JP2007084788A - Ionization radiation-curable composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ionization radiation-curable composition which can provide a cured product capable of sufficiently satisfying all of light resistance, transparency and curability and therefore can be useful in much more applications in addition to optical members, lighting members, and automobile members. <P>SOLUTION: The ionization radiation-curable composition is used after cured by ionization radiation energy, wherein a cured product produced by curing the curable composition by ionization radiation energy of 2J/cm<SP>2</SP>satisfies: an initial light transmittance of 80% or more at a wavelength of 380 nm, and a light transmittance retention of 90% or more after 200 hours of accelerated light resistance test. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to an ionizing radiation curable composition. More specifically, the present invention relates to an ionizing radiation curable composition widely used for various uses such as an optical member, a lighting member, and an automobile member.

An ionizing radiation curable composition is a curable composition used by being cured by ionizing radiation energy such as electromagnetic waves, ultraviolet rays, visible rays, infrared rays, electron beams, gamma rays, etc., compared to transparent inorganic materials such as glass. Since the molding processability is good, it is widely used in various applications such as optical members, lighting members, and automobile members. In these applications, the cured product has a property that it is difficult to cause coloring, alteration, or deterioration with respect to light from a light source having a light emission wavelength distribution from the short wavelength region to the ultraviolet region of visible light, that is, light resistance. Although particularly required, it is also required to have a high degree of transparency and a sufficient curing strength in order to have a higher appearance and an excellent practicality. However, no cured product using a conventional curable composition can sufficiently satisfy these requirements.

As conventional ionizing radiation curable compositions, curable (meth) acrylic compositions are known, and specifically, bisphenol A dimethacrylate modified with ethylene oxide, hydroxypivalic acid and neopentyl glycol An optical component formed by a curable (meth) acrylic composition containing a diacrylate of an ester and phenoxy (ethoxy) ethyl acrylate is disclosed (for example, see Patent Document 1). However, a cured product (transparent resin) obtained by curing such a composition does not have sufficient light resistance, and is sufficient in terms of discoloration and alteration over time compared to transparent inorganic materials such as glass. Therefore, by sufficiently improving the light resistance, for example, optical components that can be directly exposed to sunlight when using solar cells, outdoor electric bulletin boards, etc. There is room for improvement to make it suitable for optical members such as light-emitting diodes, optical cables, and display devices using light sources having a light emission wavelength distribution in a region, and to be useful for many applications.

Moreover, the photocurable composition containing alkylene (oxy) di (meth) acrylate, a predetermined photoinitiator, and a predetermined ultraviolet absorber in a predetermined ratio is disclosed (for example, refer to Patent Document 2). However, a cured product (transparent resin) obtained by curing such a composition cannot sufficiently satisfy all of light resistance, transparency and curability, and this point has been improved. In addition to optical members, illumination members, automobile members, etc., there was room for improvement in order to be able to be suitably used for many applications.
JP-A-6-263831 (page 2) JP-A-4-180904 (first page)

The present invention has been made in view of the above-described present situation, and can provide a cured product that can sufficiently satisfy all of light resistance, transparency, and curability, such as an optical member, a lighting member, an automobile member, and the like. It is another object of the present invention to provide an ionizing radiation curable composition useful for more applications.

As a result of various studies on the ionizing radiation curable composition, the present inventors have determined the initial light transmittance and light transmittance retention in a cured product obtained by curing the curable composition with specific ionizing radiation energy. By setting the value, it has excellent transparency, and it is difficult to cause coloring, alteration, or deterioration even for light from a light source having a light emission wavelength distribution from the short wavelength region to the ultraviolet region of visible light, that is, "light resistance" The present inventors have found that it is possible to obtain a curable composition that provides a cured product having a high hardness and sufficient curing strength, and have conceived that the above problems can be solved brilliantly. Here, when a photopolymerization initiator is added to a normal curable composition, light resistance and transmittance in the short wavelength region of visible light may not be sufficient due to the addition of the photopolymerization initiator. By using the curable composition of the present invention, it becomes possible to sufficiently reduce the amount of photopolymerization initiator added, so that the light resistance and transmittance in the short wavelength region of visible light are further improved. It has been found that it is possible to make it suitable for the application. Moreover, about such an ionizing radiation curable composition, it shall contain a specific (meth) acrylic acid ester, or specify a sulfonic acid (salt) and / or sulfonic acid ester content rate, It has been found that the amount of photopolymerization initiator added can be greatly reduced, and it has been found that the effects of the present invention can be fully exhibited due to this. is there.

That is, the present invention is a curable composition used by being cured with ionizing radiation energy, and the above-mentioned ionizing radiation curable composition is obtained by curing with an ionizing radiation energy of ² J / cm ^2. The ionizing radiation curable composition satisfies the initial light transmittance of 80% or more and a light transmittance retention of 90% or more after 200 hours of accelerated light resistance test.
The present invention is described in detail below.

The ionizing radiation curable composition of the present invention (hereinafter also referred to as “curable composition”) is a curable composition that is used after being cured with ionizing radiation energy, but the ionizing radiation energy is not particularly limited. Examples thereof include electromagnetic waves, ultraviolet rays, visible rays, infrared rays, electron beams, gamma rays, and the like. Among these, ultraviolet rays are particularly preferable. In the case of curing by ultraviolet irradiation, it is preferable to use a light source including light within a wavelength range of 150 to 450 nm. As such a light source, a solar ray, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, a gallium lamp, a xenon lamp, a carbon arc lamp, and the like are preferable. Heat combined with high frequency heating or the like is also possible.

In the case of curing by electron beam irradiation, it is preferable to use an electron beam having an acceleration voltage of 10 to 500 kV. More preferably, it is 20-300 kV, More preferably, it is 30-200 kV. It is preferable that the irradiation amount of an electron beam is 2-500 kGy, More preferably, it is 3-300 kGy, More preferably, it is 5-200 kGy. In addition to the electron beam, it is possible to use heat by infrared rays, far infrared rays, hot air, high-frequency heating or the like.

In the present invention, it is appropriate that a cured product obtained by curing the curable composition with an ionizing radiation energy of ² J / cm ² satisfies an initial light transmittance of 80% or more at a wavelength of 380 nm. When the initial light transmittance is less than 80%, a high degree of transparency is required, such as optical members such as LED (light-emitting diode) sealants, optical cables, optical waveguides, and lens sheets. Therefore, there is a possibility that the effect of the present invention, which is useful for more applications, cannot be sufficiently exhibited. Preferably it is 82% or more, More preferably, it is 85% or more.
The initial light transmittance at the wavelength of 380 nm can be measured, for example, as follows.

<Initial light transmittance at a wavelength of 380 nm>
1. Preparation of cured product (test piece) A 400 μm-thick frame is provided on the glass surface, a curable composition is poured into the frame, and a 250 μm PET (polyethylene terephthalate) film is placed on the glass surface. Using an ultra-high pressure mercury lamp, UV light having a main wavelength of 365 nm and an irradiation intensity of 43 mJ / cm ² · second is irradiated for 46.5 seconds to be sufficiently cured, and then removed from the mold to obtain a test piece.
2. Measurement of initial light transmittance The light transmittance (%) at 380 nm of the above test piece is measured using a spectrophotometer UV-3100 (manufactured by Shimadzu Corporation).

In the present invention, it is also appropriate that a cured product obtained by curing the curable composition with ionizing radiation energy of ² J / cm ² satisfies a light transmittance retention of 90% or more after 200 hours of accelerated light resistance test. It is. When the light transmittance holding ratio is less than 90%, for example, an optical member such as an LED sealant, an optical cable, an optical waveguide, and a lens sheet is suitable in a field where high light resistance is required. Therefore, there is a possibility that the effect of the present invention, which is useful for more applications, cannot be sufficiently exhibited. Preferably, it is 95% or more, and more preferably, the light transmittance retention after 300 hours of the accelerated light resistance test is 90% or more.
The light transmittance retention after 200 hours (or 300 hours) of the accelerated light resistance test can be measured, for example, as follows.

<Light transmittance retention after 200 hours of accelerated light resistance test>
1. Preparation of cured product (test piece) A test piece is obtained in the same manner as the method for preparing a cured product (test piece) in the measurement of the initial light transmittance at the wavelength of 380 nm.
2. Measurement of light transmittance holding ratio For the above test piece, first, the light transmittance (%) at 380 nm was measured using a spectrophotometer UV-3100 (manufactured by Shimadzu Corporation). Light transmittance (%) ". Then, this test piece is irradiated at an irradiation intensity of 90 mW / cm ² , a wavelength of 295 to 450 nm, a humidity of 70% Rh, and a temperature of 50 ° C. using a super energy irradiation tester (manufactured by Suga Test Instruments Co., Ltd.). The test piece after irradiation for 200 hours (or 300 hours) was again measured for light transmittance (%) at 380 nm using a spectrophotometer UV-3100 (manufactured by Shimadzu Corporation). Transmittance (%) ”. Thereafter, the light transmittance retention rate (%) is obtained by the following formula.
Light transmittance retention (%) = (light transmittance after accelerated light resistance test / light transmittance before accelerated light resistance test) × 100

In the present invention, it is further preferable that a cured product obtained by curing the curable composition with ionizing radiation energy of ² J / cm ² exhibits a pencil hardness of B or higher. Thus, by setting it as the curable composition which gives the hardened | cured material which has high sclerosis | hardenability, it becomes possible to fully exhibit the effect of this invention. More preferably, it indicates a pencil hardness of HB or higher.
As said pencil hardness, it can measure as follows, for example.

<Pencil hardness>
1. Preparation of cured product (test piece) A test piece is obtained in the same manner as the method for preparing a cured product (test piece) in the measurement of the initial light transmittance at the wavelength of 380 nm.
2. Measurement of pencil hardness Pencil hardness is measured according to JIS K5600-5-4: 1999 about the said test piece.

As the ionizing radiation curable composition of the present invention, for example, a (meth) acrylic acid ester product (hereinafter referred to as “(meth) acrylic acid ester product (A)”) of a compound having two or more hydroxyl groups in one molecule. It is preferable that it contains. Such (meth) acrylic acid ester (A) is a compound having two or more hydroxyl groups in one molecule (hereinafter also referred to as “polyol compound”), (meth) acrylic acid (methacrylic acid and (Or acrylic acid).
The content of the (meth) acrylic acid ester (A) is, for example, preferably 10 to 95% by mass with respect to 100% by mass of the total amount of the ionizing radiation curable composition. By setting within this range, the cured product obtained by curing the curable composition can have a better balance of heat resistance, dimensional stability, and moldability. More preferably, it is 20-90 mass%, More preferably, it is 30-85 mass%.

The polyol compound preferably has no aromatic hydrocarbon structure, and thereby, the light resistance of the cured product obtained by curing the curable composition is more sufficiently improved. Is possible.
Examples of such a polyol compound, that is, a compound having no aromatic hydrocarbon structure and having two or more hydroxyl groups in one molecule include, for example, ethylene glycol, propylene glycol, 1,2-butanediol, 1, 3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10 -Decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,15-pentadecanediol, 1,16-hexadecanediol, 3-methyl -1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,2 Of alkanediols such as cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, tricyclodecane dimethanol, cyclohexanedimethanol, hydrogenated bisphenol A, neopentyl glycol, butylethylpropane diol, and neopentyl glycol Esterified products with hydroxypivalic acid, β, β, β ′, β′-tetramethyl-2,4,8,10-tetraoxaspiro [5,5] undecane-3,9-dienol, etc., trimethylol Examples include ethane, trimethylolpropane, trimethylolbutane, trimethylolhexane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, glycerin, polyglycerin, and the like. One or more of these can be used. That.

The compound having no aromatic hydrocarbon structure and having two or more hydroxyl groups in one molecule is also a compound not containing β-hydrogen with respect to the hydroxyl group (that is, the hydroxyl group possessed by itself). Is preferred. Thereby, in the hardened | cured material obtained by hardening the said curable composition, it becomes possible to fully improve the tolerance with respect to deterioration and discoloration by light.
Examples of such a polyol compound include neopentyl glycol, butyl ethyl propane diol, esterified product of neopentyl glycol with hydroxypivalic acid, β, β, β ′, β′-tetramethyl-2, 4, 8, Examples include 10-tetraoxaspiro [5,5] undecane-3,9-dienol, trimethylolethane, trimethylolpropane, trimethylolbutane, trimethylolhexane, ditrimethylolpropane, pentaerythritol, dipentaerythritol and the like. Of these, neopentyl glycol and trimethylolpropane are preferred.
In addition, the alcohol having no β-hydrogen relative to the hydroxyl group (that is, the hydroxyl group possessed by itself) is, in other words, an alcohol compound (alcohol), which is a β-position carbon atom with respect to the hydroxyl group possessed by itself. Is a compound in which all atoms to which etc. are bonded are carbon atoms other than hydrogen atoms. In these alcohol compounds, all atoms to which the carbon atoms at the β-position are bonded are carbon atoms, do not have an aromatic hydrocarbon structure, and have two or more hydroxyl groups in one molecule. It will have a common chemical structure and will exhibit the same performance and effects in the present invention. This is because a skeleton having β-hydrogen is easily deteriorated by light, and the target product may be discolored by the elimination of β-hydrogen. Therefore, the cured product obtained by curing the curable composition can be excellent.

As said (meth) acrylic acid ester product (A), a commercial item may be used and it may adjust and use itself. As a method of adjusting itself, for example, a method of producing the above-described polyol compound and (meth) acrylic ester by dealcoholization reaction in the presence of a catalyst (transesterification method), the above-mentioned polyol compound and (meth) It is preferable to use a method (dehydration condensation method) for producing acrylic acid by dehydration reaction in the presence of a catalyst.

Although it does not specifically limit as (meth) acrylic acid ester which can be used for the said transesterification method, For example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate Etc. are suitable.

In the transesterification method, the charged molar ratio of the polyol compound to the (meth) acrylic acid ester (hydroxyl group in the polyol compound: (meth) acrylic acid ester) is, for example, 1: 1 to 1:20. Is preferred. More preferably, it is 1: 1.5-1: 10, More preferably, it is 1: 2-1: 5.

Although it does not specifically limit as a catalyst which can be used for the said transesterification method, For example, alkali metal alcoholate, magnesium alcoholate, aluminum alcoholate, titanium alcoholate, dibutyltin oxide, anion exchange resin etc. are mentioned. It is preferable that the usage-amount of a catalyst is 0.01-10 mass% with respect to 100 mass% of total preparation amounts of reaction, for example. More preferably, it is 0.05-5 mass%, More preferably, it is 0.1-3 mass%. After the reaction, it is preferable to remove the catalyst by a usual method.

Although it does not specifically limit as a solvent which can be used for the said transesterification method, For example, pentane, cyclopentane, hexane, cyclohexane, methylcyclohexane, heptane, cycloheptane, octane, isooctane, benzene, toluene, cymene etc. are mentioned. It is preferable that the usage-amount of a solvent is 1-70 mass% with respect to 100 mass% of total preparation amounts of reaction, for example. More preferably, it is 5-50 mass%, More preferably, it is 10-30 mass%.

As reaction temperature in the said transesterification method, it is preferable to set it as 50-150 degreeC, for example. More preferably, it is 70-140 degreeC, More preferably, it is 90-130 degreeC.

In the dehydration condensation method, the molar ratio of the polyol compound and (meth) acrylic acid (hydroxyl group in the polyol compound: (meth) acrylic acid) is preferably, for example, 1: 1 to 1: 5. . More preferably, it is 1: 1.01-1: 2, More preferably, it is 1: 1.05-1: 1.5.

Although it does not specifically limit as a catalyst which can be used for the said dehydration condensation method, For example, sulfuric acid, hydrochloric acid, phosphoric acid, p-toluenesulfonic acid, benzenesulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, cation exchange resin etc. An acid catalyst is mentioned. It is preferable that the usage-amount of a catalyst is 0.01-10 mass% with respect to 100 mass% of total preparation amounts of reaction, for example. More preferably, it is 0.05-5 mass%, More preferably, it is 0.1-3 mass%. After the reaction, it is preferable to remove the catalyst by a usual method.
Among the above catalysts, a cation exchange resin is preferable from the viewpoint of further reducing the content of the sulfonic acid derivative (sulfur component) in the resulting curable composition. Examples of the cation exchange resin include Amberlist (registered trademark) and Amberlite (registered trademark) manufactured by Rohm and Haas, Diaion (registered trademark) manufactured by Mitsubishi Chemical Corporation, and the like. When a cation exchange resin is used as a catalyst, it is preferable to thoroughly wash with an organic solvent such as toluene or methanol or water before use to prevent elution of the sulfonic acid derivative (sulfur component).

The type and amount of the solvent that can be used in the dehydration condensation method are not particularly limited, and for example, the above-described embodiment in the transesterification method may be mentioned as a preferable embodiment. The reaction temperature in the dehydration condensation method is not particularly limited. For example, the reaction temperature is preferably set as described above in the transesterification method.

In the transesterification method and dehydration condensation method, it is preferable to add a polymerization inhibitor to the reaction system for the purpose of preventing the polymerization of (meth) acrylic acid ester during the transesterification reaction or dehydration condensation reaction. . Examples of the polymerization inhibitor include 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (4H-TEMPO) and its derivatives (TEMPO derivatives); phenols such as hydroquinone and hydroquinone monomethyl ether; Examples include quinones such as benzoquinone and diphenylbenzoquinone; phenothiazines; copper salts and the like, and one or more of these can be used. It is preferable that the usage-amount of a polymerization inhibitor is 0.0001-2 mass% with respect to 100 mass% of total preparation amounts of reaction, for example. More preferably, it is 0.005-0.5 mass%.

As the (meth) acrylic ester (A), the following general formula (1);

(Wherein R ¹ , R ² and R ³ are the same or different and represent at least one group selected from the group consisting of a hydrogen atom, a methyl group and an ethyl group, provided that R ¹ , R ² and The total number of carbon atoms of R ³ is 0 to 2. n preferably represents an ether structure represented by 1 to 100. By allowing such an ether structure to be present in the (meth) acrylic acid ester (A), curing can proceed efficiently even with a very small amount of photopolymerization initiator, so that light resistance, transparency and curing can be achieved. It becomes possible to obtain a cured product that can more fully satisfy all of the properties. That is, as described above, due to the addition of the photopolymerization initiator, the light resistance and the transmittance in the short wavelength region of visible light may not be sufficient, but the ether structure represented by the above general formula (1) Since the amount of photopolymerization initiator added can be significantly reduced, the yellowing component and the component that absorbs light with a short wavelength can be sufficiently reduced, and the effects of the present invention can be reduced. It can be more fully demonstrated.

The ether structure is a structure having an alkylene oxide unit as a repeating unit, but the alkylene oxide unit may have a side chain that satisfies the above-described conditions depending on circumstances. To produce such an ether structure, it consists of ethylene oxide, propylene oxide and butylene oxide (1,2-butylene oxide, 2,3-butylene oxide, isobutylene oxide) as precursors for adding alkylene oxide units. It is preferred to use at least one alkylene oxide selected from the group.

In the ether structure, the number of repeating alkylene oxide units (n in the general formula (1)) is 1 to 100. If n is too small, sufficient light resistance may not be obtained. Conversely, if n is too large, water resistance and hardness may not be sufficient. Preferably, it is 1-15, More preferably, it is 1-10, More preferably, it is 1-8. In some cases, a (meth) acrylic acid ester (A) to which a number of alkylene oxide units outside the above preferred range is added may be used.

As the (meth) acrylic acid ester product (A) having the ether structure, a commercially available product may be used, or it may be adjusted and used by itself. As a method for adjusting itself, for example, after adding an alkylene oxide unit to a hydroxyl group of a polyol compound by a usual method, the compound and (meth) acrylic acid (or (meth) acrylic acid ester) are exchanged as described above. It is preferable to obtain the (meth) acrylic acid ester product (A) having the above ether structure by esterification by a method or a dehydration condensation method. In addition, when the polyol compound to which the alkylene oxide unit is added is commercially available, only the esterification reaction may be performed by itself using the product.
As a particularly preferred form of the (meth) acrylic acid ester (A) having an ether structure, an alkylene oxide is added to a compound having no aromatic hydrocarbon structure and having two or more hydroxyl groups in one molecule. (Meth) acrylic acid ester product of a compound obtained by adding A, wherein the alkylene oxide is at least one selected from the group consisting of ethylene oxide, propylene oxide and butylene oxide.

The content of the ether structure is preferably 5% by mass or more with respect to 100% by mass of the total amount of the ionizing radiation curable composition. If the amount is less than 5% by mass, the above-described effect exhibited by the presence of the ether structure may not be sufficiently obtained. The performance of the cured product obtained by curing the curable composition is less likely to cause discoloration, alteration, or deterioration of the cured product with respect to light from a light source having an emission wavelength distribution from the short wavelength region to the ultraviolet region ( That is, from the viewpoint of further improving the light resistance), the content of the ether structure is preferably as large as possible, and specifically, it is preferably more than 5% by mass. More preferably, it is 10 mass% or more, More preferably, it is 20 mass% or more. Moreover, the upper limit of the content of the ether structure is not particularly limited, but from the viewpoint of improving the water resistance of the cured product, it is 65% by mass or less with respect to 100% by mass of the total amount of the ionizing radiation curable composition. Is preferred. More preferably, it is 60 mass% or less, More preferably, it is 55 mass% or less.
The content of the ether structure can be determined as follows, for example.

<Content of ether structure>
The curable composition (15 mg) and 48% by weight hydrobromic acid (200 mg) were placed in a 5 mL aluminum sealed vial, sealed through a Teflon silicone septum, and oven oven at 150 ° C. for 2 hours. After heating and allowing the bromic acid decomposition reaction to proceed, the ether structure in the curable composition is brominated. After completion of the reaction, the content of bromide (for example, 1,2-dibromopropane, 1,2-dibromobutane, 1,4-dibromobutane, etc.) in the reaction solution is measured by gas chromatography and compared with a calibration curve. Quantify by The content of the ether structure in the curable composition is calculated from the determined bromide content.

In order to make the content of the ether structure within the above-described range, for example, a precursor of an ether structure (for example, an alkylene oxide) when the (meth) acrylic acid ester (A) having the ether structure is produced. A method of adjusting the amount of use can be preferably employed.

As the ionizing radiation curable composition, the content of a sulfonic acid, a sulfonic acid salt and / or a sulfonic acid ester (hereinafter also simply referred to as “sulfonic acid derivative”) that can be contained in the curable composition is as follows. The total content of the curable composition is preferably 100 ppm or less in terms of sulfur content. That is, the sulfonic acid (salt) and / or sulfonic acid ester content in the curable composition is preferably 100 ppm or less in terms of sulfur content. This makes it possible to sufficiently prevent the cured product from being colored, altered, or deteriorated due to the sulfonic acid derivative. More preferably, it is 50 ppm or less, More preferably, it is 30 ppm or less, More preferably, it is 20 ppm or less, Especially preferably, it is 10 ppm or less.
The “sulfonic acid (salt)” means sulfonic acid and / or sulfonate.
The sulfonic acid derivative content can be determined, for example, as follows.

<Sulphonic acid derivative content>
The curable composition is dissolved in toluene, and after adding water, sulfonic acid and sulfonate are extracted into the aqueous layer with a separatory funnel. The aqueous layer is separated, concentrated using an evaporator, and water is removed using a hot air dryer. Thereafter, the sample is dissolved in acetone, the content of sulfonic acid is measured by gas chromatography, and quantified by comparison with a calibration curve.

In order to make the content of the sulfonic acid derivative in the curable composition within the above-mentioned range, for example, (1) Do not use a sulfonic acid derivative in the production process of the curable composition, or (2) cure When a sulfonic acid derivative is used in the production process of the composition, it is preferable to use a technique of further performing a removal step of removing the sulfonic acid derivative.
In the case of the above method (1), for example, a dehydration condensation method using a compound (for example, cation exchange resin) other than a sulfonic acid derivative (particularly, p-toluenesulfonic acid) that is usually used as a catalyst. Alternatively, the (meth) acrylic acid ester product (A) may be produced by a transesterification method using a metal alcoholate or the like as a catalyst. According to such a method, the content rate of the sulfonic acid derivative is theoretically zero and it is not necessary to add a removal step, which is preferable from the viewpoint of manufacturing cost.
In the case of the above method (2), as a means for removing the sulfonic acid derivative, for example, a washing method using water or an alkaline aqueous solution, an adsorption using a basic inorganic salt (for example, MgO) or an anion exchange resin is used. Filtration methods can be employed.

As a particularly preferred form of the ionizing radiation curable composition, the sulfonic acid (salt) and / or sulfonic acid ester content in the curable composition is 100 ppm or less in terms of sulfur content, and the curable composition The composition comprises a (meth) acrylate ester of a compound having no aromatic hydrocarbon structure and having two or more hydroxyl groups in one molecule, and the (meth) acrylate ester is It has an ether structure represented by the general formula (1), and the ether structure is in a form of 5% by mass or more with respect to 100% by mass of the curable composition. In such a form, in a cured product obtained by curing the curable composition, coloring, alteration, and deterioration due to light from a light source having a light emission wavelength distribution from the short wavelength region to the ultraviolet region of visible light. It is drastically suppressed and the effects of the present invention can be more fully exhibited.

As the ionizing radiation curable composition of the present invention, it is preferable to contain a polymer and / or copolymer of (meth) acrylic acid ester, thereby curing the resin while maintaining sufficient light resistance. It is possible to sufficiently improve molding defects and dimensional stability due to shrinkage at the time.
As such a polymer and / or copolymer, a monomer component containing 50 mol% or more of (meth) acrylic acid ester and / or (meth) acrylic acid with respect to 100 mol% of all monomer components. It is preferable that it is obtained by polymerizing and the specific form is not particularly limited. In addition, such a polymer and / or copolymer can be contained in one kind or two or more kinds.

As a monomer component which comprises the polymer and / or copolymer of the said (meth) acrylic acid ester, 1 type (s) or 2 or more types, such as the following compound, can be used, for example.
Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) Monofunctional such as acrylate, cyclohexylmethyl (meth) acrylate, (meth) acrylic acid, adamantyl (meth) acrylate, norbornyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, α-hydroxymethyl butyl acrylate (Meth) acrylate;
Monofunctional (meth) acrylamides such as N, N-dimethyl (meth) acrylamide and N-methylol (meth) acrylamide;
Monofunctional vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, 2-ethylhexyl vinyl ether, n-nonyl vinyl ether, lauryl vinyl ether, cyclohexyl vinyl ether, chloroethyl vinyl ether;

Monofunctional N-vinyl compounds such as N-vinylpyrrolidone, N-vinylcaprolactam, N-vinyl-N-methylformamide, N-vinylimidazole, N-vinylformamide, N-vinylacetamide;
Monofunctional vinyl compounds such as styrene, α-methylstyrene, vinyl toluene, allyl acetate, vinyl acetate, vinyl propionate, vinyl benzoate;
Maleic anhydride, maleic acid, dimethyl maleate, diethyl maleate, monomethyl maleate, monoethyl maleate, fumaric acid, dimethyl fumarate, diethyl fumarate, monomethyl fumarate, monoethyl fumarate, itaconic anhydride, itaconic acid, itacone Dimethyl acid, Diethyl itaconate, Monomethyl itaconate, Monoethyl itaconate, Methylenemalonic acid, Dimethyl methylenemalonate, Monomethyl methylenemalonate, Cinnamic acid, Methyl cinnamate, Ethyl cinnamate, Crotonic acid, Methyl crotonate, Ethyl crotonate Monofunctional α, β-unsaturated compounds such as
Polyfunctional vinyl ethers such as hexanediol divinyl ether, trimethylolpropane trivinyl ether, ditrimethylolpropane tetravinyl ether, glycerin trivinyl ether, pentaerythritol tetravinyl ether, dipentaerythritol pentavinyl ether, dipentaerythritol hexavinyl ether;
Polyfunctional vinyl compounds such as divinylbenzene.

The polymer and / or copolymer of the (meth) acrylic acid ester preferably has a functional group capable of being polymerized with the (meth) acrylic acid ester (A). Thereby, it becomes possible to improve more sufficiently the optical characteristics of the cured product obtained by curing the curable composition, for example, the toughness and water resistance of the cured product.
Although it does not specifically limit as a manufacturing method of the polymer and / or copolymer of (meth) acrylic acid ester which have such a functional group, For example, the manufacturing method of following (1)-(5) etc. are mentioned. In addition, methods other than these can also be used.

(1) A method of reacting a copolymer of a polymerizable monomer containing a carboxyl group with a (meth) acrylic ester and a polymerizable monomer containing a glycidyl group, or containing a glycidyl group A method of reacting a copolymer of a polymerizable monomer and a (meth) acrylic acid ester with a polymerizable monomer containing a carboxyl group.
(2) A method of reacting a copolymer of a polymerizable monomer containing a hydroxyl group with a (meth) acrylic acid ester and a polymerizable monomer containing an isocyanate group, or polymerization containing an isocyanate group A method of reacting a copolymer of a polymerizable monomer and a (meth) acrylic acid ester with a polymerizable monomer containing a hydroxyl group.
(3) reacting a copolymer of a polymerizable monomer containing a hydroxyl group and / or a carboxyl group with a (meth) acrylic acid ester and a polymerizable monomer containing a vinyl ether group and another polymerizable group Or a copolymer of a polymerizable monomer containing a vinyl ether group and another polymerizable group and a (meth) acrylic acid ester, and a polymerizable monomer containing a hydroxyl group and / or a carboxyl group How to react.
(4) A method of reacting a copolymer of a polymerizable monomer containing a hydroxyl group with a (meth) acrylic ester and a polymerizable monomer containing an acid anhydride group, or an acid anhydride group A method of reacting a copolymer of a polymerizable monomer containing a methacrylic acid ester and a polymerizable monomer containing a hydroxyl group.
(5) A method in which a monomer component containing a polyfunctional monomer is partially polymerized to leave part of the double bond in the side chain of the polymer.

As a content rate of the polymer and / or copolymer of the said (meth) acrylic acid ester, it is preferable that it is 5-50 mass% with respect to 100 mass% of whole quantity of the said ionizing radiation-curable composition, for example. Thereby, especially the shrinkage | contraction at the time of hardening is suppressed more fully, and a further favorable moldability will be obtained. More preferably, it is 10-40 mass%, More preferably, it is 10-30 mass%.

The ionizing radiation curable composition may also contain a polymerizable monomer other than the (meth) acrylic acid ester. In this case, the viscosity of the curable composition is reduced or the curing rate is increased. The effect of improvement can be obtained.
Such a polymerizable monomer is not particularly limited. For example, one or more of the above-described compounds as a monomer component for obtaining the polymer and / or copolymer of the (meth) acrylic acid ester or Two or more types can be used.

It does not specifically limit as content of the said polymerizable monomer, For example, it is suitable that it is 0.1-50 mass% with respect to 100 mass% of whole quantity of the said ionizing radiation-curable composition. By setting within this range, it is possible to sufficiently obtain the effects such as reduction of the viscosity of the curable composition and improvement of the curing rate.

The ionizing radiation curable composition may also contain a polymerizable oligomer. In this case, an effect of improving the toughness of a cured product obtained by curing the curable composition can be obtained. .
As such a polymerizable oligomer, 1 type (s) or 2 or more types, such as the following compound, can be used, for example.
A saturated or unsaturated polybasic acid or anhydride thereof (eg, maleic acid, succinic acid, adipic acid, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, etc.) and a saturated or unsaturated polyhydric alcohol ( For example, ethylene glycol, propylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, polyethylene glycol, polypropylene glycol, 1,4-dimethylolbenzene Polyester (meth) acrylate obtained by reaction of (meth) acrylic acid with trimethylolpropane, pentaerythritol, etc .;
Polyfunctional epoxy compounds (for example, bisphenol A diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, 3,4-epoxycyclohexenyl-3 ', 4'-epoxycyclohexene carboxylate, hexahydrophthalic acid diglycidyl ether, triglycidyl Epoxy (meth) acrylate obtained by reaction of isocyanurate and the like with (meth) acrylic acid;

Polyfunctional oxetane compounds (eg, 4,4′-bis [(3-ethynyl-3-oxetanyl) methoxymethyl] biphenyl, bis [(3-ethynyl-3-oxetanyl) methyl] ester of 1,4-benzenedicarboxylic acid 9,9-bis [2-methyl-4- {2- (3-oxetanyl)} butoxyphenyl] fluorene, 9,9-bis [4 [2- {2- (3-oxetanyl)} butoxy] ethoxyphenyl ] Oxetane (meth) acrylate obtained by reaction of fluorene and the like with (meth) acrylic acid;
Saturated or unsaturated polyhydric alcohol (for example, ethylene glycol, neopentyl glycol, polytetramethylene glycol, polyester polyol, polycaprolactone polyol, etc.) and organic polyisocyanate (for example, tolylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, etc.) ) And a hydroxyl group-containing (meth) acrylate (for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 1,4-butanediol mono (meth) acrylate, etc.)) (Meth) acrylate;
Polysiloxane poly (meth) acrylate obtained by reaction of polysiloxane with (meth) acrylic acid;
Polyamide poly (meth) acrylate obtained by reaction of polyamide and (meth) acrylic acid.

It does not specifically limit as content of the said polymeric oligomer, For example, it is suitable that it is 0.1-50 mass% with respect to 100 mass% of whole quantity of the said ionizing radiation-curable composition. By setting within this range, it is possible to sufficiently obtain the effect of improving the toughness of the cured product obtained by curing the curable composition.

The ionizing radiation curable composition may further contain a polymer other than the above-described (meth) acrylic acid ester polymer and / or copolymer.
Examples of such polymers include one or two of polycarbonate, polystyrene, silicon resin, polyimide, polyamide, saturated polyester, polyvinyl acetate, polyvinyl chloride, polyvinyl alcohol, polyvinyl acetal, AS resin, EVA resin, and the like. The above can be used. By blending such a polymer in the curable composition, it is possible to obtain an effect such as improvement of optical properties and mechanical properties of a cured product obtained by curing the curable composition.

It does not specifically limit as content of said other polymer, For example, it is suitable that it is 0.1-50 mass% with respect to 100 mass% of whole quantity of the said ionizing radiation-curable composition. By setting within this range, it is possible to sufficiently obtain the effects such as improvement of optical characteristics and mechanical characteristics obtained by curing the curable composition.

The ionizing radiation curable composition of the present invention preferably contains a polymerization initiator. When the polymerization initiator is blended in the curable composition, polymerization (curing) is performed according to a predetermined polymerization initiation factor. Will be started.
What is necessary is just to use what is normally used as said polymerization initiator, For example, a photoinitiator, a thermal-polymerization initiator, etc. are mentioned. Among them, it is preferable to use at least a photopolymerization initiator, and thereby the production efficiency of an optical component or the like using the curable composition of the present invention can be improved. In addition, when a photopolymerization initiator is added to a normal curable composition, light resistance and transmittance in the short wavelength region of visible light may not be sufficient due to the addition of the photopolymerization initiator, By using the curable composition of the present invention, it is possible to sufficiently reduce the amount of photopolymerization initiator added, so that the light resistance and the short wavelength region of visible light are further improved, and an optical member and an illumination member In addition to automobile members, etc., it can be made more suitable for various uses. Moreover, you may use together a photoinitiator and a thermal-polymerization initiator, and since the addition amount of a photoinitiator can be reduced further in this case, it is suitable.

It does not specifically limit as said photoinitiator, For example, 1 type (s) or 2 or more types, such as the following compound, can be used.
Diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl Phenylketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone, 2-hydroxy-2-methyl- Acetophenones such as 1- [4- (1-methylvinyl) phenyl] propanone oligomer; benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether;

Benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4′-methyl-diphenyl sulfide, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, 2,4 , 6-trimethylbenzophenone, 4-benzoyl-N, N-dimethyl-N- [2- (1-oxo-2-propenyloxy) ethyl] benzenemethananium bromide, (4-benzoylbenzyl) trimethylammonium chloride, etc. Benzophenones;
2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2- (3-dimethylamino-2-hydroxy) -3,4- Thioxanthones such as dimethyl-9H-thioxanthone-9-one mesochloride;
2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenyl Acyl phosphine oxides such as phosphine oxide.

The thermal polymerization initiator is not particularly limited, and for example, one or more of the following organic peroxide initiators and azo initiators can be used.
Methyl ethyl ketone peroxide, cyclohexanone peroxide, methylcyclohexanone peroxide, methyl acetoacetate peroxide, acetyl acetate peroxide, 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1- Bis (t-hexylperoxy) -cyclohexane, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) -2-methylcyclohexane 1,1-bis (t-butylperoxy) -cyclohexane, 1,1-bis (t-butylperoxy) cyclododecane, 1,1-bis (t-butylperoxy) butane, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) pro , P-menthane hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-hexyl hydroperoxide, t-butyl hydroperoxide, α , Α′-bis (t-butylperoxy) diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, t-butylcumyl peroxide, di-t -Butyl peroxide,

2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3, isobutyryl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide Oxide, succinic acid peroxide, m-toluoylbenzoyl peroxide, benzoyl peroxide, di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, di 2-ethoxyethyl peroxydicarbonate, di-2-ethoxyhexyl peroxydicarbonate, di-3-methoxybutyl peroxydicarbonate, di-s-butyl peroxydicarbonate, di (3-methyl- -Methoxybutyl) peroxydicarbonate, α, α'-bis (neodecanoylperoxy) diisopropylbenzene, cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxypi Valet, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate,

2,5-dimethyl-2,5-bis (2-ethylhexanoylperoxy) hexanoate, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexa Noate, t-butylperoxy-2-ethylhexanoate, t-hexylperoxyisopropyl monocarbonate, t-butylperoxyisobutyrate, t-butylperoxymalate, t-butylperoxy-3, 5,5-trimethyl hexanoate, t-butyl peroxylaurate, t-butyl peroxyisopropyl monocarbonate, t-butyl peroxy-2-ethylhexyl monocarbonate, t-butyl peroxyacetate, t-butyl peroxy Oxy-m-toluylbenzoate, t-butyl par Xylbenzoate, bis (t-butylperoxy) isophthalate, 2,5-dimethyl-2,5-bis (m-toluylperoxy) hexane, t-hexylperoxybenzoate, 2,5-dimethyl-2,5 -Bis (benzoylperoxy) hexane, t-butylperoxyallyl monocarbonate, t-butyltrimethylsilyl peroxide, 3,3 ', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, 2,3- Organic peroxide initiators such as dimethyl-2,3-diphenylbutane;

2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile, 1-[(1-cyano-1-methylethyl) azo] formamide, 1,1′-azobis (cyclohexane-1-carbonitrile), 2, 2'-azobis (2-methylbutyronitrile), 2,2'-azobisisobutyronitrile, 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2- Methylpropionamidine) dihydrochloride, 2,2′-azobis (2-methyl-N-phenylpropionamidine) dihydrochloride, 2,2′-azobis [N- (4-chlorophenyl) -2-methylpropionamidine] dihydride Chloride, 2,2′-azobis [N- (4-hydrophenyl) -2-methylpropionamidine] dihydrochloride, 2 2'-azobis [2-methyl-N- (phenylmethyl) propionamidine] dihydrochloride, 2,2'-azobis [2-methyl-N- (2-propenyl) propionamidine] dihydrochloride, 2,2'- Azobis [N- (2-hydroxyethyl) -2-methylpropionamidine] dihydrochloride, 2,2′-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2 '-Azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride,

2,2′-azobis [2- (4,5,6,7-tetrahydro-1H-1,3-diazepin-2-yl) propane] dihydrochloride, 2,2′-azobis [2- (3,4) , 5,6-tetrahydropyrimidin-2-yl) propane] dihydrochloride, 2,2′-azobis [2- (5-hydroxy-3,4,5,6-tetrahydropyrimidin-2-yl) propane] dihydrochloride 2,2′-azobis [2- [1- (2-hydroxyethyl) -2-imidazolin-2-yl] propane] dihydrochloride, 2,2′-azobis [2- (2-imidazolin-2-yl) ) Propane], 2,2'-azobis [2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide], 2,2'-azobis [2-methyl-N- [1 , 1-bis (hydroxymethyl) ethyl] propionamide], 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) propionamide], 2,2′-azobis (2-methylpropionamide) 2,2′-azobis (2,4,4-trimethylpentane), 2,2′-azobis (2-methylpropane), dimethyl-2,2-azobis (2-methylpropionate), 4,4 Azo initiators such as' -azobis (4-cyanopentanoic acid), 2,2'-azobis [2- (hydroxymethyl) propionitrile], and the like.
Among these polymerization initiators, those not containing an aromatic hydrocarbon structure can be suitably used.

The thermal polymerization initiator may contain a thermal polymerization accelerator, for example, a metal soap such as cobalt, copper, tin, zinc, manganese, iron, zirconium, chromium, vanadium, calcium, potassium; One kind or two or more kinds of secondary, tertiary amine compounds; quaternary ammonium salts; thiourea compounds; ketone compounds can be used. Of these, acetylacetone and methyl acetoacetate are preferable.

The blending amount of the polymerization initiator (total amount of photopolymerization initiator and thermal polymerization initiator) is, for example, 0.001 to 10% by mass with respect to 100% by mass of the total amount of the ionizing radiation curable composition. Preferably there is. If it is less than 0.001% by mass, the polymerizability may not be sufficient. If it exceeds 10% by mass, a cured product that can exhibit sufficient light resistance may not be obtained. More preferably, it is 0.001-5 mass%, More preferably, it is 0.001-3 mass%, Most preferably, it is 0.005-1 mass%, Most preferably, it is 0.01- 0.5% by mass.

Moreover, when using together a photoinitiator and a thermal polymerization initiator as said polymerization initiator, as mass ratio (thermal polymerization initiator / photoinitiator) of these compounding quantities, it is 1-100 / 1, for example. Preferably there is. If the ratio of the thermal polymerization initiator is less than 1, the weather resistance may not be sufficiently improved, and if it exceeds 100, the curability may not be sufficient. More preferably, it is 2-100 / 1, More preferably, it is 2-50 / 1, More preferably, it is 2-30 / 1, Especially preferably, it is 3-20 / 1, The most Preferably, it is 5-20 / 1.

Examples of the ionizing radiation curable composition include plasticizers, ultraviolet absorbers, antioxidants, inorganic fillers, antifoaming agents, thickeners, thixotropic agents, leveling agents, hindered amine light stabilizers, release agents. Various additives such as a mold may be contained, and these additives can be used according to ordinary usage forms. The selection of the release agent is important when molding a precise optical material or the like.
As said inorganic filler, the microparticles | fine-particles which consist of a metal oxide from a viewpoint that an optical characteristic is not impaired are preferable. Examples of the metal oxide used in the fine particles include silicon, titanium, zirconium, hafnium, zinc, iron, antimony, tin, indium, cerium, aluminum, tungsten, niobium, chromium, ruthenium, lanthanum, ytterbium, scandium, yttrium. And oxides such as these and complex oxides thereof. The particle size is defined in a range that does not impair the optical properties, but is preferably in the range of 1 nm to 10 μm.

Although it does not specifically limit as said antioxidant, For example, the 1 type (s) or 2 or more types of a phosphorus antioxidant or a phenolic antioxidant can be used.
The phenol-based antioxidant is not particularly limited, and for example, Sumilizer GM, Sumilizer GS, Sumilizer BHT, Sumilizer S, Sumilizer GA-80, Sumilizer WX-R (all trade names, manufactured by Sumitomo Chemical Co., Ltd.); AO-20, ADK STAB AO-30, ADK STAB AO-40, ADK STAB AO-50, ADK STAB AO-60, ADK STAB AO-70, ADK STAB AO-330 (all trade names, manufactured by Asahi Denka Kogyo Co., Ltd.); ANTAGE DBH, ANTAGE DAH, ANTAGE W-400, ANTAGE W-500 (all trade names, manufactured by Kawaguchi Chemical Industry Co., Ltd.), IRGANOX 1010, IRGANOX 1035, IRGANOX 1076, IRGANOX 1135 (manufactured by Ciba Specialty Chemicals) And the like. These may be used alone or in combination of two or more. Among these, it is preferable to use ADK STAB AO-60 and IRGANOX1010 because they have a high effect of preventing coloration over a long period of time. As a compounding quantity of the said phenolic antioxidant, it is preferable to contain 0.01-10 mass% of phenolic antioxidants with respect to 100 mass% of said ionizing radiation curable compositions whole quantity, for example. More preferably, it is 0.1-5 mass%.

The phosphorus antioxidant is not particularly limited, and for example, ADK STAB PEP-4C, ADK STAB PEP-8, ADK STAB PEP-11C, ADK STAB PEP-24G, ADK STAB PEP-36, ADK STAB HP-10, ADK STAB 2112 and ADK STAB 260. , Adeka tub 522A, ADEKA STAB 329K, ADEKA STAB 1178, ADEKA STAB 1500, ADEKA STAB C, ADEKA STAB 135A, ADEKA STAB 3010, ADEKA STAB TPP (all trade names, manufactured by Asahi Denka Kogyo Co., Ltd.) and the like. These may be used alone or in combination of two or more. Among these, it is preferable to use ADK STAB 2112 because it has a high effect of preventing coloration over a long period of time. As a compounding quantity of the said phosphorus antioxidant, it is preferable to contain 0.01-10 mass% of phosphorus antioxidant with respect to 100 mass% of said ionizing radiation curable compositions whole quantity, for example. More preferably, it is 0.1-5 mass%.

The hindered amine light stabilizer is not particularly limited. For example, ADK STAB LA-52, ADK STAB LA-57, ADK STAB LA-62, ADK STAB LA-67, ADK STAB LA-63P, ADK STAB LA-68LD, ADK STAB LA-77, Examples include ADK STAB LA-82, ADK STAB LA-87 (all trade names, manufactured by Asahi Denka Kogyo Co., Ltd.); Tinuvin 111FDL, Tinuvin 144, Tinuvin 123, Tinuvin 292 (all manufactured by Ciba Specialty Chemicals, Inc.) May be used alone, or two or more of them may be used in combination, and among them, Adeka Stub LA-52, Adeka Stub LA-62, Tinuvin 111FDL, and Tinuvin 292 are used because of high anti-coloring effect over a long period of time. It is preferable.
As a compounding quantity of the said hindered amine light stabilizer, it is preferable to contain 0.01-10 mass% of hindered amine light stabilizers with respect to 100 mass% of said ionizing radiation curable compositions whole quantity, for example. More preferably, it is 0.1-5 mass%.

Examples of the mold release agent include metal soaps such as zinc stearate, calcium stearate, magnesium stearate, lithium stearate, barium stearate, sodium stearate; caproic acid, caprylic acid, capric acid, lauric acid, myristic acid. Fatty acids such as palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, myristoleic acid, palmitoleic acid, oleic acid, linoleic acid, linolenic acid, 12-hydroxystearic acid, ricinoleic acid; lauryl alcohol, stearyl alcohol, Higher alcohols such as behenyl alcohol; fatty acid esters such as methyl stearate, stearyl stearate, behenyl behenate, sorbitan monostearate; KF96, KF965, KF410, KF41 , KF4701, KF54, KS61, KM244F, KS702, KF725, KS707, KS800P (all trade names, manufactured by Shin-Etsu Chemical Co., Ltd.) and the like; Polyfox PF-136A, PF-156A, PF-151N, One or two fluorine surfactants such as PF-636, PF-6320, PF-656, PF-6520, PF-651, PF-652, PF-3320 (all trade names, manufactured by Omninova) or the like More than seeds can be used. Among these, fatty acids, higher alcohols, fatty acid esters, and fluorine-based surfactants are preferable from the viewpoint that release properties can be expressed while maintaining sufficient transparency.

As described above, the ionizing radiation curable composition of the present invention preferably contains the (meth) acrylic acid ester (A), and particularly as a method for producing such a curable composition. It is not limited, For example, it can obtain by mixing the said (meth) acrylic ester ester (A) and another component as needed. Further, when a curable composition containing a polymer and / or copolymer of the (meth) acrylic acid ester is used, for example, the polymer and / or copolymer of the (meth) acrylic acid ester is used. A mixture of a (meth) acrylic polymer and / or copolymer and a (meth) acrylic monomer is prepared by partial polymerization, and the (meth) acrylic acid ester (A) and the necessary product are added to this mixture. Depending on the case, it can be produced by adding other components. Furthermore, by preparing a polymer and / or copolymer of a (meth) acrylic acid ester having a functional group by partial polymerization, and mixing and reacting with a methacrylate having another functional group capable of reacting with the functional group The (meth) acrylic acid ester product (A), a polymer and / or copolymer of (meth) acrylic acid ester, and, if necessary, a mixture containing other components may be produced.

The ionizing radiation curable composition of the present invention becomes a cured product by curing using ionizing radiation energy as described above. Such a cured product has various physical properties such as light resistance, transparency, and curing strength. For example, LED sealing agents, optical cables, optical waveguides, lens sheets such as prism sheets and lenticular lens sheets, optical members such as optical films and optical lenses, illumination members such as illumination covers and decorative materials, and headlamps It can be particularly suitably used for automobile parts such as parts and instrument panel parts. Among these, it is preferable to use as a lens sheet.
The lens sheet using the ionizing radiation curable composition of the present invention is a film or sheet in which a large number of lens arrays or microlens arrays made of a cured product of an ionizing radiation curable composition are arranged on at least one surface of a substrate. It is preferable that it is in a shape. The lens array or the microlens array has various shapes depending on the purpose. Examples of the lens array include a prism shape, a lenticular lens shape, and a wave shape. Examples of the cross-sectional shape of the lens array include an isosceles triangle, an unequal triangle, a trapezoid, a semicircle, an ellipse, and a polygon. The thickness of the lens sheet is preferably 0.1 to 3 mm, and the pitch of the lens rows is preferably 10 μm to 0.5 mm.
The substrate of the lens sheet is preferably a sheet or film using a material having a high light transmittance and a relatively high refractive index. For example, a glass plate, an acrylic resin, a polycarbonate resin, polyethylene terephthalate or polyethylene naphthalate. Examples thereof include polyester resins such as phthalates, MS (acryl-styrene copolymer) resins, vinyl chloride resins, polystyrene resins, TAC (cellulose triacetate), and cyclopolyolefin resins. In order to increase the adhesion between the base material and the ionizing radiation curable composition, it is preferable to use a base material that has been subjected to surface treatment such as corona discharge treatment, ozone treatment or primer treatment.
As a method for producing the lens sheet, for example, an ionizing radiation curable composition is injected into a lens mold in which a predetermined lens pattern is formed, and after overlapping the base material, it is cured by irradiation with ionizing radiation. The method of taking out is mentioned.
In the lens sheet, an antioxidant, an anti-yellowing agent, a light stabilizer, a bluing agent, a fluorescent whitening agent, a diffusing agent, a pigment, etc. in the substrate and / or ionizing radiation curable composition as necessary These additives can also be added.
Also, a lens shape similar to the above lens sheet is formed on at least one surface of an optical sheet or film such as a light guide plate, a light diffusive sheet, a reflective polarizing sheet (such as DBEF manufactured by Sumitomo 3M), etc. It is also one of the preferable usage forms.

The ionizing radiation curable composition of the present invention has the above-described configuration, and can provide a cured product that can sufficiently satisfy all of light resistance, transparency and curability. For example, an optical member, an illumination member In addition to automobile members and the like, it is useful for more applications.

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.

Synthesis example 1
(M-1: NPG-2EO dimethacrylate)
In a flask equipped with a stirrer, thermometer, condenser, air and nitrogen mixed gas introduction tube, 192 g of neopentyl glycol ethylene oxide 2-mole adduct (hereinafter abbreviated as “NPG-2EO”), methyl methacrylate (hereinafter referred to as “NPG-2EO”) , "MMA") 400 g, dibutyltin oxide (hereinafter abbreviated as "DBTO") 3.84 g and 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (hereinafter "4H"). -Abbreviated as “TEMPO”.) 19.2 mg was added and stirred, and the temperature was raised to 110 ° C. Only the methanol produced | generated by reaction was distilled off and transesterification was performed over 6 hours. MMA was distilled off from the obtained reaction liquid, and dimethacrylate of ethylene oxide 2 mol adduct to neopentyl glycol was obtained. This was made into the compound (M-1).
When the content rate of the sulfur atom contained in the obtained compound (M-1) was measured by inductively coupled plasma analysis (hereinafter referred to as “ICP”), no sulfur atom was observed.

Synthesis example 2
(M-2: NPG-4EO dimethacrylate)
In a flask equipped with a stirrer, a thermometer, a condenser, and a mixed gas introduction tube of air and nitrogen, 280 g of neopentyl glycol ethylene oxide 4 mol adduct (hereinafter abbreviated as “NPG-4EO”), MMA 400 g, DBTO 5.60 g And 4H-TEMPO28.0mg was put and stirred, and it heated up at 110 degreeC. Only the methanol produced | generated by reaction was distilled off and transesterification was performed over 6 hours. MMA was distilled off from the obtained reaction liquid, and dimethacrylate of ethylene oxide 4 mol adduct to neopentyl glycol was obtained. This was made into the compound (M-2).
When the content rate of the sulfur atom contained in the obtained compound (M-2) was measured by ICP, the sulfur atom was not observed.

Synthesis example 3
(M-3: NPG-6EO dimethacrylate)
A flask equipped with a stirrer, a thermometer, a condenser, and a mixed gas introduction tube of air and nitrogen was added with 368 g of neopentyl glycol ethylene oxide 6 mol adduct (hereinafter abbreviated as “NPG-6EO”), MMA 400 g, DBTO 7.36 g. 4H-TEMPO 36.8 mg was added and stirred, and the temperature was raised to 110 ° C. Only the methanol produced | generated by reaction was distilled off and transesterification was performed over 6 hours. MMA was distilled off from the resulting reaction solution to obtain dimethacrylate of adduct of 6 mol of ethylene oxide to neopentyl glycol. This was made into the compound (M-3).
When the content rate of the sulfur atom contained in the obtained compound (M-3) was measured by ICP, the sulfur atom was not observed.

Synthesis example 4
(M-4: NPG-2EO diacrylate)
NPG-2EO192g, ethyl acrylate 400g, DBTO 3.84g and 4H-TEMPO 19.2mg were put in a flask equipped with a stirrer, thermometer, condenser, and mixed gas introduction tube of air and nitrogen, and the temperature was raised to 110 ° C. Warm up. Only ethanol produced by the reaction was distilled off, and transesterification was carried out over 6 hours. Ethyl acrylate was distilled off from the resulting reaction solution to obtain a diacrylate of an ethylene oxide 2-mol adduct to neopentyl glycol. This was made into the compound (M-4).
When the content rate of the sulfur atom contained in the obtained compound (M-4) was measured by ICP, the sulfur atom was not observed.

Synthesis example 5
(M-5: TMP-3EO trimethacrylate)
To a flask equipped with a stirrer, thermometer, condenser, and mixed gas introduction tube of air and nitrogen, trimethylolpropane ethylene oxide 3-mol adduct (hereinafter abbreviated as “TMP-3EO”) 266 g, MMA 600 g, DBTO 5.32 g And 4H-TEMPO26.6mg was put and stirred, and it heated up at 110 degreeC. Only the methanol produced | generated by reaction was distilled off and transesterification was performed over 6 hours. MMA was distilled off from the resulting reaction solution to obtain trimethacrylate of adduct of 3 mol of ethylene oxide to trimethylolpropane. This was made into the compound (M-5).
When the content rate of the sulfur atom contained in the obtained compound (M-5) was measured by ICP, the sulfur atom was not observed.

Synthesis Example 6
(M-6: NPG-2EO dimethacrylate (potassium butoxide catalyst))
NPG-2EO192g, MMA400g, potassium t-butoxide 3.84g and 4H-TEMPO19.2mg were put into a flask equipped with a stirrer, thermometer, condenser, and mixed gas introduction tube of air and nitrogen, and stirred at 110 ° C. The temperature rose. Only the methanol produced | generated by reaction was distilled off and transesterification was performed over 6 hours. MMA was distilled off from the resulting reaction liquid, and the catalyst was removed by washing with water to obtain dimethacrylate of an ethylene oxide 2-mol adduct to neopentyl glycol. This was made into the compound (M-6).
When the content rate of the sulfur atom contained in the obtained compound (M-6) was measured by ICP, the sulfur atom was not observed.

Synthesis example 7
(M-7: 1,6-hexanediol dimethacrylate)
In a flask equipped with a stirrer, a thermometer, a condenser, and a mixed gas introduction tube of air and nitrogen, 118 g of 1,6-hexanediol, 400 g of MMA, 2.36 g of DBTO and 11.8 mg of 4H-TEMPO were added and stirred, and the mixture was heated to 110 ° C. The temperature rose. Only the methanol produced | generated by reaction was distilled off and transesterification was performed over 6 hours. MMA was distilled off from the resulting reaction solution to obtain 1,6-hexanediol dimethacrylate. This was made into the compound (M-7).
When the content rate of the sulfur atom contained in the obtained compound (M-7) was measured by ICP, the sulfur atom was not observed.

Synthesis example 8
(M-8: NPG dimethacrylate)
In a flask equipped with a stirrer, thermometer, condenser, and mixed gas introduction tube of air and nitrogen, 135 g of fully dehydrated neopentyl glycol, 400 g of MMA, 1.35 g of potassium t-butoxide and 13.5 mg of 4H-TEMPO were stirred. The temperature was raised to 110 ° C. Only methanol produced by the reaction was distilled off, and transesterification was carried out over 4 hours. After removing unreacted MMA from the obtained reaction solution, unreacted neopentyl glycol, neopentyl glycol monomethacrylate and catalyst were removed by washing with water to obtain neopentyl glycol dimethacrylate. This was made into the compound (M-8).
When the content rate of the sulfur atom contained in the obtained compound (M-8) was measured by ICP, the sulfur atom was not observed.

Synthesis Example 9
(M-9: NPG-2EO dimethacrylate synthesized by dehydration condensation using para-toluenesulfonic acid)
In a flask equipped with a stirrer, a thermometer, a condenser, and a mixed gas introduction tube of air and nitrogen, 192 g of NPG-2EO, 189 g of methacrylic acid (hereinafter abbreviated as “MAA”), p-toluenesulfonic acid (hereinafter “PTS”) Abbreviated as “.) 7.5 g, 50 g of toluene and 19.2 mg of 4H-TEMPO were added and stirred, and the temperature was raised to 110 ° C. Water generated by the reaction was distilled off, and dehydration esterification reaction was performed over 6 hours. After completion of the reaction, the operation of washing with water and allowing to stand and separating the aqueous layer portion was repeated three times, and toluene and unreacted MAA were removed by heating and depressurization to obtain dimethacrylate of ethylene oxide 2 mol adduct to neopentyl glycol. . This was made into the compound (M-9).
When the content rate of the sulfur atom contained in the obtained compound (M-9) was measured by ICP, the sulfur atom content rate was 400 ppm.

Synthesis Example 10
(P-1)
MMA 190g, MAA 8.6g and toluene 463g were put into a flask equipped with a stirrer, a thermometer, a condenser and a nitrogen gas introduction tube, and the temperature was raised to 70 ° C. Next, a solution obtained by diluting 0.99 g of 2,2′-azobis (2,4-dimethylvaleronitrile) (manufactured by Wako Pure Chemical Industries, Ltd., V-65) with 50 g of toluene was slowly added dropwise while paying attention to heat generation. After reacting at 70 ° C. for 3 hours, the reaction was performed at 90 ° C. for 2 hours to complete radical polymerization.
Next, 0.68 g of methoquinone, 156 g of glycidyl methacrylate, and 2.71 g of tetraphenylphosphonium bromide are added, and the temperature is raised to 100 ° C. while blowing a mixed gas of air and nitrogen, so that the acid value becomes 5 or less. The reaction was continued until The obtained polymer solution was reprecipitated with n-hexane, and then n-hexane was removed under reduced pressure to obtain compound (P-1).
When the molecular weight of the obtained compound (P-1) was measured by gel permeation chromatography (GPC), the number average molecular weight (Mn) was 35000, and the weight average molecular weight (Mw) was 78000.
Moreover, when the content rate of the sulfur atom contained in the obtained compound (P-1) was measured by ICP, the sulfur atom was not observed.

Examples 1-8, Comparative Examples 1-6
The ionizing radiation curable compositions of Examples 1 to 8 and Comparative Examples 1 to 6 were prepared according to the formulations shown in Tables 1 and 2. When preparing this composition, first, each component is sufficiently heated and mixed at 95 ° C. to obtain a uniform solution, and then cooled to room temperature, so that each component is well compatible with each other. I adjusted things. For each of the obtained ionizing radiation curable compositions, as described above, the ether group content (% by mass) in the composition, the sulfonic acid derivative content (ppm) in the composition, the pencil hardness, and the wavelength of 380 nm. And the light transmittance retention after 200 hours and 300 hours of the accelerated light resistance test were obtained. The results are shown in Tables 1 and 2.

Examples 9-16
The ionizing radiation curable compositions of Examples 9 to 16 were prepared according to the formulation shown in Table 1. When preparing this composition, first, each component is sufficiently heated and mixed at 95 ° C. to obtain a uniform solution, and then cooled to room temperature, so that each component is well compatible with each other. I adjusted things. For each of the obtained ionizing radiation curable compositions, as described above, the ether group content (% by mass) in the composition, the sulfonic acid derivative content (ppm) in the composition, the pencil hardness, and the wavelength of 380 nm. And the light transmittance retention after 200 hours and 300 hours of the accelerated light resistance test were obtained. The results are shown in Table 1.

The descriptions in Tables 1 and 2 are as follows.
“PMMA”: polymethyl methacrylate (trade name “SUMIPEX LG-6A”, manufactured by Sumitomo Chemical Co., Ltd.)
“D-1173”: 2-hydroxy-2-methyl-1-phenylpropan-1-one (photopolymerization initiator, trade name “Darocur 1173”, manufactured by Ciba Specialty Chemicals)
“PEG400”: Polyethylene glycol having an average molecular weight of 400 (manufactured by Wako Pure Chemical Industries, Ltd.)
“* Note”: Indicates that the cured product was gel-like (insufficiently cured) and could not be measured.

In Tables 1 and 2, Examples 1-16 and Comparative Examples 3 and 5 show a large difference in initial light transmittance. That is, in Examples 1 to 16, the initial light transmittance is 80% or more, while in Comparative Examples 3 and 5, the initial light transmittance is 50 and 55%. The ionizing radiation curable compositions of Examples 1 to 15 have an ether structure in the (meth) acrylic acid ester. On the other hand, in the ionizing radiation curable compositions of Comparative Examples 3 and 5, the ether structure does not exist in the (meth) acrylic acid ester. From this, it can be said that the transmittance can be more sufficiently improved by the presence of the (meth) acryloyl group in the ether structure-containing compound. In Comparative Examples 3 and 5, it is considered that an ether structure-containing compound having no (meth) acryloyl group is phase-separated at the time of curing to lower the transmittance.

Example 17 (Example of lens sheet)
Prepare a prism sheet-making lens mold by cutting a prism array whose cross-sectional shape is an isosceles triangle having an apex angle of 90 degrees at a pitch of 50 μm, and inject the composition prepared by the formulation shown in Example 9 into the mold. Then, it was covered with an acrylic resin sheet having a thickness of 200 μm and uniformly spread with a roll.
In the same manner as in the preparation of the cured product (test piece), after ultraviolet rays having an irradiation intensity of 43 mJ / cm ² · second were irradiated for 46.5 seconds and sufficiently cured, the prism sheet was prepared from the mold.
The prism sheet is placed on a liquid crystal backlight device having a light source, a light source reflector, a reflector, a light guide plate, and a diffusion sheet as shown in FIG. 1, and the front luminance of the emitted light is measured. The accelerated light resistance test was conducted for 200 hours at an irradiation intensity of 90 mW / cm ² , a wavelength of 295 to 450 nm, a humidity of 70% Rh, and a temperature of 50 ° C. using a super energy irradiation tester. The prism sheet after the test was placed on the liquid crystal backlight device and the front luminance of the emitted light was measured. As a result, the luminance was not changed at all. Further, no yellowing was observed on the prism sheet after the test.

FIG. 18 is a schematic view showing a liquid crystal backlight device used in an accelerated light resistance test of Example 17.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source 2 Light source reflector 3 Reflector plate 4 Light guide plate 5 Diffusion sheet 6 Prism sheet

Claims (5)

A curable composition used by being cured with ionizing radiation energy,
In the ionizing radiation curable composition, a cured product obtained by curing with ionizing radiation energy of ² J / cm ² has an initial light transmittance of 80% or more at a wavelength of 380 nm, and a light transmittance after 200 hours of accelerated light resistance test. An ionizing radiation curable composition satisfying a retention rate of 90% or more. The ionizing radiation curable composition has a sulfonic acid (salt) and / or sulfonic acid ester content in the curable composition of 100 ppm or less in terms of sulfur content,
The curable composition comprises a (meth) acrylic ester of a compound having no aromatic hydrocarbon structure and having two or more hydroxyl groups in one molecule;
The (meth) acrylic ester product is represented by the following general formula (1);

(Wherein R ¹ , R ² and R ³ are the same or different and represent at least one group selected from the group consisting of a hydrogen atom, a methyl group and an ethyl group, provided that R ¹ , R ² and The total number of carbon atoms of R ³ is 0 to 2. n represents an ether structure represented by the following formula:
The ionizing radiation curable composition according to claim 1, wherein the ether structure is 5% by mass or more with respect to 100% by mass of the curable composition. 3. The compound according to claim 2, wherein the compound having no aromatic hydrocarbon structure and having two or more hydroxyl groups in one molecule is a compound not containing β-hydrogen with respect to the hydroxyl group. Ionizing radiation curable composition. The (meth) acrylic acid ester product is a (meth) acrylic acid compound obtained by adding alkylene oxide to a compound having no aromatic hydrocarbon structure and having two or more hydroxyl groups in one molecule. An esterified product,
The ionizing radiation-curable composition according to claim 2 or 3, wherein the alkylene oxide is at least one selected from the group consisting of ethylene oxide, propylene oxide, and butylene oxide. The ionizing radiation curable composition according to any one of claims 1 to 4, wherein the ionizing radiation curable composition contains a polymer and / or copolymer of a (meth) acrylic acid ester.

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