JP2017141356A - Optical photosensitive resin composition and optical material using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical photosensitive resin composition which has a high Abbe number, is excellent in transparency, has higher photocurability, is suitable as an optical material and has a low index of refraction, and to provide an optical material using the same.SOLUTION: There is provided an optical photosensitive resin composition that is a resin which contains (A) and (B) components as resin components and has a chemical structure having no aromatic ring, and further contains a (C) component; and is obtained by curing the optical photosensitive resin composition. The (A) component is a dicyclopentadiene type epoxy resin having no aromatic ring, the (B) component is a monofunctional oxetane resin having no aromatic ring, and the component (C) is a photoacid generator.SELECTED DRAWING: None

Description

  The present invention relates to an optical photosensitive resin composition having high transparency that allows optical signals to pass through with low loss in a transparent resin for optical applications, and high photocurability, and an optical material using the same. It is about.

  Conventionally, various materials have been studied as materials for adhesives, sealing materials, filters, and optical lenses for optical components. Among such materials, a photocurable resin composition mainly composed of an epoxy resin having a high Abbe number and excellent transparency has been attracting attention.

  As such a photocurable resin composition, for example, a photosensitive resin composition in which a resin such as an alicyclic epoxy resin, a hydrogenated epoxy resin, an aromatic epoxy resin, or an oxetane resin is appropriately used in combination has been proposed ( Patent Document 1).

  A photocurable resin composition using an epoxy resin having a dicyclopentadiene skeleton represented by the following general formula (i) has also been proposed (Patent Document 2).

Japanese Patent Laying-Open No. 2015-61929 JP 2014-1367 A

  By the way, in the technical field of optical photosensitive resin compositions, there has been a high demand for a high refractive index specification. For example, in the optical lens field, a high refractive index lens and a low refractive index lens are overlapped. Often combined. Therefore, a low-refractive index specification (particularly, a refractive index of 1.52 or less) optical resin composition having a high Abbe number, excellent transparency, and further high photocurability, and an optical system using the same The need for materials is also increasing in recent years. In particular, from the viewpoint of reducing chromatic aberration, it is preferable that the Abbe number is as high as possible.

  However, the photosensitive resin composition disclosed in Patent Document 1 has a problem inferior in photocurability, and cannot sufficiently meet the above needs.

  In addition, the photocurable resin composition disclosed in Patent Document 2 does not exhibit a refractive index or an Abbe number that can meet the above-described needs, and further, there is no suggestion that an oxetane resin is used in combination. It is also difficult to achieve both compatibility and photocurability.

  The present invention has been made in view of such circumstances, and has a low refractive index and an optical photosensitive resin composition suitable as an optical material having a high Abbe number, excellent transparency, and high photocurability. The object is to provide a product and an optical material using the product.

In order to achieve the above object, the present invention provides an optical photosensitive resin composition, the resin component of which has a chemical structure having no aromatic ring, including the following components (A) and (B): The first gist is an optical photosensitive resin composition containing the following component (C) together with the resin component.
(A) A dicyclopentadiene type epoxy resin having no aromatic ring.
(B) A monofunctional oxetane resin having no aromatic ring.
(C) A photoacid generator.

  Moreover, this invention makes the 2nd summary the optical material obtained by hardening the photosensitive resin composition for optics of the said 1st summary.

  That is, the present inventor has intensively studied to solve the above problems. In the course of the research, as a resin component in the optical photosensitive resin composition, for example, a resin having a chemical structure having an aromatic ring as shown in the general formula (i) is not used. The knowledge that it becomes possible to achieve the refractive index was obtained. Based on this knowledge, various investigations have been made on a high Abbe number resin that can be photocured by a photoacid generator. As a result, a dicyclopentadiene type epoxy resin having no aromatic ring and a single resin having no aromatic ring are obtained. When the functional oxetane resin was used in combination, it was found that both high photocurability and high transparency were achieved, and as a result, the intended purpose could be achieved.

Thus, the present invention provides a chemical structure in which the resin component does not have an aromatic ring, including a dicyclopentadiene type epoxy resin (A) having no aromatic ring and a monofunctional oxetane resin (B) having no aromatic ring. And an optical photosensitive resin composition containing a photoacid generator (C) together with the resin component. Therefore, a low refractive index optical photosensitive resin composition suitable for an optical material having a high Abbe number, excellent transparency, and further high photocurability, and an optical material using the same are provided. it can.
In addition, since the optical photosensitive resin composition can be photocured on a transparent substrate such as a glass plate, a high-quality hybrid lens can be produced by integrating with the transparent substrate. Therefore, when the optical photosensitive resin composition of the present invention is used for a molding material for optical parts such as lenses and a photo-curing adhesive for fixing optical parts, an optical material having high reliability can be obtained. Because it is useful.

  In particular, the content of the component (A) with respect to the total amount of the resin component is 10 to 50% by weight, the content of the component (B) is 5 to 30% by weight, and the amount of the component (C) with respect to 100 parts by weight of the total resin component When the content is 0.3 to 3 parts by weight, a high Abbe number is obtained along with an even lower refractive index.

  Among optical materials obtained by curing the above-mentioned optical photosensitive resin composition, in particular, an optical material having a refractive index of 1.52 or less and an Abbe number of 54 or more is low. It meets the needs for optical materials with refractive index specifications and is useful.

  Next, embodiments of the present invention will be described in detail. However, the present invention is not limited to this embodiment.

<< Optical photosensitive resin composition >>
The optical photosensitive resin composition of the present invention (hereinafter sometimes referred to as photosensitive resin composition or resin composition) is a dicyclopentadiene type epoxy resin (A) whose resin component does not have an aromatic ring. ) And a monofunctional oxetane resin (B) having no aromatic ring, and having a chemical structure not having an aromatic ring, and containing a photoacid generator (C) together with the resin component.
Hereinafter, various components will be described in order.

<Dicyclopentadiene type epoxy resin (A) having no aromatic ring>
The epoxy resin (A) is an epoxy resin having a chemical structure having a dicyclopentadiene skeleton but no aromatic ring, specifically, an epoxy resin represented by the following general formula (1), Examples thereof include an epoxy resin represented by the general formula (2). These may be used alone or in combination.

  In the said General formula (1), it is preferable that n is 0-2. Moreover, it is preferable to use especially the epoxy resin represented by the said General formula (1) among the said epoxy resins (A).

  As an epoxy resin represented by the above general formula (1), commercially available products include Adeka Resin EP-4088S, EP-4088L (both manufactured by ADEKA), and the epoxy resin represented by the above general formula (2). Examples of commercially available products include dicyclopentadiene diepoxide (manufactured by Synquest).

<Monofunctional oxetane resin having no aromatic ring (B)>
The oxetane resin (B) is a oxetane resin having a chemical structure that is monofunctional and does not have an aromatic ring. Specifically, 3-methyl-3-hydroxymethyloxetane, 3-ethyl-3-hydroxy Methyl oxetane, 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane, isobutoxymethyl (3-ethyl-3-oxetanylmethyl) ether, isobornyloxyethyl (3-ethyl-3-oxetanylmethyl) ether , Isobornyl (3-ethyl-3-oxetanylmethyl) ether, 2-ethylhexyl (3-ethyl-3-oxetanylmethyl) ether, ethyl diethylene glycol (3-ethyl-3-oxetanylmethyl) ether, and the like. These may be used alone or in combination.

<Other resins>
In the present invention, other resins having no aromatic ring can be used in combination with the above (A) and (B). By using such a resin together, there is an effect that the polymerization rate and the refractive index can be easily adjusted. In addition, if it is a range which does not inhibit the effect of this invention, it is also possible to add also about the epoxy resin which has an aromatic ring.

  Examples of other resins having no aromatic ring include alicyclic epoxy resins, aliphatic epoxy resins, polyfunctional oxetane resins, vinyl ether compounds, and hydroxyl-terminated compounds. These may be used alone or in combination of two or more.

  Examples of the alicyclic epoxy resin having no aromatic ring as described above include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-1-methylcyclohexyl-3. , 4-epoxy-1-methylhexanecarboxylate, 6-methyl-3,4-epoxycyclohexylmethyl-6-methyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-3-methylcyclohexylmethyl-3 , 4-epoxy-3-methylcyclohexanecarboxylate, 3,4-epoxy-5-methylcyclohexylmethyl-3,4-epoxy-5-methylcyclohexanecarboxylate, bis (3,4-epoxycyclohexylmethyl) adipate, 3, , 4-Epoxy-6-methyl Cyclohexyl carboxylate, methylene bis (3,4-epoxycyclohexane), propane-2,2-diyl-bis (3,4-epoxycyclohexane), 2,2-bis (3,4-epoxycyclohexyl) propane dicyclopentadiene Epoxide, ethylene bis (3,4-epoxycyclohexanecarboxylate), 1-epoxyethyl-3,4-epoxycyclohexane, 1,2-epoxy-2-epoxyethylcyclohexane and the like can be mentioned. In particular, it is preferable to use these alicyclic epoxy resins in combination because the reactivity is improved while maintaining high transparency.

  Examples of the aliphatic epoxy resin having no aromatic ring as described above include 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, triglycidyl ether of glycerin, and trimethylolpropane. Triglycidyl ether, tetraglycidyl ether of sorbitol, hexaglycidyl ether of dipentaerythritol, diglycidyl ether of polyethylene glycol, diglycidyl ether of polypropylene glycol, glycidyl ether of polyhydric alcohol, propylene glycol, trimethylolpropane, glycerin, etc. Polyglycidyl ether of polyether polyol obtained by adding one or more alkylene oxides to aliphatic polyhydric alcohol Diglycidyl ester of aliphatic long-chain dibasic acid, monoglycidyl ether of higher aliphatic alcohol, phenol, cresol, butylphenol, and monoglycidyl ether of polyether alcohol obtained by adding alkylene oxide to these, higher fatty acid Examples thereof include glycidyl ester, epoxidized soybean oil, octyl epoxy stearate, butyl epoxy stearate, epoxidized soybean oil, and epoxidized polybutadiene.

  Examples of the polyfunctional oxetane resin having no aromatic ring as described above include di [1-ethyl (3-oxetanyl)] methyl ether and 3,7-bis (3-oxetanyl) -5-oxa-nonane. 1,2-bis [(3-ethyl-3-oxetanylmethoxy) methyl] ethane, 1,3-bis [(3-ethyl-3-oxetanylmethoxy) methyl] propane, ethylene glycol bis (3-ethyl-3 -Oxetanylmethyl) ether, tricyclodecanediyldimethylene (3-ethyl-3-oxetanylmethyl) ether, trimethylolpropane tris (3-ethyl-3-oxetanylmethyl) ether, 1,4-bis (3-ethyl- 3-Oxetanylmethoxy) butane, 1,6-bis (3-ethyl-3-oxetanylmethoxy) hexane Pentaerythritol tris (3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether, polyethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol hexakis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol pentakis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether and the like.

  Examples of the vinyl ether compound having no aromatic ring as described above include ethyl vinyl ether, isobutyl vinyl ether, hydroxybutyl vinyl ether, butanediol divinyl ether, cyclohexyl vinyl ether, N-butyl vinyl ether, tert-butyl vinyl ether, triethylene glycol diether. Examples include vinyl ether octadecyl vinyl ether, cyclohexane dimethanol divinyl ether, diethylene glycol divinyl ether, cyclohexane dimethanol monovinyl ether, and the like.

  Examples of the hydroxyl-terminated compound having no aromatic ring as described above include methanol, ethanol, cyclohexane methanol, cyclohexane ethanol, 2-propanol, butanol, propanol, neopentyl glycol, trimethylolpropane, and the like. It is preferable to add the hydroxyl-terminated compound within a range that does not impair the effects of the present invention.

<Photoacid generator (C)>
The photoacid generator (photocation polymerization initiator) (C) is used to impart curability to the photosensitive resin composition by light irradiation (for example, ultraviolet irradiation). As the photoacid generator (C), for example, an onium salt photoacid generator (photocation polymerization initiator) such as sulfonium salt or iodonium salt can be used.

Examples of the anion component in the onium salt system include phosphate ions such as PF ₆ ⁻ and PF ₄ (CF ₂ CF ₃ ) ₂ ^— , antimonate ions such as SbF ₆ ^— , and fluoroalkyl sulfones such as trifluoromethanesulfonate. Examples include acid ions.

  Examples of the cation component in the onium salt system include sulfonium such as aromatic sulfonium, iodonium such as aromatic iodonium, phosphonium such as aromatic phosphonium, and sulfoxonium such as aromatic sulfoxonium.

  Examples of such an onium salt include a sulfonium salt such as an aromatic sulfonium salt, an iodonium salt such as an aromatic iodonium salt, a phosphonium salt such as an aromatic phosphonium salt, and an aromatic sulfoxo having the anion component as a counter anion. Examples thereof include sulfoxonium salts such as nium salts.

  Such photoacid generators (C) can be used alone or in combination of two or more.

  Of these photoacid generators (C), when photocurability is taken into consideration, an aromatic sulfonium salt-based photoacid generator is preferably used.

  Here, in the optical photosensitive resin composition of the present invention, in particular, the content of the component (A) is 10 to 50% by weight and the content of the component (B) is 5 to 30% by weight with respect to the total amount of the resin component. In addition, it is preferable that the content of the component (C) is 0.3 to 3 parts by weight with respect to 100 parts by weight of the total resin component because a higher Abbe number is obtained with a lower refractive index. More preferably, the content of the component (A) with respect to the total amount of the resin component is 10 to 30% by weight, the content of the component (B) is 10 to 30% by weight, and (C) with respect to the total amount of the resin component of 100 parts by weight. The component content is 0.3 to 2 parts by weight. In addition, when blending a resin having no aromatic ring other than the components (A) and (B) as described above, it is preferably 20 to 70% by weight based on the total amount of the resin component, more Preferably, it is in the range of 30 to 70% by weight.

  In addition to the above components (A), (B), (C) and other resins not having an aromatic ring, the optical photosensitive resin composition of the present invention includes, for example, a photosensitizer, an acid proliferation agent, Silane or titanate coupling agents, and other flexibility and synthetic agents such as synthetic rubbers and silicone compounds, antioxidants, antifoaming agents, etc. can be blended in appropriate proportions depending on the purpose and application. . Moreover, inorganic additives such as various pigments, dyes, and inorganic fillers can be appropriately blended as necessary.

  The optical photosensitive resin composition of the present invention is prepared by, for example, blending the above components (A), (B), (C), and other additives as required, at a predetermined ratio, and mixing by heating and melting. It can produce by doing.

  The optical photosensitive resin composition of the present invention is used, for example, as follows. That is, the resin composition is potted on a transparent substrate such as glass, and a desired molding die is pressed onto the resin composition to fill the resin composition into the molding die, and light is irradiated there. It can be cured by doing so. Then, by removing the molding die, a cured body of the resin composition integrated on the transparent substrate (an optical material that is a molded product) can be obtained. Alternatively, the resin composition can be filled into a transparent mold that transmits light and photocured. The optical photosensitive resin composition of the present invention can produce, for example, a hybrid lens by such a production method. In addition, the optical photosensitive resin composition of the present invention can be cured by itself in a molding die to be an optical component such as an optical lens. Furthermore, you may heat-process at the predetermined temperature with respect to the said hardening body after the said light irradiation as needed. By the heating, the heat resistance stability of the cured body can be improved, and particularly in the case of a laminate with a transparent substrate, the adhesion between the substrate and the cured resin can be improved.

For the light irradiation, for example, an ultraviolet (UV) lamp or a single band lamp having a specific wavelength can be used as an apparatus. As the amount of irradiation, for example, preferably 500~10000mJ / cm ^2, more preferably 1000~8000mJ / cm ^2. The irradiation wavelength and the irradiation amount can be appropriately changed according to the desired thickness of the cured product. That is, when the irradiation amount is less than the above range, it is difficult to sufficiently cure the photosensitive resin composition, and it tends to be difficult to mold the obtained optical material into a desired cured product shape on the transparent substrate. It is done. Moreover, it is because there exists a possibility that the malfunction that photodegradation will arise by excessive irradiation may arise when it exceeds the said range. Since the photosensitive resin composition can be sufficiently cured when the irradiation amount is within the above range, for example, the photosensitive resin composition can be molded into a desired cured product shape on a transparent substrate. In addition, it is possible to prevent light deterioration due to excessive irradiation.

  Moreover, as conditions for the heat treatment performed as necessary after the light irradiation, for example, the heat treatment temperature is preferably 60 to 200 ° C., more preferably 80 to 170 ° C., and the heat treatment time is preferably 0. .5-3 hours, more preferably 0.5-2 hours.

  In addition, the optical photosensitive resin composition of this invention can also be shape | molded in a sheet form irrespective of the above shaping | molding molds.

  The optical photosensitive resin composition of the present invention obtained as described above can be used as a molding material (optical material) for optical parts by mounting it on a printed circuit board or the like by solder reflow.

  The optical photosensitive resin composition of the present invention can be used as a molding material (optical material) for optical parts such as optical lenses by the production method as described above, and is also a light curing type for fixing optical waveguides and optical parts. It can be used for various applications such as adhesives.

  Among optical materials obtained by curing the above-mentioned optical photosensitive resin composition, in particular, an optical material having a refractive index of 1.52 or less and an Abbe number of 54 or more is low. It meets the needs for optical materials with refractive index specifications and is useful. The refractive index is determined by, for example, polishing the surface of the optical material with a grinder and then using the refractometer (manufactured by Atago Co., Ltd.) with a sodium d line in a 25 ° C. environment. A value obtained by measuring a refractive index is shown. The Abbe number can be obtained from the measured refractive index values in these cases using the refractometer and simultaneously measuring sodium c-line and f-line under the above conditions.

  Next, the present invention will be described based on examples. However, the present invention is not limited to these examples. In the examples, “parts” means weight basis unless otherwise specified.

  First, each material shown below was prepared.

<Epoxy resin>
[A-1]
Alicyclic epoxy resin having no aromatic ring (Daicel Chemical Industries, Cel2021P)
[A-2]
Alicyclic epoxy resin that does not have an aromatic ring (EHPE3150, manufactured by Daicel Chemical Industries)
[A-3]
Dicyclopentadiene type epoxy resin having no aromatic ring (ADEKA, EP-4088L)
[A-4]
Bisphenol A type epoxy resin (Mitsubishi Gas Chemical Company, YL6810)
[A-5]
Linear aliphatic epoxy resin (made by ADEKA, ED-523L)

<Oxetane resin>
[B-1]
Bifunctional oxetane resin having no aromatic ring (OXT-221, manufactured by Toagosei Co., Ltd.)
[B-2]
Monofunctional oxetane resin not having an aromatic ring (OXT-101, manufactured by Toagosei Co., Ltd.)
[B-3]
Aromatic oxetane resin (manufactured by Toa Gosei Co., Ltd., OXT-211)

<Photoacid generator (photopolymerization initiator)>
[C-1]
50% by weight propylene carbonate solution of a mixture mainly composed of diphenyl-4-thiophenoxyphenylsulfonium hexafluoroantimonate and bis [4- (diphenylsulfonio) phenyl] sulfide-bis-hexafluoroantimonate (manufactured by ADEKA, SP -170)
[C-2]
50% by weight solution of propylene carbonate in a mixture mainly composed of a compound represented by the following structural formula

<Antioxidant>
Tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane (manufactured by Sakai Chemical Industry Co., Ltd., SOGNNOX1010)

[Examples 1 to 10, Comparative Examples 1 to 4]
The above components were blended in the proportions shown in Tables 1 and 2 below, and heated, melted and mixed to prepare an optical photosensitive resin composition.

  With respect to the optical photosensitive resin compositions of Examples and Comparative Examples thus obtained, each characteristic evaluation was performed according to the following criteria. The results are shown in Tables 1 and 2 below.

≪Refractive index and Abbe number≫
The optical photosensitive resin composition (liquid) is poured into a transparent mold having a size of 1 × 1.5 × 0.5 cm, cured by irradiating with ultraviolet rays (UV) at 6000 mJ / cm ² , and then taken out from the mold. Further, an optical material (cured body) was produced by performing a heat treatment at 150 ° C. for 1 hour. After polishing the surface of the optical material thus obtained using a grinder, the refractive index of the optical material at the sodium d line in a 25 ° C. environment is measured using a refractometer (manufactured by Atago Co., Ltd.). It was measured. At the same time, the measurement wavelength was set to sodium c-line and f-line, and the Abbe number was obtained from the measured values of the refractive index in these cases.
Further, based on the above measured values, each characteristic (refractive index and Abbe number) was evaluated according to the following criteria.
Refractive index:
X Over 1.52.
* 1.52 or less.
Abbe number:
X Less than 54.
○ 54 or more.

≪Transparency / Photocurability≫
A film was formed on a PET film (Mitsubishi Chemical Polyester Film Co., Ltd., Diafoil MRF-50) that had been subjected to silicone release treatment so as to have a thickness of 500 μm. / Cm ² ) and then heat-treated at 150 ° C. for 1 hour to obtain a cured product.
And the transparency of the said hardening body measures the transmittance | permeability of 400 nm with a spectrophotometer (the JASCO Corporation make, UV-VIS), and evaluates transparency according to the following references | standards based on the measured value. I did it.
transparency:
X Less than 90%.
△ 90% or more and less than 94%.
* More than 94%.
Moreover, the hardening state of the cured body surface after the said light irradiation was evaluated on the following references | standards, and it was set as photocurability evaluation.
Photocurability:
X: Insufficient curing, difficult to release, and high tackiness.
〇 Hardened and releasable, no tack.

  From the above results, the resin component includes a dicyclopentadiene type epoxy resin (a-3) having no aromatic ring and a monofunctional oxetane resin (b-2) having no aromatic ring, and a chemical having no aromatic ring. The optical photosensitive resin composition of Example, which is a resin having a structure, has a low refractive index and a high Abbe number. In particular, Examples 5, 6, 7, 9, and 10 have a high Abbe number of 57, which is more useful from the viewpoint of reducing chromatic aberration. Therefore, by using the optical photosensitive resin composition of the example, it is possible to provide an optical material such as an optical lens having a low refractive index and a high Abbe number.

  On the other hand, Comparative Example 1 does not contain a monofunctional oxetane resin having no aromatic ring. Further, Comparative Examples 3 and 4 do not contain a dicyclopentadiene type epoxy resin having no aromatic ring. In Comparative Example 2, a dicyclopentadiene type epoxy resin having no aromatic ring also contains a dicyclopentadiene type epoxy resin having no aromatic ring, but since an aromatic oxetane resin is contained, The resin component is not a resin having a chemical structure having no aromatic ring. From the above, none of the optical photosensitive resin compositions of Comparative Examples has the desired low refractive index and high Abbe number required for the present invention.

  The optical photosensitive resin composition of the present invention has a high photocurability, and can be a three-dimensional structure (cured material) having a low refractive index and a high Abbe number while having high transparency. It is useful for optical applications such as a molding material (optical material) for optical components such as, and a photo-curing adhesive for fixing optical components. Moreover, since the optical material using the optical photosensitive resin composition of the present invention has high reliability, it can be used for optical products such as optical lenses.

Claims (4)

An optical photosensitive resin composition, the resin component of which is a resin having a chemical structure having no aromatic ring, including the following components (A) and (B), and together with the resin component, the following component (C) A photosensitive resin composition for optics, comprising:
(A) A dicyclopentadiene type epoxy resin having no aromatic ring.
(B) A monofunctional oxetane resin having no aromatic ring.
(C) A photoacid generator.   The content of the component (A) with respect to the total amount of the resin component is 10 to 50% by weight, the content of the component (B) is 5 to 30% by weight, and the content of the component (C) with respect to 100 parts by weight of the total amount of the resin component The optical photosensitive resin composition according to claim 1, wherein is 0.3 to 3 parts by weight.   An optical material obtained by curing the optical photosensitive resin composition according to claim 1.   The optical material according to claim 3, wherein the refractive index is 1.52 or less and the Abbe number is 54 or more.