JP2010254893A - Hydroxy group-containing oxetane oligomer, method for producing the same, photo-curable resin composition, and cured product thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydroxy group-containing oxetane oligomer exhibiting high UV cationic curing properties, to provide a method for producing the same, to provide a photo-curable resin composition using the hydroxy group-containing oxetane oligomer and to provide a cured product thereof. <P>SOLUTION: The hydroxy group-containing oxetane oligomer having 5 to 7 mmol/g content of oxetanyl groups is formed by reacting oxetane alcohols (a) and an epihalohydrin (b) in the presence of a basic catalyst (c) under a temperature condition of 35 to 150°C. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to an active energy ray-curable composition such as an ultraviolet ray and an electron beam, and in particular, the present invention relates to a curable composition useful for paints and inks.

In the field of UV curable coatings, radical curable acrylate materials, cationic curable epoxy compounds, vinyl ether compounds, oxetane compounds and the like are widely used.

Among these, cationically curable epoxy compounds are widely used industrially, but they are toxic and mutagenic, and especially glycidyl ether compounds that have a significantly lower reaction rate in UV cationic curing systems. Met.

On the other hand, oxetane ether compounds have attracted attention in recent years due to their low toxicity and faster curing speed than glycidyl ether compounds, and high molecular weight oxetane compounds have the advantage of low cure shrinkage during polymerization. In recent years, it has attracted attention.

Such a characteristic that the curing shrinkage is low is industrially useful because it exhibits excellent adhesiveness to various substrates when a resin material for paint or a varnish for printing ink is used. As such an oxetane ether compound, for example, a technology for producing a resin having a pendant oxetanyl group by anionically reacting 3- [oxiranylmethoxy-methyl] -oxetane to cause ring-opening polymerization of an epoxy group. Is known (see Patent Document 1).

However, anionic polymerization of a glycidyl group has a problem that it is necessary to use a high-purity raw material in an environment in which air and moisture are completely blocked, and a polar organic solvent cannot be used. Specifically, it is necessary to purify the raw material monomer, the catalyst, and the nonpolar organic solvent in advance and perform the reaction in a nitrogen atmosphere, and industrial production is extremely difficult. In addition, anionic cationic impurities are mixed in the resulting polymer, resulting in a low UV curability of the finally obtained oligomer.

US Pat. No. 6,770,737

The problem to be solved by the present invention is to provide a hydroxyl group-containing oxetane oligomer exhibiting high UV cation curability, a production method thereof, a photocurable resin composition using the hydroxyl group-containing oxetane oligomer, and a cured product thereof. It is in.

As a result of intensive investigations to solve the above problems, the present inventors have reacted with oxetane alcohols and epihalohydrin to increase the molecular weight, thereby providing excellent industrial productivity and easy molecular weight adjustment. Furthermore, the present inventors have found that an oxetane oligomer having excellent curability can be obtained and completed the present invention.

That is, the present invention provides the following general formula 1

（ここで、Ｒは炭素原子数１〜１０のアルキル基、Ｒ^１は水素原子又はメチル基、ｎは２〜１００の数、ｍは０〜１０の数を表す。）で表される分子構造を有することを特徴とするヒドロキシ含有オキセタンオリゴマーに関する。

Where R is an alkyl group having 1 to 10 carbon atoms, R ¹ is a hydrogen atom or a methyl group, n is a number from 2 to 100, and m is a number from 0 to 10. The present invention relates to a hydroxy-containing oxetane oligomer characterized by having

The present invention further includes the following general formula 2

（Ｒは炭素原子数１〜１０のアルキル基、Ｒ^１は水素原子又はメチル基、ｍは０〜１０の数を表す。）で表されるオキセタンアルコール類（ａ）とエピハロヒドリン（ｂ）とを、塩基性触媒（ｃ）の存在下、３５〜１５０℃の温度条件で反応させることを特徴とする水酸基含有オキセタンオリゴマーの製造方法に関する。

An oxetane alcohol (a) and an epihalohydrin (b) represented by (R is an alkyl group having 1 to 10 carbon atoms, R ¹ is a hydrogen atom or a methyl group, and m is a number from 0 to 10). The present invention relates to a method for producing a hydroxyl group-containing oxetane oligomer, wherein the reaction is carried out at a temperature of 35 to 150 ° C. in the presence of a basic catalyst (c).

The present invention further relates to a photocurable resin composition comprising the hydroxyl group-containing oxetane oligomer and a photopolymerization initiator as essential components.

The present invention further relates to a cured product obtained by curing the photocurable resin composition.

ADVANTAGE OF THE INVENTION According to this invention, the photocurable resin composition using the hydroxyl-containing oxetane oligomer which expresses high UV cation curability, its manufacturing method, this hydroxyl-containing oxetane oligomer, and its hardened | cured material can be provided.

FIG. 1 is a GPC chart showing changes in the GPC chart when starting materials are added to the reaction system in multiple stages and reacted in Example 1. FIG. FIG. 2 is a gas chromatography chart showing the presence of intermediates A, B, and C produced by the reaction in Example 1. FIG. 3 is a chart of a mass spectrum (chemical ionization with isobutane) indicating the presence of intermediate A produced by the reaction in Example 1. FIG. 4 is a chart of mass spectrum (chemical ionization with isobutane) showing the presence of intermediate A produced by the reaction in Example 1. FIG. 5 is a chart of a mass spectrum (chemical ionization with isobutane) showing the presence of intermediate A produced by the reaction in Example 1.

Hereinafter, the present invention will be described in detail.

The hydroxyl group-containing oxetane oligomer of the present invention can be produced by reacting an oxetane alcohol represented by the following general formula 2 with an epihalohydrin under a basic catalyst, as shown below.

ここでＲは炭素原子数１〜１０のアルキル基、Ｒ^１は水素原子又はメチル基、ｎは２〜１００の数、ｍは０〜１０の数を表し、Ｘは塩素原子又は臭素原子を表す。

Here, R represents an alkyl group having 1 to 10 carbon atoms, R ¹ represents a hydrogen atom or a methyl group, n represents a number of 2 to 100, m represents a number of 0 to 10, and X represents a chlorine atom or a bromine atom. .

Here, the oxetane alcohols represented by the general formula 2 used as a raw material are specifically 3-methyl-3-hydroxymethyl oxetane, 3-ethyl-3-hydroxymethyl oxetane, 3-n-heptyl- Examples include 3-hydroxymethyl oxetane, 3-ethyl-3-hydroxy-poly (ethyleneoxy) methyl oxetane, and 3-ethyl-3-hydroxy-poly (propyleneoxy) methyl oxetane.

On the other hand, epihalohydrin includes epichlorohydrin and epibromohydrin. In the present invention, epichlorohydrin is preferable from the viewpoint of excellent reactivity with the oxetane alcohols.

In the above reaction, first, the oxetane alcohol is mixed with a base catalyst. Examples of the base catalyst used here include sodium carbonate, sodium hydroxide, sodium methoxide, potassium carbonate, potassium hydroxide, potassium methoxide, and calcium hydroxide.

After mixing the oxetane alcohols and the base catalyst, epihalohydrins are added. The reaction is an exothermic reaction, and the start of the reaction can be confirmed by increasing the temperature of the reaction system, and the epihalohydrin is consumed by decreasing the temperature of the reaction system, and the end point of the reaction can be confirmed. In the present invention, the molecular weight can be adjusted by further adding a base catalyst, epihalohydrin, or oxetane alcohol and further allowing the reaction to proceed. For introducing such a base catalyst, epihalohydrin, and oxetane alcohol into the reaction system, for example, they may be intermittently added to the reaction vessel, or these may be alternately introduced into the reaction vessel. The molecular weight of the hydroxyl group-containing oxetane oligomer can be controlled by the addition and reaction of such raw material components and catalyst, and the molecular weight of the final product can be further increased by increasing the number of inputs.

The reaction can be performed in a non-solvent or an inert solvent, and examples of the inert solvent include toluene or water.

The reaction between oxetane alcohols and epichlorohydrin can be carried out under a temperature condition of 35 to 150 ° C, preferably 60 to 115 ° C.

In the above reaction, the oxetane alcohols, basic catalyst, and epihalohydrin are used in a molar ratio [the oxetane alcohols / basic catalyst / epihalohydrin] of [2 / 1.05 / 1] to [0. .5 / 1.25 / 1] is preferable.

The state of increase in the molecular weight of the hydroxyl group-containing oxetane oligomer during the reaction can be confirmed by size exclusion chromatography shown in FIG.

Specifically, the formation scheme of the oligomer structure is, for example, when 3-ethyl-3-oxetanylmethanol is used as the oxetane alcohol, sodium hydroxide is used as the basic catalyst, and epichlorohydrin is used as the epihalohydrin. Can be represented.

As described above, intermediate A is produced from the raw material components initially charged in the reaction vessel, and intermediates B and C are formed by further introducing the raw materials into the reaction system. Can be increased. In the above reaction scheme, the hydroxyl groups of the low molecular weight intermediates A, B and C can be derivatized with trimethylsilane and separated by gas chromatography, and then confirmed by mass spectrum. Specifically, the presence of the intermediate can be confirmed by the gas chromatography chart of FIG. 2 and the mass spectrum of FIGS. 3-5.

After completion of the reaction, the formed salt is removed by filtration. At this time, an inert solvent such as toluene can be added to facilitate filtration of the various mixtures. The reaction solution is neutralized with, for example, acetic acid, and washed with water several times to remove residual oxetane alcohols and salts. The water used in this washing step is preferably a 10 to 20% by mass sodium chloride aqueous solution from the viewpoint of better separation performance. Here, when impurities remain in the product, the curability by UV irradiation is lowered, so that it is preferable to sufficiently wash with water. The target hydroxyl group-containing oxetane oligomer can be obtained by drying the product after washing with water and removing the organic solvent. A slightly colored viscous hydroxyl group-containing oxetane oligomer is thus obtained.

The hydroxyl group-containing oxetane oligomer thus obtained has a molecular structure represented by the general formula 1, and its weight average molecular weight (Mw) is preferably in the range of 500 to 60000. The amount of oxetanyl group in the molecular structure can be measured by titration with a strong acid such as perchloric acid, and is preferably in the range of 5 to 7 mmol / g from the viewpoint of curability.

Patent Document 1
Compared to the oxetane compound described in (US Pat. No. 6,770,737), the hydroxyl group-containing oxetane oligomer of the present invention is characterized by having a hydroxyl group in the molecular structure. Here, the amount of the hydroxyl group decreases as the molecular weight of the hydroxyl group-containing oxetane oligomer increases. The amount of the hydroxyl group is preferably in the range of 0.1 to 2.5 mmol / g, and in particular in the range of 0.5 to 1.5, the adhesion to the substrate and dual curing described later. It is preferable from the viewpoint of easy application to the system. The amount of the hydroxyl group can be determined by hosting the amount of acetic acid produced by the reaction between the hydroxyl group and acetic anhydride with a strong base such as potassium hydroxide.

The hydroxyl group-containing oxetane oligomer of the present invention described in detail above can be mixed or dissolved with a cationic photopolymerization initiator to form the UV curable composition of the present invention. Here, it is preferable that the compounding quantity of a photocationic polymerization initiator is the range of 0.3-20 mass% on the basis of the total mass with a hydroxyl-containing oxetane oligomer, and when using this composition for coating materials, it is 2. It is preferable that it is the range used as -6 mass%. Moreover, when applying this composition for printing inks, it is preferable that it is the range of 4-12 mass%.

Examples of the cationic photopolymerization initiator that can be used here include aryl-sulfonium salts, aryl-iodonium salts, and the like. Specifically, arylsulfonium hexafluorophosphate, arylsulfonium hexafluoroantimonate, arylsulfonium tetrakis (pentafluoro). ) Borate, dialkylphenacylsulfonium hexafluorophosphate and the like are preferable from the viewpoint of excellent reactivity.

In addition to the hydroxyl group-containing oxetane oligomer and the photocationic polymerization initiator, the photocurable resin composition of the present invention includes other polyols, photosensitizers such as dimethylanthracene, and cationic curing such as vinyl ethers, epoxy compounds, and oxetane compounds. Reactive diluents, pigments, dyes, fillers, organic solvents, surfactants, and other additives. In the present invention, alicyclic epoxies such as 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, 3,4-epoxycyclohexanecarboxylate, bis (3,4-epoxycyclohexyl) adipate It is preferable to use the compound in combination from the viewpoint that the reactivity in the photocation curing reaction is good, the viscosity can be adjusted, and the physical properties of the coating film are also improved. Moreover, it is preferable from a sclerosing | hardenable point that this invention does not contain non-reactive media, such as an organic solvent or water.

The photocurable resin composition of the present invention can be applied to various coating methods such as roller coating, spray coating, brushing, and bar coating. The wavelength of the UV light is usually in the range of 200 to 400 nm, and the UV source used for UV irradiation is a high pressure mercury valve, medium pressure mercury valve, xenon bulb, carbon arc, metal halide bulb, or solar Light. Although an irradiation amount changes with coating-film thickness and a use, it is the range of 10-3000 mJ / cm < ² > normally, and it is preferable that it is the range of 20-500 mJ / cm < ² > especially. Moreover, the said valve | bulb can be suitably selected according to the absorption spectrum of a photoinitiator.

In addition, the hydroxyl group-containing oxetane oligomer of the present invention can be cured by other reactions of the active energy ray curing system described above. For example, the cationically polymerizable compound (a) can be cationically cured by adding a strong acid such as hexafluorophosphoric acid.

Furthermore, since the hydroxyl group-containing oxetane oligomer of the present invention becomes a reactive site, a dual cure system that is precured by UV irradiation and then completed by a thermosetting reaction can be employed. Here, examples of the curing agent used for the thermosetting reaction include polyfunctional isocyanate compounds. Specifically, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,4′-diphenylmethane diisocyanate. 4,4'-diphenylmethane diisocyanate, m-xylene diisocyanate, p-xylene diisocyanate, m-trimethylxylene diisocyanate, m-tetramethylxylene diisocyanate, bis- (4,4'-isocyanatophenyl) methane Isocyanate, cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated 4,4′-diphenylmethane diisocyanate, bis (4,4′-isocyanatocyclohexyl) propane, 1,3-bis (isocyanatomethi) ) Skeletons such as cycloaliphatic polyisocyanates such as cyclohexane, 1,6-hexamethylene diisocyanate, 1,4-tetramethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, etc. And aliphatic polyisocyanates.

The cured product of the present invention can be obtained by curing the composition detailed above by light irradiation and, if necessary, using a dual curing system, and the cured product obtained is poly (ethylene terephthalate). Excellent adhesion to flexible plastic substrates such as poly (carbonate) and metal substrates. Therefore, the photocurable resin composition of the present invention is useful as a coating material for protecting flexible substrates such as plastic films and metal thin films, as well as other UV curable paints and varnishes for printing inks.

Next, the present invention will be specifically described with reference to Examples and Comparative Examples. In the following, “parts” and “%” are based on weight unless otherwise specified. In addition, the measurement conditions of GPC and the measurement conditions of GC-MS are as follows. [GPC] Column: “PPS SD 5 μm 100A” manufactured by PSS + “PPS SD 5 μm 500 A” manufactured by PSS Detector: UV detector “Knauer Multiple Wavelength, RI-Detector Shodex” manufactured by Knauer Pump unit: Agilent “Agilent 1200 Series” data processing: “PSS WIN GPC6” manufactured by PSS Measurement conditions: Column temperature 40 ° C. Developing solvent Tetrahydrofuran Flow rate 1.0 ml / min Standard: Polystyrene standard manufactured by PSS

[GC-MS] column: Agilent 30 m × 0.25 mm × 0.25 μm HP5-MS detector: mass detector “MSD 5975 B (80-800 amu)” oven unit: Agilent 6890 flow rate: 0.9 ml / min split: 50: 1 Carrier gas: Helium Cl Sample gas: Isobutane 2.8 (20%) Interface temperature: 300 ° C

Example 13 464.0 g (4.0 mol) of ethyl-3-hydroxymethyloxetane and 180.0 g (4.5 mol) of sodium hydroxide were mixed, purged with nitrogen gas and heated to 50 ° C. did. Then, 368.0 g (4.0 mol) of epichlorohydrin was added so that the temperature in the system did not exceed 70 ° C. Thereafter, the system was stirred for 1 hour while maintaining the temperature in the system at 70 ° C. (Reaction 1).

Next, 46.4 g (0.4 mol) of 3-ethyl-3-hydroxymethyloxetane was added, and after 30 minutes, 18.0 g (0.4 mol) of sodium hydroxide and 36.8 g (0 mol of epichlorohydrin) were added. 4 mol) was added and stirred for 1 hour (reaction 2). Further, 3-ethyl-3-hydroxymethyloxetane, sodium hydroxide, and epichlorohydrin were similarly added under the temperature condition of 80 ° C. (Reaction 3). After further stirring for 1 hour, 3-ethyl-3-hydroxymethyloxetane, sodium hydroxide, and epichlorohydrin were similarly added under the temperature condition of 90 ° C. (Reaction 4). After further stirring for 1 hour, 3-ethyl-3-hydroxymethyloxetane, sodium hydroxide, and epichlorohydrin were similarly added at a temperature of 100 ° C. (Reaction 5). Further, the reaction solution was stirred for 2 hours at a temperature of 90 to 100 ° C., cooled to room temperature, then 600 ml of toluene was added, and the precipitated salt was removed by suction filtration. The mother liquor was extracted twice with 500 ml of 20% aqueous sodium chloride solution. The product was then neutralized with acetic acid and extracted twice with 500 ml of 10% aqueous sodium chloride solution. The organic layer was separated and dried over anhydrous sodium sulfate. Subsequently, filtration and toluene were distilled off under reduced pressure at 60 ° C. to obtain a viscous and slightly colored target product (yield: 593 g). The GPC chart which shows the change of the molecular weight in the said reactions 1-5 is shown in FIG. Hereinafter, the obtained hydroxyl group-containing oxetane oligomer is abbreviated as “oxetane compound (A)”. The property values of the obtained oxetane compound (A) are as follows.

Gardner Color Number: 3 Viscosity (Cone Plate Viscometer: 25 degrees): 9.5 Pa Oxetane Content (Titration with Perchloric Acid): 5.7 mmol / g Average Number of Oxetane Functional Groups per Molecule: About 10 Hydroxyl Number: 1 .4 mmol / g weight average molecular weight (Mw): 1610

In addition, FIG. 2 shows a gas chromatographic chart showing the presence of low molecular weight components (intermediates A, B, and C in reaction formula 1) in the obtained oxetane compound (A), and FIG. 3 shows a mass spectrum chart of the intermediate B, and FIG. 5 shows a mass spectrum chart of the intermediate C. Note that the peak value 361 in FIG. 3 is a value of “[molecular weight of intermediate A (288) + molecular weight of TMS (72)] + 1”, and peak value 533 in FIG. 460) + TMS (72)] + 1 ”, and the peak value 705 is a value of“ [molecular weight of intermediate C (632) + TMS (72)] + 1 ”.

[Curability Test] 69.5% by mass of the oxetane compound (A), 5.5% by mass of a photopolymerization initiator (“Syracure UVI6992” manufactured by Dow Chemical Company), epoxy compound: 3,4-epoxycyclohexylmethyl- 3,4-cyclohexane carbonate (“UVR6105” manufactured by Dow Chemical Co., Ltd., hereinafter abbreviated as “epoxy compound (A)”) was blended at a ratio of 25% by mass to obtain a coating composition.

Next, the obtained coating composition was applied on a card board using a spiral applicator so as to have a film thickness of 10 μm. After forming the coating film, irradiation was performed using a Fusion H-bulb (120 W / cm). The irradiation amount was determined by measuring the irradiation amount on the coating film surface with an illuminometer “Powerpack” (UVA (320 to 390 nm), UVB (280 to 320 nm), UVC (250 to 260 nm)) manufactured by EIT. For the evaluation of curability, the tack-free time until the coating surface was dried after UV irradiation was measured. The results are shown in Table 1.

Comparative Example 1 69.5% by mass of oxetane polymer (weight average molecular weight: 5400, number of oxetanyl groups per molecule: about 32) obtained according to Example 1 of US Pat. No. 6,770,737 (Patent Document 1), photopolymerization started 5.5% by mass of an agent (“Syracure UVI6992” manufactured by Dow Chemical Company), 25% by mass of “epoxy compound”: 3,4-epoxycyclohexylmethyl-3,4-cyclohexane carbonate (“UVR6105” manufactured by Dow Chemical Company) A coating composition was obtained by blending at a ratio of

Next, a coating film was formed from the obtained coating composition in the same manner as in Example 1, and irradiated with UV light to evaluate curability. The results are shown in Table 1.

表１中の各成分及び評価の詳細は以下の通りである。「オキセタン化合物（Ａ）」：前記実施例１で得られた水酸基含有オキセタンオリゴマー「オキセタン化合物（Ｂ）」：米国特許公報第６７７０７３７号記載のオキセタンオリゴマー「エポキシ化合物（Ａ）」：３，４−エポキシシクロヘキシルメチル−３，４−シクロヘキサンカーボネート（ダウケミカル社製「ＵＶＲ６１０５」）「光重合開始剤」：アリルスルフォニウム−ヘキサフルオロフォスフェート（ダウケミカル社製「シラキュア ＵＶＩ６９９２」）

Details of each component and evaluation in Table 1 are as follows. “Oxetane compound (A)”: hydroxyl group-containing oxetane oligomer obtained in Example 1 “oxetane compound (B)”: oxetane oligomer “epoxy compound (A)” described in US Pat. No. 6,770,737: 3,4- Epoxycyclohexylmethyl-3,4-cyclohexane carbonate (“UVR6105” manufactured by Dow Chemical Co.) “photopolymerization initiator”: allylsulfonium hexafluorophosphate (“Syracure UVI6992” manufactured by Dow Chemical Co.)

As is clear from the above results, it can be seen that the hydroxyl group-containing oxetane oligomer of the present invention exhibits remarkably superior curability as compared with the oxetane oligomer described in US Pat. No. 6,770,737.

Usually, the oxetane compound having a higher molecular weight has more oxetanyl groups in the molecule, so that the curability is higher, and it is the common knowledge of those skilled in the art, but the above result is a phenomenon contrary to this. . That is, the hydroxyl group-containing oxetane oligomer (weight average molecular weight 1610, average functional group number 10) of the present invention has a molecular weight higher than that of the oxetane oligomer (weight average molecular weight 5400, average functional group number 32) described in US Pat. No. 6,770,737. Although it is small, it exhibits excellent curability, and such a result can be said to be a remarkable effect contrary to the technical common knowledge of those skilled in the art.

Example 2-7 3-Ethyl-3-oxetanyl-methanol (A), sodium hydroxide (B), epichlorohydrin (C), toluene (D), and methylene chloride (D) were used in the composition ratio shown in Table 2. Reaction was carried out in the same manner as in Example 1 to produce a hydroxyl group-containing oxetane oligomer. Table 2 shows the property values of each hydroxyl group-containing oxetane oligomer.

In addition, the reaction temperature of Example 4 is 60 ° C., the reaction temperature of Example 5 is 80 ° C., and in Example 6, a 50 mass% sodium hydroxide aqueous solution is used as sodium hydroxide (C). The reaction was carried out while continuously feeding the raw material into the reaction system, not a multi-stage reaction.

Example 8-13 Each hydroxyl group-containing oxetane oligomer (oxetane compounds (C) to (H)) was added to a photopolymerization initiator [allylsulfonium-hexafluorophosphate (“Syracure UVI6992” manufactured by Dow Chemical Co., Ltd.) and Table 2 It mix | blended in the ratio of description, and apply | coated on the black cardboard in the ratio of 15 g / cm < ² >.

Irradiation was performed using a fusion H-bulb (187 W / cm) at an irradiation dose of 250 mJ / cm ² . The curability was evaluated in the same manner as in Example 1. Moreover, the solvent resistance of the obtained coating film and gloss were evaluated. These results are shown in Table 3. The solvent resistance was evaluated by performing MEK rubbing twice. The gloss is an average value obtained by measuring 10 points of the coating film.

Example 14-19 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexenecarboxylate (“Celoxide 2021” manufactured by Daicel) was used as the epoxy compound (hereinafter referred to as “epoxy compound (B)”. The coating composition was adjusted according to the composition shown in Table 4 below, and coated on a glass substrate so that the coating amount was about 50 g / m ² , Fusion H-bulb (187 W / cm). And irradiated with UV light at a dose of 250 mJ / cm ² . The curability was evaluated in the same manner as in Example 1. Moreover, the coating-film intensity | strength at the time of 4 hour passage after UV light irradiation was measured. The results are shown in Table 4.

A: Intermediate AB in Reaction 1 AB: Intermediate BC in Reaction 1 Intermediate C in Reaction 1

Claims (11)

The following general formula 1

Where R is an alkyl group having 1 to 10 carbon atoms, R1 is a hydrogen atom or a methyl group, n is a number from 2 to 100, and m is a number from 0 to 10. A hydroxyl group-containing oxetane oligomer characterized by having. The hydroxyl group-containing oxetane oligomer according to claim 1, wherein the content of the oxetanyl group is in the range of 5 to 7 mmol / g. The hydroxy-containing oxetane oligomer according to claim 1, wherein the weight average molecular weight (Mw) is in the range of 500 to 60,000. The following general formula 2

An oxetane alcohol (a) and an epihalohydrin (b) represented by (R is an alkyl group having 1 to 10 carbon atoms, R ¹ is a hydrogen atom or a methyl group, and m is a number from 0 to 10). A method for producing a hydroxyl group-containing oxetane oligomer, wherein the reaction is carried out at a temperature of 35 to 150 ° C. in the presence of a basic catalyst (c). Oxetane alcohols (a), epihalohydrin (b), and basic catalyst (c) on a molar basis [the oxetane alcohols (a) / basic catalyst (c) / epihalohydrin (b)] The manufacturing method according to claim 4, which is in a range of 3 / 1.05 / 1] to [0.5 / 1.25 / 1]. The oxetane alcohols (a), the epihalohydrin (b), and the basic catalyst (c) are used on a molar basis [the oxetane alcohols (a) / basic catalyst (c) / epihalohydrin (b). )] In a ratio of [1: 1: 1] to [1: 1.25: 1] (step 1), then the oxetane alcohols (a) and the epihalohydrin (b And the basic catalyst (c) is added to the reaction system and the reaction is continued (Step 2). The manufacturing method of Claim 6 which adds the said process 2 to a reaction system in order of a basic catalyst (c), the said epihalohydrin (b), and the said oxetane alcohol (a). A photocurable resin composition comprising the hydroxyl group-containing oxetane oligomer according to any one of claims 1 to 3 and a photopolymerization initiator as essential components. The photocurable resin composition of Claim 8 which contains an epoxy compound in addition to the said hydroxyl-containing oxetane oligomer and a photoinitiator. The photocurable resin composition of Claim 8 or 9 which does not contain a non-reactive medium. Hardened | cured material formed by hardening | curing the photocurable resin composition as described in any one of Claims 8-10.

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