JP4251058B2 - Cationic curable resin composition - Google Patents

Description

  The present invention relates to a cation polymerizable polymer as a blending raw material in a curable resin that is cationically polymerized by irradiation or heating of active energy rays such as ultraviolet rays and electron beams, and a resin composition containing the same. The present invention also relates to a cationically curable resin having good curability and capable of producing a cured product having excellent flexibility, low elasticity at room temperature, and excellent restorability after shape change.

  Most of the curable resins that undergo cationic polymerization upon irradiation or heating with active energy rays such as ultraviolet rays and electron beams are epoxy resins. Epoxy resins are generally excellent in heat resistance, adhesiveness, chemical resistance, etc., but most of them are two-component thermosetting systems based on addition reactions such as amines and acid anhydrides, and curing systems based on cationic polymerization. Are not as widely used. However, since the cationic curing system does not have polar groups such as amines and esters, it is advantageous in reducing the water absorption rate of the cured product. In addition, epoxy-based and oxetane-based photocationic curable resins containing a photocationic polymerization initiator have recently attracted attention for the following reasons. That is, the epoxy compound and the oxetane compound have a small curing shrinkage ratio, excellent adhesion to the base material, low water absorption, and oxygen in the air, compared with the (meth) acrylate type that occupies most of the photocurable resin. This is because the polymerization is not hindered. On the other hand, in a thermosetting system, if a latent thermal cationic polymerization initiator is used, a one-component type cured product having a low water absorption rate can be obtained. For these reasons, cation curable resins, especially photocation curable resins, are attracting attention, but they are more expensive than epoxy and amine curing systems, so electronic materials and optical materials rather than general-purpose materials. It is attracting attention in fields that require specific physical properties.

  As one of the unique physical properties required for electronic materials and optical materials, for example, it is excellent in resilience after shape change even though it is softer than or more soft than an adhesive at room temperature (around 25 ° C). There are physical properties. In other words, in the dynamic viscoelasticity measurement, the physical property is that the storage elastic modulus G ′ is low and tan δ is also low (hereinafter abbreviated as low elastic modulus / low tan δ). However, no conventional epoxy cation curable resin can be found in terms of such physical properties, excluding silicone. In addition, since it is difficult to adhere | attach the cured | curing material of a silicone type resin with another material generally, a use is limited.

  However, an epoxy-based composition using an epoxidized polybutadiene is known in order to obtain a level of softness generally called a flexible resin. For example, addition of a polybutadiene having a carboxyl group at the terminal and an epoxy compound having two cyclohexene oxide structures in one molecule as an epoxy resin for improving flexibility as compared with an epoxidized polybutadiene currently on the market There exists a reaction material etc. (for example, refer patent document 1). However, it is not clear what kind of composition this compound can exhibit in terms of curability and low elasticity and low tan δ.

  A photocurable resin composition for optical three-dimensional modeling comprising an epoxy compound, an oxetane compound and a photocationic polymerization initiator is disclosed (for example, see Patent Document 2). Although various possible compounds and compositions are listed in this, they are different from the low elastic modulus resin aimed at by the present invention.

  A method for producing a macromonomer having an oxetane-containing group at the terminal is disclosed (see, for example, Patent Document 3), and a polyisoprene containing an oxetane ring at one terminal is shown as a compound. However, the physical properties as a cationic curable resin have not been clarified, and the terminal structure does not show the structure in the present invention. Moreover, since this compound contains many double bonds in a molecule | numerator, it is easy to receive deterioration by oxidation. In addition, the production method of the patent can be obtained by adding a polymerization terminator having an oxetane ring to the active terminal of an anionically polymerized polymer, but this method is based on moisture in the air or a small amount of moisture in the reaction solution. Since it is obstructed, a strict dehydration process is necessary, and a production facility suitable for such a precise reaction is necessary. In addition, an anionic polymerization initiator such as butyl lithium is not easily handled because it is decomposed by moisture in the air.

JP 2001-329045 (Claims) JP-A-10-168165 (Claims) JP-A-7-309856 (Claims, Examples)

  The problem to be solved by the present invention is that the viscosity before curing can be adjusted to a wide range of several hundred mPa · s to several tens Pa · s, and the cured product is excellent in curability and flexibility. An object of the present invention is to provide a cationic curable resin composition that gives a cured product that has a low elastic modulus at room temperature (around 25 ° C.) and is excellent in resilience after a shape change.

As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by the following, and have completed the present invention.
The novel oxetane compound used in the composition of the present invention is a compound produced from an ethylene-butylene copolymer having a hydroxyl group at one end having a weight average molecular weight of 1,000 to 10,000, which is represented by the following formula (1): Is a compound having an oxetanyl group at one end.

In Formula (1), R ¹ represents a hydrogen atom or an optionally branched alkyl group having the number of 1 to 6 carbon, R ² is an ethylene - represents a butylene copolymer.

The manufacturing method of Formula (1) which does not require a strict dehydration process or a difficult-to-handle compound is, for example, after tosylation or mesylation of an ethylene-butylene copolymer having one terminal hydroxyl group, It reacts with a compound .

In Formula (2), R ¹ represents a hydrogen atom or an alkyl group that may have 1 to 6 carbon atoms.

  The cationic curable resin composition of the present invention comprises a compound represented by the formula (1) and a cationic polymerization initiator that is activated by active energy rays or heat. The cationic curable resin composition of the present invention is a cationic curable resin composition that may further contain a compound containing an epoxy group and / or a compound having two or more oxetanyl groups in one molecule. Or they may contain a compound having one oxetanyl group in one molecule other than the formula (1).

Hereinafter, the present invention will be described in detail.
○ Ethylene one terminal for the synthesis of the compound represented by formula (1) used in the compositions is a hydroxyl group of the compound represented by the present invention by formula (1) - The butylene copolymer, at one end The polymerization method is not particularly limited as long as it has a hydroxyl group. For example, an ethylene-butylene copolymer by coordination polymerization can be mentioned.
The molecular weight of the ethylene-butylene copolymer having a hydroxyl group at one end is not particularly limited, but is preferably 500 to 50,000 in terms of polystyrene-reduced weight average molecular weight (Mw) by GPC, more preferably 1, 000 to 10,000. When the molecular weight is less than 500, it is not preferable from the viewpoint of obtaining a high viscosity cationic curable resin, and when it is more than 50,000, the compatibility with other monomers and polymerization initiator is deteriorated.

The compound represented by the formula (1) of the present invention is obtained from a product obtained by tosylation or mesylation of a hydroxyl group of the above-mentioned raw material polymer (referred to as a tosylate or a mesylate), but is not limited thereto. . For example, a raw material polymer and tertiary amine or pyridine (hereinafter simply referred to as tertiary amine) are dissolved in a solvent, and tosyl chloride or mesyl chloride is added and heated. Examples of the tertiary amine used here include triethylamine, tributylamine, N, N-dimethylbenzylamine, and 4- (N, N-dimethyl) -aminopyridine, but are less harmful and easily available. Therefore, triethylamine can be particularly preferably used. Examples of the solvent include ether solvents such as tetrahydrofuran (THF), 1,2-diethoxyethane, and dibutyl ether, aliphatic hydrocarbon solvents such as heptane, aromatic hydrocarbon solvents such as toluene, and chloroform. Although a chlorine type solvent etc. are mentioned, an ether type solvent is especially suitable. Regarding the selection of tosyl chloride and mesyl chloride, tosyl chloride is preferred in view of ease of handling.
The amount of tosyl chloride or mesyl chloride used is preferably equimolar or more, more preferably 1.2 to 6 times the mole of the hydroxyl group when a polymer having one hydroxyl group at one end is used.
The amount of tertiary amine charged is preferably more than the amount of tosyl chloride. The upper limit of the charged amount of the tertiary amine is not particularly limited, but is preferably 100 times or less in terms of mole from the economical aspect.
The reaction temperature is not particularly limited as long as it does not cause side reactions or decomposition, and a sufficient reaction rate can be obtained, but it is preferably in the range of 50 ° C to 150 ° C. The atmosphere of the reaction system does not require strict dehydration as much as anionic polymerization, and is preferably passed through an inert gas such as nitrogen gas.
When using a polymer in which a plurality of hydroxyl groups are bonded such that both ends have a hydroxyl group, less than two oxetanyl groups may be bonded in the polymer, preferably one.

  In the present invention, the compound represented by the formula (2) can be directly charged after the above-mentioned tosylation or mesylation, but in this method, the compound represented by the formula (2) This is not preferable because a mesylated product and an ether compound (for example, di (1-ethyl (3-oxetanyl)) methyl ether) between the compounds represented by the formula (2) are formed. That is, since these have a high boiling point and are difficult to separate from the target compound represented by the formula (1), in order to increase the purity of the compound represented by the formula (1), It is preferable to use the mesylated product after purification.

  Examples of purification of tosylate or mesylate are as follows. First, the solution of the reaction product is put into a solvent in which tosyl chloride or mesyl chloride is insoluble and tosyl chloride or mesyl chloride is soluble, for example, a ketone solvent such as alcohol having 1 to 3 carbon atoms or acetone to precipitate the target substance. It is a method of collecting. As a method for further increasing the purity, this precipitate is dissolved in a hydrocarbon solvent such as hexane and heptane, or an ether solvent such as THF, 1,2-diethoxyethane, and dibutyl ether, and reprecipitation purification is repeated. A method is mentioned. In the purification, a more preferable method is a method in which a hydrocarbon solvent solution of the compound represented by the formula (1) is mixed with an alcohol having 1 to 3 carbon atoms, and then separated into two layers and washed. . In this method, the amount of solvent used can be reduced. Here, a method of washing with water according to a conventional method may be mentioned. However, since this method may emulsify, washing with an alcohol having 1 to 3 carbon atoms, particularly methanol, is particularly preferable. Here, it is also possible to use a mixed solvent of water and methanol.

  An oxetanyl group can be bonded to the tosylate or mesylate by reacting with the compound represented by the formula (2), but an alkali catalyst is preferably added during this reaction. In addition, this reaction can be performed without a solvent, but it is preferably dissolved in a solvent. Examples of the alkali catalyst used in this reaction include alkali metal hydroxides and tertiary amines. Sodium hydroxide and potassium hydroxide are preferred, and potassium hydroxide is particularly preferred. Here, there is a method in which the compound represented by the formula (2) is used as alkoxide by sodium hydride or the like. However, since it is not easy to handle industrially, it is preferable to use an alkali metal hydroxide. Examples of the solvent in this reaction include hydrocarbon solvents such as hexane and heptane, and ether solvents such as THF, 1,2-diethoxyethane, and dibutyl ether, and preferred are ether solvents. Of these, those having a high boiling point such as 1,2-diethoxyethane and dibutyl ether can be particularly preferably used.

The amount of the compound represented by formula (2) is not particularly limited as long as it is equimolar or more with the tosyl group or mesyl group of the polymer in terms of mole, but it is preferably 1.2 times or more. The upper limit is not particularly limited, but is preferably 100 times or less from the viewpoint of the yield with respect to the volume of the reactor. When the compound represented by formula (2) is used in excess, the target polymer and the solution containing the compound represented by formula (2) may be separated into two layers. The layer containing the represented compound can also be recovered, distilled and reused.
The reaction temperature is preferably 60 ° C to 150 ° C, particularly preferably 90 ° C to 130 ° C.
The atmosphere of this reaction system is preferably a nitrogen atmosphere from the viewpoint of suppressing the generation of peroxide.

  For purification after this reaction, a method of adding a large amount of methanol or the like and precipitating (reprecipitation purification) can be carried out according to a conventional method, but the following method is particularly preferred in that the solvent used can be reduced. . That is, by removing the excess of the compound represented by the formula (2) which precipitates tosylate and separates into two layers, it is washed with a two-layer system of a hydrocarbon solvent such as hexane and methanol. is there. Here, since washing with water may cause emulsification, it is not very suitable. Since the purified polymer having an oxetanyl group at one end is contained in the hydrocarbon solvent layer, it can be obtained by removing the solvent from this layer.

○ Cation curable resin composition of the present invention The compound having an oxetanyl group at one end according to the present invention is excellent in cationic polymerizability, and therefore by adding a cationic polymerization initiator activated by active energy rays or heat, It can be suitably used as a component of the curable resin composition.

  Cationic polymerization initiators that initiate cationic polymerization of the cationic curable resin composition of the present invention by irradiation with active energy rays include diazonium salts, iodonium salts, sulfonium salts, selenium salts, pyridinium salts, ferrocenium salts, phosphonium salts. In particular, aromatic iodonium salts and aromatic sulfonium salts, more preferably diaryl iodonium salts and dialkylphenacyl sulfonium salts, and particularly preferably diaryl iodonium salts can be used.

When onium salt photocationic polymerization initiators such as aromatic iodonium salts and aromatic sulfonium salts are used in the cationic curable resin composition of the present invention, BF ₄ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ and PF ₆ are used as anions. ^-, and _{B (C 6 F 5) 4} - but like, preferably SbF ₆ ^-, PF ₆ ^-, and _{B (C 6 F 5) 4} - and is, particularly preferably SbF ₆ ^- or B (C ₆ F _{5) 4} ^- is.

  Specific examples of the cationic polymerization initiator include bis (dodecylphenyl) iodonium hexafluoroantimonate (manufactured by GE Toshiba Silicone, UV-9380C main component), tricumyliodonium tetrakis (pentafluorophenyl) borate (Rhodia) PHOTOINITIATOR 2074), bis (alkyl (C = 10-14) phenyliodonium) hexafluoroantimonate (Wako Pure Chemical photocationic polymerization initiator WPI-016), and the like.

  As the active energy ray for curing the cationic curable resin composition of the present invention, an X-ray, an electron beam or the like can be used, but preferably ultraviolet light or visible light, and particularly preferably ultraviolet light. When ultraviolet rays are used, the wavelength range is not particularly limited, but is preferably 150 to 400 nm, and more preferably 200 to 380 nm. When ultraviolet rays are used, cationic polymerization can be efficiently started.

  In addition, a sensitizer can be used in combination with the cationic curable resin composition of the present invention as necessary in order to further increase the activity of the cationic polymerization initiator. As a sensitizer that can be used in the present invention, it is possible to use a compound disclosed by Crivello in Advanced in Polymer Science (Adv. In Polymer Sci., 62, 1 (1984)). Specific examples include pyrene, perylene, acridine orange, thioxanthone, 2-chlorothioxanthone, and benzoflavine. In addition, compounds widely used as photo radical polymerization initiators can also be used, and specifically, thioxanthones such as benzophenone, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, and 2,4-dichlorothioxanthone. Benzoin ethers such as benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether, benzyl dimethyl ketals such as 2,2-dimethoxy-1,2-diphenylethane-1-one, and 2-hydroxy-2-methyl-1 Α-hydroxyalkylphenones such as phenylpropan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, α such as camphorquinone -Dicarboni And the like. In the present invention, thioxanthones and α-hydroxyalkylphenones can be particularly preferably used.

  The compounding quantity of the cationic polymerization initiator to the cation curable resin composition of this invention can be suitably adjusted according to the kind and irradiation amount of an active energy ray. For example, in the case of ultraviolet rays, the amount is preferably 0.1 to 5 parts by mass, more preferably 1 to 3 parts, with respect to 100 parts by mass in total of the resin composition. When the amount is less than 0.1 part, the curability may be inferior. On the other hand, when the amount is more than 5 parts by weight, the properties necessary for the cured product may be decreased to reduce the physical properties of the cured product. May become intensely colored.

  The compounding amount in the case of adding a sensitizer to the cationic curable resin composition of the present invention can be appropriately adjusted according to the type of active energy ray and the irradiation amount. For example, in the case of ultraviolet rays, the amount is preferably 5 parts by mass or less, more preferably 0.2 to 2 parts, with respect to 100 parts by mass in total of the resin composition. When the amount is more than 5 parts by mass, the components that are truly necessary for the cured product may be reduced to deteriorate the physical properties of the cured product, or the cured product may be intensely colored.

  When the active energy ray is ultraviolet light or visible light, the resin is exposed to the air. At this time, it is not necessary to limit the humidity of the atmosphere, but it is preferable that the humidity is low, and preferably 80% humidity. H. 70% R.V. H. More preferably, it is as follows. Here, when ultraviolet rays or visible light is installed in the production line, a method of sending dry air in front of the line or a method of reducing the humidity by attaching a heating device can be employed.

  A compound that is activated by heat to initiate cationic polymerization, that is, a thermal cationic polymerization initiator, can also be used in the cationic curable resin composition of the present invention. Examples of this include various onium salts such as quaternary ammonium salts, phosphonium salts and sulfonium salts, and combinations of alkoxysilanes and aluminum complexes. Available products include Adeka Opton CP-66 and Adeka Opton CP-77 (both trade names, manufactured by Asahi Denka Kogyo Co., Ltd.), Sun-Aid SI-60L, Sun-Aid SI-80L, and Sun-Aid SI-100L (both trade names) Sanshin Chemical Industry Co., Ltd.), and CI series (Nihon Soda Co., Ltd.).

  The blending ratio of the thermal cationic polymerization initiator to the cationic curable resin composition of the present invention is preferably in the range of 0.01 to 5 parts by mass with respect to 100 parts by mass of the resin composition. When the blending ratio is less than 0.01 parts by mass, the ring-opening reaction of the ring-opening polymerizable group may not be allowed to proceed sufficiently even if it is activated by the action of heat. Moreover, even if it mix | blends exceeding 5 mass parts, the effect | action which advances superposition | polymerization does not increase any more, and conversely, hardening performance may fall.

In the photocationic curable resin composition, a resin composition containing a compound represented by the formula (1), a compound containing an epoxy group, and a photocationic polymerization initiator is preferable in terms of curability.
In photocationic polymerization, oxetane has better polymerizability than epoxy, but the reaction at the beginning of polymerization is slower, so by adding a small amount of epoxy compound to the cation curable resin composition with oxetane compound, As a result, the curability is improved.

  In terms of improving the curability as a whole, various epoxy compounds can be used and may be monofunctional or polyfunctional. Moreover, as an epoxy group, the thing which oxidized the double bond in a molecule | numerator, or glycidyl ether may be sufficient. What oxidized the double bond in a molecule | numerator may have oxidized not only alicyclic epoxy but chain molecules, such as an olefin and polybutadiene.

In order to obtain a flexible cured product at room temperature (around 25 ° C.) and a cured product that has a low elastic modulus and excellent resilience after shape change, that is, a soft but solid cured product. For the above-mentioned epoxy compound, a compound having two or more epoxy groups in one molecule is a preferred means. As another means, it is also preferable to blend a compound having two or more oxenyl groups in one molecule. In this case, it is preferable to mix an epoxy compound in terms of curability, but a compound having one epoxy group in one molecule is also preferable. Moreover, it is also possible to mix | blend the compound which contains both an epoxy group and oxetanyl group in 1 molecule. Moreover, in the composition of this invention, the viscosity of resin can be adjusted without impairing sclerosis | hardenability by mix | blending the compound which has one oxetanyl group in 1 molecule other than Formula (1). Of course, it is also possible to use these compounds in combination. From the viewpoint of safety, the oxetane compound is preferable to the epoxy compound. That is, many epoxy compounds having a small molecular weight are suspected to be mutagenic. However, in the case of an oxetane compound, for example, 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane (Aron manufactured by Toagosei Co., Ltd.) having a small molecular weight is used. This is because oxetane OXT-212) is negative for mutagenicity. In addition, since the polymer is a viscoelastic body, it is difficult to say the distinction between a solid and a liquid. Here, a polymer having a tan δ of 1 or less in dynamic viscoelasticity measurement is called a solid. A cured product having a small tan δ is excellent in resilience after a shape change even if its elastic modulus is low. Furthermore, the cured product obtained from the composition of the present invention has a dynamic viscoelasticity (G ′) at 25 ° C. of 1 × 10 ⁸ Pa or less by preparing the content of the compound of the present invention and the compound to be blended. Can be obtained, 10 ⁷ Pa or less can be obtained, or 10 ⁶ Pa or less can be obtained.
Focusing on the compound represented by the formula (1), a compound in which R ² of the formula (1) is an ethylene-butylene copolymer is used from the viewpoint of storage stability and oxidation resistance of the cured product.

  Here, room temperature refers to the vicinity of 25 ° C., and is actually in the range of 0 ° C. to 40 ° C. because it is often used inside an electronic device used indoors. In this temperature range, the glass transition temperature is preferably −10 ° C. or lower, and more preferably −25 ° C., in order to make the cured product excellent in resilience after shape change while having a low elastic modulus. ° C or lower, particularly preferably -40 ° C or lower.

  Various compounds can be used as the compound containing one epoxy group used in the cationic curable resin composition of the present invention. Examples of the commercialized compounds include α-olefin epoxides such as 1,2-epoxyhexadecane, phenyl glycidyl ether, 2-ethylhexyl glycidyl ether, dodecyl glycidyl ether, glycidyl methacrylate, and the like.

Various compounds can be used as the compound containing two or more epoxy groups used in the cationic curable resin composition of the present invention. However, a polymer selected from the group consisting of maleated polybutadiene, maleated polyisoprene, hydroxyl group-containing polybutadiene, hydroxyl group-containing polyisoprene, hydroxyl group-containing hydrogenated polybutadiene and hydroxyl group-containing hydrogenated polyisoprene, one oxetanyl group and one Polymers having two or more oxetanyl groups produced from a compound having the above hydroxyl group are excluded.
Examples of those commercialized with this compound, dicyclopentadiene dioxide, limonene dioxide, 4-vinylcyclohexene dioxide, (3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate, di (3,4-epoxycyclohexyl) adipate, bisphenol A type epoxy resin, halogenated bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol S diglycidyl ether, bisphenol F type epoxy resin, o-, m-, p-cresol novolac epoxy resin, phenol novolac epoxy resin, 1,6-hexanediol diglycidyl ether, polytetramethylene glycol diglycidyl ether, trimethylolpropane Liglycidyl ether, pentaerythritol tetraglycidyl ether, internal epoxidized product of polybutadiene, compound in which both ends of polybutadiene are glycidyl etherified, compound in which double bond of butadiene in styrene-butadiene copolymer is partially epoxidized, ethylene -A compound in which a part of polyisoprene in the block copolymer of butylene copolymer and polyisoprene is epoxidized (K-RATON L-207), a compound in which the vinyl group of 4-vinylcyclohexene oxide ring-opening polymer is epoxidized Epoxidized vegetable oil, etc. Here, the number of epoxy groups per molecule is not particularly limited, but is preferably 50 or less, particularly preferably 20 or less. Elasticity with a small amount when there are many Unfavorably to improve.

In the composition of the present invention, by mixing a compound having one oxetanyl group in one molecule other than the formula (1), physical properties such as viscosity are adjusted while maintaining the characteristics of good curability and low elastic modulus. can do.
As a compound having one oxetanyl group in one molecule used in the cationic curable resin composition of the present invention (the name in parentheses is the trade name or the developed product name, manufactured by Toagosei Co., Ltd.), 3-ethyl-3- (2-ethyl Hexyloxymethyl) oxetane (Aron oxetane OXT-212 (EHOX)), 3-ethyl-3- (cyclohexyloxymethyl) oxetane (CHOX), 3-ethyl-3- (dodecyloxymethyl) oxetane (OXR-12) 3-ethyl-3- (octadecasiloxymethyl) oxetane (OXR-18), 3-ethyl-3- (phenoxymethyl) oxetane (Aron oxetane OXT-211 (POX)), 3-ethyl-3-hydroxymethyl And oxetane (OXA).

Various compounds can be used as the compound containing two or more oxetanyl groups used in the cationic curable resin composition of the present invention. Examples of this compound are (trade names or developed product names in parentheses, manufactured by Toagosei Co., Ltd.), 1,4-bis {[(3-ethyl-3-oxetanyl) methoxy] methyl} benzene (Aron oxetane OXT-121 (XDO)), di [1-ethyl (3-oxetanyl)] methyl ether (Aron oxetane OXT-221 (DOX)), oxetanylsilsesquioxane (OX-SQ), phenol novolac oxetane (PNOX-1009), norbornane Etherified product (NDMOX) of dimethanol and 3-ethyl-3-chloromethyloxetane (hereinafter abbreviated as OXC), etherified product of trimethylolpropane and OXC (TMPOX), etherified product of hydroquinone and OXC (HQOX), resorcinol and OXC Etherified product (RSOX) of 2, Etherified product of '-biphenol and OXC (2,2'-BPOX), 4,4'-biphenol and OXC (4,4'-BPOX), etherified product of bisphenol F and OXC (BisFOX), tricyclo Examples include etherified products of decanedimethanol and OXC, alkoxides (OX-SC) using OXA and silicon, and the like.
Here, the number of oxetanyl groups per molecule is not particularly limited, but is preferably 20 or less, more preferably 5 or less, and particularly preferably 3 or less.

  It is preferable that the composition in which these are blended is finally uniformly and transparently dissolved. However, particularly preferable examples of the compatibility are L-207, 1,2-epoxyhexadecane, norbornane di produced by KRATON. Methanol dioxetane, 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane (EHOX), 3-ethyl-3- (cyclohexyloxymethyl) oxetane (CHOX), 3-ethyl-3- (dodecyloxymethyl) An example is oxetane (OXR-12).

  You may mix | blend fillers, such as a silica, an alumina, and another metal oxide, with the composition of this invention as needed. Thereby, the thixotropy can be imparted. Moreover, when using as an electrical insulation material, it is preferable to mix | blend the material which has ion exchange ability, More preferably, it is an inorganic type, Especially preferably, it has anion exchange ability. Examples of suitable inorganic anion exchangers include IXE-500, IXE-530, IXE-550, IXE-700, and IXE-800 (all manufactured by Toagosei Co., Ltd.).

  Furthermore, a coupling agent such as a silane coupling agent can be added to the resin composition of the present invention for the purpose of improving adhesion to an inorganic material. Suitable silane coupling agents include β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (manufactured by Shin-Etsu Chemical, KBM-303), γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical, KBM-403). ), Γ-glycidoxypropyltriethoxysilane (manufactured by Shin-Etsu Chemical, KBE-403), γ-glycidoxypropylmethyldiethoxysilane (manufactured by Shin-Etsu Chemical, KBM-402), 3-ethyl-3-{[3 -(Triethoxysilyl) propoxy] methyl} oxetane (manufactured by Toagosei Co., Ltd., OXT-610).

The composition of the present invention, when requiring oxidation resistance Ru can be an antioxidant.

Examples of the antioxidant contained in the composition of the present invention include phenolic antioxidants, sulfur antioxidants, phosphorus antioxidants, and amine antioxidants. Particularly preferred are phenolic antioxidants. It is an agent.
Examples of phenolic antioxidants include hydroquinone monomethyl ether, 2,6-di-t-butylhydroxytoluene, 2,2'-methylenebis- (4-methyl-6-t-butylphenol), 4,4'-butylidenebis- (3-methyl-6-tert-butylphenol), triethylene glycol-bis- [3- (3′-tert-butyl-4-hydroxy-5-methylphenyl)] propionate, pentaerythritol-tetrakis [3- (3 , 5-di-t-butyl-4-hydroxyphenyl) propionate] (Irganox 1010 manufactured by Ciba Specialty Chemicals), n-octadecyl-3-[(3 ′, 5′-di-t-butyl-4 ′ -Hydroxyphenyl) propionate], 4,4′-thiobis (3-methyl-6-tert-butyl) phenone , And the like.

  The cationic curable resin composition of the present invention can be selected depending on the application as to whether an active energy ray curable system or a thermosetting system is selected. For example, a curing system using an active energy ray such as an ultraviolet curing system is suitable for use as a resist or for applying a fine shape with a stamper (mold) or the like. In addition, a curing system using an active energy ray is suitable for coating, screen printing, adhesion of a transparent material, and the like in terms of high production speed and energy saving. However, a thermosetting system is suitable for applications where active energy rays cannot reach the resin, such as adhesion between opaque materials and sealing of parts including metals. However, even in applications such as adhesion between opaque materials, using the dark reaction unique to cation curing, for example, after irradiating light to a photocurable resin applied to an opaque material, other opaque materials It is also possible to bond them together by completing the curing by a dark reaction. Further, heat curing can be combined after curing with active energy rays.

  The cationic curable resin composition of the present invention can give a cured product that is as soft as or more than an adhesive from a soft cured product generally called a flexible resin, and has a low elasticity that is comparable to an adhesive. It is possible to make the material excellent in the resilience after the shape change although it is a ratio, so it is suitable as an adhesive, coating agent, sealing agent, sealant, insulating material, etc. mainly in electronic materials and optical materials Can be used for In particular, the active energy ray-curable resin is particularly suitable because it can realize physical properties that are difficult to achieve with conventional materials. Among these, those using ultraviolet rays or visible light as the active energy rays are particularly preferable because they are relatively inexpensive and can be produced by a small production line.

<Example>
Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to these examples.

-Synthesis of compound (1) <Tosylation of ethylene-butylene copolymer having a hydroxyl group at one end>
A 2 L separable flask is charged with 240 g of an ethylene-butylene copolymer having a hydroxyl group at one end (L-1203 manufactured by KRATON Polymers) (about 60 mmol as a hydroxyl group), 328 g of tetrahydrofuran (THF), and 36.4 g of triethylamine. A lid for the mouth, a stirring blade, a thermometer, and a cooling tube were attached, and the mixture was stirred and dissolved in an oil bath while nitrogen was passed through. Tosyl chloride 51.5 g (270 mmol) was added thereto, and the mixture was stirred at 62 ° C. for 27 hours to be reacted. The reaction crude product was slowly added to 2.5 kg of isopropyl alcohol (IPA) stirred at room temperature, and then stirred for 30 minutes and left for 1 hour. Then, after removing the IPA layer by decantation, 700 g of n-hexane was added to dissolve the precipitate. This was transferred to a 2 L separatory funnel, 120 g of methanol was added and stirred, and then 300 g of n-hexane was added and lightly mixed to separate the two layers. After removing the lower methanol layer, 120 g of methanol was further added, shaken and allowed to stand for 15 minutes, and the lower methanol layer was removed. After washing with methanol as described above twice more, the n-hexane layer containing the product was transferred to a separable flask, and the solvent was distilled off at 65 ° C. or lower in an oil bath while reducing the pressure. 222 g of product was obtained. From the ¹ H-NMR spectrum of the product, it was confirmed that the hydroxyl group of the polymer was tosylated.

<Oxetaneation of tosylated ethylene-butylene copolymer>
In a 2 L separable flask, 204 g of tosylated ethylene-butylene copolymer, 204 g of di-n-butyl ether, 255 g of 3-ethyl-3-hydroxymethyloxetane (OXA, manufactured by Toagosei Co., Ltd.), 6.5 g of 95% potassium hydroxide were added. Charged, a four-necked lid, a stirring blade, a thermometer, and a cooling pipe were attached, and the reaction was carried out by stirring for 6 hours at 120 ° C. in an oil bath with nitrogen flowing. Since a precipitate was formed, only the liquid was transferred to a 2 L separatory funnel by decantation, this precipitate was washed with 200 g of n-hexane, and the washing solution was added to the separatory funnel by decantation. Since this solution was separated into two layers, the lower layer containing OXA was removed. Next, 200 g of methanol and 500 g of n-hexane were added and stirred, and then 100 g of n-hexane was further added and lightly mixed to separate two layers. This lower layer was removed, and washing with 200 g of methanol was repeated three times. At this time, 100 g of n-hexane was appropriately added to make the two-layer separation quick and clear. The n-hexane layer containing the product was transferred to a 2 L separable flask, and most of the solvent was distilled off in an oil bath at 100 to 110 ° C. while bubbling nitrogen, and then a small amount of the remaining solvent was removed. The pressure was reduced in an oil bath at 5 ° C. for 5 hours to obtain 183 g of a pale yellow transparent product. The ¹ H-NMR spectra of L-1203 and the product are shown in FIGS. 1 and 2, respectively. From this, it was confirmed that the tosyl group at the end of the polymer was substituted with OXA. Moreover, when GPC of a product was measured and molecular weight distribution was confirmed, Mw of polystyrene conversion was 5630 and Mw / Mn was 1.04. On the other hand, the raw material polymer had Mw of 5510 and Mw / Mn of 1.03.

<Synthesis Example 1>
Synthesis of urethane acrylate (PTGUA) In a 500 mL separable flask, 88.8 g (0.40 mol) of isophorone diisocyanate (IPDI), 0.34 g of dibutyltin dilaurate, 2,6-di-t-butyl-4-methylphenol (BHT) 0.102 g was charged, and while blowing air, 203.8 g (0.20 mol) of polytetramethylene glycol having a molecular weight of about 1000 (PTG1000SN manufactured by Hodogaya Chemical Industry) was dropped and reacted, and further at 60 ° C. Reacted for hours. Then, 46.4 g (0.40 mol) of 2-hydroxyethyl acrylate (HEA) was added dropwise and reacted at 80 ° C. for 1 hour to obtain urethane acrylate.

○ Formulation and physical property evaluation The components shown in Tables 1 and 2 were mixed according to a conventional method to prepare a cationic curable composition, and then various physical properties were evaluated. The abbreviations in Table 1 indicate the following compounds. Moreover, the numerical value of Table 1 and Table 2 is a mass part.
L1203: L-1203 manufactured by KRATON Polymers (ethylene-butylene copolymer having a hydroxyl group at one end, molecular weight based on hydroxyl group of ¹ H-NMR is about 4000, Tg-63 ° C.)
L1203OX: product of Example 1 obtained by oxetaneation of hydroxyl group of L1203 manufactured by KRATON Polymers L207: L-207 manufactured by KRATON Polymers (block in which the end of L1203 containing no hydroxyl group is epoxidized polyisoprene) Copolymer, molecular weight based on hydroxyl group of ¹ H-NMR is about 6000, epoxy equivalent is about 670, Tg-53 ° C.)
EHOX: 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane (Aron Oxetane OXT-212 manufactured by Toagosei Co., Ltd.)
CHOX: 3-ethyl-3- (cyclohexyloxymethyl) oxetane (CHOX manufactured by Toagosei Co., Ltd.)
POX: 3-ethyl-3- (phenoxymethyl) oxetane (Aron Oxetane OXT-211 manufactured by Toagosei Co., Ltd.)
PGE: Phenyl glycidyl ether (Denacol EX-141 manufactured by Nagase ChemteX)
WPI016: Bis (alkyl (C = 10-14) phenyliodonium) hexafluoroantimonate (Photocation polymerization initiator WPI-016 manufactured by Wako Pure Chemical Industries, Ltd.)
# 2074: Tolylcumyl iodonium tetrakis (pentafluorophenyl) borate (PHOTOINITIATOR 2074 manufactured by Rhodia)
Irg184: Photo radical polymerization initiator Irgacure 184 (1-hydroxycyclohexyl-phenyl ketone, used as a sensitizer for photocation polymerization in the present invention) manufactured by Ciba Specialty Chemicals
PTGUA: Product of Synthesis Example 1 BADMA: Dimethacrylate of alcohol obtained by adding four ethylene oxides to bisphenol A (Kyoeisha Chemical Light Ester BP-4EM)
M120: 2-ethylhexyl carbitol acrylate (Aronix M-120 manufactured by Toagosei Co., Ltd.)
EHMA: 2-ethylhexyl methacrylate POA: Phenoxyethyl acrylate (Kyoeisha Chemical Light Acrylate POA)

  The viscosities and curing processes of the compositions described in Tables 1 and 2 and the dynamic viscoelasticity of the cured products were measured. These evaluation results are shown in Table 3.

Viscosity Viscosity (Pa · s) at 25 ° C. was measured with an E-type viscometer manufactured by Toki Sangyo, and the results are shown in Table 3.
○ Measurement of curing process and dynamic viscoelasticity of cured product (25 ℃)
The curing process by light irradiation and the viscoelasticity after curing were measured with a photocuring viscoelasticity measuring device manufactured by Relogia (Sweden). That is, a liquid resin before curing is placed on a quartz plate and sandwiched by a rotor having a diameter of 10 mm from above (gap 0.2 mm). A xenon lamp (L8222, manufactured by Hamamatsu Photonics, adjusted to 50 mW / cm ² @ 365 nm) was irradiated to measure viscoelasticity. Table 3 shows the elastic moduli G ′ (Pa) and tan δ finally reached by photocuring the resin and the brittleness of the obtained cured product. However, the comparative example 6 has shown the thing at the time of stopping light irradiation in the middle of hardening, and shows the elasticity modulus G '(Pa) and tan-delta at that time, and the brittleness of the obtained hardened | cured material.
The brittleness was evaluated as follows according to the state of removing the cured product from the quartz plate.
○: Even if it deforms greatly, it is not torn and can be removed as a disk-shaped cured product. (Not fragile)
Δ: Breaks when deformed greatly, and is difficult to remove as a disk-shaped cured product. (Slightly brittle)
X: It tears by a slight deformation | transformation, and when it removes, it will be shattered. (Very fragile)
-: The word brittleness is inappropriate because it is too soft or is intermediate between solid and liquid.

○ Curability in coating film The compositions of Examples 3 and 4 and Comparative Example 3 listed in Table 1 were coated on a PET film with a bar coater to a film thickness of 20 microns, and this was applied to 80 W / cm high-pressure mercury. Curability was evaluated by the number of passes until the coating film changed to a solid at a lamp (1 lamp), a lamp height of 10 cm, and a conveyor speed of 50 m / min or 80 m / min. The atmosphere at this time was a temperature of 26 ° C. and a relative humidity of 66%. The results are shown in Table 4.

○ Preparation of 1 mm thick cured product and measurement of dynamic viscoelasticity After creating a 1 mm thick frame on a polytetrafluoroethylene plate and pouring the compositions of Example 3 and Example 4 described in Table 1, Ultraviolet rays were irradiated with a high-pressure mercury lamp. After irradiating with an intensity of 150 mW / cm ² at 365 nm for 2 minutes and confirming that it was cured to the back surface, it was turned over and irradiated under the same conditions. The dynamic viscoelasticity of the obtained cured product was measured at a frequency of 1 Hz using RDS-II manufactured by TA Instruments, and the storage elastic modulus (G ′) and tan δ were evaluated. The temperature dependence of this dynamic viscoelastic spectrum is shown in FIG.

Ethylene at one end of the present invention having an oxetanyl group - butylene copolymer, suitably can be used as a mixed material of a curable resin having excellent cationic curability, particularly, flexibility excellent cured product and has to, room temperature However, when a cured product having a low elastic modulus and excellent in resilience after a shape change is required, it can be suitably used. The resulting cured product is flexible and not brittle. It is also possible to adjust the viscosity before curing in a wide range. Furthermore, it can be suitably used as an active energy ray curable resin such as a photocurable resin. Therefore, it can be suitably used as an electronic material or an optical material that requires the above physical properties.
On the other hand, the method for producing the compound represented by the formula (1) of the present invention uses a readily available material and does not require equipment or operation for strict dehydration. This is a manufacturing method suitable for producing a relatively small amount of materials.

¹ H-NMR spectrum of an ethylene-butylene copolymer having a hydroxyl group at one end (raw material L-1203 manufactured by KRATON), which is a raw material polymer of Example 1, is shown. The ¹ H-NMR spectrum of the ethylene-butylene copolymer having an oxetanyl group at one end, which is the product of Example 1, is shown. The dynamic viscoelastic spectrum (temperature dependence) of the hardened | cured material which hardened the composition of Example 3 and Example 4 with the ultraviolet-ray is shown.

Explanation of symbols

Horizontal axis in Fig. 3: Temperature ° C
Right vertical axis in FIG. 3: tan δ value (logarithmic scale)
Left vertical axis in FIG. 3: storage elastic modulus (G ′) value (Pa, logarithmic scale)
The thick solid line in FIG. 3: a curve showing the storage elastic modulus (G ′) of the cured product obtained by curing the composition of Example 3 with ultraviolet rays. The thin solid line in FIG. 3: the cure obtained by curing the composition of Example 4 with ultraviolet rays. Curve showing storage elastic modulus (G ′) of product Thick broken line in FIG. 3: Curve showing tan δ of cured product obtained by curing composition of Example 3 with ultraviolet light Thin broken line in FIG. 3: Composition of Example 4 Curve showing tan δ of cured product cured with ultraviolet light

Claims (3)

A compound produced from an ethylene-butylene copolymer having a hydroxyl group at one end with a weight average molecular weight of 1,000 to 10,000, and having an oxetanyl group at one end represented by the following formula (1) :
And an epoxy group-containing compound and / or a compound having two or more oxetanyl groups in one molecule (however, maleated polybutadiene, maleated polyisoprene, hydroxyl group-containing polybutadiene, hydroxyl group-containing polyisoprene, hydroxyl group-containing hydrogenated polybutadiene and hydroxyl group) And a polymer selected from the group consisting of hydrogenated polyisoprene, and a cation curable resin composition comprising a polymer having two or more oxetanyl groups produced from a compound having one oxetanyl group and one hydroxyl group) object.

(In the formula (1), R ¹ represents a hydrogen atom or an optionally branched alkyl group having the number of 1 to 6 carbon, R ² is an ethylene - represents a butylene copolymer.) A cationic curable resin composition comprising a compound represented by the above formula (1) and a cationic polymerization initiator activated by an active energy ray or heat. The cation curable resin composition of Claim 1 or Claim 2 containing the compound which has one oxetanyl group in 1 molecule other than Formula (1).

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