Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
  • C09J11/02—Non-macromolecular additives
  • C09J11/06—Non-macromolecular additives organic
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
  • C09J11/08—Macromolecular additives
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J163/00—Adhesives based on epoxy resins; Adhesives based on derivatives of epoxy resins

Definitions

• the present invention relates to adhesives for optical components, optical elements, and optical devices.
• Patent Document 1 proposes an adhesive for optical members that contains a compound with an oxiranyl group and an onium salt compound.
• a stereoscopic imaging device uses two optical components (light control panels) with multiple light-reflecting surfaces made of strip-shaped metal films bonded together to form a two-dimensional or three-dimensional image in the air.
• the present invention has been made in consideration of the above circumstances. Specifically, the objective is to provide an adhesive for optical components that, even when used to bond optical components containing metals, does not cause deterioration of the optical components and is less likely to cause warping in the bonded optical components, as well as optical elements and optical devices that use the same.
• the present invention provides the following adhesive for optical members.
• An adhesive for optical components comprising an alicyclic epoxy compound, an oxetanyl group-containing compound, a tackifier resin, and a photopolymerization initiator, wherein the adhesive for optical components is applied to a thickness of 100 ⁇ m, and irradiated with 3,000 mJ of light with a wavelength of 365 nm to produce a cured product, which is then immersed in ultrapure water and heated at 100° C. for 20 hours to extract fluorine ions, and the amount of fluorine ions extracted is 10 ⁇ g/g or less relative to the mass of the cured product.
• the present invention also provides the following optical element and optical device.
• An optical element wherein the adhesive layer is a cured product of an adhesive for optical components comprising an alicyclic epoxy compound, an oxetanyl group-containing compound, and a tackifier resin, and when the adhesive layer is immersed in ultrapure water and heated at 100°C for 20 hours to extract fluorine ions, the amount of extracted fluorine ions is 10 ⁇ g/g or less relative to the mass of the adhesive layer.
• optical element according to [7] or [8], wherein at least one of the first optical member and the second optical member has an uneven portion in an area adjacent to the cured product [10] The optical element according to any one of [7] to [9], which is an optical imaging element. [11] The optical element according to any one of [7] to [10], which is an optical imaging element for vehicle mounting. [12] An optical device including the optical element according to any one of [7] to [11] above, which forms an image in the air by using the optical element.
• the present invention provides an adhesive for optical components that, even when used to bond optical components that contain metal, does not cause deterioration of the optical components and is less likely to cause warping of the bonded optical components.
• a numerical range expressed using “ ⁇ ” means a range that includes the numerical values written before and after " ⁇ " as the lower and upper limits.
• the adhesive for optical members of the present invention is a composition containing at least an alicyclic epoxy compound, an oxetanyl group-containing compound, a tackifier resin, and a photopolymerization initiator.
• the adhesive for optical members may further contain other components as necessary.
• the adhesive for optical members is preferably used when adhering an optical member containing a metal to the adhesive surface.
• the use of the adhesive for optical members of the present invention is not limited thereto, and may be used, for example, to adhere an optical member not containing a metal, and may also be used as an adhesive for adhering members other than optical members.
• the amount of fluorine ions eluted from the cured product of the adhesive for optical components is set to a certain value or less, as described below. Therefore, even if an optical element containing the cured product of the adhesive for optical components is used in a high-temperature, high-humidity environment, the adhesive surface (metal) is unlikely to deteriorate, and the optical element can be used stably for a long period of time.
• the adhesive for optical members of the present invention combines an alicyclic epoxy compound and an oxetanyl group-containing compound with a tackifier resin. Therefore, the shrinkage force that occurs when the alicyclic epoxy compound and the oxetanyl group-containing compound in the adhesive for optical members are photopolymerized is mitigated by the tackifier resin, making it difficult for the adhered member to warp.
• each component of the adhesive for optical members of the present invention will be described.
• an alicyclic epoxy compound refers to a compound having an epoxy group and an alicyclic structure, and capable of being photocured by the action of a photopolymerization initiator described below.
• the adhesive for optical components may contain only one type of alicyclic epoxy compound, or may contain two or more types.
• an adhesive for optical components contains an alicyclic epoxy compound
• the visible light transmittance of the cured product tends to be good.
• the alicyclic epoxy compound may contain structures other than epoxy groups and alicyclic structures in the molecule, but it is preferable that it does not contain aromatic rings from the viewpoint of preventing coloration of the cured product, etc.
• the number of epoxy groups contained in the alicyclic epoxy compound may be 1 or more, but is preferably 2 to 10, and more preferably 2 to 5. When the number of epoxy groups is 2 or more, the alicyclic epoxy compound is more easily photocured. On the other hand, when the number of epoxy groups is more than 10, depending on the curing conditions, the curing of the adhesive for optical components may proceed excessively in some parts, and unreacted components of the adhesive for optical components may remain, resulting in a low curing rate. Furthermore, the number of alicyclic structures in the alicyclic epoxy compound is not particularly limited, and may be only one, or may be two or more.
• Examples of alicyclic epoxy compounds include compounds having an epoxycyclo structure represented by the following general formula (A):
• the epoxycyclo structure is a structure obtained by epoxidizing a cycloalkene with an oxidizing agent such as a peroxide, and has an aliphatic ring and an epoxy group composed of two carbon atoms and an oxygen atom that constitute the aliphatic ring.
• M represents an aliphatic ring (alicyclic structure).
• the number of carbon atoms in the aliphatic ring is preferably 4 to 8, and more preferably 5 to 6. When the number of carbon atoms in the aliphatic ring of the epoxycyclo structure is within this range, the viscosity of the adhesive for optical members tends to fall within the desired range.
• alicyclic epoxy compounds are preferable in that they are less likely to contain halogen ions such as chlorine compared to other epoxy compounds.
• epoxycyclo structure examples include epoxycyclohexane and epoxycyclopentane, with epoxycyclohexane being preferred.
• the number of epoxycyclo structures in the alicyclic epoxy compound is not particularly limited, and may be only 1 or may be 2 or more.
• Examples of the alicyclic epoxy compound containing only one epoxycyclo structure include compounds represented by the following general formula (A-1).
• M 1 in the above general formula (A-1) represents an aliphatic ring (alicyclic structure) and the number of carbon atoms therein is preferably 4 to 8, and more preferably 5 to 6.
• the alicyclic structure represented by M 1 may have a substituent such as a halogen atom, an alkyl group, a fluoroalkyl group, an aryl group, a furyl group, or a thienyl group bonded thereto.
• Examples of halogen atoms bonded to the alicyclic structure include fluorine.
• alkyl groups bonded to the alicyclic structure include linear or branched alkyl groups having 1 to 6 carbon atoms (methyl, ethyl, propyl, butyl, pentyl, and hexyl groups, etc.).
• fluoroalkyl groups bonded to the alicyclic structure include linear or branched fluoroalkyl groups having 1 to 6 carbon atoms (perfluoromethyl, perfluoroethyl, and perfluoropropyl groups, etc.).
• aryl groups bonded to the alicyclic structure include aryl groups having 6 to 18 carbon atoms (phenyl, naphthyl, etc.).
• X1 in the above general formula (A-1) is a single bond or a linking group.
• the linking group include a divalent hydrocarbon group, a carbonyl group, an ether bond, a thioether bond, an ester bond, a carbonate bond, an amide bond, or a group in which a plurality of these are linked together.
• Examples of the divalent hydrocarbon group include an alkylene group having 1 to 18 carbon atoms, or a divalent alicyclic hydrocarbon group.
• Examples of the alkylene group having 1 to 18 carbon atoms include a methylene group, a methylmethylene group, a dimethylmethylene group, an ethylene group, a propylene group, and a trimethylene group.
• Examples of the divalent alicyclic hydrocarbon group include a divalent cycloalkylene group (including a cycloalkylidene group) such as a 1,2-cyclopentylene group, a 1,3-cyclopentylene group, a cyclopentylidene group, a 1,2-cyclohexylene group, a 1,3-cyclohexylene group, a 1,4-cyclohexylene group, and a cyclohexylidene group.
• X 1 in the above general formula (A-1) is preferably a single bond.
• Examples of the alicyclic compound represented by the above general formula (A-1) include compounds represented by the following chemical formulas (A-1a) and (A-1b).
• examples of alicyclic epoxy compounds containing two epoxycyclo structures include compounds represented by the following general formula (A-2).
• M2 and M3 represent an alicyclic structure (aliphatic ring), and the number of carbon atoms in the alicyclic structure is preferably 4 to 8, and more preferably 5 to 6.
• the alicyclic structures may each independently be bonded to a substituent such as a halogen atom, an alkyl group, a fluoroalkyl group, an aryl group, a furyl group, or a thienyl group. Specific examples of these are the same as the substituents bonded to the alicyclic structure of the compound represented by the above general formula (A-1).
• X2 in the above general formula (A-2) is a single bond or a linking group.
• the linking group include a divalent hydrocarbon group, a carbonyl group, an ether bond, a thioether bond, an ester bond, a carbonate bond, an amide bond, or a group in which a plurality of these are linked together, and are the same as the linking group represented by X1 in the above general formula (A-1).
• alicyclic epoxy compounds represented by the above general formula (A-2) include 1,2-bis(3,4-epoxycyclohexane-1-yl)ethane, 2,2-bis(3,4-epoxycyclohexane-1-yl)propane, ⁇ -caprolactone-modified 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate, and compounds represented by the following structural formula.
• l is an integer from 1 to 10
• m is an integer from 1 to 30.
• R is an alkylene group having 1 to 8 carbon atoms (preferably an alkylene group having 1 to 3 carbon atoms, such as a methylene group, an ethylene group, a propylene group, or an isopropylene group).
• alicyclic epoxy compounds containing three epoxycyclo structures include compounds represented by the following general formula: In this general formula, n1 and n2 each represent an integer of 1 to 30.
• examples of the epoxy compound containing an epoxycyclo structure include the compound represented by the following general formula (A-3).
• M4 and M5 represent an alicyclic structure (aliphatic ring), and the number of carbon atoms in the alicyclic structure is preferably 4 to 8, and more preferably 5 to 6.
• the alicyclic structures may each independently be bonded to a substituent such as a halogen atom, an alkyl group, a fluoroalkyl group, an aryl group, a furyl group, or a thienyl group. Specific examples of these are the same as the substituents bonded to the alicyclic structure of the compound represented by the above general formula (A-1).
• alicyclic epoxy compounds include compounds having a glycidyl ether group.
• examples of alicyclic compounds having a glycidyl ether group include hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, and alkylene oxide adducts thereof.
• 3',4'-epoxycyclohexylmethyl (3,4-epoxy)cyclohexanecarboxylate is particularly preferred in terms of viscosity, reactivity, and transparency.
• the weight average molecular weight is preferably 200 or more from the viewpoint of the strength of the resulting cured product.
• the weight average molecular weight is preferably 1000 or less, and more preferably 500 or less, from the viewpoint of setting the viscosity of the adhesive for optical components in the desired range.
• the weight average molecular weight (Mw) is a styrene-equivalent value determined by gel permeation chromatography (GPC).
• the epoxy equivalent of the alicyclic epoxy compound is not particularly limited, but is preferably 90 g/eq or more and 250 g/eq or less, and more preferably 100 g/eq or more and 190 g/eq or less.
• the epoxy equivalent of the alicyclic epoxy compound is within this range, the photocuring properties tend to be good.
• the cure shrinkage of the adhesive for optical components can be kept within an appropriate range.
• the epoxy equivalent of the alicyclic epoxy compound can be measured in accordance with JIS K7236:2001.
• the amount of alicyclic epoxy compound in the adhesive for optical components is appropriately selected depending on the application of the adhesive for optical components, but is preferably 10% by mass to 40% by mass, more preferably 12% by mass to 35% by mass, and even more preferably 15% by mass to 30% by mass. If the amount of alicyclic epoxy compound is within this range, the photocuring properties of the adhesive for optical components are more likely to be improved.
• the amount of the alicyclic epoxy compound is preferably 30 parts by mass or more and 70 parts by mass or less, more preferably 32 parts by mass or more and 65 parts by mass or less, and even more preferably 33 parts by mass or more and 60 parts by mass or less.
• the photocurability tends to be good.
• the oxetanyl group-containing compound refers to a compound having at least one oxetanyl group in the molecule, which is photocurable by the action of a photopolymerization initiator described below.
• the number of oxetanyl groups in the oxetanyl group-containing compound is preferably 1 to 5, but from the viewpoint of photocurability, the number of oxetanyl groups is more preferably 2 or more, and particularly preferably 2.
• the adhesive for optical components may contain only one type of oxetanyl group-containing compound, or may contain two or more types.
• oxetanyl group-containing compounds having only one oxetanyl group examples include 2-ethylhexyl oxetane, 3-ethyl-3-hydroxymethyl oxetane, 3-(meth)allyloxymethyl-3-ethyl oxetane, (3-ethyl-3-oxetanylmethoxy)methylbenzene, 2-ethylhexyl (3-ethyl-3-oxetanylmethyl) ether, ethyl diethylene glycol (3-ethyl-3-oxetanylmethyl) ether, 3-cyclohexylmethyl-3-ethyl-oxetane, etc.
• 2-ethylhexyl oxetane e.g., Aron Oxetane OXT-212, manufactured by Toa Gosei Chemical Industry Co., Ltd.
• Aron Oxetane OXT-212 manufactured by Toa Gosei Chemical Industry Co., Ltd.
• oxetanyl group-containing compounds having two oxetanyl groups examples include 1,4-bis ⁇ [(3-ethyl-3-oxetanyl)methoxy]methyl ⁇ benzene, 3-ethyl-3 ⁇ [(3-ethyloxetan-3-yl)methoxy]methyl ⁇ oxetane, 1,4-bis[(3-ethyl-3-oxetanyl)methoxy]benzene, 1,3-bis[(3-ethyl-3-oxetanyl)methoxy]benzene, 3,7-bis(3-oxetanyl) 5-oxa-nonane, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, 1,2-bis[(3-ethyl-3-oxetanylmethoxy)methyl]ethane, 1,2-bis[(3-ethyl-3-oxetanylmethoxy
• 3-ethyl-3 ⁇ [(3-ethyloxetan-3-yl)methoxy]methyl ⁇ oxetane e.g. Aron Oxetane OXT-221, manufactured by Toa Gosei Chemical Co., Ltd.
• Aron Oxetane OXT-221, manufactured by Toa Gosei Chemical Co., Ltd. is preferred from the viewpoint of availability, etc.
• oxetanyl group-containing compounds having three or more oxetanyl groups examples include trimethylolpropane tris(3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tris(3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tetrakis(3-ethyl-3-oxetanylmethyl) ether, and dipentaerythritol pentakis(3-ethyl-3-oxetanylmethyl) ether.
• the amount of the oxetanyl group-containing compound in the adhesive for optical components is appropriately selected depending on the application of the adhesive for optical components, but is preferably 10% by mass to 45% by mass, more preferably 12% by mass to 43% by mass, and even more preferably 15% by mass to 40% by mass. When the amount of the oxetanyl group-containing compound is within this range, the adhesive for optical components will have an appropriate curing speed and good photocurability.
• the amount of the oxetanyl group-containing compound and the compound having an epoxy group is preferably 75 parts by mass or less, more preferably 70 parts by mass or less, and more preferably 50 parts by mass or less.
• the amount of the oxetanyl group-containing compound is within this range, the storage stability of the adhesive for optical components is further improved, and uneven curing is further prevented.
• a tackifier resin refers to a resin for imparting tackiness to an adhesive for optical components, and the tackifier resin is preferably a thermoplastic resin that does not react with alicyclic epoxy compounds or oxetanyl group-containing compounds.
• an adhesive for optical components contains a tackifier resin, not only is the adhesiveness of the adhesive for optical components increased, but the cure shrinkage is also reduced.
• the tackifier resin may contain only a single compound (resin), but is usually a mixture of multiple compounds (resins).
• examples of such tackifier resins include aromatic hydrocarbon resins, unsaturated aliphatic hydrocarbon resins, and saturated aliphatic hydrocarbon resins.
• the adhesive for optical components may contain only one of these, or may contain two or more types.
• aromatic hydrocarbon resins include C9 petroleum resins and terpene phenol resins.
• unsaturated aliphatic hydrocarbon resins include rosin hydrocarbon resins, polyterpene resins, and C5 petroleum resins.
• saturated aliphatic hydrocarbon resins include hydrogenated products of the above aromatic hydrocarbon resins and hydrogenated products of the above unsaturated aliphatic hydrocarbon resins.
• saturated aliphatic hydrocarbon resins are preferred as tackifier resins, and hydrogenated rosin hydrocarbon resins are even more preferred.
• the amount of tackifier resin in the adhesive for optical components is appropriately selected depending on the application of the adhesive for optical components, but is preferably 20% by mass or more and 70% by mass or less, more preferably 30% by mass or more and 50% by mass or less, and even more preferably 30% by mass or more and 40% by mass or less.
• the amount of the tackifier resin is preferably 30 parts by mass or more and 250 parts by mass or less, more preferably 50 parts by mass or more and 100 parts by mass or less, and even more preferably 60 parts by mass or more and 80 parts by mass or less.
• the amount of the tackifier resin is within this range, the effect of suppressing warping of the adherend member is more easily obtained.
• the amount of the compound having an epoxy group and the oxetanyl group-containing compound is sufficiently large, the photocurability is more likely to be improved.
• Photopolymerization initiator is not particularly limited as long as it is a compound that can be activated by light irradiation and can cure the above-mentioned alicyclic epoxy compound or oxetanyl group-containing compound.
• the adhesive for optical components may contain only one type of photopolymerization initiator, or may contain two or more types.
• photopolymerization initiators include cationic polymerization initiators (photoacid generators) that generate acid when irradiated with light.
• the cation of the cationic polymerization initiator may be any monovalent positive ion, and includes oxonium ions, ammonium ions, sulfonium ions, and iodonium ions.
• oxonium ions examples include oxonium ions such as trimethyloxonium, diethylmethyloxonium, triethyloxonium, and tetramethylenemethyloxonium; pyrilinium ions such as 4-methylpyrilinium, 2,4,6-trimethylpyrilinium, 2,6-di-tert-butylpyrilinium, and 2,6-diphenylpyrilinium; and chromenium and isochromenium ions such as 2,4-dimethylchromenium and 1,3-dimethylisochromenium.
• oxonium ions such as trimethyloxonium, diethylmethyloxonium, triethyloxonium, and tetramethylenemethyloxonium
• pyrilinium ions such as 4-methylpyrilinium, 2,4,6-trimethylpyrilinium, 2,6-di-tert-butylpyrilinium, and 2,6-diphenylpyrilin
• ammonium ions include pyrrolidinium ions such as N,N-dimethylpyrrolidinium, N-ethyl-N-methylpyrrolidinium, and N,N-diethylpyrrolidinium; imidazolinium ions such as N,N'-dimethylimidazolinium, N,N'-diethylimidazolinium, N-ethyl-N'-methylimidazolinium, 1,3,4-trimethylimidazolinium, and 1,2,3,4-tetramethylimidazolinium; tetrahydropyrimidinium ions such as N,N'-dimethyltetrahydropyrimidinium; morpholinium ions such as N,N'-dimethylmorpholinium; These include piperidinium ions such as N,N'-diethylpiperidinium; pyridinium ions such as N-methylpyridinium, N-benzylpyridinium, and N-phenacylpyr
• phosphonium ions include tetraarylphosphonium ions such as tetraphenylphosphonium, tetra-p-tolylphosphonium, tetrakis(2-methoxyphenyl)phosphonium, tetrakis(3-methoxyphenyl)phosphonium, and tetrakis(4-methoxyphenyl)phosphonium; triarylphosphonium ions such as triphenylbenzylphosphonium, triphenylphenacylphosphonium, triphenylmethylphosphonium, and triphenylbutylphosphonium; tetraalkylphosphonium ions such as triethylbenzylphosphonium, tributylbenzylphosphonium, tetraethylphosphonium, tetrabutylphosphonium, tetrahexylphosphonium, triethylphenacylphosphonium, and tributylphenacylphosphon
• sulfonium ions include triphenylsulfonium, tri-p-tolylsulfonium, tri-o-tolylsulfonium, tris(4-methoxyphenyl)sulfonium, 1-naphthyldiphenylsulfonium, 2-naphthyldiphenylsulfonium, tris(4-fluorophenyl)sulfonium, tri-1-naphthylsulfonium, tri-2-naphthylsulfonium, tris(4-hydroxyphenyl)sulfonium, 4-(phenylthio)phenyldiphenylsulfonium, 4-(p-tolylthio)phenyldiphenylsulfonium, -p-tolylsulfonium, 4-(4-methoxyphenylthio)phenylbis(4-methoxyphenyl)sulfonium
• iodonium ions include diphenyliodonium, di-p-tolyliodonium, bis(4-dodecylphenyl)iodonium, bis(4-methoxyphenyl)iodonium, (4-octyloxyphenyl)phenyliodonium, bis(4-decyloxy)phenyliodonium, 4-(2-hydroxytetradecyloxy)phenylphenyliodonium, 4-isopropylphenyl(p-tolyl)iodonium, and 4-isobutylphenyl(p-tolyl)iodonium ions.
• ammonium ions, phosphonium ions, sulfonium ions, or iodonium ions are more preferred, sulfonium ions or iodonium ions are even more preferred, and sulfonium ions are even more preferred.
• sulfonium ions triarylsulfonium ions are also preferred.
• the type of counter anion that forms a salt with the cation of the cationic polymerization initiator is not particularly limited, but the anion preferably contains a central atom and a ligand coordinated to the central atom.
• the central atom include P, As, Sb, and Ga.
• the ligand include F - , Cl - , (CF 2 CF 3 ) n F (6-n) , substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, etc.
• Examples of preferred structures of the counter anion include PF 6 - , (CF 2 CF 3 ) n PF (6-n) - , AsF 6 - , SbF 6 - , BF 4 - , SbCl 6 - , (C 6 F 6 ) 4 B - , and anions having a structure represented by the following general formula (D-1).
• (CF 2 CF 3 ) n PF (6-n) - and anions having a structure represented by the following general formula (D-1) are preferred, and anions having a structure represented by the following general formula (D-1) are particularly preferred.
• R 11 , R 12 , R 13 , and R 14 each independently represent an optionally substituted alkyl group having from 1 to 18 carbon atoms, or an optionally substituted aryl group having from 6 to 14 carbon atoms. Furthermore, at least one of R 11 , R 12 , R 13 , and R 14 , preferably two or more, and more preferably three or more, is an optionally substituted aryl group having from 6 to 14 carbon atoms.
• the alkyl group having 1 to 18 carbon atoms may be linear, branched, or cyclic, and examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, n-pentyl, isopentyl, t-pentyl, sec-pentyl, n-hexyl, isohexyl, n-heptyl, sec-heptyl, n-octyl, n-nonyl, sec-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, cyclopentyl, and
• the alkyl group having a prime number of 1 to 18 may have a substituent.
• substituents include an alkoxy group having 1 to 18 carbon atoms; an aromatic group such as a phenyl group, a biphenyl group, a terphenyl group, a quaterphenyl group, a tolyl group, an indenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a pyrenyl group, a phenanthryl group, or a mestyl group; a furanyl group, a thienyl group, a thienothienyl group, a pyrrolyl group, an imidazolyl group, an N-methylimidazolyl group, a thiazolyl group, an oxazolyl group, a pyridyl group, a pyrazyl group, a pyrimidyl group,
• heterocyclic groups such as an allyl group, a pyridinnothiazolyl group, a benzimidazolyl group, a pyridinoimidazolyl group, an N-methylbenzimidazolyl group, a pyridino-N-methylimidazolyl group, a benzoxazolyl group, a pyridinooxazolyl group, a benzothiadiazolyl group, a pyridinothiadiazolyl group, a benzoxadiazolyl group, a pyridinooxadiazolyl group, a carbazolyl group, a phenoxazinyl group, and a phenothiazinyl group; halogen atoms such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom; a hydroxyl group; a mercapto group; a nitro group; an alkyl-
• aryl groups having 6 to 14 carbon atoms include phenyl, biphenyl, terphenyl, quaterphenyl, tolyl, indenyl, naphthyl, anthryl, fluorenyl, pyrenyl, phenanthenyl, and mestyl groups.
• an aryl group having 6 to 14 carbon atoms may also have a substituent.
• substituents include an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, an aromatic group, a heterocyclic group, a halogen atom, a hydroxyl group, a mercapto group, a nitro group, an alkyl-substituted amino group, an aryl-substituted amino group, an unsubstituted amino group ( NH2 group), a cyano group, an isocyano group, and the like, and specific examples thereof are the same as those described above.
• R 11 , R 12 , R 13 and R 14 in the above general formula (D-1) are preferably an alkyl group having a halogen atom (particularly a fluorine atom) as a substituent, or an aryl group having a halogen atom (particularly a fluorine atom) as a substituent.
• cationic polymerization initiator examples include triarylsulfonium salts represented by the following general formula, and triarylsulfonium salts containing the above-mentioned triarylsulfonium ion (cation) and the anion represented by the above general formula (D-1).
• the cationic polymerization initiator may be a commercially available product. Suitable commercially available examples of the cationic polymerization initiator include CPI-210S (a triarylsulfonium salt having (CF 2 CF 3 ) n PF (6-n) - as a counter anion) manufactured by San-Apro Co., Ltd., CPI-310FG (a triarylsulfonium salt having a counter anion having a structure represented by the above general formula (D-1)) manufactured by San-Apro Co., Ltd., and the like.
• CPI-210S a triarylsulfonium salt having (CF 2 CF 3 ) n PF (6-n) - as a counter anion
• CPI-310FG a triarylsulfonium salt having a counter anion having a structure represented by the above general formula (D-1) manufactured by San-Apro Co., Ltd., and the like.
• the amount of photopolymerization initiator in the adhesive for optical components is preferably 0.01 parts by mass or more and 2.0 parts by mass or less when the total amount of the oxetanyl group-containing compound and the compound having an epoxy group (the alicyclic epoxy compound and other epoxy compounds described below) is taken as 100 parts by mass. This range makes it possible to efficiently cure the oxetanyl group-containing compound, the alicyclic epoxy compound, and other epoxy compounds while keeping the amount of fluorine ions within the desired range.
• the adhesive for optical components may contain a compound having an epoxy group (also referred to as "other epoxy compounds" in this specification) in addition to the above-mentioned alicyclic epoxy compounds.
• the other epoxy compounds may be any compound that has an epoxy group in the molecule and does not contain an alicyclic structure, for example, a compound having an aromatic ring, a compound having a linear or branched structure, or a compound containing both of these.
• the adhesive for optical components may contain only one type of other epoxy compound, or may contain two or more types.
• the number of epoxy groups in the other epoxy compound may be only one, or may be two or more, but two or more is more preferable.
• the other epoxy compound preferably contains an ether bond.
• Examples of epoxy compounds containing an ether bond include epoxy compounds containing a glycidyl ether group and an aromatic ring.
• epoxy compounds containing a glycidyl ether group and an aromatic ring include bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, and their alkylene oxide adducts (e.g., ethylene oxide adducts, propylene oxide adducts, the same below).
• alkylene oxide adducts e.g., ethylene oxide adducts, propylene oxide adducts, the same below.
• the propylene oxide adduct of bisphenol A diglycidyl ether is preferred.
• the refractive index of the cured product tends to be high and it tends to be more rigid.
• the amount of other epoxy compounds in the adhesive for optical components is preferably 10% by mass or more and 50% by mass or less, and more preferably 15% by mass or more and 30% by mass or less. When the amount of other epoxy compounds is within this range, the adhesive for optical components tends to have good curing properties, and the cured product tends to have good optical transparency.
• the content of the other epoxy compounds is preferably 30 parts by mass or more and 70 parts by mass or less, more preferably 32 parts by mass or more and 65 parts by mass or less, and even more preferably 33 parts by mass or more and 66 parts by mass or less, when the total amount of the oxetanyl group-containing compound and the compound having an epoxy group (the alicyclic epoxy compound and the other epoxy compounds described below) is taken as 100 parts by mass.
• the adhesive for optical components may further contain other components as necessary.
• other components include various silane coupling agents, antioxidants, leveling agents, defoamers, stabilizers, polymerization initiators, antiaging agents, wettability improvers, surfactants, plasticizers, UV absorbers, preservatives, and antibacterial agents.
• the adhesive for optical components may contain only one of these, or may contain two or more of them.
• Method for preparing adhesive for optical components is not particularly limited, and all components may be mixed at once, or the components may be mixed in two or more batches.
• the alicyclic epoxy compound, the oxetanyl group-containing compound, the tackifier resin, and other epoxy compounds may be mixed first, and then other components (e.g., photopolymerization initiator, additives, etc.) may be further mixed.
• heating may be performed as necessary.
• the heating temperature is appropriately selected depending on the type of alicyclic epoxy compound, etc., the softening point, etc., but is preferably 80°C or higher and 150°C or lower, and more preferably 100°C or higher and 140°C or lower.
• the heating time is also appropriately selected, and is usually preferably 30 minutes or higher and 120 minutes or lower, and more preferably 40 minutes or higher and 80 minutes or lower.
• the viscosity of the adhesive for optical members is appropriately selected depending on the application of the adhesive for optical members, but for example, the viscosity measured at 23°C with an R-type viscometer is preferably 100 mPa ⁇ s or more and 100,000 mPa ⁇ s or less, more preferably 300 mPa ⁇ s or more and 7,000 mPa ⁇ s or less. If the viscosity of the adhesive for optical members is within this range, when the adhesive for optical members is used to bond optical members having uneven parts on the bonding surface, the adhesive for optical members easily penetrates into the uneven parts. In addition, the adhesive for optical members is easily applied by various application devices.
• the curing conditions for the adhesive for optical components are appropriately selected depending on the type of photopolymerization initiator, but it can usually be cured by irradiation with ultraviolet light or visible light, and it is preferable to cure by irradiation with light having a wavelength of 365 nm to 425 nm.
• the integrated light amount at this time is preferably 1000 J to 5000 J, and more preferably 2000 J to 5000 J.
• heating may be performed in addition to the light irradiation.
• the heating temperature is usually preferably 40°C or higher and 110°C or lower, and more preferably 60°C or higher and 90°C or lower.
• the heating time is usually 10 minutes or longer and 120 minutes or shorter.
• the amount of fluorine ions extracted from the cured product under specified conditions is 10 ⁇ g/g or less per unit mass of the cured product.
• the adhesive for optical components is applied to a thickness of 100 ⁇ m, and irradiated with 3000 mJ of light with a wavelength of 365 nm to produce a cured product.
• the cured product is then immersed in ultrapure water and heated at 100°C for 20 hours to extract fluorine ions.
• the amount of fluorine ions extracted in the pure water can be determined by ion chromatography.
• the amount of fluorine ions extracted by the above-mentioned method is within the above range, as described above, when an optical component containing a metal is bonded, the metal is less likely to become cloudy or corroded.
• the amount of fluorine ions extracted from the cured product can be reduced by the type of photopolymerization initiator (particularly the type of counter anion) and the amount of photopolymerization initiator.
• the cured product of the adhesive for optical components has excellent light transmittance.
• the average parallel light transmittance of a 100 ⁇ m-thick cured product of the adhesive for optical components at wavelengths of 380 nm to 780 nm is preferably 90% or more, more preferably 93% or more, and even more preferably 95% or more. If the parallel light transmittance of the adhesive for cured components is 90% or more, it is unlikely to affect the performance of optical elements, making it easier to use for various purposes.
• the parallel light transmittance can be determined using an ultraviolet-visible spectrophotometer.
• the haze of a 1 mm thick cured product of the adhesive for optical components is preferably 7.0% or less, more preferably 6.0% or less, even more preferably 5.0% or less, and particularly preferably 3.0% or less. If the haze is within this range, the adhesive for optical components becomes difficult to visually recognize. The haze is measured with a haze meter.
• the ratio of the refractive index at the D line of the cured product of the adhesive for optical components to the refractive index at the D line of the adherend (optical component) is preferably 0.996 or more and 1.005 or less, more preferably 0.998 or more and 1.004 or less, and particularly preferably 1.000.
• the refractive index is a value measured with a multi-wavelength Abbe refractometer.
• the adhesive for optical components are not particularly limited, and it can be used to bond optical components of various optical elements together, or to bond optical components to other components.
• the adhesive for optical components is very useful for bonding optical components containing metal on the bonded surface, since it is difficult to cause clouding on the metal surface when the metal is bonded, and is also difficult to corrode the metal.
• the adhesive for optical components has good adhesion not only to various metals, but also to various resins such as polyolefins and polycarbonates. Therefore, it can be used in a wide range of applications.
• optical elements using the adhesive for optical members described above will be described, but optical elements for which the adhesive for optical members can be used are not limited to this embodiment.
• the optical element of the present invention includes a first optical member, a second optical member, and an adhesive layer that bonds them together, and the adhesive layer is a cured product of the adhesive for optical members described above.
• the adhesive layer includes a cured product of the alicyclic epoxy compound and the oxetanyl group-containing compound described above, and a tackifier resin.
• the amount of fluorine ions extracted is 10 ⁇ g/g or less relative to the mass of the adhesive layer (immersed in ultrapure water). If the amount of fluorine ions is 10 ⁇ g/g or less relative to the mass of the adhesive layer, the adhesive layer is unlikely to affect the first optical member or the second optical member, and is unlikely to deteriorate the first optical member or the second optical member over time, even if the first optical member or the second optical member is an optical member having a reflective surface containing metal.
• optical elements examples include optical imaging elements for stereoscopic imaging devices that combine two-dimensional or three-dimensional videos or images in the air, such as the optical imaging device described in WO 2009/131128, the optical imaging device described in JP 2015-14777A, the stereoscopic imaging device described in Japanese Patent No. 6203989, the stereoscopic imaging element described in JP 2018-13585A, the optical imaging device described in JP 2011-90117A, and the optical imaging means described in WO 2013/129063.
• optical imaging elements for stereoscopic imaging devices that combine two-dimensional or three-dimensional videos or images in the air such as the optical imaging device described in WO 2009/131128, the optical imaging device described in JP 2015-14777A, the stereoscopic imaging device described in Japanese Patent No. 6203989, the stereoscopic imaging element described in JP 2018-13585A, the optical imaging device described in JP 2011-90117A, and the optical imaging means described in WO 2013/129063.
• the first optical member having an uneven portion and the second optical member having an uneven portion are arranged so that their uneven portions face each other.
• the uneven portions of the first optical member and the second optical member each consist of a plurality of linear convex ridges, which are arranged in parallel.
• a metal film such as an aluminum vapor deposition film is arranged on a surface perpendicular to the thickness direction of the convex ridges, and the metal film is used as a light reflecting surface.
• the adhesive layer is arranged between the first optical member and the second optical member so as to fill the uneven portions of the first optical member and the second optical member without any gaps.
• the method for manufacturing the optical imaging element is not particularly limited, but for example, after arranging the first optical member and the second optical member in a predetermined orientation, the above-mentioned optical member adhesive is filled between the first optical member and the second optical member. The optical member adhesive is then irradiated with light of a desired wavelength (e.g., ultraviolet light) and cured to obtain the optical imaging element.
• a desired wavelength e.g., ultraviolet light
• the optical imaging element may be an optical imaging element for vehicle mounting.
• An optical imaging element for vehicle mounting may be exposed to a high temperature and high humidity environment, and if a conventional adhesive for optical members is used to bond the first optical member and the second optical member, the metal film in the area adjacent to the adhesive layer is likely to deteriorate.
• the first optical member and the second optical member are bonded together using the above-mentioned adhesive for optical members, the metal film in the area adjacent to the adhesive layer is less likely to deteriorate, and the optical imaging element can be used stably for a long period of time.
• the bonded first optical member and second optical member are less likely to warp, so the optical imaging element can be used stably.
• the optical device of the present invention only needs to include the optical imaging element described above, and the other components can be of known configurations.
• OXT-221 (3-ethyl-3 ⁇ [(3-ethyloxetan-3-yl)methoxy]methyl ⁇ oxetane (product name: ARON OXETANE OXT-221, manufactured by Toagosei Co., Ltd.) represented by the following structural formula
• EP-4010S Propylene oxide adduct of bisphenol A diglycidyl ether (manufactured by ADEKA Corporation)
• KE-100 Hydrogenated rosin-based hydrocarbon resin (product name: Pine Crystal KE-100, manufactured by Arakawa Chemical Industries, Ltd.)
• CPI-100P a triarylsulfonium salt represented by the following structural formula (manufactured by San-Apro Co., Ltd.)
• CPI-210S Triarylsulfonium salt represented by the following structural formula (manufactured by San-Apro Co., Ltd.)
• CPI-310FG Triarylsulfonium salt represented by the following structural formula (manufactured by San-Apro Co., Ltd.)
• R 1 , R 2 and R 3 each independently represent an organic group
• X represents an atomic group represented by the above general formula (D-1).
• PI2074 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate (manufactured by Arakawa Chemical Industries, Ltd.) represented by the following structural formula
• KBM-403 3-glycidoxypropyltrimethoxysilane (product name: KBM ⁇ 403, manufactured by Shin-Etsu Chemical Co., Ltd.)
• Phenolic antioxidant product name: Irganox 1010, manufactured by BASF
• Phosphorus-based antioxidant product name: Adeka STAB PEP-36, manufactured by ADEKA Corporation
• Sulfur-based antioxidant product name: Adeka STAB 135A, manufactured by ADEKA Corporation
• Defoamer product name: BYK-1790, manufactured by BYK Japan
• Adhesives for Optical Components (Examples 1 to 5 and Comparative Examples 1 to 5) An alicyclic epoxy compound, an oxetanyl group-containing compound, other epoxy compounds, and a tackifier resin were charged into a flask in the composition (mass ratio) shown in Table 1, and heated at 120°C for 1 hour. It was then confirmed that the tackifier resin had dissolved. Thereafter, the mixture was cooled to room temperature (25°C), and a photopolymerization initiator, a silane coupling agent, and other components in the composition (mass ratio) shown in Table 1 were added, and these were mixed to prepare an adhesive for optical components.
• the adhesive for optical components was evaluated as follows. The results are shown in Table 1.
• PET films Two polyethylene terephthalate (PET) films (thickness: 188 ⁇ m) with a size of 100 mm x 120 mm and subjected to a release treatment were prepared.
• the adhesives for optical members prepared in the examples and comparative examples were poured into the frame, and the same PET film as above was placed on the adhesive for optical members.
• the adhesive for optical members was irradiated with light having a wavelength of 365 nm so that the accumulated light amount was 3000 mJ. Then, it was heated at 80 ° C. for 30 minutes. Then, the PET film and the frame were removed to obtain a cured product of the adhesive for optical members in the form of a film.
• the mass of the cured product was measured.
• the cured product was then immersed in 5 mL of ultrapure water, sealed, and heated in a dryer at 100°C (set temperature) for 20 hours. It was then cooled to room temperature, and the extract was collected. The extract was then diluted, and the amount of fluoride ions was determined using ion chromatography (IC) (measuring device: ICS-3000, manufactured by Thermo Fisher Scientific).
• IC ion chromatography
• the amount of fluoride ions relative to the mass of the cured product [ ⁇ g/g] was then determined from the measured amount of fluoride ions and the mass of the cured product.
• a conveyor-type UV irradiation device was used to irradiate the adhesive for optical members with 3000 mJ of light with a wavelength of 365 nm. Then, the adhesive was heated at 80 ° C. for 30 minutes. Then, the PET film and the frame were removed to obtain a cured product of the adhesive for optical members in the form of a film.
• the cured product was stored in a laminated state with the PP plate at 20° C. and 60% Rh for 1000 hours, or at 65° C. and 95% Rh for 1000 hours.
• the state of the aluminum vapor deposition film after storage was evaluated according to the following criteria. ⁇ : No change in appearance ⁇ : Slightly cloudy ⁇ : Cloudy
• the cured product was prepared by the same method as the quantification of the amount of fluorine ions.
• two polypropylene (PP) plates (thickness: 0.5 mm) of 100 mm x 150 mm were prepared.
• the adhesive for optical members prepared in the examples and comparative examples was poured into the frame, and the same PP plate as above was placed on the adhesive for optical members.
• a conveyor-type UV irradiation device was used to irradiate the adhesive for optical members with 3000 mJ of light with a wavelength of 365 nm. Then, it was heated at 80 ° C for 30 minutes. Then, the obtained sample (cured product of the adhesive sandwiched between two PP plates) was placed on a flat table, and the presence or absence of lift at the four corners of the PP plate was visually confirmed. Then, it was evaluated according to the following criteria. ⁇ : No lifting was observed at the four corners of the PP plate. ⁇ : The maximum warp height of the PP plate was more than 0 mm and 1 mm or less. ⁇ : The maximum warp height of the PP plate was more than 1 mm.
• the adhesive for optical components of the present invention even when used to bond optical components that contain metal on the bonding surface, is unlikely to cause clouding or corrosion of the metal. In addition, the resulting optical elements are also unlikely to warp. Therefore, it is extremely useful in the manufacture of various optical elements.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Adhesives Or Adhesive Processes (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=92421513

Family Applications (1)

Country Status (3)

Citations (4)

Family Cites Families (2)

• 2023
  • 2023-12-18 JP JP2025500678A patent/JPWO2024171602A1/ja active Pending
  • 2023-12-18 WO PCT/JP2023/045276 patent/WO2024171602A1/ja not_active Ceased
• 2024
  • 2024-01-02 TW TW113100008A patent/TW202440855A/zh unknown

Patent Citations (4)

Also Published As

Similar Documents

Legal Events