Photoreactive composition

Abstract

To provide a photoreactive composition capable of efficiently curing to a deep part.SOLUTION: A photoreactive composition includes a compound having a radical-polymerizable functional group, a photosensitizer, and a heat radical generator, where a conversion ratio at a position of 10 cm from a top edge of the photoreactive composition is 20% or more when injecting the photoreactive composition so as to occupy a portion of 15 cm length of a glass tube composed of borosilicate glass having an outer diameter of 4.932 mm to 4.970 mm, a wall thickness of 0.38 mm, and a length of 17.78 cm, irradiating a portion of 1 cm from a top edge of the injected photoreactive composition by a light intensity of 2,000 mW / cm2 for 60 seconds using an LED lamp having a center wave length of 365 nm, and standing for one hour at 25°C.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a photoreactive composition that is cured by irradiation with light. [Background technology]

[0002] Conventionally, photoreactive compositions have been known that can be cured in a short time by light irradiation and can be patterned by using a photomask, a laser irradiation device, etc. Photoreactive compositions are widely used, for example, as hard coats for films and molded products, resist materials, etc.

[0003] Known methods for curing photoreactive compositions include frontal photoreaction and domino free radical photopolymerization (DFRP).

[0004] In the frontal photoreaction, radicals generated from a photoradical generator by irradiation with light induce a polymerization reaction of a monomer, and the heat of the reaction activates a thermal radical generator, which is believed to enable hardening of deep areas where photoexcitation is not possible. However, since the frontal photoreaction is a system that hardens by heat generation, the reaction system becomes hot, and there is a problem that, for example, when a molded product is produced in contact with a non-heat-resistant adherend, the adherend is deformed.

[0005] On the other hand, in the DFRP system, as described in Non-Patent Document 1, for example, a base is generated from a photobase generator by irradiation with light, and the base is used as a catalyst to react with a base multiplier, increasing the concentration of the base component. The reduction of the base component causes the thermal radical generator to decompose at a low temperature, resulting in free radical polymerization of the vinyl monomer. Non-Patent Document 1 shows that a DFRP system further having a base multiplier shortens the induction time and improves the reaction rate compared to a system using a photobase generator and a thermal radical generator as catalysts. Since the DFRP system is not a system that cures by heat generation, it is said that even if heat rise cannot be expected, curing progresses in deep areas where photoexcitation is not possible, and a high conversion rate can be obtained. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] Minghui He, et al., Journal of Polymer Science, PART A:POLYMER CHEMISTRY 2014, 52,1560-1569 Summary of the Invention [Problem to be solved by the invention]

[0007] As a result of intensive research, the present inventors have found that even in the DFRP system, when producing a molded body that is poorly light-transmitting, a molded body with a thick film, a molded body with a complex shape, etc., depending on the type of monomer, only the surface is cured and it is difficult to cure deep inside.

[0008] An object of the present invention is to provide a photoreactive composition that can be cured efficiently to a deep portion. [Means for solving the problem]

[0009] The photoreactive composition according to the present invention is a photoreactive composition comprising a compound having a radically polymerizable functional group, a photosensitizer, and a thermal radical generator, the photoreactive composition being injected into a glass tube made of borosilicate glass having an outer diameter of 4.932 mm to 4.970 mm, a wall thickness of 0.38 mm, and a length of 17.78 cm, so as to occupy a portion of the tube in a length of 15 cm, and a light intensity of 2000 mW / cm was applied to a portion of the injected photoreactive composition 1 cm from the upper end of the tube using an LED lamp having a central wavelength of 365 nm. 2 When the photoreactive composition is irradiated with light at 400 nm for 60 seconds and then allowed to stand at 25° C. for 1 hour, the conversion rate at a position 10 cm from the top end of the photoreactive composition is 20% or more.

[0010] In a specific aspect of the photoreactive composition according to the present invention, the photoreactive composition is injected into a glass tube made of borosilicate glass having an outer diameter of 4.932 mm to 4.970 mm, a wall thickness of 0.38 mm, and a length of 17.78 cm, so as to occupy a portion of the tube in a length of 15 cm, and a light intensity of 20 mW / cm is applied to a portion 1 cm from the upper end of the injected photoreactive composition using an LED lamp having a central wavelength of 365 nm. 2 When the photoreactive composition is irradiated with light at 350° C. for 25 seconds and then allowed to stand at 25° C. for 1 hour, the conversion rate at a position 10 cm from the top end of the photoreactive composition is 20% or more.

[0011] In a specific aspect of the photoreactive composition according to the present invention, the compound having a radically polymerizable functional group has an SP value of 10-18.

[0012] In another specific aspect of the photoreactive composition according to the present invention, the compound having a radically polymerizable functional group is a vinyl monomer containing a nitrogen atom.

[0013] In yet another specific aspect of the photoreactive composition according to the present invention, the vinyl monomer containing a nitrogen atom is at least one selected from the group consisting of (meth)acryloylmorpholine, N-vinyl-2-pyrrolidone, vinylpyridine, N-vinylcarbazole, (meth)acrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, isopropylacrylamide, hydroxyethylacrylamide, and dimethylaminopropylamide. Preferably, the vinyl monomer containing a nitrogen atom is (meth)acryloylmorpholine.

[0014] In still another specific aspect of the photoreactive composition according to the present invention, the compound having the radically polymerizable functional group is a compound having a plurality of radically polymerizable functional groups.

[0015] In yet another specific aspect of the photoreactive composition according to the present invention, the compound having a plurality of radically polymerizable functional groups is at least one selected from the group consisting of trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, and polytetraethylene glycol di(meth)acrylate.

[0016] In still another specific aspect of the photoreactive composition according to the present invention, the compound having a radically polymerizable functional group is a vinyl monomer containing an oxygen atom.

[0017] In yet another specific aspect of the photoreactive composition according to the present invention, the vinyl monomer containing an oxygen atom is at least one selected from the group consisting of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, acrylic acid, carboxyethyl acrylate, and tetrahydrofurfuryl acrylate.

[0018] In yet another specific aspect of the photoreactive composition according to the present invention, the photosensitizer is at least one selected from the group consisting of benzophenone derivatives, thioxanthone derivatives, and anthraquinone derivatives. Preferably, the photosensitizer is a thioxanthone derivative.

[0019] In still another specific aspect of the photoreactive composition according to the present invention, the thermal radical generator is an organic peroxide. Effect of the Invention

[0020] According to the present invention, it is possible to provide a photoreactive composition that can be cured efficiently to a deep portion. [Brief description of the drawings]

[0021] [Figure 1]FIG. 1 is a schematic front view showing a glass tube used for measuring the conversion rate in a photoreactive composition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The present invention will be described in detail below.

[0023] The photoreactive composition of the present invention contains a compound having a radically polymerizable functional group, a photosensitizer, and a thermal radical generator.

[0024] In the present invention, when light is applied to a portion 1 cm from the upper end 2a of the photoreactive composition 2 injected into the glass tube 1 shown in Figure 1, the conversion rate at a position 10 cm from the upper end 2a of the photoreactive composition 2 in the glass tube 1 is 20% or more.

[0025] More specifically, in measuring the conversion rate, first, a glass tube 1 is prepared. The glass tube 1 may have an outer diameter D of 4.932 mm to 4.970 mm, a wall thickness of 0.38 mm, and a length from one end 1a to the other end 1b of the glass tube 1 of 17.78 cm (7 inches). The glass tube 1 is made of borosilicate glass. As such a glass tube 1, for example, a commercially available NMR tube (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product number "291-47851 NMR Test Tube S-Type") may be used. It is preferable to use a glass tube 1 having the above dimensions, but the outer diameter D of the glass tube 1 may have an error of ±2.0 mm. The wall thickness of the glass tube 1 may have an error of ±0.3 mm. The length of the glass tube 1 may be 15 cm or more.

[0026] Next, the photoreactive composition 2 is poured into the prepared glass tube 1 so as to occupy a portion of the glass tube 1 having a length of 15 cm. Note that the length of the photoreactive composition 2 in the glass tube 1 is the length from the upper end 2a to the lower end 2b of the photoreactive composition 2.

[0027] Next, a 1 cm long section of the photoreactive composition 2 in the glass tube 1 was irradiated with light of a light intensity of 2000 mW / cm using an LED lamp having a central wavelength of 365 nm. 2 The glass tube 1 is irradiated with light for 60 seconds. At this time, only a portion of the photoreactive composition 2 in the glass tube 1 that is 1 cm long from the upper end 2a is irradiated with light, and the lower end 2b of the photoreactive composition 2 is not irradiated with light. In other words, it is preferable to irradiate with light while covering the portion other than the irradiated portion so that it is not exposed to light. After the light irradiation, the glass tube 1 is left to stand for 1 hour at 25°C. Note that these operations are performed with the glass tube 1 standing as shown in Figure 1. After leaving it to stand, the conversion rate is measured at a position 10 cm from the upper end 2a to the lower end 2b of the photoreactive composition 2 in the glass tube 1.

[0028] The conversion rate was measured by measuring the Raman spectrum before and after irradiation at a position 10 cm from the upper end 2a of the photoreactive composition 2 toward the lower end 2b in the glass tube 1, and calculating the intensity of the reference peak and the peak intensity at 1600 to 1680 cm attributed to the C=C stretching vibration of the vinyl group. -1 The change in peak intensity before and after irradiation with light in the vicinity of the wavelength is calculated using the following formula.

[0029] Conversion rate (%) = (1-peak intensity ratio after irradiation / peak intensity ratio before irradiation) x 100 Peak intensity ratio before irradiation = (C = C peak intensity before light irradiation / reference peak intensity before light irradiation) Peak intensity ratio after irradiation = (C = C peak intensity after light irradiation / reference peak intensity after light irradiation)

[0030] The peak before light irradiation refers to a peak measured before light irradiation after injecting the photoreactive composition 2. The peak after light irradiation refers to a peak measured after leaving the composition at rest at 25° C. for 1 hour after light irradiation.

[0031] The reference peak refers to a peak attributable to a functional group or bond that does not change before and after irradiation with light having a central wavelength of 365 nm. Examples of the reference peak include a peak attributable to an ester group, a peak attributable to (CN) of an amide group, and a peak attributable to a cyclic ether (COC).

[0032] In the present invention, the conversion rate of the photoreactive composition measured in this manner is preferably 20% or more, more preferably 30% or more, even more preferably 40% or more, and particularly preferably 60% or more. The upper limit of the conversion rate of the photoreactive composition is not particularly limited, but can be, for example, 100% or less.

[0033] In the present invention, the only condition for light irradiation is a light intensity of 20 mW / cm 2 When the time is changed to 25 seconds at 100° C., the conversion rate at a position 10 cm from the upper end 2a of the photoreactive composition 2 in the glass tube 1 is preferably 20% or more, more preferably 30% or more, even more preferably 40% or more, and particularly preferably 60% or more. In this case, the molded body obtained by light irradiation can be cured more efficiently to the depths. The upper limit of the conversion rate of the photoreactive composition is not particularly limited, but can be, for example, 100% or less.

[0034] In the photoreactive composition of the present invention, the photosensitizer is excited by irradiation with light, and the photosensitizing action of the excited photosensitizer induces decomposition of the thermal radical generator at low temperature to generate radicals, which allows free radical polymerization of a compound having a radically polymerizable functional group. Therefore, in the present invention, free radical polymerization of a compound having a radically polymerizable functional group can be performed at low temperature without generating a base by a photobase generator.

[0035] In the present invention, the conversion rate of the photoreactive composition can be adjusted by the type of compound having a radically polymerizable functional group, the amount of the photosensitizer, or the amount of the thermal radical generator.

[0036] In the case of a photoreactive composition using a photobase generator, carbon dioxide gas is generated during the reaction, and voids may occur inside the obtained molded body. Therefore, it is preferable that the photoreactive composition of the present invention does not substantially contain a photobase generator or a base multiplier. In this specification, "substantially does not contain" means that the amount is less than 1 part by weight relative to 100 parts by weight of the photoreactive composition. However, in the present invention, a photobase generator or a base multiplier may be contained.

[0037] In the photoreactive composition of the present invention, when a portion of the photoreactive composition 2 containing a compound having a radically polymerizable functional group is irradiated with light at a position 1 cm away from the upper end 2a, the conversion rate at a position 10 cm away from the upper end 2a is equal to or greater than the lower limit value. Therefore, the composition can be applied to a wide range of monomers having a radically polymerizable functional group, and the photoreactive composition can be efficiently cured deep inside.

[0038] The temperature reached during the reaction of the photoreactive composition of the present invention is not particularly limited, but is preferably 100° C. or less, more preferably 80° C. or less. The temperature reached during the reaction of the photoreactive composition of the present invention can be measured by thermography.

[0039] The photoreactive composition of the present invention can be cured up to the shadow areas at low temperatures even in cast polymerization in which a mold having a complex shape (e.g., a mold having voids) having areas that become shadowed by light is used and the photoreactive composition is injected into the mold to cause a reaction.

[0040] In addition, even if the photoreactive composition of the present invention contains a filler and light does not reach the deep part, it can be cured deep at a low temperature by irradiating the surface part with light. Therefore, the photoreactive composition of the present invention can be cured efficiently deep even when producing a molded body that is difficult to transmit light. Here, low temperature means that the photoreactive composition proceeds without adjusting the environmental temperature so that the reaction does not need to be promoted by heating after irradiation with light.

[0041] Hereinafter, each material constituting the photoreactive composition of the present invention will be described in detail.

[0042] (Compound having a radically polymerizable functional group) The photoreactive composition of the present invention contains a compound having a radical polymerizable functional group. The radical polymerizable functional group is not particularly limited, but is a functional group in which an addition reaction proceeds in a chain reaction manner due to radicals generated by decomposition of a radical generator. Examples of the radical polymerizable functional group include an ethynyl group, an allyl group, a propenyl group, an acetyl group, an acryloyl group, a methacryloyl group, a styryl group, a vinyloxy group, and a vinyl ester group. Among them, a (meth)acryloyl group is preferable from the viewpoint of higher reactivity. At least one radical polymerizable functional group may be contained in one molecule, and it is preferable that a plurality of radical polymerizable functional groups are contained. When a plurality of radical polymerizable functional groups are contained in one molecule, the composition can be cured by crosslinking even if the conversion rate is small. In this specification, "(meth)acryloyl" refers to "acryloyl" or "methacryloyl".

[0043] The SP value of the compound having a radical polymerizable functional group is preferably within the range of 10 to 18. In this case, the compatibility with photosensitizers such as benzophenone derivatives, thioxanthone derivatives, and anthraquinone derivatives, and with thermal radical generators can be further improved. The SP value is a measure of the intermolecular force acting between a solvent and a solute, and is a measure of the affinity between substances. The SP value can be determined based on the theory of regular solutions of Hidebrand. The SP value can be obtained from literature information, as well as by the calculation method of Hansen or Hoy, the estimation method of Fedors, and the like. In this specification, the Fedors formula δ 2 =ΣE / ΣV (δ is the SP value, E is the evaporation energy, and V is the molar volume). The unit of the SP value is (cal / cm 3 ) 0.5 The Fedors method is described in the Journal of the Japan Adhesion Association, Vol. 22, p. 566, 1986.

[0044] Compounds with multiple radically polymerizable functional groups in one molecule: Examples of compounds having multiple radically polymerizable functional groups in one molecule include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, divinylbenzene, etc. Among them, trimethylolpropane tri(meth)acrylate is preferable from the viewpoint of more efficient curing to the depth of the molded article obtained by light irradiation.

[0045] In this specification, "(meth)acrylate" refers to "acrylate" or "methacrylate".

[0046] The compound having a radically polymerizable functional group is not particularly limited, but is preferably a vinyl monomer containing a nitrogen atom.

[0047] Vinyl monomers containing nitrogen atoms; The vinyl monomer containing a nitrogen atom is not particularly limited, and examples thereof include (meth)acryloylmorpholine, N-vinyl-2-pyrrolidone, vinylpyridine, N-vinylcarbazole, (meth)acrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, isopropylacrylamide, hydroxyethylacrylamide, and dimethylaminopropylacrylamide. These vinyl monomers may be used alone or in combination. Among them, from the viewpoint of more efficiently curing the molded body obtained by light irradiation to the depth thereof, the vinyl monomer containing a nitrogen atom is preferably a vinyl monomer containing a nitrogen-containing ring, and is preferably (meth)acryloylmorpholine.

[0048] Vinyl monomers containing oxygen atoms; The vinyl monomer containing oxygen atoms is not particularly limited, and examples thereof include hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, acrylic acid, carboxyethyl acrylate, and tetrahydrofurfuryl acrylate. These vinyl monomers may be used alone or in combination. Among them, from the viewpoint of more efficient curing to the depth of the molded body obtained by light irradiation, the vinyl monomer containing oxygen atoms is preferably tetrahydrofurfuryl acrylate.

[0049] Other vinyl monomers; The photoreactive composition of the present invention may further contain another vinyl monomer different from the vinyl monomer containing at least one of a nitrogen atom and an oxygen atom in the side chain substituent. Examples of the other vinyl monomer include a vinyl monomer that does not contain a nitrogen atom or an oxygen atom in the side chain substituent.

[0050] Examples of other vinyl monomers include (meth)acrylic acid and its esters, such as (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. Examples of other vinyl monomers that may be used include vinyl monomers such as vinyl chloride, vinylidene chloride, vinyl acetate, methyl vinyl ether, styrene, and divinylbenzene, and compounds having unsaturated double bonds, such as isoprene. Examples of other vinyl monomers that may be used include (meth)acrylamide, (meth)acrylamide derivatives such as isopropylacrylamide, and (meth)acrylonitrile.

[0051] These other vinyl monomers may be used alone or in combination of two or more kinds.

[0052] The content of the compound having a radical polymerizable functional group is not particularly limited, but is preferably 20 parts by weight or more, more preferably 50 parts by weight or more, and preferably 99.9 parts by weight or less, more preferably 98 parts by weight or less, relative to 100 parts by weight of the total amount of the photoreactive composition. When the content of the compound having a radical polymerizable functional group is within the above upper limit range, the molded article obtained by light irradiation can be cured more efficiently to the depth thereof.

[0053] In this specification, "(meth)acrylic" refers to "acrylic" or "methacrylic".

[0054] (Photosensitizer) The photoreactive composition of the present invention contains a photosensitizer. The photosensitizer is a substance that is excited by irradiation with light and induces decomposition of the thermal radical generator at a temperature equal to or lower than the 10-hour half-life temperature due to the photosensitizing effect of the excited photosensitizer. Examples of the light to be irradiated include infrared light, visible light, and ultraviolet light.

[0055] The photosensitizer is not particularly limited, but examples thereof include benzophenone derivatives, thioxanthone derivatives, anthraquinone derivatives, anthracene derivatives, and benzoin derivatives. Among them, the photosensitizer is preferably a benzophenone derivative, a thioxanthone derivative, or an anthraquinone derivative from the viewpoint of being sensitized by light irradiation in the visible light range. Among them, the thioxanthone derivative is more preferable from the viewpoint of being sensitized by light irradiation in the visible light range and being soluble in a compound having a radical polymerizable functional group. The photosensitizer may be used alone or in combination with a plurality of types.

[0056] Examples of the benzophenone derivatives include benzophenone, p,p'-aminobenzophenone, 2-hydroxy-4-alkoxybenzophenone, p,p'-tetramethyldiaminobenzophenone, and p,p'-tetraethylaminobenzophenone.

[0057] Examples of thioxanthone derivatives include 2-alkylthioxanthone, 2,4-dialkylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone, and 2,4-diethylthioxanthone.

[0058] Examples of the anthraquinone derivatives include anthraquinone, 2-alkylanthraquinone, 2,4-dialkylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, and 1,2-benzanthraquinone.

[0059] Examples of the anthracene derivatives include anthracene, 9,10-dialkoxyanthracene, 9,10-diphenylanthracene, and 9-ethoxyanthracene.

[0060] Examples of benzoin derivatives include benzoin, benzoin ether, benzoin ethyl ether, and benzoin-i-butyl ether.

[0061] The content of the photosensitizer is not particularly limited, but is preferably 0.01 parts by weight or more, more preferably 0.05 parts by weight or more, even more preferably 0.1 parts by weight or more, and even more preferably 0.2 parts by weight or more, based on 100 parts by weight of the total amount of the photoreactive composition. The content of the photosensitizer is preferably 5 parts by weight or less, more preferably 2 parts by weight or less, even more preferably 1 part by weight or less, and even more preferably 0.9 parts by weight or less. When the content of the photosensitizer is equal to or more than the lower limit, the molded body obtained by light irradiation can be cured more efficiently to the deep part. When the content of the photosensitizer is equal to or less than the upper limit, the amount of light absorbed by the photosensitizer itself is reduced, and the molded body obtained by light irradiation can be cured more efficiently to the deep part.

[0062] (Thermal radical generator) The photoreactive composition of the present invention contains a thermal radical generator, such as an organic peroxide or a polysulfide.

[0063] The organic peroxide is not particularly limited, and examples thereof include benzoyl peroxide, diisopropyl peroxycarbonate, dioctyl peroxydicarbonate, t-butyl peroxylaurate, lauroyl peroxide, dioctanoyl peroxide, hydrogen peroxide, acetyl peroxide, cumyl peroxide, t-butyl peroxide, propionyl peroxide, benzoyl peroxide, chlorobenzoyl peroxide, dichlorobenzoyl peroxide, bromomethylbenzoyl peroxide, lauroyl peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, diisopropyl peroxycarbonate, tetralin hydroperoxide, 1-phenyl-2-methylpropyl-1-hydroperoxide, t-butyl pertriphenylacetate hydroperoxide, t-butyl performate, t-butyl peracetate, t-butyl perbenzoate, t-butyl perphenylacetate, t-butyl permethoxyacetate, t-butyl per-N-(3-toluyl)carbamate, ammonium bisulfate, and sodium bisulfate.

[0064] The polysulfide is not particularly limited, and examples thereof include sulfur compounds such as 2-mercaptobenzothiazole, dibenzothiazyl disulfide, and trimethylolpropane tris(3-mercaptopropionate).

[0065] These thermal radical generators may be used alone or in combination of two or more kinds.

[0066] The content of the thermal radical generator is not particularly limited, but is preferably 0.01 parts by weight or more, more preferably 0.1 parts by weight or more, preferably 10 parts by weight or less, more preferably 2 parts by weight or less, based on 100 parts by weight of the total amount of the photoreactive composition. When the content of the thermal radical generator is equal to or more than the lower limit, the radical polymerization of the compound having a radically polymerizable functional group proceeds more easily. When the content of the thermal radical generator is equal to or less than the upper limit, the storage stability is further improved. In addition, when the content of the thermal radical generator is equal to or more than the lower limit and equal to or less than the upper limit, the molded body obtained by light irradiation can be cured more efficiently to the depth thereof.

[0067] (Filler) The photoreactive composition of the present invention may further contain a filler. By containing a filler, the photoreactive composition can further increase the mechanical strength, electrical conductivity, thermal conductivity, etc. of the obtained molded article. Alternatively, the obtained molded article can be colored or imparted with light-shielding property or heat-shielding property.

[0068] The photoreactive composition of the present invention can be cured more efficiently to the deep part of a molded article even in a case where light is difficult to reach the deep part such as a part containing a filler, and can further increase electrical conductivity and thermal conductivity. Therefore, in this case, the composition can be suitably used for applications such as conductive tape and thermal conductive adhesive.

[0069] The filler is not particularly limited, and may be an inorganic filler or an organic filler. Among them, an inorganic filler is preferable. Note that an inorganic filler and an organic filler may be used in combination.

[0070] Examples of the organic filler that can be used include polyethylene fine particles, polypropylene fine particles, polyvinyl alcohol fine particles, polyvinyl butyral fine particles, polyvinyl chloride fine particles, polyvinylidene chloride fine particles, polyvinylidene fluoride fine particles, acrylonitrile fine particles, acrylic rubber fine particles, polystyrene fine particles, divinylbenzene fine particles, polyethylene terephthalate fine particles, polyimide fine particles, polyamide fine particles, cellulose fine particles, etc. These may be used alone or in combination of two or more.

[0071] Examples of inorganic fillers that can be used include metal oxides, metal carbonates, natural minerals, metal hydroxides, carbon materials, metal materials, hollow inorganic fillers, etc. These may be used alone or in combination of two or more.

[0072] Examples of the metal oxide include silica, aluminum oxide, titanium oxide, zirconium oxide, zinc oxide, lead oxide, and indium tin oxide.

[0073] Examples of the metal carbonate include calcium carbonate, magnesium carbonate, and barium carbonate.

[0074] Natural minerals include talc, mica, clay, and the like.

[0075] Examples of the metal hydroxide include aerosil, magnesium hydroxide, and aluminum hydroxide.

[0076] Examples of the carbon material include graphite, carbon black, and carbon nanotubes.

[0077] Examples of the metal material include copper, gold, silver, iron, aluminum, stainless steel, platinum, and palladium.

[0078] Examples of the hollow inorganic filler include glass balloons and shirasu balloons.

[0079] The inorganic filler may be surface-treated with a surface treatment agent such as a silane coupling agent.

[0080] Examples of silane coupling agents include 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane, 3-glycidylpropylmethyldimethoxysilane, 3-glycidylpropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-propylisocyanatemethyldimethoxysilane, 3-propylisocyanatetrimethoxysilane, etc. These may be used alone or in combination of two or more.

[0081] The content of the filler is not particularly limited, but is preferably 1 part by weight or more, more preferably 10 parts by weight or more, preferably 100 parts by weight or less, more preferably 80 parts by weight or less, based on 100 parts by weight of the total amount of the photoreactive composition. When the content of the filler is equal to or more than the lower limit, the mechanical strength, electrical conductivity, and thermal conductivity of the molded body produced can be further improved. When the content of the filler is equal to or less than the upper limit, the molded body obtained by light irradiation can be cured more efficiently to the depth thereof.

[0082] The photoreactive composition of the present invention contains such a large amount of filler, and even in cases where light does not reach deep inside, it can be cured deep inside at a low temperature by irradiating the surface portion with light.

[0083] (Other additives) The photoreactive composition of the present invention may contain other additives as long as the additives do not impair the object of the present invention. Examples of the other additives include a photobase generator and a base amplifier.

[0084] The photobase generator is a substance that generates a base by irradiation with light. The photobase generator is not particularly limited, and examples thereof include oxime ester compounds, ammonium compounds, benzoin compounds, dimethoxybenzylurethane compounds, and orthonitrobenzylurethane compounds.

[0085] The base amplifier is a substance that uses a base generated from a photobase generator as a catalyst to decompose the base and generate a new base. The generated base functions as a new catalyst, autocatalytically generating a large number of bases, and the concentration of the base component increases. The base amplifier may be a low molecular weight compound or a high molecular weight compound. An example of such a base amplifier is 1-(9-fluorenylmethoxycarbonyl)piperidine.

[0086] In addition, as other additives, it may contain antioxidants such as phenol-based, phosphorus-based, amine-based, or sulfur-based, and ultraviolet absorbers such as benzotriazole-based or hydroxyphenyltriazine-based. Alternatively, as other additives, it may contain halogenated flame retardants such as hexabromobiphenyl ether or decabromodiphenyl ether, flame retardants such as ammonium polyphosphate or trimethyl phosphate, and antistatic agents. In addition, it may contain additives such as stabilizers, pigments, dyes, silane coupling agents, titanium coupling agents, plasticizers, thickeners, viscosity reducers, and thixotropy-imparting agents. These additives may be used alone or in combination.

[0087] Further, as other additives, resins such as polystyrene, acrylic resins, methacrylic resins, polyester resins, polycarbonate resins, polyurethane resins, polyamide resins, polyimide resins, polyether resins, polyvinyl alcohol, polyvinyl acetal resins, polyvinyl acetate resins, etc. may be used in combination. Further, as other additives, resins such as polyvinyl chloride, chlorinated polyvinyl chloride, polyvinylidene chloride, polytetrafluoroethylene, silicone resins, etc. may be used in combination.

[0088] The present invention will now be described in more detail with reference to specific examples and comparative examples, although the present invention is not limited to the following examples.

[0089] Example 1 First, N-acryloylmorpholine (ACMO, manufactured by Tokyo Chemical Industry Co., Ltd.) was prepared as a compound having a radical polymerizable functional group. 2-isopropylthioxanthone (manufactured by Tokyo Chemical Industry Co., Ltd.) was prepared as a photosensitizer. Benzoyl peroxide (BPO, manufactured by Tokyo Chemical Industry Co., Ltd.) was prepared as a thermal radical generator.

[0090] Next, 8 g of N-acryloylmorpholine, 0.02 g of 2-isopropylthioxanthone, and 0.04 g of benzoyl peroxide were placed in a brown glass container having a volume of 20 mL, and the container was appropriately shaken at room temperature until the solid components were uniformly dissolved, thereby preparing a photoreactive composition.

[0091] Example 2 A photoreactive composition was prepared in the same manner as in Example 1, except that trimethylolpropane triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) was used as the compound having a radically polymerizable functional group.

[0092] (Examples 3 to 4) Photoreactive compositions were prepared in the same manner as in Example 1, except that in Example 3, the amount of 2-isopropylthioxanthone added as a photosensitizer was changed as shown in Table 1 below, and in Example 4, the amounts of the photosensitizer and benzoyl peroxide added as a thermal radical generator were changed as shown in Table 1 below.

[0093] (Examples 5 to 9) Photoreactive compositions were prepared in the same manner as in Example 1, except that the compounds shown in Table 1 below were used as compounds having a radical polymerizable functional group, and the amount of 2-isopropylthioxanthone added as a photosensitizer was changed as shown in Table 1 below. As compounds having a radical polymerizable functional group, dimethylacrylamide (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) was used in Example 5, and pentaerythritol triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) was used in Example 6. Hydroxyethyl acrylate (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) was used in Example 7, carboxyethyl acrylate (manufactured by Daicel-Allnex Corporation) was used in Example 8, and tetrahydrofurfuryl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.) was used in Example 9.

[0094] Comparative Example 1 A photoreactive composition was prepared in the same manner as in Example 2, except that 2-(9-oxoxanthen-2-yl)propionic acid 1,5,7-triazabicyclo[4.4.0]dec-5-ene (manufactured by Tokyo Chemical Industry Co., Ltd.) was used as a photobase generator instead of benzoyl peroxide as a thermal radical generator.

[0095] Comparative Example 2 A photoreactive composition was prepared in the same manner as in Example 1, except that n-butyl acrylate (manufactured by Nippon Shokubai Co., Ltd.) was used as an alkyl group-containing monomer instead of N-acryloylmorpholine as a compound having a radical polymerizable functional group.

[0096] Comparative Example 3 A photoreactive composition was prepared in the same manner as in Example 1, except that 2-ethylhexyl acrylate (manufactured by Nippon Shokubai Co., Ltd.) was used as an alkyl group-containing monomer instead of N-acryloylmorpholine, and the amount of 2-isopropylthioxanthone added as a photosensitizer was changed as shown in Table 1 below.

[0097] [evaluation] The photoreactive composition was injected into a borosilicate glass tube (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product number "291-47851 NMR Test Tube S-Type") having an outer diameter of 4.932 to 4.970 mm, a wall thickness of 0.38 mm, and a length of 17.78 cm, so as to occupy a 15 cm portion of the tube.

[0098] Next, a portion of the photoreactive composition in the tube, 1 cm long from the top end, was irradiated with ultraviolet light from an LED lamp having a central wavelength of 365 nm to polymerize the composition. 2 The height of the LED lamp was adjusted so that the UV light was irradiated for 60 seconds (120,000 mJ / cm 2 ) The portions other than the irradiated portion were covered to prevent light from reaching them during the irradiation. After the irradiation, the tube was left standing at 25°C for 1 hour in an upright position. The temperature reached during the reaction of the photoreactive composition was measured by thermography.

[0099] After standing, the conversion rate was measured at a position 10 cm long from the top of the photoreactive composition in the tube. The conversion rate was calculated by measuring the Raman spectrum at a position 10 cm long from the top of the photoreactive composition in the tube. When N-acryloylmorpholine was used, the 850 cm -1 The peak at 1615 cm is attributed to the C=C stretching vibration of the vinyl group. -1 The peak intensity ratio was calculated from the peak intensity ratio before and after irradiation. When N,N-dimethylacrylamide was used, the peak intensity at 1430 cm -1 The peak at 1630 cm is attributed to the C=C stretching vibration of the vinyl group. -1 On the other hand, when trimethylolpropane triacrylate was used, the peak intensity at 1750 cm -1 The peak at 1620 cm is attributed to the C=C stretching vibration of the vinyl group. -1 The peak intensity ratio was calculated from the peak intensity ratio before and after light irradiation. Measurements were also performed similarly for other acrylates. Note that "before light irradiation" refers to the state before polymerization, and "after light irradiation" refers to the state after light irradiation and leaving the material at rest at 25°C for 1 hour. Raman spectroscopy was performed using an "FT / IR6600" device (manufactured by JASCO Corporation) at a measurement wavelength of 4000 to 400 cm. -1 The measurements were performed with 16 scans.

[0100] The conversion rate was calculated according to the following formula. Conversion rate (%) = (1-peak intensity ratio after irradiation / peak intensity ratio before irradiation) x 100 Peak intensity ratio before irradiation = (C = C peak intensity before light irradiation / reference peak intensity before light irradiation) Peak intensity ratio after irradiation = (C = C peak intensity after light irradiation / reference peak intensity after light irradiation)

[0101] After standing for 1 hour at 25° C., the other end of the photoreactive composition in the tube was visually observed to evaluate deep curing. In the evaluation of deep curing, a case in which the photoreactive composition did not flow even when the tube was tilted was marked with an O, and a case in which the photoreactive composition flowed when the tube was tilted was marked with an X.

[0102] The light irradiation conditions were a light intensity of 20 mW / cm 2 for 25 seconds (500 mJ / cm 2 ) and irradiated with light, the conversion rate was measured in the same manner.

[0103] The results are shown in Table 1 below.

[0104] [Table 1] [Explanation of symbols]

[0105] 1. Glass tube 1a…one end 1b...other end 2...Photoreactive composition 2a…Top end 2b…lower end

Claims

1. A photoreactive composition comprising a compound having a radically polymerizable functional group, a photosensitizer, and a thermal radical generator, The photoreactive composition was injected into a glass tube made of borosilicate glass having an outer diameter of 4.932 mm to 4.970 mm, a wall thickness of 0.38 mm, and a length of 17.78 cm, so as to occupy a portion of the tube in a length of 15 cm. The photoreactive composition was then irradiated with light of a light intensity of 2000 mW / cm using an LED lamp having a central wavelength of 365 nm in a portion 1 cm from the upper end of the injected photoreactive composition. ２ A photoreactive composition, which has a conversion rate of 20% or more at a position 10 cm from the top end of the photoreactive composition when irradiated with light at 400 nm for 60 seconds and allowed to stand at 25° C. for 1 hour.

2. The photoreactive composition was injected into a 15 cm long portion of a glass tube made of borosilicate glass having an outer diameter of 4.932 mm to 4.970 mm, a wall thickness of 0.38 mm, and a length of 17.78 cm, and an LED lamp having a central wavelength of 365 nm was used to illuminate the injected photoreactive composition at a light intensity of 20 mW / cm at a portion 1 cm from the upper end. ２ 2. The photoreactive composition according to claim 1, wherein the photoreactive composition has a conversion of 20% or more at a position 10 cm from the top end when irradiated with light at 350° C. for 25 seconds and allowed to stand at 25° C. for 1 hour.

3. 3. The photoreactive composition according to claim 1, wherein the compound having a radically polymerizable functional group has an SP value of 10 to 18.

4. 4. The photoreactive composition according to claim 1, wherein the compound having a radically polymerizable functional group is a vinyl monomer containing a nitrogen atom.

5. The photoreactive composition according to claim 4, wherein the vinyl monomer containing a nitrogen atom is at least one selected from the group consisting of (meth)acryloylmorpholine, N-vinyl-2-pyrrolidone, vinylpyridine, N-vinylcarbazole, (meth)acrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, isopropylacrylamide, hydroxyethylacrylamide, and dimethylaminopropylamide.

6. 6. The photoreactive composition of claim 4, wherein the nitrogen atom-containing vinyl monomer is (meth)acryloylmorpholine.

7. The photoreactive composition according to any one of claims 1 to 3, wherein the compound having a radically polymerizable functional group is a compound having a plurality of radically polymerizable functional groups.

8. 8. The photoreactive composition according to claim 7, wherein the compound having a plurality of radically polymerizable functional groups is at least one selected from the group consisting of trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and dipentaerythritol hexa(meth)acrylate.

9. 4. The photoreactive composition according to claim 1, wherein the compound having a radically polymerizable functional group is a vinyl monomer containing an oxygen atom.

10. 10. The photoreactive composition of claim 9, wherein the vinyl monomer containing an oxygen atom is at least one selected from the group consisting of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, acrylic acid, carboxyethyl acrylate, and tetrahydrofurfuryl acrylate.

11. The photoreactive composition according to any one of claims 1 to 10, wherein the photosensitizer is at least one selected from the group consisting of benzophenone derivatives, thioxanthone derivatives, and anthraquinone derivatives.

12. 12. The photoreactive composition of claim 11, wherein the photosensitizer is a thioxanthone derivative.

13. The photoreactive composition of any one of claims 1 to 12, wherein the thermal radical generator is an organic peroxide.

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