JP5301409B2 - Cationic curable resin composition and cured product thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cation curable resin composition which can sufficiently develop an effect by a cation curable compound and can give a cured material that shows a sufficient curability, can be cured in a short time, and is excellent in productivity and a low coloring property; and to provide a cured material obtained by curing the composition. <P>SOLUTION: The cation curable resin composition is a resin composition that comprises the cation curable compound and a cation curing catalyst and is cation-cured, in which the cation curable resin composition contains a water content of 0.03-2 mass% with respect to 100 mass% of the resin composition. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

The present invention relates to a cationic curable resin composition and a cured product thereof. More specifically, the present invention relates to a resin composition that contains a cation curable compound and can be cured by a cation curing reaction with a cation curing catalyst that generates cationic species by heat or light, and a cured product obtained by curing the resin composition.

The cationic curable resin composition is a resin composition that contains a cation curable compound and can be cured by a cation curing reaction with a cation curing catalyst that generates a cationic species by heat, light, or the like. In addition to optical members and molding materials, various applications such as paints and adhesive materials have been studied. Generally, a radical polymerization reaction by a vinyl group or the like is well known as a curing reaction (polymerization reaction), but cationic curing does not cause curing inhibition by oxygen compared to radical polymerization, and shrinkage during curing is small. There are advantages. On the other hand, the curing speed is regarded as a problem, and a technique capable of realizing curing for a short time has been demanded.

Therefore, for example, an epoxy resin composition containing an epoxy resin, a cationic curing initiator, and an epoxidized polybutadiene having a hydroxyl group is disclosed (see Patent Documents 1 and 2, etc.). In Patent Documents 1 and 2, since the epoxidized polybutadiene having a hydroxyl group has a hydroxyl group and is liquid and the molecular chain easily moves, and has a chain transfer effect in a cationic curing system, The polymerization rate (curing rate) is improved by including an epoxidized polybutadiene having a hydroxyl group, and the epoxidized polybutadiene having a hydroxyl group is an aliphatic non-glycidyl ether epoxy resin having a large molecular weight, and the reactivity of the epoxy group is fat. It is described as being comparable to a cyclic epoxy resin and being incorporated into a curing system, so that it is possible to suppress a decrease in hygroscopicity and heat resistance of the cured product.

Also disclosed is a photocurable addition polymerizable composition comprising an epoxy resin, a hydroxy group-containing substance, and a photoinitiator system containing an iodonium salt, a visible light sensitizer, and an electron donor compound (Patent Literature). See 3 etc.). In Patent Document 3, when a photoinitiator system containing an iodonium salt, a visible light sensitizer, and an electron donor compound is used, efficient cationic polymerization can be performed under conditions of room temperature and standard pressure. Both cationic polymerization and free radical polymerization can be initiated under mild conditions, and the time required to cure the epoxy and hydroxy group-containing resin composition to form a tack-free gel or solid is greatly increased. Describes that it can be reduced.

By the way, as a technique for improving the storage stability of a cationically polymerizable compound, the total content of other cationic compounds, metal compounds and strongly acidic compounds including a cationically polymerizable compound and a cationic polymerization initiator is specified. In addition, a technique for containing water in the cationically polymerizable composition is disclosed (see Patent Document 4). This cationically polymerizable composition is mainly intended for inkjet ink use, and Patent Document 4 states that the storage stability of the cationically polymerizable compound cannot be sufficiently improved if the water content is insufficient. In the examples, a cationically polymerizable composition having a water content of 3.5 to 4% by mass is specifically described.

JP 2006-152016 A (2nd and 5th pages) JP 2007-31555 A (2nd and 7th pages) Japanese translation of PCT publication No. 2001-520759 (2nd page, 10-11) JP 2006-89722 A (pages 2, 8, 13)

As described above, various techniques relating to the cationic curable resin composition have been studied, but there is room for improvement in order to further improve the productivity in order to further increase the productivity. Further, the techniques of Patent Documents 1 to 3 are components incorporated into a cured product skeleton as components for improving the curing rate, that is, epoxidized polybutadiene having a hydroxyl group if Patent Documents 1 and 2 are used. For example, since a hydroxy group-containing substance is used, there is a possibility that the characteristics of the cationic curable compound in the cured product cannot be exhibited to the maximum. Therefore, there has been room for improvement to increase the productivity by increasing the curing rate with high curability while maximizing the effect of the cationic curable compound. In addition, when the water content is 3.5 to 4% by mass as in Patent Document 4, there is a possibility that the high transparency required for the optical member application and the like cannot be achieved. Therefore, there is room for improvement to obtain a cured product having excellent transparency.

By the way, when a cured product is obtained using a cationic curing catalyst, such a cured product is sufficiently suppressed in coloration compared with the case of using a conventional curing agent such as acid anhydrides, amines, and phenol resins. However, depending on the amount of the cationic curing catalyst used, the cationic curing catalyst may cause coloring of the cured product during curing, post-processing (reflow process), light irradiation during use, etc. . On the other hand, when the usage-amount of a cationic curing catalyst is reduced, there exists a possibility that a resin composition may not fully harden | cure. Therefore, it is possible to exhibit sufficient curability even if the amount of the cationic curing catalyst used is reduced, and to devise it to be more suitably applicable to applications requiring a high level of transparency such as optical materials. There was room.

The present invention has been made in view of the above-described present situation, and can fully express the effect of the cationic curable compound, exhibit sufficient curability, and can be cured in a short time, resulting in productivity and low colorability. It is an object of the present invention to provide a cationic curable resin composition capable of giving an excellent cured product, and a cured product obtained by curing it.

The inventors of the present invention have studied various techniques for shortening the curing time in the cationic curing system. When a small amount of water coexists in the mixture containing the cationic curing compound and the cationic curing catalyst, the curing rate by the cationic curing catalyst is increased. It has been found that it dramatically increases, can be cured in a short time, and productivity is significantly improved. Since the resin composition containing such a cationic curing compound, a cationic curing catalyst, and moisture has sufficient curability, sufficient curability can be expressed even if the amount of the cationic curing catalyst used is reduced. It has been found that it is particularly useful for applications requiring low colorability. Moreover, it has been found that a cured product having a high glass transition temperature (Tg) and excellent transparency can be obtained by using a resin composition containing a specific content of water, and the above-mentioned problems can be solved brilliantly. I thought that I could do it. Such a resin composition is useful for various applications such as optical members, mechanical component materials, electrical / electronic component materials, automotive component materials, civil engineering and building materials, molding materials, paint materials, adhesive materials, and the like. The present invention has been found to be particularly suitable for use as an optical member, and the present invention has been achieved.

As described above, in the present invention, it is possible to dramatically increase the curing rate by containing a small amount of water in the cationic curable resin composition. This is because of the following cationic curing reaction (polymerization reaction). It is presumed that the mechanism is caused by the promotion of the decomposition reaction represented by the following formula (1). The following formula is an example in which an epoxy resin is used as a cation curable compound and an aromatic sulfonium salt is used as a cation curing catalyst, but the same is true when other cation curable compounds and cation curing catalysts are used. It is thought that it becomes the mechanism of.

In the above formulas (1) to (3), R, R ′, R ″ and R ′ ″ are the same or different and represent an organic group, R ′ ⁺ is a cationic species, and X ⁻ is Anionic species. n is a number exceeding 0.
In the decomposition reaction represented by the above formula (1), if the stability of the generated cation species (R ′ ⁺ in the above formula) is increased, the reaction rate of the decomposition reaction represented by the formula (1) is increased. If the stability is too high, there is a risk that the subsequent cationic polymerization (curing) represented by the above formulas (2) and (3) will not be promptly transferred. Therefore, if the cationic species can be appropriately stabilized, that is, if the cationic species can be stabilized to an extent that does not inhibit cationic polymerization (curing), the overall speed consisting of the above formulas (1) to (3), so-called resin composition It is considered that the curing rate of the is improved. Since the water molecule has an unshared electron pair in the oxygen atom, it is presumed that the cation generated by the decomposition reaction by heat or photoexcitation of the cation curing catalyst can be moderately stabilized.

In the present invention, by containing a small amount of water, it is possible to suppress the coloring of the cured product at the same time as improving the curing rate, and to improve the low coloring property (colorlessness). In addition to the effect of suppressing the coloring of the cured product itself and the heat-resistant coloring of the cured product by reducing the amount of the catalyst due to the fact that the curing rate can be accelerated even if the amount of the catalyst is small, it is directly attributable to the inclusion of moisture. It is an effect.

In general, in a curing system using a cation curable compound and a cation curing catalyst, water is not allowed to coexist. For example, an organic solvent may be used as a medium for dissolving / dispersing the cationic curable compound in order to make the resin composition suitable for coating applications, but the cationic curable compound is usually water-insoluble. Therefore, water is considered unsuitable as such a medium. In addition, since moisture has a low refractive index, it may cause turbidity, yellowing, etc., and so on for applications that require high levels of transparency and low coloring such as optical members. It is considered undesirable to contain moisture. In particular, in mold molding, the moisture in the resin composition is likely to remain after molding and curing, as compared to the coating film, and the bubbles generated by the evaporation of moisture in the molding and curing process are likely to remain. It is the conventional technical common sense that mixing of moisture should be suppressed as much as possible. Therefore, it can be said that the resin composition of the present invention is a unique invention that cannot be easily conceived from the conventional technical common sense in that it adopts a configuration in which moisture is allowed to coexist in a cation curable compound and a cation curing catalyst. In addition, the resin composition of the present invention contains a trace amount of moisture, but it is because the moisture accelerates the curing rate, or surprisingly, a composition that does not contain moisture as shown in the examples below. A cured product having curability and optical properties equivalent to or higher than those of the above can be provided.

That is, the present invention is a resin composition that includes a cation curable compound and a cation curing catalyst and is cation-cured, and the cation curable resin composition is 0.03 to 100% by mass of the resin composition. It is a cationic curable resin composition containing 2% by mass of water.
The present invention is also a cured product obtained by curing the cationic curable resin composition.
The present invention is described in detail below.

The cation curable resin composition of the present invention (also simply referred to as “resin composition”) contains a cation curable compound, a cation curing catalyst, and moisture, but the component of the present invention (limited to essential components). In addition, an arbitrary component is also included.) Can be used alone or in combination of two or more.
In the resin composition, the water content is suitably 0.03 to 2% by mass with respect to 100% by mass of the resin composition. If it is less than 0.03% by mass, the resin composition cannot be sufficiently cured in a short time, and the productivity may not be improved. If it exceeds 2% by mass, the water of the cationic curable compound may be lost. There is a possibility that the properties such as transparency and low colorability may not be sufficiently exhibited due to the poor compatibility with. The water content is preferably 0.08% by mass or more, more preferably 0.1% by mass or more, and still more preferably 0.12% by mass or more with respect to 100% by mass of the resin composition. Moreover, 1 mass% or less is preferable, More preferably, it is less than 1.00 mass%. When the content is 1.00% by mass or more, in the optical member, in particular, in the optical member that is molded and cured by mold molding, the moisture contained in the resin composition is vaporized at the time of curing, so that bubbles are generated in the cured product and the transparency. May not be enough. Therefore, when the resin composition is used for optical member applications, the moisture content is less than 1.00% by mass in order to achieve high transparency required for optical applications in addition to improving the curing rate. It is particularly preferred. In addition, among optical members, in a lens, light scattering due to a small amount of air bubbles in the lens can also be a problem. Therefore, the water content in the resin composition that causes air bubbles to be generated is less than 1.00% by mass. Particularly preferred. More preferably, it is 0.8 mass% or less, More preferably, it is less than 0.80 mass%, Especially preferably, it is 0.7 mass% or less, Most preferably, it is less than 0.70 mass%.

In the above resin composition, the cationic curable compound (also referred to as “cationic curable resin”) may be a compound that can be cured (polymerized) by a cationic curing reaction, and is preferably a compound having a cationic polymerizable group. It is. By using a cationic curable compound, it exhibits heat resistance comparable to that of inorganic glass while exhibiting workability equivalent to that of conventional thermosetting plastic materials, and fully exhibits properties such as excellent moldability and workability. be able to. Moreover, although hardened | cured material becomes the thing excellent in mold release property (mold release strength), when a mold release agent is used together, the mold release property will be exhibited synergistically.

Examples of the cationic polymerizable group include an epoxy group, an oxetane group (oxetane ring), a dioxolane group, a trioxane group, a vinyl ether group, and a styryl group. Thus, the cationic polymerizable group is an epoxy group or an oxetane. A form that is at least one group selected from the group consisting of a group, a dioxolane group, a trioxane group, a vinyl ether group, and a styryl group is one of the preferred forms of the present invention. The curing characteristics of these cationically polymerizable groups are influenced not only by the type of group but also by the organic skeleton to which the group is bonded.
The “epoxy group” in the present specification includes an oxirane ring that is a three-membered ether. In addition to a narrowly-defined epoxy group, a group in which the oxirane ring is bonded to carbon, a glycidyl group ( A group containing an ether or ester bond, an epoxycyclohexane ring, and the like, such as a glycidyl ether group and a glycidyl ester group.

Among the cationic polymerizable groups, an epoxy group and an oxetane group are preferable. That is, the cationic curable compound preferably includes an epoxy compound (also referred to as “epoxy group-containing compound” or “epoxy resin”) and / or an oxetane compound (also referred to as “oxetane group-containing compound”). Moreover, as an epoxy compound, an aromatic epoxy compound, an aliphatic epoxy compound, an alicyclic epoxy compound, and a hydrogenated epoxy compound are suitable. Aromatic epoxy compounds usually take longer to cure than aliphatic epoxy compounds, cycloaliphatic epoxy compounds, hydrogenated epoxy compounds and oxetane compounds, but the curing rate can be increased by coexisting a small amount of moisture. The present invention is particularly effective because it can be significantly increased. In addition, the aliphatic epoxy compound, the alicyclic epoxy compound, the hydrogenated epoxy compound, and the oxetane compound having excellent curability can further increase the curing rate and further improve the productivity. Will be more prominently exhibited. Thus, a form in which the cationic curable compound includes an aromatic epoxy compound, an aliphatic epoxy compound, an alicyclic epoxy compound, a hydrogenated epoxy compound, and / or an oxetane compound is also one of the preferable forms of the present invention. It is.

Below, an epoxy compound and an oxetane compound are demonstrated concretely.
Regarding the epoxy compound, the aromatic epoxy compound is a compound having an aromatic ring and an epoxy group in the molecule. For example, an aromatic ring conjugated system such as a bisphenol skeleton, a fluorene skeleton, a biphenyl skeleton, a naphthalene ring, or an anthracene ring is used. Among them, a glycidyl compound having a bisphenol skeleton and / or a fluorene skeleton is preferable in order to achieve a higher refractive index. More preferably, it is a compound having a fluorene skeleton, whereby the refractive index can be remarkably increased. Aromatic glycidyl ether compounds are also suitable. Also, it is preferable to use a brominated compound of an aromatic epoxy compound because a higher refractive index can be achieved, but it is preferable to use it appropriately depending on the application.

As the aromatic epoxy compound, for example, a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, a fluorene type epoxy compound, an aromatic epoxy compound having a bromo substituent, and the like are preferable. A fluorene epoxy compound is preferred. Specifically, bisphenol A type epoxy compound (Japan Epoxy Resin Co., Ltd., 828EL, 1003 or 1007), bisphenol F type epoxy compound, fluorene type epoxy compound (Osaka Gas Chemical Co., Ltd., ONCOAT EX-1020 or OGSOL EG-) 210), a fluorene-based epoxy compound (Osaka Gas Chemical Co., Ltd., ONCOAT EX-1010 or OGSOL PG) and the like are preferably used. More preferred are bisphenol A type epoxy compounds and fluorene type epoxy compounds (Ossol EG-210, manufactured by Osaka Gas Chemical Company).

As the aromatic epoxy compound, an aromatic glycidyl ether compound is also suitable, but as the aromatic glycidyl ether compound, for example, an epibis type glycidyl ether type epoxy resin, a high molecular weight epibis type glycidyl ether type epoxy resin, A novolak aralkyl type glycidyl ether type epoxy resin may be mentioned.
As said epibis type glycidyl ether type epoxy resin, what is obtained by condensation reaction of bisphenols, such as bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, and epihalohydrin, for example is suitable.
The high molecular weight epibis type glycidyl ether type epoxy resin can be obtained, for example, by subjecting the epibis type glycidyl ether type epoxy resin to an addition reaction with bisphenols such as bisphenol A, bisphenol F, bisphenol S, and fluorene bisphenol. Are preferred.

Examples of the novolak aralkyl type glycidyl ether type epoxy resin include phenols, cresol, xylenol, naphthol, resorcin, catechol, bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, and other phenols, formaldehyde, acetoaldehyde, propion Polyhydric phenols obtained by condensation reaction of aldehyde, benzaldehyde, hydroxybenzaldehyde, salicylaldehyde, dicyclopentadiene, terpene, coumarin, paraxylylene glycol dimethyl ether, dichloroparaxylylene, bishydroxymethylbiphenyl, etc., and epihalohydrin What is obtained by performing a condensation reaction is suitable.

Examples of the aromatic epoxy compound further include, for example, an aromatic crystalline epoxy resin obtained by condensation reaction of tetramethylbiphenol, tetramethylbisphenol F, hydroquinone, naphthalene diol, and the like with epihalohydrin, and the bisphenols and tetramethyl. High molecular weight polymer of aromatic crystalline epoxy resin obtained by addition reaction of biphenol, tetramethylbisphenol F, hydroquinone, naphthalene diol, etc .; obtained by condensation reaction of tetrahydrophthalic acid, hexahydrophthalic acid, benzoic acid and epihalohydrin The glycidyl ester type epoxy resin etc. which can be used can also be used.

The aliphatic epoxy compound is a compound having an aliphatic epoxy group, but an aliphatic glycidyl ether type epoxy resin is suitable.
Examples of the aliphatic glycidyl ether type epoxy resin include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol (PEG 600), propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, polypropylene glycol ( PPG), glycerol, diglycerol, tetraglycerol, polyglycerol, trimethylolpropane and multimers thereof, pentaerythritol and multimers thereof, mono / polysaccharides such as glucose, fructose, lactose, maltose, etc., and epihalohydrin Preferred are those obtained, those having a propylene glycol skeleton, an alkylene skeleton, an oxyalkylene skeleton, etc. A. Among these, aliphatic glycidyl ether type epoxy resins having a propylene glycol skeleton, an alkylene skeleton, and an oxyalkylene skeleton as the central skeleton are preferable.

The alicyclic epoxy compound is a compound having an alicyclic epoxy group. Examples of the alicyclic epoxy group include an epoxycyclohexane group (epoxycyclohexane skeleton), a cyclic aliphatic hydrocarbon directly or a hydrocarbon. And an epoxy group (particularly an oxirane ring) added via Among these, a compound having an epoxycyclohexane group is preferable. Moreover, the polyfunctional alicyclic epoxy compound which has two or more alicyclic epoxy groups in a molecule | numerator is suitable at the point which can raise a hardening rate more. A compound having one alicyclic epoxy group in the molecule and an unsaturated double bond group such as a vinyl group is also preferably used.

Examples of the epoxy compound having an epoxycyclohexane group include 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, epsilon-caprolactone modified 3,4-epoxycyclohexylmethyl 3 ′, 4′-epoxy. Cyclohexanecarboxylate, bis- (3,4-epoxycyclohexyl) adipate and the like are suitable. Examples of the alicyclic epoxy compound other than the epoxy compound having the epoxycyclohexane group include 1,2-epoxy-4- (2-oxiranyl) cyclohexane of 2,2-bis (hydroxymethyl) -1-butanol. Examples include adducts and alicyclic epoxides such as epoxy resins containing heterocycles such as triglycidyl isocyanurate.

The hydrogenated epoxy compound is preferably a compound having a glycidyl ether group bonded directly or indirectly to a saturated aliphatic cyclic hydrocarbon skeleton, and a polyfunctional glycidyl ether compound is preferred. Such a hydrogenated epoxy compound is preferably a complete or partial hydrogenated product of an aromatic epoxy compound, more preferably a hydrogenated product of an aromatic glycidyl ether compound, and still more preferably an aromatic polyfunctional compound. It is a hydrogenated product of a glycidyl ether compound. Specifically, hydrogenated bisphenol A type epoxy compounds, hydrogenated bisphenol S type epoxy compounds, hydrogenated bisphenol F type epoxy compounds, and the like are preferable. More preferred are hydrogenated bisphenol A type epoxy compounds and hydrogenated bisphenol F type epoxy compounds.

As the epoxy compound, a tertiary amine-containing glycidyl ether type epoxy resin which is obtained by condensation reaction of hydantoin, cyanuric acid, melamine, benzoguanamine and epihalohydrin at room temperature can also be used.

The oxetane compound is a compound having an oxetane group (oxetane ring). For example, ETERNACOLL (R) EHO, ETERNACOLL (R) OXBP, ETERNACOLL (R) OXMA, ETERNCOLLL (R) HBOX, ETERRNACOLL (R) OXIPA (R) OXIPA OBT-101, OXT-121, OXT-211, OXT-221, OXT-212, OXT-610 (manufactured by Toa Gosei Co., Ltd.) and the like are preferable.

The oxetane compound is preferably used in combination with an alicyclic epoxy compound and / or a hydrogenated epoxy compound from the viewpoint of curing speed. Further, when obtaining a high refractive index cured product (preferably a high refractive index optical member, more preferably a high refractive index lens), it is selected from the group consisting of oxetane compounds, alicyclic epoxy compounds and hydrogenated epoxy compounds. A form in which at least one of the above and an aromatic epoxy compound are used in combination; a form using an oxetane compound having an aryl group or an aromatic ring in the molecule described later; an oxetane compound having an aryl group or an aromatic ring in the molecule; and an aromatic A form in which an epoxy compound is used in combination is preferable.

As the oxetane compound, it is preferable to use an oxetane compound having an aryl group or an aromatic ring in the molecule from the viewpoint of improving the refractive index while maintaining the curing rate. In particular, when obtaining a cured product having a higher refractive index, as described above, an oxetane compound having an aryl group or an aromatic ring in the molecule and an aromatic epoxy compound are used in combination. On the other hand, from the viewpoint of improving light resistance, it is preferable to use an oxetane compound having no aryl group or aromatic ring. On the other hand, from the viewpoint of improving the strength of the cured product, it is preferable to use a polyfunctional oxetane compound, that is, a compound having two or more oxetane rings in one molecule.

Among the oxetane compounds having no aryl group or aromatic ring, examples of the monofunctional oxetane compound include 3-methyl-3-hydroxymethyl oxetane, 3-ethyl-3-hydroxymethyl oxetane, and 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane, isobutoxymethyl (3-ethyl-3-oxetanylmethyl) ether, isobornyloxyethyl (3-ethyl-3-oxetanylmethyl) ether, isobornyl (3-ethyl-3- Oxetanylmethyl) ether, 2-ethylhexyl (3-ethyl-3-oxetanylmethyl) ether, ethyl diethylene glycol (3-ethyl-3-oxetanylmethyl) ether and the like are preferable.

Among the oxetane compounds having an aryl group or an aromatic ring, examples of monofunctional oxetane compounds include 3-methyl-3- (phenoxymethyl) oxetane, 3-ethyl-3- (phenoxymethyl) oxetane, and dicyclopentadiene. (3-ethyl-3-oxetanylmethyl) ether, dicyclopentenyloxyethyl (3-ethyl-3-oxetanylmethyl) ether, dicyclopentenyl (3-ethyl-3-oxetanylmethyl) ether, and the like are preferable.

Among the oxetane compounds having no aryl group or aromatic ring, examples of the polyfunctional oxetane compound include di [1-ethyl (3-oxetanyl)] methyl ether and 3,7-bis (3-oxetanyl) -5. -Oxa-nonane, 1,2-bis [(3-ethyl-3-oxetanylmethoxy) methyl] ethane, 1,3-bis [(3-ethyl-3-oxetanylmethoxy) methyl] propane, ethylene glycol bis (3 -Ethyl-3-oxetanylmethyl) ether, tricyclodecanediyldimethylene (3-ethyl-3-oxetanylmethyl) ether, trimethylolpropane tris (3-ethyl-3-oxetanylmethyl) ether, 1,4-bis ( 3-ethyl-3-oxetanylmethoxy) butane, 1,6-bis (3-ethyl-3-o Cetanylmethoxy) hexane, pentaerythritol tris (3-ethyl-3-oxetanylmethyl) ether, pentaerythritoltetrakis (3-ethyl-3-oxetanylmethyl) ether, polyethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether Dipentaerythritol hexakis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol pentakis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether Etc. are preferred.

Among the oxetane compounds having an aryl group or an aromatic ring, examples of the polyfunctional oxetane compound include phenol novolac oxetane, dioxetane compound having biphenyl skeleton (manufactured by Ube Industries, ETERNACOLL (R) OXBP), and phenyl skeleton. Preferred are dioxetane compounds (Ube Industries, Ltd., ETERNACOLL (R) OXTP and OXIPA), dioxetane compounds having a fluorene skeleton, and the like.

Among the above cationic curable compounds, alicyclic epoxy compounds and hydrogenated epoxy compounds are particularly suitable. These are hard to be colored of the epoxy compound itself at the time of curing, are less likely to be colored or deteriorated by light, that is, excellent in transparency and low colorability, light resistance, if a resin composition containing these, An optical member which is not colored and is superior in light resistance can be obtained with high productivity. Moreover, it becomes possible to fully exhibit the effect of this invention of high sclerosis | hardenability and raising a cure rate. Thus, the form in which the cationic curable compound contains an alicyclic epoxy compound and / or a hydrogenated epoxy compound is also one of the preferred forms of the present invention.

In the form in which the cation curable compound includes an alicyclic epoxy compound and / or a hydrogenated epoxy compound, the total content of these alicyclic epoxy compounds and hydrogenated epoxy compounds is the above cation curable compound. It is suitable that it is 50 mass% or more with respect to the total amount of 100 mass%. As a result, it is possible to further exert the effects of using the above-described alicyclic epoxy compound and / or hydrogenated epoxy compound. Thus, the cation curable compound includes an alicyclic epoxy compound and / or a hydrogenated epoxy compound, and the total amount of the alicyclic epoxy compound and the hydrogenated epoxy compound is 100 masses of the cation curable compound. A form that is 50% by mass or more with respect to% is also a preferred form of the present invention. More preferably, it is 60 mass% or more, More preferably, it is 70 mass% or more.

The cationic curable compound is also preferably a compound having two or more cationic polymerizable groups in one molecule, that is, a polyfunctional cationic curable compound. Thereby, sclerosis | hardenability is improved more and the hardened | cured material which is excellent with various characteristics can be obtained. The compound having two or more cationic polymerizable groups in one molecule may be a compound having two or more identical cationic polymerizable groups, or a compound having two or more different cationic polymerizable groups. However, the polyfunctional cation curable compound is particularly preferably a polyfunctional alicyclic epoxy compound or a polyfunctional hydrogenated epoxy compound. By using these, a cured product can be obtained in a shorter time.

As one of preferable forms when applied to an optical member, the cationic curable compound preferably further contains a compound having an Abbe number of 45 or more. The content of the cationic curable compound having an Abbe number of 45 or more is preferably 1% by mass or more with respect to 100% by mass of the total amount of the cationic curable compound used. More preferably, it is 5 mass% or more, More preferably, it is 10 mass% or more. In particular, for optical member applications requiring a high Abbe number, the content of the cationic curable compound having an Abbe number of 45 or more is 60% by mass or more with respect to 100% by mass of the total amount of the cationic curable compound used. It is preferably 70% by mass or more. Moreover, in the optical member use which may have a low Abbe number, the content of the cationic curable compound having an Abbe number of 45 or more is 1 to 70% by mass with respect to 100% by mass of the total use amount of the cationic curable compound. More preferably, it is 10-60 mass%, More preferably, it is 20-50 mass%.

The cationic curable compound having an Abbe number of 45 or more is preferably an epoxy compound, and a preferable form of the epoxy resin having an Abbe number of 45 or more is the above-described preferred form of the epoxy compound. Can be mentioned. Specifically, alicyclic epoxy compounds and hydrogenated epoxy compounds are suitable. Among them, alicyclic epoxy compounds, hydrogenated bisphenol A type epoxy resins, hydrogenated bisphenol S type epoxy resins, hydrogenated bisphenol F type epoxy resins, and the like are preferable, and alicyclic epoxy compounds are particularly preferable. By using the alicyclic epoxy compound, the Abbe number can be further improved and the optical properties are further improved, and therefore, it can be suitably used for various applications.

In addition, as the cationic curable compound having an Abbe number of 45 or more, an alicyclic compound other than an epoxy compound can be used. For example, alicyclic modified neopentyl glycol (meth) acrylate (“R-629” or “R-644” manufactured by Nippon Kayaku Co., Ltd.); tetrahydrofurfuryl (meth) acrylate, morpholinoethyl (meth) acrylate, etc. Alicyclic acrylate having an oxygen atom and / or a nitrogen atom in the structure; alicyclic monofunctional maleimides such as N-cyclohexylmaleimide; N, N′-methylenebismaleimide, N, N′-ethylenebismaleimide, N , N′-trimethylene bismaleimide, N, N′-hexamethylene bismaleimide, N, N′-dodecamethylene bismaleimide, 1,4-dimaleimidocyclohexane, and the like.

In the above resin composition, the cation curing catalyst is not particularly limited as long as it is a compound capable of generating a cationic species that initiates polymerization by heat, photoexcitation, or the like, but a thermal latent cationic curing catalyst or a photolatent cationic curing catalyst. It is preferable that By using a heat-latent cationic curing catalyst, a compound containing a cationic species is excited by heating, a thermal decomposition reaction occurs, and thermal curing proceeds. Further, by using a photolatent cationic curing catalyst, a compound containing a cationic species is excited by light, a photodecomposition reaction occurs, and photocuring proceeds. Thus, a form in which the cationic curing catalyst is a heat latent cationic curing catalyst and / or a photolatent cationic curing catalyst is one of the preferred forms of the present invention. Especially, when using the said resin composition for an optical member use, it is especially suitable to use a heat | fever latent cationic curing catalyst at least.

The thermal latent cationic curing catalyst is also called a thermal acid generator, a thermal latent curing agent, a thermal latent cation generator, or a cationic polymerization initiator. When the curing temperature is reached in the resin composition, the thermal latent cationic curing catalyst is substantially used as a curing agent. It demonstrates a typical function. Unlike the acid anhydrides, amines, phenolic resins, etc., which are generally used as curing agents, the heat latent cationic curing catalyst can be used even if it is contained in the resin composition. One-part resin with excellent handling properties that can effectively accelerate the curing reaction as an action of the heat-latent cationic curing catalyst without causing a significant increase in viscosity or gelation. A composition (one-component material) can be provided.
Also, by using a heat-latent cationic curing catalyst, the moisture resistance of the cured product obtained from the resulting resin composition is dramatically improved, and the excellent optical properties of the resin composition are maintained even in harsh usage environments. Thus, it can be suitably used for various applications.

Usually, when moisture is contained in the resin composition or its cured product, the cured product becomes cloudy if it remains because the moisture has a low refractive index, or the resin constituting the cured product is deteriorated by ultraviolet rays or the like, or It was a common technical knowledge of those skilled in the art that foaming during curing and transparency and mechanical strength decrease, but in a cation curable resin composition cured using a cation curing catalyst,
1) Presence of a predetermined amount of moisture not only improves the curing rate described above, but also surprisingly does not cause a decrease in transparency and mechanical strength due to moisture coexistence. Therefore, excellent moisture resistance and light resistance that can be exhibited by a cured product obtained by curing a cationically curable resin composition using a cationic curing catalyst can be exhibited.
2) Furthermore, the cationic curing catalyst causes coloring of the cured product at the time of curing, or the catalyst residue remaining in the cured product is caused by light or heat that is exposed in the secondary processing of the cured product or in the use environment. There was also a problem of causing subsequent decomposition to cause coloring of the cured product. In the cation curable resin composition of the present invention, since the amount of the cation curing catalyst can be reduced by containing a predetermined amount of moisture, the above-described coloring problem can be suppressed.
Therefore, the cationic curable resin composition of the present invention is suitable for optical members such as lenses that require productivity, transparency, colorlessness, and mechanical strength, and further, it is possible to reduce cost and improve optical quality. This is particularly useful as a required raw material for micro optical members. Examples of the micro optical member include a camera lens such as an imaging lens for a mobile phone and an imaging lens for a digital camera, a light beam condensing lens, a light diffusion lens, and an optical pickup lens. In addition, the cationic curable resin composition of the present invention can be suitably applied.

Examples of the heat latent cationic curing catalyst include the following general formula (4):
_{^{(R 1 a R 2 b R}} 3 c R 4 d Z) + m (AXn) -m (4)
(In the formula, Z represents at least one element selected from the group consisting of S, Se, Te, P, As, Sb, Bi, O, N and halogen elements. R ¹ , R ² , R ³ and R ⁴ is the same or different and represents an organic group, a, b, c and d are 0 or a positive number, and the sum of a, b, c and d is equal to the valence of Z. Cation (R ¹ _a R ² _b R ³ _c R ⁴ _d Z) ^{+ m} represents an onium salt, A represents a metal element or metalloid which is a central atom of a halide complex, B, P, As, Al, It is at least one selected from the group consisting of Ca, In, Ti, Zn, Sc, V, Cr, Mn, and Co. X represents a halogen element, and m is the net charge of the halide complex ion. N is the number of halogen elements in the halide complex ion Is preferred).

Specific examples of the anion (AXn) ^-m of the general formula (4) include tetrafluoroborate (BF ⁴⁻ ), hexafluorophosphate (PF ⁶⁻ ), hexafluoroantimonate (SbF ⁶⁻ ), hexafluoro arsenates ^{(AsF 6-),} hexachloroantimonate (SbCl ^6-), and the like.
Further formula AXn (OH) ^- anions may be used which is represented by. Other anions include perchlorate ion (ClO ₄ ⁻ ), trifluoromethyl sulfite ion (CF ₃ SO ₃ ⁻ ), fluorosulfonate ion (FSO ₃ ⁻ ), toluenesulfonate ion, and trinitrobenzenesulfone. An acid ion etc. are mentioned.

Specific examples of the heat latent cationic curing catalyst include diazonium salt types such as AMERICURE series (manufactured by American Can), ULTRASET series (manufactured by Adeka), and WPAG series (manufactured by Wako Pure Chemical Industries); Iodonium salt types such as UVE series (manufactured by General Electric), FC series (manufactured by 3M), UV9310C (manufactured by GE Toshiba Silicone), Photoinitiator 2074 (manufactured by Rhone-Poulenc), WPI series (manufactured by Wako Pure Chemical Industries) CYRACURE series (manufactured by Union Carbide), UVI series (manufactured by General Electric), FC series (manufactured by 3M), CD series (manufactured by Satomer), optomer SP series, optomer CP series (manufactured by Adeka), N'eido SI series (Sanshin Chemical Industry Co., Ltd.), CI series (manufactured by Nippon Soda Co., Ltd.) (manufactured by Wako Pure Chemical Industries) WPAG series, CPI series (manufactured by San-Apro Ltd.) sulfonium salt type or the like, and the like. Among the above, the sulfonium salt type is preferable in terms of high invention effects.

The photolatent cationic curing catalyst is also called a photocationic polymerization initiator, and exhibits a substantial function as a curing agent when irradiated with light. By using a photolatent cationic curing catalyst, a compound containing a cationic species is excited by light, a photodecomposition reaction occurs, and photocuring proceeds.

Examples of the photolatent cationic curing catalyst include triphenylsulfonium hexafluoroantimonate, triphenylsulfonium phosphate, p- (phenylthio) phenyldiphenylsulfonium hexafluoroantimonate, p- (phenylthio) phenyldiphenylsulfonium hexafluorophosphate, 4-chlorophenyldiphenylsulfonium hexafluorophosphate, 4-chlorophenyldiphenylsulfonium hexafluoroantimonate, bis [4- (diphenylsulfonio) phenyl] sulfide bishexafluorophosphate, bis [4- (diphenylsulfonio) Phenyl] sulfide bishexafluoroantimonate, (2,4-cyclopentadien-1-yl) [(1-methyl) Ethyl) benzene] -Fe- hexafluorophosphate, diaryliodonium hexafluoroantimonate and the like.

Specific products of the photolatent cationic curing catalyst include, for example, UVI-6950, UVI-6970, UVI-6974, UVI-6990 (manufactured by Union Carbide); Adeka optomer SP-150, SP-151, SP-170, SP-172 (manufactured by ADEKA); Irgacure 250 (manufactured by Ciba Japan); CI-2481, CI-2624, CI-2639, CI-2064 (manufactured by Nippon Soda); CD-1010, CD- 1011, CD-1012 (manufactured by Sartomer); DTS-102, DTS-103, NAT-103, NDS-103, TPS-103, MDS-103, MPI-103, BBI-103 (manufactured by Midori Chemical); PCI -061T, PCl-062T, PCl-020T, PCl-022T (Nippon Kayaku) CPl-100P, CPT-101A, CPI-200K (manufactured by Sun Apro); Sun-Aid SI-60L, Sun-Aid SI-80L, Sun-Aid SI-100L, Sun-Aid ST-110L, Sun-Aid SI-145, Sun-Aid SI-150, Diazonium salt type, iodonium salt type, and sulfonium salt type such as Sun-Aid SI-160, Sun-Aid SI-180L (manufactured by Sanshin Chemical Industry Co., Ltd.); WPAG series (manufactured by Wako Pure Chemical Industries, Ltd.) are preferred.

In the resin composition, the content of the cation curing catalyst is 0.01 to 10 parts by weight with respect to 100 parts by weight of the cation curable compound as an amount of solid content as an effective component amount not including a solvent or the like. Is preferred. If it is less than 0.01 part by weight, the curing rate cannot be increased sufficiently, and there is a possibility that the effect of the present invention that it can be sufficiently cured in a short time and can be molded cannot be fully exhibited. More preferably, it is 0.05 weight part or more, More preferably, it is 0.1 weight part or more. On the other hand, if the amount exceeds 10 parts by weight, there is a risk of coloring during curing or heating of the molded article. For example, when the molded body is reflow-mounted after the molded body is obtained, heat resistance of 200 ° C. or higher is necessary, and therefore it is preferably 10 parts by weight or less from the viewpoint of colorlessness and transparency. . More preferably, it is 5 parts by weight or less, more preferably 3 parts by weight or less, and particularly preferably 2 parts by weight or less.

The resin composition also preferably includes a flexible component (flexible component), which makes it possible to obtain a resin composition with a sense of unity.
The flexible component may be a compound different from the cationic curable compound, or at least one of the cationic curable compounds may be a flexible component.

Specifically, the flexible component is a compound having an oxyalkylene skeleton represented by — [— (CH ₂ ) _n —O—] _m — (n is 2 or more, and m is an integer of 1 or more. Preferably, n is 2 to 12, m is an integer of 1 to 1000, and more preferably, n is 3 to 6 and m is an integer of 1 to 20.), for example, (1) An epoxy compound containing an oxybutylene group (Japan Epoxy Resin, YL-7217, epoxy equivalent 437, liquid epoxy compound (10 ° C. or higher)) is preferred. As other suitable flexible components, (2) polymer epoxy compounds (for example, hydrogenated bisphenol (manufactured by Japan Epoxy Resin, YX-8040, epoxy equivalent 1000, solid hydrogenated epoxy compound)); 3) Alicyclic solid epoxy compound (EHPE-3150 manufactured by Daicel Industries, Ltd.); (4) Alicyclic liquid epoxy compound (Delcel Industries, Celoxide 2081); (5) Liquid rubber such as liquid nitrile rubber, polybutadiene, etc. Polymer rubber, fine particle rubber having a particle size of 100 nm or less, and the like are preferable.

Among these, a cationic curable compound containing a cationic curable functional group at the terminal, side chain, main chain skeleton or the like is more preferable.
As described above, a cationically curable compound can be suitably used as the flexible component. However, the compound is preferably a compound containing an epoxy group, and more preferably an oxybutylene group (-[ - _{(CH 2)} 4 -O-] _m - (m is ibid.) is a compound having a).

The content of the flexible component is preferably 40% by mass or less with respect to 100% by mass of the total amount of the cationic curable compound and the flexible component. More preferably, it is 30 mass% or less, More preferably, it is 30 mass% or less, Most preferably, it is 20 mass% or less. Moreover, 0.01 mass% or more is preferable, More preferably, it is 0.1 mass% or more, More preferably, it is 0.5 mass% or more.

The resin composition also preferably contains a release agent. As the release agent, a compound having a group that promotes rather than inhibiting the curing reaction by the cationic curing catalyst is preferable. That is, a compound capable of further synergistically exhibiting the effect of the present invention that it can be cured in a short time when combined with moisture is preferable. From such a viewpoint, specifically, a compound having an alcoholic OH group and / or a carbonyl group (including a carboxyl group and an ester group) is preferable as the release agent, and further compatible with the cationic curable resin composition. From the viewpoint of a high mold release effect, those having a hydrocarbon group having 8 or more carbon atoms are preferred. More preferably, at least one compound selected from the group consisting of an alcohol having 8 to 36 carbon atoms, a carboxylic acid having 8 to 36 carbon atoms, a carboxylic acid ester having 8 to 36 carbon atoms, and a carboxylate having 8 to 36 carbon atoms. It is. By containing such a release agent, the effect of the present invention that it can be cured in a short time is further exhibited, and the mold can be easily peeled off when cured using a mold, and the cured product Since the appearance can be controlled and the transparency can be expressed without damaging the surface of the resin, the resin composition can be made more useful for electric / electronic component material use and optical member use.

Among these compounds, alcohols, carboxylic acids, and carboxylic acid esters are more preferable, and carboxylic acids (particularly higher fatty acids) and carboxylic acid esters are more preferable. Carboxylic acids and carboxylic acid esters are preferred because they can sufficiently exhibit the release effect without inhibiting the cationic curing reaction. In addition, since amines may inhibit a cation hardening reaction, it is preferable not to use as a mold release agent.
The above-mentioned compound may have any structure such as linear, branched or cyclic, and is preferably branched.
The number of carbon atoms of the compound is preferably an integer of 8 to 36, and thereby, a cured product exhibiting excellent peelability without impairing functions such as transparency and workability of the resin composition; Become. More preferably, it is 8-20 as carbon number, More preferably, it is 10-18.

The alcohol having 8 to 36 carbon atoms is a monovalent or polyhydric alcohol, and may be linear or branched. Specifically, octyl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, lauryl alcohol, tridecyl alcohol, tetradecyl alcohol, pentadecyl alcohol, palmityl alcohol, margaryl alcohol, stearyl alcohol, nonadecyl alcohol, eicosyl Alcohol, ceryl alcohol, myricyl alcohol, methylpentyl alcohol, 2-ethylbutyl alcohol, 2-ethylhexyl alcohol, 3.5-dimethyl-1-hexanol, 2,2,4-trimethyl-1-pentanol, dipentaerythritol 2-phenylethanol and the like are preferred. The alcohol is preferably an aliphatic alcohol, and more preferably octyl alcohol (octanol), lauryl alcohol, 2-ethylhexyl alcohol (2-ethylhexanol), and stearyl alcohol.

The carboxylic acid having 8 to 36 carbon atoms is a monovalent or polyvalent carboxylic acid, and includes 2-ethylhexanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, lauric acid, tridecanoic acid, and tetradecanoic acid. Pentadecanoic acid, palmitic acid, 1-heptadecanoic acid, stearic acid, nonadecanoic acid, eicosanoic acid, 1-hexacosanoic acid, behenic acid and the like are suitable. Preferred are octanoic acid, lauric acid, 2-ethylhexanoic acid, and stearic acid.

The carboxylic acid ester having 8 to 36 carbon atoms includes (1) carboxylic acid ester obtained from the above alcohol and the above carboxylic acid, (2) methanol, ethanol, propanol, heptanol, hexanol, glycerin, benzyl alcohol and the like. Carboxylic acid ester obtained by a combination of an alcohol having 1 to 7 carbon atoms and the above carboxylic acid, (3) A combination of a carboxylic acid having 1 to 7 carbon atoms such as acetic acid, propionic acid, hexanoic acid, butanoic acid and the above alcohol (4) a carboxylic acid ester obtained from an alcohol having 1 to 7 carbon atoms and a carboxylic acid having 1 to 7 carbon atoms, and a compound having a total carbon number of 8 to 36. Is preferred. Among these, the carboxylic acid esters of (2) and (3) are preferable, and stearic acid methyl ester, stearic acid ethyl ester, acetic acid octyl ester, and the like are more preferable.

The carboxylate having 8 to 36 carbon atoms is a carboxylic acid obtained by a combination of the carboxylic acid and an amine, Na, K, Mg, Ca, Mn, Fe, Co, Ni, Cu, Zn, or Sn. Salts and the like are preferred. Among these, Zn stearate, Mg stearate, Zn 2-ethylhexanoate and the like are preferable.

Of the above-mentioned compounds, stearic acid compounds such as stearic acid and stearic acid esters, and alcohol compounds are more preferable, and stearic acid compounds are more preferable.

The content of the release agent is preferably 10% by mass or less with respect to 100% by mass of the resin composition. If it exceeds 10% by mass, the resin composition may be hard to be cured. More preferably, it is 0.01-5 mass%, More preferably, it is 0.1-2 mass%.

In addition to the above-described essential components and suitable components, the resin composition is not limited to inorganic fine particles, a curing catalyst / curing agent other than the cationic curing catalyst, a curing accelerator, and reactivity, as long as the effects of the present invention are not impaired. Diluents, saturated compounds without unsaturated bonds, pigments, dyes, antioxidants, UV absorbers, light stabilizers, plasticizers, non-reactive compounds, chain transfer agents, thermal polymerization initiators, anaerobic polymerization initiators , Polymerization inhibitor, adhesion improver such as inorganic filler and organic filler, coupling agent, heat stabilizer, antibacterial / antifungal agent, flame retardant, matting agent, antifoaming agent, leveling agent, wetting / dispersing Agent, anti-settling agent, thickener / anti-sagging agent, anti-coloring agent, emulsifier, anti-slip / scratch agent, anti-skinning agent, desiccant, antifouling agent, antistatic agent, conductive agent (electrostatic aid) ) And the like.

The resin composition preferably has a viscosity of 10,000 Pa · s or less. As a result, the processing characteristics are excellent, and for example, it is more excellent for a molded body forming application (particularly, for forming a mold molded body). More preferably, it is 1000 Pa.s or less, More preferably, it is 200 Pa.s or less. Further, it is preferably 1 Pa · s or more, more preferably 5 Pa · s or more, and further preferably 10 Pa · s or more.
The viscosity can be measured at 25 ° C. using a cone plate type rotational viscometer.

As a method for curing the resin composition, various methods such as thermosetting and photocuring can be suitably used. However, if necessary, other materials are mixed with the above-described essential components to form a one-component composition. A method is preferably used in which the composition is applied or injected into a mold that matches the shape of the cured product and cured, and then the cured product is removed from the mold.

In the curing method, the curing conditions such as the curing temperature and the curing time may be appropriately set according to the resin composition to be cured, etc., but when using a heat latent cationic curing catalyst as the cationic curing catalyst, these are: In general, cations are generated at the curing temperature. As a curing temperature, 25-250 degreeC is preferable, More preferably, it is 60-200 degreeC, More preferably, it is 80-180 degreeC, Especially preferably, it is 100-180 degreeC, Most preferably, it is 110-150 degreeC. In order to improve productivity, the curing time is preferably within 10 minutes, more preferably within 5 minutes, and even more preferably within 3 minutes.
Further, the curing temperature may be changed stepwise. For example, for the purpose of improving productivity in producing a cured product of the resin composition, the mold is held in the mold at a predetermined temperature and time, and then removed from the mold and left in an air or inert gas atmosphere. It is also possible to perform heat treatment. In this case, the heat treatment temperature is preferably set so that the in-mold holding temperature is 25 ° C to 250 ° C, more preferably 60 ° C to 200 ° C, and still more preferably 80 ° C to 180 ° C. The holding time is preferably 10 seconds to 5 minutes, more preferably 30 seconds to 5 minutes.

The strength of the cured product obtained by the above-described curing method may be a strength that can be taken out from the mold and keep the shape. For example, the shape change ratio when extruded with a force of 1 kgf / cm ² or more is 10%. The following compressive strength is preferred. The ratio of the shape change is preferably 1% or less, more preferably 0.1% or less, and still more preferably 0.01% or less.

In the above-described curing method, it is also preferable that the cured product is cured in a short time using a mold as described above, and then the cured product is taken out of the mold and subjected to heat treatment (baking). By performing the heat treatment, the cured product has sufficient strength and can be suitably used for various applications. Moreover, in heat processing, it is excellent in the handleability from the point which further hardens | cures the hardened | cured material with a certain amount of strength. Therefore, there is an advantage that a large amount of products can be heat-treated in a small area because it is not necessary to use a mold.
In the heat treatment, the curing temperature and the curing time can be appropriately set according to the resin composition to be cured, and it is preferable to set the in-mold holding temperature and the holding time as described above.

The cationic curable resin composition of the present invention can provide a cured product that can be sufficiently cured in a short time as described above, and can exhibit excellent productivity, low colorability, transparency, optical properties, and the like. is there. Thus, the hardened | cured material formed by hardening | curing the said cationic curable resin composition is also one of this invention. The shape of such a cured product is a curing (molding) method (for example, an injection molding method, a compression molding method, a casting method) using a mold (referred to as a “mold”) made of metal, ceramic, glass, resin, or the like. The shape of a molded body by a molding method such as a molding method or a sandwich molding method), the shape of a film, a sheet, a pellet, or the like, or the shape of a coating film (coating film) It may be. Preferably, for the reasons described above, a molded body such as a mold molded body, and the cured product is a molded body, and the resin composition is a molded resin forming resin composition are also present. It is contained in the suitable form of invention.

As said hardened | cured material, it is a thing useful for various uses, such as an optical member, a machine component material, an electrical / electronic component material, an automobile component material, a civil engineering building material, a molding material, etc., and a paint, an adhesive material, etc. is there. Especially, it can use suitably for an optical member, an optical device member, a display device member, etc. Specific examples of such applications include spectacle lenses, (digital) cameras, camera imaging lenses such as mobile phones and vehicle cameras, lenses such as light beam condensing lenses, light diffusion lenses, filters, Optical applications such as diffraction gratings, prisms, light guides, watch glasses, transparent glasses such as cover glasses for display devices, and cover glasses; photosensors, photoswitches, LEDs, light emitting elements, optical waveguides, multiplexers, Opto device applications such as wavers, disconnectors, optical splitters, fiber optic adhesives; LCD, organic EL and PDP display element substrates, color filter substrates, touch panel substrates, display protective films, display backlights, conductors Use for display devices such as a light plate, an antireflection film, and an antifogging film is suitable.

Among these uses, an optical member is particularly suitable. Thus, the form in which the cured product is an optical member and the form in which the cationic curable resin composition is a resin composition for an optical member are also included in preferred forms of the present invention.
The optical member is particularly preferably a lens. The lens is preferably a camera lens, a light beam condensing lens, a light diffusion lens and an optical pickup lens, and more preferably a camera lens. Among camera lenses, imaging lenses such as an imaging lens for a mobile phone and an imaging lens for a digital camera are preferable. Further, these micro optical lenses are preferable.
In addition, when the said resin composition is a resin composition for optical members, according to the use of an optical member, the other component may be included suitably. Specifically, UV absorber, IR cut agent, reactive diluent, pigment, washing agent, antioxidant, light stabilizer, plasticizer, non-reactive compound, chain transfer agent, thermal polymerization initiator, anaerobic polymerization Initiators, light stabilizers, polymerization inhibitors, antifoaming agents and the like are suitable.

Since the cation curable resin composition of the present invention is configured as described above, the effects of the cation curable compound can be sufficiently expressed, the curable resin can exhibit sufficient curability, and can be cured in a short time. And a cured product having excellent low colorability. Such a cured product can be suitably applied to various uses such as optical materials, mechanical component materials, electrical / electronic component materials, automotive component materials, civil engineering and building materials, molding materials, paint materials, adhesive materials, etc. Particularly useful as an optical member.

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. Unless otherwise specified, “part” means “part by mass” and “%” means “% by mass”.

Example 1
In a 20 ml screw tube equipped with a temperature sensor, 100 parts of a hydrogenated epoxybisphenol A epoxy compound (Japan Epoxy Resin, Epicoat YX-8000, epoxy equivalent 205, liquid hydrogenated epoxy resin) as a cationic curable compound, and a cation As a curing catalyst, 1 part of Sun-Aid SI-80L (trade name, manufactured by Sanshin Chemical Industry Co., Ltd., heat latent cationic curing catalyst, solid content 50%) was added and mixed so as to be uniform. After adding water to this mixture and stirring to obtain a resin composition (1) having a water content of 0.14%, the curing properties, total calorific value, cured product properties and cured product are obtained by the following methods. The presence or absence of coloring was evaluated. The results are shown in Table 1.

Examples 2-29
Except having changed as shown in Tables 1-3 the kind and quantity of the cation curable compound and cation curing catalyst which comprise a resin composition, and the water content by addition of water, it carried out similarly to Example 1. A resin composition was obtained. About this resin composition, the curing property, the total calorific value, the cured product properties, and the presence or absence of coloring of the cured product were evaluated. The results are shown in Tables 1-3.

Comparative Examples 1-3
Except having changed the kind and quantity of the cation curable compound and cation curing catalyst which comprise a resin composition as shown in Tables 1-3, and not having added water, it carried out similarly to Example 1. A resin composition was obtained. About this resin composition, the curing property, the total calorific value, the cured product properties, and the presence or absence of coloring of the cured product were evaluated. The results are shown in Tables 1-3.
In addition, the water addition amount of Comparative Examples 1 to 3 described in Tables 1 to 3 is the water content (water content) of the resin composition obtained by using the purchased product (cationic curable compound and cation curing catalyst) as they are. ).

<Curing characteristics>
After obtaining the resin composition, the screw tube was immersed in a constant temperature bath at 35 ° C. for 30 minutes to adjust the liquid temperature to 35 ° C. Thereafter, the screw tube was immersed in an oil bath at 120 ° C., and the following GT (second) and MCT (second) were tracked. This operation was performed twice and the average value of each was obtained.
GT (seconds): Time required for reaching 125 ° C. (unit: seconds), assuming that the internal temperature (liquid temperature) reaches 50 ° C. at t = 0 (seconds).
MCT (seconds): Time required to reach the maximum temperature (unit: seconds) with the time when the internal temperature (liquid temperature) reached 50 ° C. as t = 0 (seconds).
Note that GT and MCT are indicators of the curing rate because the temperature rises faster due to the heat generated by the curing reaction.

<Total calorific value (mJ / mg)>
After obtaining the resin composition, using a differential scanning calorimeter (DSC6200, manufactured by Seiko Instruments Inc.), the temperature was raised to 300 ° C. at 10 ° C./min, and the calorific value was measured.

<Physical properties of cured product>
A gap of 1 mm was formed using two glass plates, and after the resin composition was charged, it was cured in an oven at 140 ° C. for 15 minutes and demolded. About the hardened | cured material obtained in this way (1 mm casting board), the glass transition temperature and the transmittance | permeability were measured on condition of the following.
Glass transition temperature (Tg, ° C.): Using a dynamic viscoelasticity measuring device (RSA-III, manufactured by TA Instruments Inc.), the temperature was raised to 200 ° C. at 10 ° C./min, and Tg was measured. .
Transmittance “blank”: The transmittance of the cured product at a wavelength of 400 nm was measured using an absorptiometer (manufactured by Shimadzu Corporation, spectrophotometer UV-3100). This transmittance is an index of transparency.
Transmittance “230 ° C. for 1 h”: The cured product was put in an oven at 230 ° C., and taken out after 1 hour in a nitrogen atmosphere, and then at a wavelength of 400 nm using an absorptiometer (manufactured by Shimadzu Corporation, spectrophotometer UV-3100). The transmittance of the cured product was measured. This transmittance is an index of heat resistance.
Transmittance "45 mW ^/ cm 2 24h" and "45 mW ^/ cm 2 100h": weatherometer (manufactured by Suga Test Instruments Co., Ltd., metering weather meter M6T) using a 24-hour or irradiation intensity of 45 mW / cm ² After irradiation for 100 hours, the transmittance of the cured product at a wavelength of 400 nm was measured using an absorptiometer (manufactured by Shimadzu Corporation, spectrophotometer UV-3100). This transmittance is an index of light resistance.

<Evaluation of colorability of cured product>
About the hardened | cured material obtained by the said hardening characteristic test (hardened | cured material obtained by hardening | curing in a screw tube), the presence or absence of coloring (colorlessness) was judged visually. As a result, among Comparative Examples 1 to 3 in which the water content was less than 0.03% by mass, coloring was particularly noticeable in Comparative Example 3 using the aromatic epoxy compound (828). Even in the example using the group epoxy compound, in Examples 23 to 25 in which the water content is within the scope of the present invention, the coloring of the cured product is suppressed, and the effect of the present invention that suppresses the coloring is particularly remarkable. It was appearing. Further, in Comparative Examples 1 and 2 using a hydrogenated epoxy compound or an alicyclic epoxy compound, the coloring was slight, but in each Example in which the water content was within the scope of the present invention, it was further excellent in colorlessness. It was a thing.

Abbreviations and the like in Tables 1 to 3 are as follows.
YX-8000: Liquid hydrogenated epoxy resin (Epicoat YX-8000), epoxy equivalent 205, Celoxide 2021P manufactured by Japan Epoxy Resin Co., Ltd .: Liquid alicyclic epoxy resin (Celoxide-2021P), epoxy equivalent 131, weight average molecular weight 260, Daicel Chemical Industry 828: Liquid Bisphenol A Glycidyl Ether Type Epoxy Resin (Epicoat 828), Epoxy Equivalents 184-194, Weight Average Molecular Weight 370, Japan Epoxy Resin EHO: Oxetane Resin (ETERRNACOLL (R) EHO), Molecular Weight 116 .16, SI-80L manufactured by Ube Industries, Ltd .: heat latent cationic curing catalyst (Sun-Aid SI-80L, sulfonium salt type), manufactured by Sanshin Chemical Industry Co., Ltd., solid content 50%
SI-100L: Thermally latent cationic curing catalyst (Sun-Aid SI-100L, sulfonium salt type), manufactured by Sanshin Chemical Industry Co., Ltd., solid content 50%
SI-110L: Thermally latent cationic curing catalyst (Sun-Aid SI-110L, phosphorus type), manufactured by Sanshin Chemical Industry Co., Ltd., solid content 50%

Here, from the viewpoint of quality stability, the cationic curable compounds used in the Examples and Comparative Examples are supplied in a state that does not contain moisture as much as possible, specifically, the moisture is usually controlled to be less than several tens of ppm. Yes. Therefore, in the preparation of the resin composition, in order to suppress the ring opening of the epoxy group of the raw material monomer and obtain a stable quality composition, the resin composition is usually prepared under an atmosphere control that suppresses mixing of moisture as much as possible. Then, the water content of the obtained resin composition is controlled to several tens ppm or less. In the present invention, such a resin composition has an important technical significance in that water is intentionally added to achieve the effects of the present invention and that an effective range of the content is found.

From the results of Examples and Comparative Examples described in Tables 1 to 3, the following was found.
First, it can be seen from the examples and comparative examples that the curing rate is remarkably increased by the addition of moisture. Specifically, it is apparent that GT (second) and MCT (second) are remarkably shortened when the water content (water addition amount) is 0.03% by mass or more. Moreover, when Examples 1 and 5 and Examples 7 and 9 and Examples 10 and 12 are compared, it can be seen that the total calorific value tends to increase to the same extent or slightly as the water content increases. Furthermore, when Examples 1 and 5 and Examples 7 and 9 are compared, it can be seen that the glass transition temperature (Tg) of the cured product increases as the water content increases.

Moreover, when the transmittance | permeability after 230 degreeC 1 hour in the comparative example 1 and Example 1 and 5 is compared, when the moisture content is 0.03 mass% or more, the transmittance | permeability will become remarkably high, ie, heat resistance is dramatic. It can be seen that it is improved. Further, from the comparison of the transmittance (blank) in Example 6 in which the water content exceeds 1.00% by mass and Examples 1 and 5 in which the water content is less than 1.00% by mass, the water content is 1.00% by mass. It turns out that the hardened | cured material which is more excellent in transparency is obtained by setting it as less than%.

Further, it has been found that by reducing the amount of the cationic curing catalyst, the heat resistance and light resistance of the cured product are improved together. Specifically, the transmittance after 1 hour at 230 ° C. in Examples 1, 7 and 10 carried out under the same conditions other than the addition amount of the cationic curing catalyst is higher as the addition amount is smaller, so that the heat resistance is improved. I understand that In Examples 1 and 7 and, in Examples 5 and 9, when comparing each transmittance after 45 mW / cm ² test, since the transmittance as the amount is less high, light resistance is improved I understand that.

Moreover, it turned out that coloring of hardened | cured material is suppressed from the test result which evaluated the presence or absence of coloring of hardened | cured material resulting from containing a water | moisture content.

Claims (8)

A resin composition comprising a cation curable compound and a cation curing catalyst and cation curing,
The cationic curable resin composition contains 0.03 to 2% by mass of water with respect to 100% by mass of the resin composition,
The cationic curable resin composition is a resin composition for optical members,
The content of the cationic curing catalyst is a solid basis weight, relative to the cationic curable compound 100 parts by weight, I 0.01-2 parts by der,
The cationic curable resin composition is an alicyclic epoxy compound, a hydrogenated epoxy compound and / or an oxetane compound . The cationic curable resin composition according to claim 1, wherein the cationic curable compound is a compound having a cationic polymerizable group. The cation polymerizable group according to claim 2, wherein the cationic polymerizable group is at least one group selected from the group consisting of an epoxy group, an oxetane group, a dioxolane group, a trioxane group, a vinyl ether group, and a styryl group. Curable resin composition. The cationic curable compound contains an alicyclic epoxy compound and / or a hydrogenated epoxy compound, and the total amount of the alicyclic epoxy compound and the hydrogenated epoxy compound is based on 100% by mass of the total amount of the cationic curable compound. The cation curable resin composition according to claim 1, wherein the cation curable resin composition is 50% by mass or more. The cation curable resin composition according to claim 1, wherein the optical member is a lens. The cationic curable resin composition according to claim 1, wherein the cationic curing catalyst is a heat latent cationic curing catalyst and / or a photolatent cationic curing catalyst. 7. The cationic curing according to claim 1, wherein the water content in the cationic curable resin composition is less than 1.00% by mass with respect to 100% by mass of the resin composition. Resin composition. An optical member, characterized in that formed by curing a cationically curable resin composition according to any one of claims 1-7.