Composition containing difunctional (meth)acrylate, and curable composition and cured product using the same

Abstract

This invention provides a composition containing a difunctional (meth)acrylate that can achieve a cured product with high transparency and high surface hardness. This invention also provides curable compositions and cured products using this composition. The difunctional (meth)acrylate composition of this invention contains at least spirodiol di(meth)acrylate as shown in formula (1), and the content of the spirodiol di(meth)acrylate shown in formula (1) is 90.0% by mass or more and 99.9% by mass or less relative to the total solid content of the above-mentioned difunctional (meth)acrylate composition; and the content of the spirodiol mono(meth)acrylate shown in formula (2) is 0.1% by mass or more and 10.0% by mass or less relative to the total solid content of the above-mentioned difunctional (meth)acrylate composition. (In formulas (1) and (2) above, R...) 1 (This can be a hydrogen atom or a methyl group.)

Description

Technical Field

[0001] This invention relates to compositions containing bifunctional (meth)acrylates, as well as curable compositions and cured products using the same. Background Technology

[0002] (Meth)acrylate compounds with a spirocyclic acetal backbone are useful compounds due to their excellent mechanical strength, heat resistance, moisture resistance, and transparency. They serve as intermediates or monomers for polymer materials such as polyacrylates, and as raw materials for coatings, inks, adhesives, lubricants, films, and sheets. Furthermore, they are widely used as polymeric compounds in a wide range of fields, including optical components such as optical lenses, lighting components, electronic materials, and automotive parts, as well as in thermosetting resin compositions, photocurable resin compositions, ionizing radiation-curable ink compositions, holographic compositions, and as additives in compositions for lithium-ion conductive electrolytes.

[0003] Methods for manufacturing (meth)acrylate compounds having a spirocyclic acetal skeleton in the molecule include, for example, the dehydration condensation method of dehydrating esterification reaction of spirodiol and (meth)acrylic acid (see Patent Documents 1-3), the transesterification method of dehydrating esterification reaction of spirodiol and ethyl acrylate (see Patent Document 4), and the transesterification method of dehydrating esterification reaction of spirodiol and methyl methacrylate (see Patent Document 5), etc.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 59-078193

[0007] Patent Document 2: Japanese Patent Application Publication No. 60-142990

[0008] Patent Document 3: Japanese Patent Application Publication No. 2005-343816

[0009] Patent Document 4: Japanese Patent Application Publication No. 57-170933

[0010] Patent Document 5: Japanese Patent Application Publication No. 2006-169374 Summary of the Invention

[0011] The technical problem to be solved by the present invention

[0012] In recent years, various high-performance materials, such as coatings, inks, adhesives, optical components, lighting components, electronic materials, and automotive parts, have demanded higher transparency and surface hardness. The aforementioned compositions containing difunctional (meth)acrylates are useful compounds as raw materials or additives for these applications. However, the influence of impurities is not yet clear. In the commercial manufacture of the aforementioned difunctional (meth)acrylates, the introduction of impurities is unavoidable; therefore, knowledge of the effects of these impurities on the finished product is necessary.

[0013] The present invention was made in view of the above-mentioned technical problems, and its object is to clarify the influence of impurities in the above-mentioned compositions containing difunctional (meth)acrylates, and to commercially and stably provide compositions containing difunctional (meth)acrylates that can achieve cured products with high transparency and high surface hardness, as well as curable compositions and cured products using the same.

[0014] Technical means to solve technical problems

[0015] The inventors of this invention conducted in-depth research and, as a result, designed and developed a composition containing spirodiol di(meth)acrylate that reduces the proportion of spirodiol mono(meth)acrylate generated as a byproduct during synthesis to below a threshold. Furthermore, they discovered that the aforementioned technical problems could be solved by using this composition, thus completing this invention.

[0016] That is, the present invention provides various embodiments as shown below.

[0017] [1] A composition containing a bifunctional (meth)acrylate, wherein,

[0018] It contains at least the spirodiol di(meth)acrylate shown in formula (1) below.

[0019] Relative to the total solid content of the above-mentioned composition containing bifunctional (meth)acrylates, the content of the above-mentioned spirodiol di(meth)acrylate shown in formula (1) is 90.0% by mass or more and 99.9% by mass or less.

[0020] The content of spirodiol mono(meth)acrylate as shown in formula (2) below is 0.1% by mass or more and 10.0% by mass or less, relative to the total amount of solid components in the above-mentioned composition containing difunctional (meth)acrylate.

[0021]

[0022] (In the above formula (1), R) 1 Each can be independently a hydrogen atom or a methyl group.

[0023]

[0024] (In the above formula (2), R) 1 (This can be a hydrogen atom or a methyl group.)

[0025] [2] The composition containing a difunctional (meth)acrylate as described in [1], wherein, relative to the total amount of solid components in the composition containing the difunctional (meth)acrylate, the spirodiol di(meth)acrylate shown in formula (1) is 98.2% by mass or more and 99.9% by mass or less.

[0026] [3] The composition containing a difunctional (meth)acrylate as described in [1] or [2], wherein the content of the spirodiol mono(meth)acrylate shown in the above formula (2) is 0.1% by mass or more and 1.8% by mass or less relative to the total amount of solid components in the above composition containing a difunctional (meth)acrylate.

[0027] [4] A composition containing a bifunctional (meth)acrylate as described in any one of [1] to [3], wherein,

[0028] It also contains spirodiol as shown in formula (3) below.

[0029] The content of the above-mentioned spirodiol as shown in formula (3) is less than 1.8% by mass relative to the total amount of solid components in the above-mentioned composition containing difunctional (meth)acrylate.

[0030]

[0031] [5] The composition containing a difunctional (meth)acrylate as described in any one of [1] to [4] is solid at 25°C.

[0032] [6] The composition containing a bifunctional (meth)acrylate as described in any one of [1] to [5] is a transesterification product of spirodiol and (meth)acrylate.

[0033] [7] A composition containing a bifunctional (meth)acrylate as described in [6], wherein the (meth)acrylate is an alkyl (meth)acrylate.

[0034] [8] A curable composition comprising any one of the difunctional (meth)acrylates described in [1] to [7].

[0035] [9] A cured product, which is a cured product of the curable composition described in [8].

[0036] Invention Effects

[0037] According to the present invention, it is commercially possible to stably provide compositions containing bifunctional (meth)acrylates that can achieve cured products with high transparency and high surface hardness, as well as curable compositions and cured products using the same. Detailed Implementation

[0038] The following is a detailed description of a method for implementing the present invention (hereinafter referred to as "this embodiment"). The embodiments described below are merely illustrative examples of the present invention, and the present invention is not limited to these embodiments. That is, the present invention can be modified and implemented in any way without departing from its spirit. Furthermore, in this specification, for example, the description of a numerical range "1 to 100" indicates a numerical range including both its lower limit "1" and upper limit "100". The same applies to the description of other numerical ranges.

[0039] In addition, in this specification, (meth)acrylic acid means either or both of acrylic acid and methacrylic acid, and (meth)acrylate means either or both of acrylate and methacrylate.

[0040] [Compositions containing bifunctional (meth)acrylates]

[0041] The composition containing difunctional (meth)acrylates in this embodiment contains at least spirodiol di(meth)acrylate (hereinafter sometimes referred to as "SPGDA") as shown in formula (1), and the content of spirodiol di(meth)acrylate as shown in formula (1) is 90.0% by mass or more and 99.9% by mass or less relative to the total solid content of the composition containing difunctional (meth)acrylates, and the content of spirodiol mono(meth)acrylate (hereinafter sometimes referred to as "SPGMA") as shown in formula (2) is 0.1% by mass or more and 10.0% by mass or less relative to the total solid content of the composition containing difunctional (meth)acrylates.

[0042]

[0043] (In the above formula (1), R) 1 Each can be independently a hydrogen atom or a methyl group.

[0044]

[0045] (In the above formula (2), R) 1 (This can be a hydrogen atom or a methyl group.)

[0046] In the composition containing difunctional (meth)acrylates of this embodiment, the content ratio of spirodiol di(meth)acrylate (SPGDA) shown in formula (1) is not particularly limited. Relative to the total solid content of the composition containing difunctional (meth)acrylates, it can be 90.0% by mass or more, 95.0% by mass or more, 97.0% by mass or more, 98.2% by mass or more, 98.5% by mass or more, or 99.0% by mass or more. Furthermore, regarding the upper limit, it is not particularly limited as long as it is 99.9% by mass or less; it can be 99.8% by mass or less, 99.7% by mass or less, 99.6% by mass or less, 99.5% by mass or less, or 99.4% by mass or less. There is a tendency that the higher the content ratio of SPGDA, the easier it is to obtain high transparency and high surface hardness in the resulting cured product.

[0047] In the composition containing difunctional (meth)acrylates of this embodiment, the content of spirodiol mono(meth)acrylate (SPGMA) shown in formula (2) is only required to be 10.0% by mass or less relative to the total amount of solid components in the composition containing difunctional (meth)acrylates. There is no particular limitation, and it can be 8.0% by mass or less, 5.0% by mass or less, 3.0% by mass or less, 1.8% by mass or less, 1.5% by mass or less, or 1.0% by mass or less. In addition, there is no particular limitation on the lower limit value side, and it can be 0.1% by mass or more, 0.2% by mass or more, 0.3% by mass or more, 0.4% by mass or more, or 0.5% by mass or more. There is a tendency that the lower the content of SPGMA, the easier it is to obtain high transparency and high surface hardness in the cured product.

[0048] Furthermore, the composition containing a bifunctional (meth)acrylate of this embodiment may further contain spirodiol (hereinafter sometimes referred to as "SPG") as shown in formula (3). For example, the composition containing a bifunctional (meth)acrylate of this embodiment may be the transesterification product of spirodiol and (meth)acrylate described later. In this case, the composition containing a bifunctional (meth)acrylate of this embodiment as the reaction product may contain spirodiol from the synthetic raw materials.

[0049]

[0050] In this embodiment, when the composition containing difunctional (meth)acrylate contains spirodiol (SPG) as shown in formula (3), the content of SPG is relatively low when the content of SPG is high. Therefore, it is preferable to have a low content of SPG. Therefore, while there is no particular limitation on the content of SPG in the composition containing difunctional (meth)acrylate of this embodiment, it is preferably 1.8% by mass or less relative to the total solid content of the composition containing difunctional (meth)acrylate, and can be 1.5% by mass or less, 1.2% by mass or less, 1.0% by mass or less, 0.5% by mass or less, 0.3% by mass or less, or 0.2% by mass or less. Furthermore, there is no particular limitation on the lower limit value, and it can be 0.01% by mass or more, 0.03% by mass or more, 0.05% by mass or more, 0.08% by mass or more, or 0.1% by mass or more. There is a tendency that the lower the content of SPG, the easier it is to obtain high transparency and high surface hardness in the resulting cured product. Therefore, the lower limit of the SPG content is targeted at 0.0% by mass.

[0051] Furthermore, as described above, the composition containing difunctional (meth)acrylates in this embodiment may contain optional components SPGMA or SPG in addition to the essential component SPGDA, but may also contain other components. For example, the composition containing difunctional (meth)acrylates in this embodiment may be a transesterification product of spirodiol and (meth)acrylates described later. In this case, it may contain (meth)acrylates from the synthetic raw materials, catalysts or polymerization inhibitors, alcohols generated as byproducts, etc. Although there is no particular limitation on the content ratio of these other components, from the viewpoint of transparency or surface hardness of the obtained cured product, it is preferable to be less than 2.0% by mass relative to the total amount of solid components in the composition containing difunctional (meth)acrylates, and may be 1.0% by mass or less, 0.5% by mass or less, 0.1% by mass or less, or 0.05% by mass or less. There is a tendency that the lower the content ratio of these other components, the easier it is to obtain high transparency and high surface hardness in the obtained cured product.

[0052] In this embodiment, the composition containing bifunctional (meth)acrylate contains SPGDA, which has a high melting point, as the main component, so it can be a solid at 25°C in its inherent form.

[0053] The composition containing a bifunctional (meth)acrylate in this embodiment can be a transesterification product of spirodiol and (meth)acrylate. In the case of this transesterification product, the (meth)acrylate can be an alkyl (meth)acrylate. As alkyl (meth)acrylates, methyl (meth)acrylate and ethyl (meth)acrylate are preferred, and methyl methacrylate and methyl acrylate are more preferred. Hereinafter, a preferred method for manufacturing the composition containing a bifunctional (meth)acrylate in this embodiment will be described in detail.

[0054] [Method for manufacturing compositions containing bifunctional (meth)acrylates]

[0055] The preferred method for manufacturing the composition containing difunctional (meth)acrylate of this embodiment includes at least the step of carrying out a transesterification reaction of spirodiol and (meth)acrylate in the presence of a polymerization inhibitor, wherein the polymerization inhibitor contains an N-oxygen compound and a polymerization inhibitor having a boiling point of 246°C or lower. By using both an N-oxygen compound and a polymerization inhibitor having a boiling point of 246°C or lower as polymerization inhibitors, the unwanted polymerization of the raw material (meth)acrylate can be suppressed during the transesterification reaction, thereby obtaining the composition containing difunctional (meth)acrylate of this embodiment as a high-purity reaction product.

[0056] The spirodiol used as raw material 1 is 3,9-bis(2-hydroxy-1,1-dimethylethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane as shown in the following formula.

[0057]

[0058] Regarding the (meth)acrylate used as raw material 2, from the viewpoint of transesterification via dealcoholization, alkyl (meth)acrylates are preferred. Here, as the alkyl group, alkyl groups with 1 to 6 carbon atoms are preferred, alkyl groups with 1 to 4 carbon atoms are more preferred, alkyl groups with 1 to 3 carbon atoms are even more preferred, and alkyl groups with 1 to 2 carbon atoms are particularly preferred. Specific examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, cyclohexyl, etc., but are not particularly limited to these. Furthermore, one type of (meth)acrylate can be used alone, or two or more can be used in combination. As alkyl (meth)acrylates, methyl (meth)acrylate and ethyl (meth)acrylate are more preferred, and methyl (meth)acrylate is most preferred.

[0059] In the method for manufacturing the composition containing a bifunctional (meth)acrylate according to this embodiment, from the viewpoint of suppressing the generation of byproduct impurities due to water formation, (meth)acrylate must be used as raw material 2. In other words, in the transesterification reaction step, it is preferable that (meth)acrylate is substantially free. Here, substantially free of (meth)acrylate means that the total amount of spirodiol and (meth)acrylate added in the transesterification reaction step is less than 10,000 ppm, preferably less than 5,000 ppm, more preferably less than 1,000 ppm, and even more preferably less than 500 ppm. In addition, it is self-evident that the preferred lower limit for the content of (meth)acrylate is 0 ppm or below the detection limit.

[0060] In the preferred manufacturing method of this embodiment, a composition containing a difunctional (meth)acrylate, comprising spirodiol di(meth)acrylate as a di(meth)acrylate compound, is obtained by transesterification reaction of the spirodiol with the alkyl (meth)acrylate described above. At this time, an alcohol is generated as a byproduct by a dealcoholization reaction.

[0061] The transesterification reaction of spirodiol with (meth)acrylate described above can be carried out using conventional methods without particular limitations. It can typically be carried out in the presence of a catalyst at a reaction solution temperature of 65–120°C. Furthermore, it is preferable to carry out the reaction under conditions where the alcohol generated as a byproduct can be removed by distillation. Therefore, the reaction solution temperature is preferably 65°C or higher, more preferably 70°C or higher, and preferably 110°C or lower, more preferably 100°C or lower. Additionally, there are no particular limitations on the reaction pressure during the transesterification reaction; it can be carried out under any conditions, including atmospheric pressure, reduced pressure, or pressurized pressure. Furthermore, there are no particular limitations on the reaction time during the transesterification reaction; from the viewpoint of industrial production efficiency, 1–12 hours is preferred.

[0062] Furthermore, transesterification reactions can be carried out using any of the batch, semi-batch, or continuous methods. In the continuous process, the continuous countercurrent contact method is industrially advantageous. As an example of a batch process, spirodiol, (meth)acrylate, and a polymerization inhibitor, along with a catalyst as needed, are added to the reactor, and the mixture is stirred at a specified temperature while bubbling oxygen-containing gas into the reaction solution as needed. Then, as the transesterification reaction proceeds, a monohydric alcohol derived from the dealcoholization reaction is generated as a byproduct. This monohydric alcohol can continue to coexist in the reaction system, but removing it from the reaction system can promote the transesterification reaction.

[0063] In the transesterification reaction, from the viewpoint of inhibiting the polymerization of (meth)acrylates, it is preferable to introduce an oxygen-containing gas into the system. Specific examples of oxygen-containing gases include air, a mixture of oxygen and nitrogen, and a mixture of air and nitrogen, but these are not particularly limited. As for the method of introducing this gas, methods such as blowing it into the reaction products (so-called bubbling) can be included. In addition, the pressure within the system when in contact with the oxygen-containing gas can be any condition including normal pressure, reduced pressure, or increased pressure. Furthermore, while there is no particular limitation on the temperature within the system when in contact with the oxygen-containing gas, it is preferably 65 to 110°C, and more preferably 70 to 100°C.

[0064] As catalysts used in transesterification reactions, any transesterification catalysts known in the art can be used without particular limitation. Examples include: organic acids such as p-toluenesulfonic acid and methanesulfonic acid; inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid; acid catalysts such as cation exchange resins; metal alkoxides, such as alkali metal alkoxides, magnesium alkoxides, aluminum alkoxides, zirconium alkoxides such as tetrabutoxyzirconium, and titanium alkoxides such as tetramethyl titanate, tetrapropyl titanate, tetraisopropyl titanate, tetrabutyl titanate, and tetraisobutyl titanate; tetraphenoxy titanium; organotin compounds such as dibutyltin oxide, dioctyltin oxide, dibutyltin dilaurate, dimethoxydibutyltin, and dibutyltin diacetate; and anion exchange resins. Furthermore, one or more of these catalysts can be used alone or in combination. However, in the manufacturing method of this embodiment, from the viewpoint of suppressing the formation of spirodiol decomposition products and the reaction byproducts of these decomposition products with (meth)acrylate, thereby obtaining reaction products of higher purity, it is preferable not to use Brønsted acid catalysts, phosphine compounds, etc. Therefore, as catalysts used in the manufacturing method of this embodiment, metal alkoxides, organotin compounds, and anion exchange resins are preferred, and metal alkoxides are more preferred. The amount of catalyst can be appropriately set according to the expected performance and is not particularly limited. A molar ratio of 1 mole relative to the total amount of spirodiol and (meth)acrylate added in the transesterification reaction step is preferably 1:0.001 to 0.2, more preferably 1:0.005 to 0.1, and even more preferably 1:0.01 to 0.05.

[0065] Furthermore, a solvent is not always necessary in transesterification reactions, and the reaction can be carried out even in the absence of solvents other than (meth)acrylates. However, a solvent may be used as needed. When a solvent is used, from the viewpoint of suppressing the formation of impurities, a solvent other than water is preferred. Specific examples of solvents other than water include: ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, acetophenone, and benzophenone; esters such as methyl benzoate and γ-butyrolactone; carbonate compounds such as dimethyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate, and 1,2-butyl carbonate; sulfones such as sulfolane; sulfoxides such as dimethyl sulfoxide; n-hexane, cyclohexane, methylcyclohexane, n-heptane, n-octane, n-nonane, n-decane, benzene, toluene, xylene, ethylbenzene, diethylbenzene, and cumene. Hydrocarbons such as pentobenzene, dipentylbenzene, tripentylbenzene, dodecylbenzene, didodecylbenzene, pentyltoluene, isopropyltoluene, naphthane, and tetrahydronaphthalene; ethers such as diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, dipentyl ether, diethyl acetal, dihexyl acetal, tert-butyl methyl ether, cyclopentyl methyl ether, tetrahydrofuran, tetrahydropyran, trioxane, dioxane, anisole, diphenyl ether, dimethyl cellosolve, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether; etc., but not specifically limited to these. Furthermore, these solvents can be used alone or in combination of two or more. Among these, ketones, ethers, and hydrocarbons are preferred from the viewpoint of removal efficiency under reflux conditions. When using a solvent, there is no particular limitation on its amount. It is preferably 1 to 70 parts by mass relative to 100 parts by mass of the total amount of spirodiol and (meth)acrylate added in the transesterification reaction process, more preferably 5 to 50 parts by mass, and even more preferably 10 to 30 parts by mass.

[0066] In the transesterification reaction, the feed ratio of spirodiol to (meth)acrylate can be appropriately set according to the expected performance and is not particularly limited. From the viewpoint of the reaction efficiency when the transesterification reaction is carried out under the condition of (meth)acrylate reflux, the feed ratio of (meth)acrylate to spirodiol is preferably equimolar to 15 times molar. More preferably, it is 5 times molar or more, further preferably 7 times molar or more, and even more preferably 12 times molar or less, further preferably 10 times molar or less.

[0067] In the transesterification reaction, an N-oxygen compound and a polymerization inhibitor with a boiling point below 246°C are used as polymerization inhibitors. While the reason why the polymerization of the raw material acrylate can be suppressed by using both of these inhibitors has not been determined, it is speculated based on the inventors' viewpoint according to the present invention. In the manufacturing method of this embodiment, the transesterification reaction is mainly carried out in a state where spirodiol is dissolved or dispersed in liquid (meth)acrylate. Here, the N-oxygen compound, present in the reaction liquid, can suppress the polymerization of (meth)acrylate. On the other hand, as the temperature of the reaction liquid increases, (meth)acrylate slowly evaporates from the reaction liquid, thus a portion of it exists in the gas phase of the reactor. The N-oxygen compound is almost absent in this gas phase, allowing the polymerization of (meth)acrylate to proceed. Therefore, in the manufacturing method of this embodiment, by using a polymerization inhibitor with a boiling point below 246°C, the polymerization inhibitor diffuses into the gas phase, thereby suppressing the polymerization of (meth)acrylate. However, the mechanism of action is not limited to this speculation.

[0068] Examples of N-oxy compounds include, for instance: 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxy, 4-oxo-2,2,6,6-tetramethylpiperidine-1-oxy, 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxy, 4-cyano-2,2,6,6-tetramethylpiperidine-1-oxy, 4-amino-2,2,6,6-tetramethylpiperidine-1-oxy, 4-carboxyl-2,2,6,6-tetramethylpiperidine-1-oxy, and 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine-1-oxy. The compounds include, but are not specifically limited to, N-oxy compounds such as 4-acetamide-2,2,6,6-tetramethylpiperidine-1-oxy, 4-maleimide-2,2,6,6-tetramethylpiperidine-1-oxy, 4-phosphono-2,2,6,6-tetramethylpiperidine-1-oxy, 4-maleimide-2,2,6,6-tetramethylpiperidine-1-oxy, pyrrolidine-1-oxy radical compounds, 3-carboxyl-2,2,5,5-tetramethylpyrrolidine-1-oxy, and 2,2,6,6-tetramethylpiperidine-1-oxy. Furthermore, for N-oxy compounds, one may be used alone, or two or more may be used in combination.

[0069] As polymerization inhibitors with a boiling point below 246°C, phenolic compounds and / or quinone compounds are preferred, with hydroquinone monomethyl ether (boiling point: 243°C) and p-benzoquinone (boiling point: ~180°C / sublimation) being more preferred. By using such polymerization inhibitors with low boiling points or sublimation properties, the inhibitor diffuses into the gas phase, thereby inhibiting the polymerization of (meth)acrylates. Furthermore, polymerization inhibitors with a boiling point below 246°C can be used alone or in combination of two or more.

[0070] The amounts of the aforementioned N-oxygen compound and the polymerization inhibitor having a boiling point of 246°C or lower can be appropriately set according to the desired performance, and there are no particular limitations. From the viewpoint of inhibiting the polymerization of (meth)acrylates, the content ratio of the N-oxygen compound is preferably 1 ppm or more and 300 ppm or less, more preferably 3 ppm or more and 200 ppm or less, and even more preferably 5 ppm or more and 100 ppm or less, relative to the total amount of spirodiol and (meth)acrylates in the transesterification process. Furthermore, from the viewpoint of inhibiting the polymerization of (meth)acrylates, the content ratio of the polymerization inhibitor having a boiling point of 246°C or lower is preferably 10 ppm or more and 3000 ppm or less, more preferably 15 ppm or more and 2500 ppm or less, and even more preferably 20 ppm or more and 2000 ppm or less, relative to the total amount of spirodiol and (meth)acrylates in the transesterification process.

[0071] The ratio of the N-oxygen compound to the polymerization inhibitor having a boiling point below 246°C can be appropriately set according to the expected performance, and there is no particular limitation. From the viewpoint of inhibiting polymerization during transesterification under reflux conditions, the ratio of the N-oxygen compound to the polymerization inhibitor having a boiling point below 246°C, expressed in ppm, is preferably 2:1 to 1:50, more preferably 1:1 to 1:40, and even more preferably 1:1.2 to 1:30.

[0072] In the manufacturing method of this embodiment, in addition to using the aforementioned N-oxygen compound and a polymerization inhibitor having a boiling point of 246°C or lower, other polymerization inhibitors may be further used in combination. Examples of other polymerization inhibitors include: organic polymerization inhibitors such as hydroquinone (boiling point: 282°C), tert-butylhydroquinone (boiling point: 288°C), 2-tert-butyl-4,6-dimethylphenol (boiling point: 249°C), dibutylhydroxytoluene (boiling point: 265°C), 2,6-di-tert-butyl-4-methylphenol (boiling point: 265°C), 2,4,6-tri-tert-butylphenol (boiling point: 277°C), 4-tert-butylcatechol (boiling point: 285°C), and phenothiazine (boiling point: 371°C); inorganic polymerization inhibitors such as copper chloride, copper sulfate, and ferric sulfate; and organic salt polymerization inhibitors such as butyl dithiocarbamate and aluminum N-nitroso-N-phenylhydroxylamine, but these are not particularly limited to these. These other polymerization inhibitors can be used alone or in combination. Furthermore, the required amount of the inhibitor can be added all at once during the transesterification reaction, or it can be added in batches. Alternatively, it can be added continuously via a distillation column.

[0073] After the transesterification reaction, it is preferable to remove or deactivate the catalyst as needed. Methods for removing or deactivating the catalyst include solid-liquid separation, hydrolysis by adding water, extraction with an aqueous solution containing acid or alkali, and adsorption. Alternatively, the catalyst can be removed by adding a poor solvent, or by solid-liquid separation after concentration by cooling or vacuum concentration. These operations can be appropriately selected depending on the type of raw material used, the type of catalyst, the type of (meth)acrylate obtained, and the reaction conditions. These operations can be used individually or in combination. For example, for metal alkoxides, adding water is sufficient to deactivate the catalyst.

[0074] Following the above transesterification reaction, the target di(meth)acrylate compound is converted into spirodiol di(meth)acrylate (i.e., spirodiol di(meth)acrylate). At this point, spirodiol mono(meth)acrylate (i.e., spirodiol mono(meth)acrylate) may also be generated as a byproduct, but it is preferable that its content is small.

[0075] In the manufacturing method of this embodiment, high-purity spirodiol di(meth)acrylate (a composition of SPGMA containing a low proportion of bifunctional (meth)acrylates) can be obtained with good reproducibility at the industrial level.

[0076] Regarding the conversion rate, it can be set appropriately according to the expected performance, without any particular limitation. From the point of view of industrial productivity, based on the mass of the spirodiol input, it is preferably 98.5% by mass or more, more preferably 99.0% by mass or more, further preferably 99.5% by mass or more, and particularly preferably 99.8% by mass or more.

[0077] Regarding the selectivity, it can be set appropriately according to the expected performance, without any particular limitation. From the point of view of industrial productivity, based on the mass of the spirodiol input, it is preferably 97.0% by mass or more, more preferably 97.5% by mass or more, further preferably 98.0% by mass or more, and particularly preferably 98.5% by mass or more.

[0078] Regarding the yield, it can be appropriately set according to the expected performance, without any particular limitation. From the viewpoint of industrial productivity, it is preferably 95.5% by mass or more, more preferably 96.5% by mass or more, further preferably 97.5% by mass or more, particularly preferably 98.0% by mass or more, and most preferably 99.0% by mass or more.

[0079] Furthermore, the manufacturing method of this embodiment may include a step of purifying the obtained product after the transesterification reaction as described above. This purification step may be a step of removing unreacted raw materials and / or byproducts. As a purification step, methods commonly used for purifying acrylates may be appropriately employed. Specifically, examples include: distillation purification; dissolving the composition containing a bifunctional (meth)acrylate in a solvent and then reprecipitating it by means of cooling or adding a poor solvent, or by dropwise addition to water; and liquid-liquid extraction. As liquid-liquid extraction conditions, liquid-liquid extraction using an aqueous solution of acetone, toluene, or sodium carbonate may be employed.

[0080] [use]

[0081] The composition containing bifunctional (meth)acrylates of this embodiment can be used alone or in combination with other resin raw materials or resins as needed. Other resin raw materials mentioned above include other (meth)acrylates or urethane (meth)acrylates, alcohols, thiols, polyamic acids, and other compounds. Other resins mentioned above include polycarbonate, polyester, polyester carbonate, polyacrylate, polyurethane, polyether polyol, epoxy resin, polyimide, silicone resin, alicyclic hydrocarbon resin, hydrocarbon resin, etc. Resins whose ends are modified to (meth)acryloyl or vinyl, acid, ester, halogen, etc., can also be listed, but are not limited to these.

[0082] Furthermore, regarding its usage, there are no particular limitations on the addition of the resin raw material or resin used in combination before or after synthesis. Specifically, a resin composition can be prepared by mixing with a resin raw material or resin used in combination. At this time, the resin composition can be formed by heating and melting, or it can be cured at this time. After the obtained resin composition is coated on the surface of glass or film, a cured product can be obtained by performing photocuring or the like. Alternatively, the obtained resin composition can be dissolved in various solvents to prepare a solution, the solution can be coated on the surface of glass or film, and then dried and photocured; other cured resins can also be impregnated in the difunctional (meth)acrylate composition of this embodiment for permeation.

[0083] Alternatively, it can be used in combination with various photoinitiators, inorganic substances such as oxide particles, semiconductor particles, pigments, viscosity modifiers such as rosin, or surfactants. It can also be added to other resins as a crosslinking agent or solubilizer.

[0084] The resin composition containing the bifunctional (meth)acrylate composition of this embodiment can be used as a raw material for coatings, adhesives, films, sheets, etc. As for their uses, they can be used as automotive parts, building parts, car windows, various parts (including optical parts) for televisions / camcorders / audio players / smartphones / monitors / computers / copiers, furniture parts such as lampshades / blinds / interior decorations, light diffusion plates, light guide plates (light guides), optical lenses, optical molding bodies (including optical disc substrates, etc.), optical elements such as light diffusion films, optical films, optical filters, protective films, transparent adhesive sheets, coating agents, LED / organic EL sealants, interlayer insulating materials for electronic components, anti-corrosion inks such as solder resists for printed circuit boards, and photocurable resin compositions for three-dimensional modeling, etc.

[0085] Example

[0086] The present invention will be described in more detail below using examples and comparative examples, but the technical scope of the present invention is not limited thereto. That is, the materials, amounts, proportions, processing contents, processing steps, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. In addition, the values ​​of various manufacturing conditions and evaluation results in the following examples have the meaning of preferred upper or lower limits in the embodiments of the present invention, and the preferred numerical range can be the range defined by the combination of the above-mentioned upper or lower limits with the values ​​of the following examples or the values ​​of the examples themselves. In addition, unless otherwise specified, "%" means "mass %" and "ppm" means "mass ppm" in the following text.

[0087] The proportions of SPGDA, SPGMA, and SPG in the composition containing bifunctional (meth)acrylates of this embodiment can be determined using the gas chromatograph described below (Shimadzu Corporation: GC-2010PLUS). The GC conditions are detailed below.

[0088] <GC Conditions>

[0089] Column: DB-1, film thickness 1.5μm, length 30M, inner diameter 0.53mm

[0090] Inlet temperature: 280℃

[0091] Injection Mode: Streaming

[0092] Gas control: pressure

[0093] Pressure: 35.7 kPa

[0094] Linear velocity: 48.0 cm / s

[0095] Oven temperature program:

[0096] Initial temperature 65℃

[0097] Keep at 65℃ for 5 minutes

[0098] Increase the temperature to 85°C at a rate of 3°C / minute and hold for 10 minutes.

[0099] Increase the temperature to 250°C at a rate of 5°C / minute and hold for 25 minutes.

[0100] Carrier gas: He

[0101] [Example 1]

[0102] First process

[0103] In a 1L flask equipped with a stirrer, thermometer, gas inlet pipe, and distillation column (a packed column with a timed reflux head connected to the front end with a cooling pipe), 152.4g (0.50mol) of SPG (spirodiol), 560.0g (6.50mol) of MA (methyl acrylate), 3.45g (12.1mmol) of TTIP (tetraisopropyl titanate) as a catalyst, 0.07g of MEHQ (4-methoxyphenol) as a polymerization inhibitor (95.9ppm relative to the total amount of SPG and MA added), and 0.05g of 4H-TEMPO (4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxy) (67.9ppm relative to the total amount of SPG and MA added) were added. Oxygen-containing gas (8 vol% oxygen and 92 vol% nitrogen) was bubbled into the liquid at a rate of 40 mL / min.

[0104] While stirring at a reaction temperature of 80°C, a transesterification reaction is carried out, and the mixture of MeOH (a byproduct) and raw material MA is removed from the reaction system by distillation through a distillation column. Furthermore, an equal weight of MA is added to the reaction solution as needed.

[0105] Stop heating 6 hours after stirring begins.

[0106] After the reaction solution temperature was cooled to below 65°C, 2.78 g (0.15 mol) of H2O was added to deactivate the TTIP catalyst.

[0107] Second process

[0108] The temperature of the reaction product obtained in the first step (reaction step) is maintained at 65°C, and H2O and MA are removed by distillation under reduced pressure. 615g of acetone is added to the remaining reaction product, and the mixture is heated to 54°C to dissolve the acrylate product. The mixture is then filtered using a filter aid (RADIOLITE #800).

[0109] By cooling the filtrate, SPGDA (spirodiol diacrylate) and other components are precipitated, and crystals (solids) of the composition containing difunctional (meth)acrylates with SPGDA are recovered.

[0110] The obtained crystals were washed with an appropriate amount of acetone and then dried in a vacuum dryer at 30°C for 3 hours to obtain crystals.

[0111] [Example 2]

[0112] First process

[0113] In a 1L flask equipped with a stirrer, thermometer, gas inlet pipe, and distillation column (a packed column with a timed reflux head connected to the front end with a cooling pipe), 125.0 g (0.41 mol) of SPG (spirodiol), 601.5 g (6.99 mol) of MA (methyl acrylate), 3.84 g (13.5 mmol) of TTIP (tetraisopropyl titanate) as a catalyst, 0.08 g of MEHQ (4-methoxyphenol) as a polymerization inhibitor (109.9 ppm relative to the total amount of SPG and MA added), and 0.06 g of 4H-TEMPO (4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxy) (82.7 ppm relative to the total amount of SPG and MA added) were added. Oxygen-containing gas (8 vol% oxygen and 92 vol% nitrogen) was bubbled into the liquid at a rate of 40 mL / min.

[0114] While stirring at a reaction temperature of 80°C, a transesterification reaction is carried out, and the mixture of MeOH (a byproduct) and raw material MA is removed from the reaction system by distillation through a distillation column. Furthermore, an equal weight of MA is added to the reaction solution as needed.

[0115] Stop heating 4 hours after stirring begins.

[0116] After the reaction solution temperature was cooled to below 65°C, 10.45 g (0.58 mol) of H2O was added to deactivate the TTIP catalyst.

[0117] Second process

[0118] The temperature of the reaction product obtained in the first step (reaction step) was maintained at 65°C, and H2O and MA were removed by distillation under reduced pressure. 526g of acetone was added to the remaining reaction product, and the mixture was heated to 54°C to dissolve the acrylate product. The mixture was then filtered using a filter aid (RADIOLITE #800).

[0119] By cooling the filtrate, SPGDA (spirodiol diacrylate) and other components are precipitated, and crystals (solids) of the composition containing difunctional (meth)acrylates with SPGDA are recovered.

[0120] The obtained crystals were washed with an appropriate amount of acetone and then dried in a vacuum dryer at 30°C for 3 hours to obtain crystals.

[0121] [Comparative Example 1]

[0122] First process

[0123] In a 300 ml flask equipped with a stirrer, thermometer, gas inlet tube, and Dean-Stark tube (connected to a condenser), add 30.6 g (0.10 mol) of SPG (spirodiol), 18.5 g (0.26 mol) of acrylic acid, 72.0 g (0.78 mol) of toluene as solvent, 0.51 g (5.3 mmol) of MSA (methanesulfonic acid) as catalyst, 0.13 g of MEHQ (4-methoxyphenol) as polymerization inhibitor (2716.2 ppm relative to the total amount of SPG and acrylic acid added), and 0.01 g of 4H-TEMPO (4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxy) (273.2 ppm relative to the total amount of SPG and acrylic acid added). Oxygen-containing gas (5 vol% oxygen and 95 vol% nitrogen) is bubbled into the liquid at a rate of 10 mL / min.

[0124] While stirring at a reaction temperature of 80°C, a dehydration esterification reaction was carried out, and a vacuum of 50 kPa abs was applied to remove the generated water from the reaction system by distillation through a Dean-Stark tube.

[0125] Heating of the reaction solution was stopped after about 8 hours.

[0126] After reaching atmospheric pressure, the temperature of the reaction solution was lowered to 70°C, 48% NaOH aqueous solution was added, and the mixture was stirred for 30 minutes.

[0127] Second process

[0128] The temperature of the reaction product obtained in the first step (reaction step) is maintained at 70°C, and H2O, acrylic acid, and toluene are removed by distillation under reduced pressure. 126g of acetone is added to the remaining reaction product, and the mixture is heated to 54°C to dissolve the acrylate product. The mixture is then filtered using a filter aid (RADIOLITE #800).

[0129] By cooling the filtrate to room temperature to precipitate SPGDA (spirodiol diacrylate), crystals (solids) of the composition containing difunctional (meth)acrylates of SPGDA are recovered.

[0130] The obtained crystals were washed with an appropriate amount of acetone and then dried in a vacuum dryer at 30°C for 3 hours to obtain crystals.

[0131] [Evaluation of the preparation of cured films]

[0132] A silicone-treated PET film (50 μm thick) was placed on a glass plate (150 mm long, 150 mm wide, and 3 mm thick) heated to 150°C using a hot plate and secured with heat-resistant polyimide tape. Separately, 2% (relative to the amount of the difunctional (meth)acrylate-containing composition obtained in the examples) of photopolymerization initiator 1-hydroxycyclohexylphenyl ketone was added to the composition containing difunctional (meth)acrylate, followed by heating and stirring to homogenize it. A 0.5 mm thick silicon wafer was used as a spacer, placed on either side of the drop-on composition. The prepared mixture was then dropped onto the PET film, and the drop-on composition was clamped with the PET film after the drop-on. An EYE GRAPHICS COMPANY desktop UV irradiation system “ESC-1511U” was used at an irradiation intensity of 604 mW / cm². 2 Cumulative light intensity: 737 mJ / cm 2 The clamped composition was irradiated to prepare an evaluation cured film with a length of 30 mm, a width of 30 mm, and a thickness of about 0.5 mm.

[0133] [Total light transmittance]

[0134] The above-mentioned evaluation film after UV curing was measured using a haze meter "COH 7700" manufactured by Nippon Denshoku Kogyo Co., Ltd., in accordance with JIS K7361-1.

[0135] [Pencil Hardness]

[0136] For the above-mentioned evaluation film after UV curing, the pencil hardness was determined according to JIS K5600-5-4 using the test method. The hardness at which no scratches were produced on the surface was recorded.

[0137] Table 1 shows the evaluation results.

[0138] [Table 1]

[0139]

Claims

1. A composition containing a bifunctional (meth)acrylate, wherein, It contains at least the spirodiol di(meth)acrylate shown in formula (1) below. The content of the spirodiol di(meth)acrylate shown in formula (1) is 90.0% by mass or more and 99.9% by mass or less, relative to the total solid content of the composition containing the bifunctional (meth)acrylate. Relative to the total solid content of the composition containing the difunctional (meth)acrylate, the content of spirodiol mono(meth)acrylate as shown in formula (2) below is 0.1% by mass or more and 10.0% by mass or less. In the above equation (1), R 1 Each can be independently a hydrogen atom or a methyl group. In equation (2), R 1 It can be a hydrogen atom or a methyl group.

2. The composition containing a bifunctional (meth)acrylate as described in claim 1, wherein, The content of the spirodiol di(meth)acrylate shown in formula (1) is 98.2% by mass or more and 99.9% by mass or less, relative to the total amount of solid components in the composition containing the difunctional (meth)acrylate.

3. The composition containing a bifunctional (meth)acrylate as described in claim 1, wherein, The content of the spirodiol mono(meth)acrylate shown in formula (2) is 0.1% by mass or more and 1.8% by mass or less, relative to the total amount of solid components in the composition containing the difunctional (meth)acrylate.

4. The composition containing a bifunctional (meth)acrylate as described in claim 1, wherein, It also contains spirodiol as shown in formula (3) below. The content of the spirodiol shown in formula (3) is less than 1.8% by mass relative to the total solid content of the composition containing the bifunctional (meth)acrylate. 。 5. The composition containing a bifunctional (meth)acrylate as described in claim 1, wherein, The composition containing bifunctional (meth)acrylate is a solid at 25°C.

6. The composition containing a bifunctional (meth)acrylate as described in claim 1, wherein, The composition containing bifunctional (meth)acrylate is a transesterification product of spirodiol and (meth)acrylate.

7. The composition containing a bifunctional (meth)acrylate as described in claim 6, wherein, The (meth)acrylate is an alkyl (meth)acrylate.

8. A curable composition, in, A composition containing the bifunctional (meth)acrylate as described in claim 1.

9. A cured product, which is a cured product of the curable composition of claim 8.

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