = q 1 = q 2 = 0 (hereinafter referred to as BPEF− 9EOA was synthesized by the method described in Patent Document 1.

100 parts by weight of BPEF-9 EOA and 3 parts by weight of Irgacure 184 (manufactured by BASF AG) as a photopolymerization initiator are mixed to form a photocurable adhesive, and UV irradiation (500 mJ / cm ² ) is repeated four times to cure Prepared.

  The heat yellowing resistance was 10.65%, and the Shore C hardness was 73.

Comparative Example 1
The same as Example 1, except that "FANKRYL 321A" manufactured by Hitachi Chemical Co., Ltd. (diacrylate of adduct obtained by adding 10 moles of ethylene oxide to 1 mole of bisphenol A) is used instead of BPEF-9 EOA. The cured product was prepared.

  The heat yellowing resistance was 25.34%, and the Shore C hardness was 63.

Comparative example 2
A cured product was prepared in the same manner as in Example 1 except that “light acrylate 9EGA” (nona ethylene glycol diacrylate) manufactured by Kyoeisha Chemical Co., Ltd. was used instead of BPEF-9 EOA.

  The heat yellowing resistance was 39.79%, and the Shore C hardness was 74.

  As is clear from the evaluation results, the difference in light transmittance before and after heating is smaller in the example than in the comparative example, probably because the compound has a 9,9-bis (polyalkoxy aryl) fluorene skeleton. It was excellent in yellowing.

  The present invention can be suitably used for adhesion of an adhesive or pressure-sensitive adhesive (in particular, OCR or OCA), that is, the transparent member exemplified in the section of [Substrate, Adherend]. Also, the primary (or secondary) optical member can be suitably used particularly for a display device or the like.

Claims (8)

A method of suppressing yellowing of an optical member due to heat treatment; an adhesion step in which the optical member adheres an adherend and a substrate at least one of which is transparent, and an adhesion step The heat treatment is included in at least one of the bonding step and the post-processing step ; and the adhesive or pressure-sensitive adhesive is represented by the following formula (1): A method for suppressing yellowing of an optical member by heat treatment using a heat- or photo-curable adhesive containing a fluorene compound or a pressure-sensitive adhesive containing a polymer of the fluorene compound.

(Wherein, Z ¹ and Z ² are each an aromatic hydrocarbon ring, R ^2a and R ^2b are each an alkylene group, m 1 and m 2 are each integers of 2 or more, n 1 and n 2 are each integers of 1 or more, R ^3a and R ^3b is a substituent inert to the reaction, p1 and p2 each is an integer of 0 or more, R ^4a and R ^4b each is a substituent inert to the reaction, q1 and q2 each is an integer from 0 to 4, X ¹ And X ² each represents the following formula (2) or the following formula (3)

(In the formula, R ¹ represents a hydrogen atom or a methyl group, respectively). ) In the formula of claim 1, wherein (1), ^{Z 1} and ^{Z 2} are _{C 6-24} aromatic hydrocarbon ring, ^{respectively, R 2a} and ^{R 2b} is _{C 2-4} alkylene group, respectively, m1 and m2 is at least 3, respectively integer, an integer of 1-3 n1 and n2 are ^{each R 3a} and ^{R 3b} are each an alkyl group, an integer of 0 to 2 p1 and p2, respectively, suppression of yellowing of q1 and q2 is claim 1, wherein each 0 Method. In the formula (1) according to claim 1, Z ¹ and Z ² each represent an aromatic hydrocarbon ring selected from a benzene ring, a naphthalene ring or a biphenyl ring, R ^2a and R ^2b each represent a C _2-3 alkylene group, 4 or an integer m1 and m2, respectively, 1-2 integer n1 and n2, ^{respectively, R 3a} and ^{R 3b} are each methyl, 0 or 1 p1 and p2, respectively, q1 and q2 are each 0, ^{X 1} and The method for suppressing yellowing according to claim 1, wherein X ² is a group represented by the formula (2).   The method for suppressing yellowing according to any one of claims 1 to 3, wherein the heat treatment is performed at 100 to 200 ° C.   An adhesive agent is a photocurable adhesive agent, The yellowing suppression method in any one of Claims 1-4.   The method for suppressing yellowing according to any one of claims 1 to 5, wherein at least one transparent member of the substrate and the adherend is a ceramic substrate or an optical film.   The method for suppressing yellowing according to any one of claims 1 to 6, wherein at least one transparent member of the substrate and the adherend is a sapphire glass substrate. The method for suppressing yellowing according to any one of claims 1 to 7, wherein the refractive index (25 ° C, wavelength 589 nm) of the adhesive layer or adhesive layer after the adhesion step is 1.46 to 1.76.