JP5505122B2 - Photosensitive resin composition, photosensitive resin varnish, photosensitive resin film, photosensitive resin cured product, and visible light guide - Google Patents

Description

  The present invention relates to a photosensitive resin composition, a photosensitive resin varnish, a photosensitive resin film, a cured product thereof, and a visible light guide path made of the cured product. More specifically, a photosensitive resin composition, a photosensitive resin varnish, and a photosensitive resin that have excellent transparency in the visible light wavelength region and can be a cured product with little deterioration such as coloring in a high-temperature and high-humidity reliability test. The present invention relates to a film and a cured photosensitive resin obtained by photocuring these films. In addition, the cured photosensitive resin of the present invention is developed especially for use in a visible light guide.

  An LED is an example of an illumination light source that has been widely used in recent years. Since LEDs have the characteristics of high brightness and low power consumption, they are widely used in various mobile devices such as mobile phones, personal digital assistants (PDAs), portable game devices, and portable audio devices. In addition, in recent years, applications for large-sized devices such as backlights for liquid crystal displays have been developed.

  Since such a device is required to further reduce power consumption, weight, and thickness, it is desired to use a more efficient lighting device. Under such a background, attention has been focused on a light guide, a light guide plate, and an illumination device using the waveguide.

  Among them, a device using a polymer is excellent in processability and can have a flexible structure. Therefore, a polymer light guide, a polymer light guide plate, and a polymer waveguide are considered to be optimal for these applications.

  The polymer material used for the lighting device is required to have high transparency in the visible light wavelength region of 380 to 780 nm from the viewpoint of the usage environment of the applied equipment. Conventionally, vinyl copolymers represented by alicyclic polyolefins, (meth) acrylic polymers, and the like have been used as polymer materials that satisfy these required characteristics. Many of these polymer materials are utilized mainly for prisms, lenses, light guide plates, etc., taking advantage of their high transparency. However, since the molding method is centered on melt molding such as injection molding or extrusion molding, it is difficult to process a small and complicated member or an extremely thin member. Further, since these polymer materials are thermoplastic resins, they have a problem of poor heat resistance reliability and moisture resistance reliability.

  As a processing technique capable of forming a complicated member, a casting method, an imprint method, a stamp method, a transfer method, and the like can be considered. Further, when a coating method, a printing method, a spin coater method or the like is used, a thin member can be formed. By injecting a liquid with photosensitivity into a mold of any shape, or by pressing the liquid into a casting mold with a mold, or pressing a material processed into a film or sheet with a mold and irradiating with light Three-dimensional cross-linking and insolubilization can easily form a complex-shaped member. Therefore, materials having photosensitivity and excellent optical characteristics, in particular, transparency in the visible light region have been studied (for example, see Patent Documents 1 and 2).

JP-A-6-128342 JP 2001-288206 A

However, in the above materials, in order to ensure transparency with visible light, the amount of photoinitiator added is increased and the amount of unreacted polymerizable compounds is reduced. Caused problems such as thermal deterioration and poor high temperature and high humidity reliability.
The present invention has been made to solve the above-described problems, and is a photosensitive resin composition and a photosensitive resin varnish that can be a cured product having high transparency in a visible light wavelength region of 380 to 780 nm and high temperature and high humidity reliability. It is an object of the present invention to provide a photosensitive resin film, a photosensitive resin cured product obtained by photocuring these, and a visible light guide path made of the photosensitive resin cured product.

  As a result of repeated investigations to solve the above-mentioned problems, the inventors of the present invention are photosensitive resin compositions having a specific amount of (A) an acrylic polymer, (B) a polymerizable compound, and (C) as essential components. A photopolymerization initiator, and (D) a hindered phenol antioxidant, and (B) the polymerizable compound contains a specific amount of polyalkylene glycol di (meth) acrylate, and the polyalkylene glycol di (meth) acrylate Has found that a photosensitive resin composition having at least a propylene glycol chain and having a polymerization degree of an alkylene glycol chain of 5 to 15 can solve the above problems.

That is, the present invention provides the following (1) to (5).
(1) A photosensitive resin composition comprising (A) an acrylic polymer, (B) a polymerizable compound, (C) a photopolymerization initiator, and (D) a hindered phenol-based antioxidant, The polymerizable compound contains polyalkylene glycol di (meth) acrylate, the polyalkylene glycol di (meth) acrylate has at least a propylene glycol chain, and the polymerization degree of the alkylene glycol chain is 5 to 15,
For the total amount of component (A) and component (B),
(A) The content of the component is 30 to 70% by mass,
(B) 30-70 mass% of content of a component,
The content of polypropylene glycol di (meth) acrylate is 15 to 70% by mass, and the total amount of component (A) and component (B) is 100 parts by mass,
The photosensitive resin composition whose content of (C) component is 0.03-3.0 mass part, and whose content of (D) component is 0.01-1.0 mass part.
(2) A photosensitive resin varnish containing the photosensitive resin composition of (1) above and an organic solvent.
(3) A photosensitive resin film obtained by applying the photosensitive resin varnish of (2) above onto a substrate film and drying it.
(4) A cured photosensitive resin obtained by irradiating and curing the photosensitive resin composition of (1), the photosensitive resin varnish of (2), or the photosensitive resin film of (3).
(5) A visible light guide path comprising the cured photosensitive resin of (4).

  According to the present invention, a photosensitive resin composition, a photosensitive resin varnish, a photosensitive resin film, which can be a cured product having high transparency in the visible light wavelength region and excellent in heat resistance, moisture resistance, and photocuring these. It is possible to provide a cured cured photosensitive resin and a visible light guide.

It is the top view (upper) and front view (lower) of the apparatus which measures white LED transmitted light intensity ratio.

  The photosensitive resin composition of the present invention comprises (A) an acrylic polymer, (B) a polymerizable compound, (C) a photopolymerization initiator, and (D) a photosensitizer obtained by containing a hindered phenol-based antioxidant. It is an adhesive resin composition.

[(B) Polymerizable compound]
The (B) polymerizable compound contained in the photosensitive resin composition of the present invention contains polyalkylene glycol di (meth) acrylate. The polyalkylene glycol di (meth) acrylate has at least a propylene glycol chain, and the polymerization degree of the alkylene glycol chain is 5 to 15.
Examples of the alkylene glycol chain of the polyalkylene glycol di (meth) acrylate include an ethylene glycol chain and a butylene glycol chain in addition to the propylene glycol chain. Among these polymers having an alkylene glycol chain, a polymer consisting only of a propylene glycol chain represented by the following general formula (1) or a copolymer consisting of a propylene glycol chain and an ethylene glycol chain is preferable.

In the general formula (1), R ₁ and R ₂ are each a hydrogen atom or a methyl group. R ₃ is represented by the following general formula (2), (3) or (4).

  In the said General formula (2), a is the range of 5-15.

  In the said General formula (3), b is 1 or more, and b + c is the range of 5-15. The repeating unit of the general formula (3) may be random or block regardless of the order. In addition, the following general formula (4) is mentioned as one aspect of the general formula (3).

  In the said General formula (4), d + f is 1 or more, and d + e + f is the range of 5-15. The repeating unit of the general formula (4) may be random or block regardless of the order.

The (B) polymerizable compound in the photosensitive resin composition contains the above-described polyalkylene di (meth) acrylate, so that the compatibility between the (A) acrylic polymer and the (B) polymerizable compound is kept good. The photosensitive resin composition, the photosensitive resin varnish, and the cured product of the photosensitive resin composition have high transparency in the visible light wavelength region, and excellent high temperature and high humidity reliability.
Moreover, the polymerization degree of the alkylene glycol chain of this polyalkylene glycol di (meth) acrylate is 5-15.
When the degree of polymerization is less than 5, mixing of (A) acrylic polymer and (B) polymerizable compound described later does not occur well, the transparency of the cured product of the photosensitive resin composition is poor, and high temperature and high humidity This is not preferable because reliability is lowered. Moreover, since the mechanical strength of the hardened | cured material of the photosensitive resin composition will fall when the said polymerization degree exceeds 15, it is unpreferable. (A) From the viewpoint of good mixing with the acrylic polymer and the mechanical strength of the resulting cured product, the degree of polymerization of the alkylene glycol chain is particularly preferably 7-12.

  In the present invention, the polymerizable compound (B) is preferably polyfunctional having two or more polymerizable groups in one molecule. By using a polyfunctional polymerizable compound, three-dimensional crosslinking proceeds, and a cured product having little shape change with respect to heat can be obtained. Furthermore, since generation | occurrence | production of the bleed-out of the unreacted substance of (B) polymeric compound can be suppressed, it is preferable. Specific examples of the compound include those described in International Publication WO2009 / 066668.

  As the polymerizable compound (B), the above-mentioned polyalkylene di (meth) acrylate may be used alone, but the polymerizable compound and one or more polyfunctional polymerizable compounds may be used in combination. If the polyalkylene glycol di (meth) acrylate is contained as an essential component, the (B) polymerizable compound is not particularly limited as long as it is polymerized by heating or irradiation with ultraviolet rays, for example, an ethylenically unsaturated group, etc. The compound which has the following polymerizable substituent is mentioned suitably. From the viewpoint of transparency of the resulting photosensitive resin composition, those having no light absorption in the visible light wavelength region of 380 to 780 nm are particularly preferable. As for the properties, any of solid, semi-solid and liquid can be used.

  Preferred examples of the polymerizable compound (B) that can be used in combination with the poly (meth) acrylate include compounds represented by the following general formula (5). The polymerizable compound is preferable because it has excellent transparency in the visible light wavelength region, has an aromatic property, has excellent heat resistance, and is inexpensive.

In the general formula (5), R ₄ and R ₅ are each a hydrogen atom or a methyl group. R ₆ is represented by the following general formula (6).

In the general formula (6), g + h is in the range of 2 to 30, R ₇ and R ₈ are each hydrogen atom or a methyl group. R ₉ is any one of divalent groups represented by the following formula (7).

In this invention, content of (B) component is 30-70 mass% with respect to the total amount of (A) component and (B) component, and content of the said polyalkylene glycol di (meth) acrylate is It is 15-70 mass%.
When the content of the component (B) is less than 30% by mass, the cured product obtained by photocuring the photosensitive resin composition has a low crosslinking density, and the curing reaction hardly proceeds. Bleed out is likely to occur, and the reliability in the high temperature and high humidity test is lowered. In order to advance the curing reaction, it can be solved by increasing the amount of (C) photopolymerization initiator to be described later, but in this method, thermal degradation is caused by the remaining unreacted (C) photopolymerization initiator and its decomposition products. This is not preferable because it is inferior in high temperature and high humidity reliability. On the other hand, when the content of the component (B) exceeds 70% by mass, it is difficult to process the photosensitive resin composition into a film, which is not preferable. From the viewpoint of the processability of the photosensitive resin composition into a film, the curability of the photosensitive resin composition, and the maintenance of high temperature and high humidity reliability, the content of the component (B) is preferably 40 to 60% by mass. More preferably, it is 45-55 mass%.

  When the content of the polyalkylene glycol di (meth) acrylate is less than 15% by mass, the (A) acrylic polymer and the (B) polymerizable compound described later do not mix well, and the resulting photosensitive resin The transparency in the visible light wavelength region of the composition, the photosensitive resin varnish, and the cured product of the photosensitive resin composition is not preferable. Moreover, when content of polyalkylene glycol di (meth) acrylate exceeds 70 mass%, since the high temperature high humidity reliability of the hardened | cured material of the photosensitive resin composition falls, it is unpreferable. From the viewpoint of compatibility of (A) acrylic polymer and (B) polymerizable compound, transparency in the visible light wavelength region of the resulting photosensitive resin composition, and high-temperature and high-humidity reliability, The content of the polyalkylene glycol di (meth) acrylate in the component B) is preferably 18 to 50% by mass, and more preferably 20 to 40% by mass.

[(A) Acrylic polymer]
The photosensitive resin composition of the present invention contains (A) an acrylic polymer. (A) Content of an acrylic polymer is the range of 30-70 mass% with respect to the total amount of (A) component and (B) component.
When the content of the component (A) is less than 30% by mass, it is difficult to process the photosensitive resin composition into a film, which is not preferable. Moreover, when content of (A) component exceeds 70 mass%, since the reliability in a high temperature, high humidity test falls, it is unpreferable. The content of the component (A) is preferably 40 to 60% by mass, more preferably 45 to 55% by mass, from the viewpoint of maintaining the processability of the photosensitive resin composition into a film and maintaining high temperature and high humidity reliability. It is.

The (A) acrylic polymer of the photosensitive resin composition of the present invention may be either a homopolymer composed of a single monomer or a copolymer composed of two or more monomers.
Among them, the (A) acrylic polymer is preferably a polymer obtained by polymerizing at least one selected from the group consisting of methyl methacrylate, butyl methacrylate, butyl acrylate, 2-hydroxyethyl acrylate, and methacrylic acid as a monomer. In particular, a homopolymer of the above monomers or two or more monomer copolymers selected from the above monomers are preferred.
Methyl methacrylate contributes to the high transparency of the acrylic polymer. Butyl methacrylate and butyl acrylate contribute to giving the acrylic polymer any glass transition temperature. 2-Hydroxyethyl acrylate and methacrylic acid contribute to an improvement in compatibility between the acrylic polymer and the polymerizable compound (B). From the above viewpoint, a specific (A) acrylic polymer is obtained using various monomers as necessary, and by using this, (B) polymerization containing polypropylene glycol di (meth) acrylate as an essential component It is possible to provide a photosensitive resin composition satisfying all of compatibility with a photosensitive compound, high transparency in the visible light wavelength region of the obtained cured product, and any glass transition temperature.

  There is no restriction | limiting in particular in the structure of the said (A) acrylic polymer, a polymerization method, and the kind of polymerization reaction. For example, a solution polymerization method, a suspension polymerization method, an emulsion polymerization method, a bulk polymerization method, a gas phase polymerization method, etc. can be used as the polymerization method, and radical polymerization, cationic polymerization, anionic polymerization, coordination can be used as the polymerization reaction. Polymerization or the like can be used.

[(C) Photopolymerization initiator]
The photosensitive resin composition of the present invention contains (C) a photopolymerization initiator. (C) Content of a photoinitiator is the range of 0.03-3.0 mass parts with respect to 100 mass parts of total amounts of (A) component and (B) component.
When the content of the component (C) is less than 0.03 parts by mass, the curing reaction does not proceed sufficiently by irradiation with light, which is not preferable. If the amount exceeds 3.0 parts by mass, the effect of coloring derived from the component (C) increases, and as a result, the transparency in the visible light wavelength region decreases, which is not preferable. From the viewpoint of photocurability of the photosensitive resin composition and transparency in the visible light wavelength region, the content of the component (C) is preferably based on 100 parts by mass of the total amount of the components (A) and (B). It is 0.1-1.5 mass parts, More preferably, it is 0.1-1.0 mass part.

  (C) At least one selected from (C-1) α-hydroxyacetophenone photoinitiators and glyoxyester photoinitiators as photopolymerization initiators, and (C-2) phosphine oxide photoinitiators It is preferable to contain. By using such a specific (C) photopolymerization initiator, it is possible to obtain a cured product that is less colored and highly transparent in the visible light wavelength region.

(C-1) α-hydroxyacetophenone photoinitiators include 1-hydroxy-cyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- [4- (2-hydroxy Ethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- (4- (4- (2-hydroxy-3,5,2-methylpropionyl) -benzyl ) -Phenyl) -2-methylpropan-1-one, and the like.
Examples of the glyoxyester photoinitiator include oxyphenylacetic acid 2- [2-oxo-2-phenylacetoxyethoxy] ethyl ester, oxyphenylacetic acid 2- (2-hydroxyethoxy) ethyl ester, and mixtures thereof. Can be mentioned. Among these, oxyphenylacetic acid 2- [2-oxo-2-phenylacetoxyethoxy] ethyl ester and oxyphenylacetic acid 2- (2-hydroxyethoxy) are less colored and highly transparent in the visible light wavelength region. ) Ethyl esters and mixtures thereof are particularly preferred.

  Examples of (C-2) phosphine oxide photoinitiators include 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2,4,6-trimethylbenzoyl-phenylphosphine oxide, and mixtures thereof. It is done. When such a photoinitiator is used, not only curing is possible with a small amount of light irradiation but also photobleaching ability, and thus the obtained photocured product has excellent transparency in the visible light region. Among these, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide is preferable because it has excellent transparency particularly in the visible light region and has high curability.

[(D) hindered phenolic antioxidant]
The photosensitive resin composition of this invention contains (D) hindered phenolic antioxidant. (D) Content of hindered phenolic antioxidant is the range of 0.01-1.0 mass part with respect to 100 mass parts of total amounts of (A) component and (B) component. When the content of the component (D) is less than 0.01 parts by mass, the high temperature and high humidity reliability is inferior, which is not preferable. Moreover, since it will superpose | polymerize in the case of photocuring when it exceeds 1.0 mass part, it is unpreferable. From the viewpoint of the curability of the photosensitive resin composition and the high temperature and high humidity reliability, the content of the component (D) is preferably 0.1 with respect to 100 parts by mass of the total amount of the components (A) and (B). It is -1.0 mass part, More preferably, it is 0.2-1.0 mass part.

  (D) As a hindered phenolic antioxidant, a hindered phenolic system that has at least one phenol group in a molecule having one methyl group and one t-butyl group on the same aromatic ring. It is especially preferable that it is antioxidant and is shown by following formula (8). When these compounds are used, the heat resistance reliability can be improved, and since the polymerization inhibition during photocuring is small, the curability is good. Further, productivity is high because the amount of light irradiation required for curing is small.

  X in the above formula (8) is any of the divalent groups of the following formulas (9) and (10).

[Other photosensitive resin compositions]
In the photosensitive resin composition of the present invention, in addition to the above components (A) to (D), if necessary, the photosensitive resin composition of the present invention includes a yellowing inhibitor, an ultraviolet absorber, You may add what is called additives, such as a visible light absorber, a leveling agent, a coloring agent, a plasticizer, a stabilizer, a filler, and a fluorescent whitening agent, in the ratio which does not have a bad influence on the effect of this invention.

  Moreover, the photosensitive resin composition of this invention can be diluted with a suitable organic solvent, and can be used as a photosensitive resin varnish. The organic solvent used here is not particularly limited as long as it can dissolve the resin composition. For example, aromatic hydrocarbons such as toluene, xylene, mesitylene, cumene, p-cymene; tetrahydrofuran, 1, 4 -Cyclic ethers such as dioxane; alcohols such as methanol, ethanol, isopropanol, butanol, ethylene glycol, propylene glycol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone; acetic acid Esters such as methyl, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate and γ-butyrolactone; carbonates such as ethylene carbonate and propylene carbonate; ethylene glycol monomethyl ether, ethylene glycol Ethyl ether, ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, Polyhydric alcohol alkyl ethers such as diethylene glycol dimethyl ether and diethylene glycol diethyl ether; ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene Polyhydric alcohol alkyl ether acetates such as glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate; N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, etc. And amides.

Among these, from the viewpoint of solubility and boiling point, methanol, ethanol, isopropanol, acetone, toluene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, ethylene glycol monomethyl ether , Ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol dimethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, and N, N-dimethylacetamide.
These organic solvents can be used alone or in combination of two or more.
Moreover, it is preferable that the solid content density | concentration in a resin varnish is 20-80 mass% normally.

[Photosensitive resin varnish]
When preparing the photosensitive resin varnish, it is preferable to mix by stirring. Although there is no restriction | limiting in particular about the stirring method, The stirring using a propeller is preferable from a viewpoint of stirring efficiency. Although there is no restriction | limiting in particular in the rotational speed of the propeller at the time of stirring, It is preferable that it is 10-1,000min- ¹ . When it is 10 min ⁻¹ or more, each of the components (A) to (D) and the organic solvent is sufficiently mixed, and when it is 1,000 min ⁻¹ or less, there is less entrainment of bubbles due to propeller rotation. Therefore, it is preferable. More preferably from the above viewpoint is 50~800min ^-1, particularly preferably 100~500min ^-1.

  Although there is no restriction | limiting in particular also about stirring time, It is preferable that it is 1 to 24 hours. If it is 1 hour or longer, each of the components (A) to (D) and the organic solvent is sufficiently mixed, and if it is 24 hours or shorter, the varnish preparation time can be shortened and sufficient. Since productivity is obtained, it is preferable.

  The prepared photosensitive resin varnish is preferably filtered using a filter having a pore diameter of 50 μm or less. It is preferable to use a filter having a pore size of 50 μm or less because large foreign matters and the like are removed, no repellency or the like occurs when applying the varnish, and scattering of light propagating through the core portion is suppressed. From the above viewpoint, it is more preferable to filter using a filter having a pore diameter of 30 μm or less, and it is particularly preferable to filter using a filter having a pore diameter of 10 μm or less.

  The prepared photosensitive resin varnish is preferably degassed under reduced pressure. There is no restriction | limiting in particular in the defoaming method, As a specific example, a degassing apparatus with a vacuum pump and a bell jar and a vacuum apparatus can be used. Although there is no restriction | limiting in particular in the pressure reduction degree at the time of pressure reduction, the range in which the organic solvent contained in a resin varnish does not boil is preferable. Although there is no restriction | limiting in particular in vacuum degassing time, It is preferable that it is 3 to 60 minutes. If it is 3 minutes or longer, it is preferable because bubbles dissolved in the resin varnish can be removed, and if it is 60 minutes or less, the organic solvent contained in the resin varnish does not volatilize.

[Photosensitive resin film]
Hereinafter, the photosensitive resin film of the present invention will be described.
The photosensitive resin film of this invention consists of the said photosensitive resin composition, apply | coats the photosensitive resin varnish containing said (A)-(D) component to a suitable base film, and uses methods, such as drying. Then, the solvent is removed to form a photosensitive resin layer (hereinafter sometimes simply referred to as “resin layer”). Can be easily manufactured. Moreover, you may apply | coat and manufacture a photosensitive resin composition directly to a base film, without varnishing.

  The base film is not particularly limited, and examples thereof include: polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefins such as polyethylene, polypropylene, and polyethylene-vinyl acetate copolymer; polyvinyl chloride, polyvinylidene chloride, Examples include polycarbonate, polyamide, polyimide, polyamideimide, polyetherimide, polyethersulfide, polyethersulfone, polyetherketone, polyphenyleneether, polyphenylenesulfide, polyarylate, polysulfone, and liquid crystal polymer.

  Among these, from the viewpoint of flexibility and toughness, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polypropylene, polyethylene-vinyl acetate copolymer, polycarbonate, polyamide, polyimide, polyamideimide, polyphenylene ether, polyphenylene sulfide, Polyarylate and polysulfone are preferred.

  The thickness of the base film may be appropriately changed depending on the intended flexibility, but is preferably 3 to 250 μm. If it is 3 μm or more, sufficient film strength is obtained, and if it is 250 μm or less, sufficient flexibility is obtained. From the above points, the thickness of the base film is more preferably 5 to 200 μm, and further preferably 7 to 150 μm. In addition, in order to improve the peelability from the resin layer, a film that has been subjected to a release treatment with a silicone compound, a fluorine-containing compound, or the like may be used as necessary.

  A photosensitive resin film produced by applying a photosensitive resin varnish or a photosensitive resin composition on a base film is affixed with a protective film on the resin layer as necessary. Or it is good also as a 3 layer structure of the resin layer and protective film which consist of photosensitive resin hardened | cured material.

  The protective film is not particularly limited, and examples thereof include polyesters such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate; polyolefins such as polyethylene and polypropylene. Among these, from the viewpoint of flexibility and toughness, polyesters such as polyethylene terephthalate; polyolefins such as polyethylene and polypropylene are preferable. In addition, from the viewpoint of improving the peelability from the resin layer, a film that has been subjected to a release treatment with a silicone compound, a fluorine-containing compound, or the like may be used as necessary.

  The thickness of the protective film may be appropriately changed depending on the intended flexibility, but is preferably 10 to 250 μm. If it is 10 μm or more, sufficient film strength can be obtained, and if it is 250 μm or less, sufficient flexibility can be obtained. From the above points, the thickness of the protective film is more preferably 15 to 200 μm, and further preferably 20 to 150 μm.

  Although there is no restriction | limiting in particular about the thickness of the resin layer of the photosensitive resin film of this invention, It is preferable that it is 5-500 micrometers normally by the thickness after drying. If it is 5 μm or more, a cured product having sufficient strength can be obtained, and if it is 500 μm or less, drying can be performed sufficiently, the amount of residual solvent in the resin film is reduced, and the cured product of the film is heated. Sometimes foaming is less likely to occur.

  The photosensitive resin film thus obtained can be easily stored, for example, by winding it into a roll. Alternatively, a roll-shaped film can be cut into a suitable size and stored in a sheet shape.

[Hardened photosensitive resin]
The photosensitive resin composition of the present invention can be quickly photocured. Here thickness 0.5 mm, the reaction rate of the cured product obtained by the light irradiation amount 3000 mJ / cm ² as 100%, it is preferable 100 mJ / cm ² irradiation time of the reaction rate is 80% or more. When such a material is used, a material excellent in productivity of a molded product can be obtained.

The type of light for curing used in the present invention is not particularly limited as long as the curing reaction proceeds, but UV light is preferable from the viewpoint of fast curing, and (C) photo initiation From the viewpoint of the absorption wavelength of the polymerizing agent, it is more preferable to cure with 365 nm i-rays in UV light. There are no particular limitations on the light source that emits 365-nm i-rays. Examples of light sources include mercury lamps such as low-pressure mercury lamps, high-pressure mercury lamps, and ultra-high-pressure mercury lamps, as well as tungsten lamps, xenon lamps, gas lasers, and semiconductor lasers. Etc.
Dose necessary for curing, the cured product of which varies in thickness and refractive index such as seeking, in general at an illuminance 1~1000mW / cm ^2, to obtain a cured product by irradiating 10 to 10000 mJ / cm ² be able to.

  It is preferable that the obtained cured product has a light transmittance of 90% or more in a test piece having a thickness of 200 μm in a visible light region of 380 to 780 nm. When such a cured product is used, light can be propagated without reducing the illuminance of light and without changing the color of the light source.

  In addition, the photosensitive fat composition of the present invention can obtain a cured product by curing reaction or polymerization reaction with light, heat, or the like. In that case, it is also possible to obtain a cured product having an arbitrary shape by making it into an arbitrary shape such as a sheet, a film, a strip, etc. in advance and then performing a curing reaction or the like. The cured product thus obtained can be used as a visible light guide for an illumination device by being used in an air clad.

  Examples of the present invention will be specifically described below, but the present invention is not limited to these examples.

[Example 1]
(1) Preparation of photosensitive resin composition In a brown plastic bottle with a capacity of 200 mL, (A) as an acrylic polymer, Hitaroid HA3204EB-1E (resin content 45 mass%, ethyl acetate / butyl acetate mixed solution, Hitachi Chemical Co., Ltd.) (Product name) 90.9 g, (B) As a polymerizable compound, NK ester APG-400 (polypropylene glycol diacrylate, average PO chain length = 7, Shin-Nakamura Chemical Co., Ltd. product name) 25.0 g, 25.0 g of FANCLIL FA-321M (EO-modified bisphenol A dimethacrylate, average EO chain = 10, trade name, manufactured by Hitachi Chemical Co., Ltd.), (C) Irgacure 754 (oxy) as a photopolymerization initiator Phenylacetic acid 2- [2-oxo-2-phenylacetoxyethoxy] ethyl ester, oxyphenylacetic acid 2- (2- (Droxyethoxy) ethyl ester mixture, 0.3 g of Ciba Specialty Chemicals Co., Ltd.), DAROCUR TPO (2,4,6-trimethylbenzoyl-diphenylphosphine oxide, Ciba Specialty Chemicals Co., Ltd.) ) 0.3 g, (D) Adeka Stub AO-80 (hindered phenol antioxidant, trade name of ADEKA Co., Ltd.) 0.2 g and acetone 10 g as a phenolic antioxidant, And stirred at room temperature for 12 hours. The obtained mixture was subjected to pressure filtration using a membrane filter having a pore size of 2 μm, and vacuum deaerated at 10 mmHg to prepare a photosensitive resin composition.

(2) Preparation of photosensitive resin film Coating the photosensitive resin composition prepared in (1) on the release-treated surface of a PET film (manufactured by Teijin DuPont Films, trade name: A53, thickness: 50 μm) (Product name: Multicoater TM-MC, manufactured by Hirano Techseed Co., Ltd.), dried at 100 ° C. for 20 minutes, and then a release PET film (manufactured by Teijin DuPont Films, trade name: A31, thickness) as a protective film 25 μm) was pasted to obtain a photosensitive resin composition film. At this time, the thickness of the resin layer can be arbitrarily adjusted by adjusting the gap of the coating machine, but in this example, the thickness after curing was adjusted to 200 μm.

(3) Creation of cured product Using the film obtained in (2), 2000 mJ / cm ² from above the release PET film using an ultraviolet exposure machine (Dainippon Screen Co., Ltd., trade name: MAP-1200-L). Irradiated with UV. Then, the base film and the protective film were peeled off to obtain a film-like photocured product. Thereafter, test pieces were cut into arbitrary shapes and used for various measurements.

(4) Evaluation of transmittance A sample obtained by cutting the cured product obtained in (3) into a size of 4 cm × 4 cm was used for evaluation. The transmittance was measured at a measurement wavelength of 200 to 800 nm using a spectrophotometer U-3310 manufactured by Hitachi, Ltd. From the measurement results, three points of 420 nm, 560 nm, and 780 nm were evaluated. When the obtained cured product was evaluated, the transmittance was 92% (420 nm), 92% (560 nm), and 92% (780 nm), and the transparency was good.

(5) Measuring method of white LED transmission intensity It demonstrates using FIG. FIG. 1 is a plan view (upper) and a front view (lower) of an apparatus for measuring a white LED transmitted light intensity ratio. Sample 3 obtained by cutting the cured product obtained in (3) into 1 cm × 10 cm size was used for evaluation. A side-emitting white LED was used as the light source 2, and light was emitted at an input current of 15 mA. Sample 3 was placed on substrate 1, and white LED light (light source transmission intensity ratio = 4.2) was incident from the end face. Measure the spectrum of the transmitted light using the “Multi-photometric system MCPD-3000” manufactured by Otsuka Electronics Co., Ltd. from the end face on the opposite side, and calculate the transmission intensity ratio from the peak intensity of the emitted light. It calculated according to the following formula.

Transmission intensity ratio = (Int ₄₆₀ / Int ₅₆₀ )
(Int ₄₆₀ : Intensity of peak mainly caused by B band seen in the vicinity of ₄₆₀ nm Int ₅₆₀ : Intensity of peak mainly seen in the vicinity of ₅₆₀ nm due to mixed light of G band and R band.)
The transmission intensity ratio is preferably 1.5 or more, and more preferably 2.0 or more. Accordingly, those having a transmission intensity ratio of less than 1.5 were rated as x, those having a transmittance of 1.5 or more but less than 2.0 were marked as ◯, and those having a transmission intensity ratio of 2.0 or more as ◎.
When the obtained cured product was evaluated, the transmission intensity ratio was 3.1, and the transmitted light was white light similar to the white LED light source.

(6) High-temperature and high-humidity reliability test The test piece evaluated in (5) was put in an oven prepared at 85 ° C./85% RH. After 250 hours, the white LED transmission intensity was measured in the same manner as in (5). The transmission intensity ratio was 2.0, and the transmitted light was white light similar to the white LED light source.

[Examples 2 to 5 and Comparative Examples 1 and 2]
According to the composition of Table 1 and Table 2, operation similar to Example 1 was performed and the photosensitive resin composition was obtained. A photocured product was prepared and evaluated in the same manner as in Example 1. The results are shown in Tables 1 and 2.

(Explanation in Tables 1 and 2)
A-1: Acrylic polymer (Hitaroid HA3204EB-1E, resin content 45% by mass, ethyl acetate / butyl acetate mixed solution, manufactured by Hitachi Chemical Co., Ltd.)
A-2: Acrylic polymer (Hitaroid HA3204EB-1, resin content 42% by mass, ethyl acetate / butyl acetate mixed solution, manufactured by Hitachi Chemical Co., Ltd.)
B-1: Polypropylene glycol diacrylate (average PO chain length = 7) manufactured by Shin-Nakamura Chemical Co., Ltd., APG-400
B-2: EO-modified bisphenol A dimethacrylate (average EO chain length = 10) manufactured by Hitachi Chemical Co., Ltd., FA-321M
B-3: EO-modified bisphenol A diacrylate (average EO chain length = 10) manufactured by Hitachi Chemical Co., Ltd., FA-321A
B-4: Polypropylene glycol diacrylate (average PO chain length = 12), manufactured by Hitachi Chemical Co., Ltd., FA-P270A
C-1: Glyoxyester photoinitiator. Oxyphenylacetic acid 2- [2-oxo-2-phenylacetoxyethoxy] ethyl ester, mixture of oxyphenylacetic acid 2- (2-hydroxyethoxy) ethyl ester, Ciba Specialty Chemicals Co., Ltd., Irgacure 754
C-2: Phosphine oxide photoinitiator. 2,4,6-trimethylbenzoyl-phenylphosphine oxide, manufactured by Ciba Specialty Chemicals Co., Ltd., DAROCUR TPO
D-1: 3,9-bis [2- {3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] -2,4,8,10 -Tetraoxaspiro [5.5] undecane, manufactured by ADEKA Corporation, ADK STAB AO-80

  As shown in Examples 1 to 5, the cured product obtained from the photosensitive resin composition of the present invention had high transparency and excellent high temperature and high humidity reliability. On the other hand, as in Comparative Examples 1 and 2, when the content of polyalkylene glycol diacrylate in the polymerizable compound (B) falls below the range defined in the present invention, the cured product is transparent in the visible light wavelength region. In particular, the transparency after the high temperature and high humidity test was greatly reduced.

  As described above, the photosensitive resin composition, the photosensitive resin varnish, the photosensitive resin film, and the photosensitive resin film, which can be a cured product having high transparency in the visible light wavelength region and excellent in heat resistance, moisture resistance, and reliability. The cured photosensitive resin obtained by curing could be provided.

  The photosensitive resin composition of the present invention is a photosensitive resin composition that has a high transparency in the visible light wavelength region and can be a cured product having excellent heat resistance, moisture resistance, and reliability. Photosensitive resin varnish, photosensitive resin Films and cured photosensitive resins obtained by photocuring them can be obtained. Therefore, they are optimal for applications such as optical waveguides and light guide materials.

1 Substrate 2 Light source 3 Sample

Claims (8)

A photosensitive resin composition comprising (A) an acrylic polymer, (B) a polymerizable compound, (C) a photopolymerization initiator, and (D) a hindered phenol-based antioxidant,
(B) The polymerizable compound contains polyalkylene glycol di (meth) acrylate, the polyalkylene glycol di (meth) acrylate has at least a propylene glycol chain, and the polymerization degree of the alkylene glycol chain is 5 to 15. Yes,
For the total amount of component (A) and component (B),
(A) The content of the component is 30 to 70% by mass,
(B) 30-70 mass% of content of a component,
The content of polypropylene glycol di (meth) acrylate is 15 to 70% by mass, and the total amount of component (A) and component (B) is 100 parts by mass,
(C) Component content of 0.03 to 3.0 parts by mass, and (D) component content of 0.01 to 1.0 parts by mass,
The photosensitive resin composition for visible light guides characterized by being. A photosensitive resin composition comprising (A) an acrylic polymer, (B) a polymerizable compound, (C) a photopolymerization initiator, and (D) a hindered phenol-based antioxidant,
(B) The polymerizable compound contains polyalkylene glycol di (meth) acrylate, the polyalkylene glycol di (meth) acrylate has at least a propylene glycol chain, and the polymerization degree of the alkylene glycol chain is 5 to 15. Yes,
For the total amount of component (A) and component (B),
(A) The content of the component is 30 to 70% by mass,
(B) 30-70 mass% of content of a component,
The content of polypropylene glycol di (meth) acrylate is 15 to 70% by mass, and
For 100 parts by mass of the total amount of component (A) and component (B),
(C) Content of component is 0.03-3.0 mass parts, and
(D) The content of the component is 0.01 to 1.0 part by mass,
Photosensitivity characterized in that the transmittance of a film-like photocured product prepared so that the film thickness after curing of the photosensitive resin composition is 200 μm is 91% or more at three points of 420 nm, 560 nm and 780 nm. Resin composition. A photosensitive resin composition comprising ( A) an acrylic polymer, (B) a polymerizable compound, (C) a photopolymerization initiator, and (D) a hindered phenol-based antioxidant,
(B) The polymerizable compound contains polyalkylene glycol di (meth) acrylate, the polyalkylene glycol di (meth) acrylate has at least a propylene glycol chain, and the polymerization degree of the alkylene glycol chain is 5 to 15. Yes,
For the total amount of component (A) and component (B),
(A) The content of the component is 30 to 70% by mass,
(B) 30-70 mass% of content of a component,
The content of polypropylene glycol di (meth) acrylate is 15 to 70% by mass, and
For 100 parts by mass of the total amount of component (A) and component (B),
(C) Content of component is 0.03-3.0 mass parts, and
(D) The content of the component is 0.01 to 1.0 part by mass,
Transmission intensity ratio of a film-like cured product prepared so that the film thickness after curing of the photosensitive resin composition is 200 μm = (Int ₄₆₀ / Int ₅₆₀ )
(However, Int ₄₆₀ : The intensity of the peak mainly due to the B band seen in the vicinity of ₄₆₀ nm, Int ₅₆₀ : The intensity of the peak mainly caused by the mixed light in the G band and the R band seen in the vicinity of ₅₆₀ nm.)
Is a photosensitive resin composition characterized by being 2.0 or more. The photosensitive resin composition according to claim 2 or 3, which is used for a visible light guide. The photosensitive resin varnish containing the photosensitive resin composition in any one of Claims 1-4 , and an organic solvent. The photosensitive resin film formed by apply | coating the photosensitive resin varnish of Claim 5 on a base film, and drying. Photosensitivity formed by irradiating light to the photosensitive resin composition according to any one of claims 1 to 4, the photosensitive resin varnish according to claim 5 , or the photosensitive resin film according to claim 6. Cured resin. The visible light light guide which consists of a photosensitive resin hardened | cured material of Claim 7 .