Resin composition, resin membrane, film, film set, optical waveguide, photoelectric composite substrate, and electronic component

Abstract

To provide a resin composition capable of improving coatability and suppressing optical loss in optical waveguides.SOLUTION: Provided is a resin composition suitable for use in optical waveguide cladding, comprising a cyclic olefin resin (A) that includes structural units (a) and (b); the structural unit (a) contains at least one structural unit having a polymer side chain, selected from a group consisting of linear alkyl groups having 4 to 20 carbon atoms, groups in which one or more hydrogen atoms in such linear alkyl groups are substituted with halogen atoms, and groups in which one or more methylene groups in such linear alkyl groups are substituted with oxygen atoms; and the structural unit (b) comprises a structural unit derived from a maleimide compound.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resin composition, a resin film, a film, a film set, an optical waveguide, an optoelectronic composite substrate, and an electronic component. [Background technology]

[0002] BACKGROUND ART In recent years, there has been a demand for components in information and communication devices that can realize more advanced information communication, such as larger information capacity and faster information communication speed, and optical waveguides are being considered as one such component.

[0003] As a technology relating to optical waveguides, for example, the technology described in Patent Document 1 can be mentioned.

[0004] Patent Document 1 describes a material for forming an optical waveguide having a lower cladding layer containing an ultraviolet absorber and a core layer. Patent Document 1 describes that the material for forming an optical waveguide is less likely to cause pattern thickening or development residue, and makes it possible to form a clear and fine pattern. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-48223 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention provides a resin composition that can improve coatability and suppress optical loss in an optical waveguide. [Means for solving the problem]

[0007] According to the present invention, there are provided the following resin compositions, resin films, films, film sets, optical waveguides, optoelectronic composite substrates, and electronic components.

[0008] [1] A resin composition that can be used for an optical waveguide clad, Contains a cyclic olefin resin (A), The cyclic olefin resin (A) contains a structural unit (a) and a structural unit (b), the structural unit (a) comprises, in a polymer side chain, a structural unit containing at least one selected from the group consisting of a linear alkyl group having from 4 to 20 carbon atoms, a group in which one or more hydrogen atoms contained in a linear alkyl group having from 4 to 20 carbon atoms are substituted with halogen atoms, and a group in which one or more methylene groups contained in a linear alkyl group having from 4 to 20 carbon atoms are substituted with oxygen atoms; The resin composition, wherein the structural unit (b) includes a structural unit derived from a maleimide compound. [2] The resin composition according to [1] above, wherein the structural unit (a) includes at least one selected from the group consisting of a structural unit represented by the following formula (a-1), a structural unit represented by the following formula (a-2), and a structural unit represented by the following formula (a-3): [ka] (In the formula (a-1), R 31 represents any one selected from the group consisting of a linear alkyl group having from 4 to 20 carbon atoms, a group in which one or more hydrogen atoms contained in a linear alkyl group having from 4 to 20 carbon atoms are substituted with a halogen atom, and a group in which one or more methylene groups contained in a linear alkyl group having from 4 to 20 carbon atoms are substituted with an oxygen atom) [ka] (In the formula (a-2), R 41 represents any one selected from the group consisting of a linear alkyl group having 4 to 20 carbon atoms, a group in which one or more hydrogen atoms contained in a linear alkyl group having 4 to 20 carbon atoms are substituted with a halogen atom, and a group in which one or more methylene groups contained in a linear alkyl group having 4 to 20 carbon atoms are substituted with an oxygen atom, and R 42each independently represents one selected from the group consisting of a hydrogen atom, a methyl group, and an ethyl group. [ka] (In the formula (a-3), R 51 represents any one selected from the group consisting of a linear alkyl group having from 4 to 20 carbon atoms, a group in which one or more hydrogen atoms contained in a linear alkyl group having from 4 to 20 carbon atoms are substituted with a halogen atom, and a group in which one or more methylene groups contained in a linear alkyl group having from 4 to 20 carbon atoms are substituted with an oxygen atom) [3] The resin composition according to [1] or [2], wherein the content of the structural unit (a) in the cyclic olefin resin (A) is 5 mol % or more and 40 mol % or less, when the total of all structural units in the cyclic olefin resin (A) is 100 mol %. [4] The resin composition according to any one of the above [1] to [3], wherein the structural unit (b) includes a structural unit represented by the following formula (b-1): [ka] (In the formula (b-1), R 21 represents any one selected from the group consisting of a hydrogen atom, a hydroxyl group, and an organic group having 1 to 30 carbon atoms. [5] The cyclic olefin resin (A) further contains a structural unit (c), The resin composition according to any one of [1] to [4] above, wherein the structural unit (c) includes a structural unit containing at least one selected from the group consisting of a crosslinkable group and a group reactive with a crosslinkable group. [6] The resin composition according to [5] above, wherein the structural unit (c) includes a structural unit represented by the following formula (c-1): [ka] (In the formula (c-1), R 11represents a group containing at least one selected from the group consisting of an epoxy group, an oxetanyl group, and a hydroxyl group. [7] The resin composition according to any one of [1] to [6] above, wherein the cyclic olefin resin (A) has a weight average molecular weight (Mw) of 5,000 or more and 50,000 or less. [8] The resin composition according to any one of [1] to [7] above, wherein the cyclic olefin resin (A) has a polydispersity (Mw / Mn) of 1.1 or more and 3.5 or less. [9] The resin composition according to any one of [1] to [8] above, wherein the 5% mass loss temperature of the cyclic olefin resin (A) is 300° C. or higher.

[10] The resin composition according to any one of [1] to [9] above, wherein the softening point of the cyclic olefin resin (A) is 100°C or higher and 300°C or lower.

[11] The resin composition according to any one of [1] to

[10] above, wherein the refractive index of the cyclic olefin resin (A) is 1.45 or more and 1.55 or less.

[12] The resin composition according to any one of [1] to

[11] , wherein the content of the cyclic olefin resin (A) in the resin composition is 20% by mass or more and 90% by mass or less, when the total content of non-volatile components in the resin composition is 100% by mass.

[13] The resin composition according to any one of the above [1] to

[12] , further comprising a compound (B) having a cyclic ether structure.

[14] The resin composition according to

[13] above, wherein the compound (B) having a cyclic ether structure includes at least one selected from the group consisting of epoxy compounds and oxetane compounds.

[15] The resin composition according to

[13] or

[14] above, wherein the compound (B) having a cyclic ether structure contains an alicyclic structure in the molecule.

[16] The resin composition according to any one of

[13] to

[15] above, wherein the compound (B) having a cyclic ether structure contains two or more cyclic ether structures in the molecule.

[17] The resin composition according to any one of the above

[13] to

[16] , wherein the compound (B) having a cyclic ether structure is liquid at 23°C.

[18] The resin composition according to any one of

[13] to

[17] above, wherein the refractive index of the compound (B) having a cyclic ether structure is 1.43 or more and 1.55 or less.

[19] The resin composition according to any one of the above [1] to

[18] , further comprising a curing agent (C).

[20] The resin composition according to

[19] above, wherein the curing agent (C) contains a cationic polymerization initiator. [twenty one] The resin composition according to

[20] , wherein the cationic polymerization initiator includes a photocationic polymerization initiator. [twenty two] The resin composition according to any one of [1] to

[21] above, which has a refractive index of 1.47 or more and 1.55 or less. [twenty three] A resin film made of the resin composition according to any one of [1] to

[22] above, The resin film has a light transmittance of 85% or more for a wavelength of 850 nm. [twenty four] The resin film according to

[23] above, having a thickness of 1 μm or more and 150 μm or less. [twenty five] A film comprising a resin layer formed from the resin composition according to any one of [1] to

[22] above.

[26] Further, a base film is provided, The film according to

[25] above, having the resin layer on the base film.

[27] The film according to

[26] above, wherein the resin constituting the base film includes at least one selected from the group consisting of polyimide and polyethylene terephthalate.

[28] The film according to any one of

[25] to

[27] above, wherein the film is a dry film.

[29] a first film and a second film, A film set, wherein at least one of the first film and the second film is the film according to any one of

[25] to

[28] above.

[30] An optical waveguide in which a first clad layer, a core layer, and a second clad layer are laminated in this order, An optical waveguide, wherein at least one of the first clad layer and the second clad layer comprises the resin composition according to any one of [1] to

[22] above.

[31] A substrate; An optical / electrical composite substrate comprising: the optical waveguide according to

[30] provided on the substrate.

[32] An electronic component comprising the optical / electrical composite substrate according to

[31] . [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a resin composition that can improve the coatability and suppress the optical loss of an optical waveguide. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view schematically showing an example of the structure of an optoelectronic composite substrate according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings are simplified and do not correspond to actual dimensional proportions. Numerical ranges "A to B" represent A or more and B or less unless otherwise specified.

[0012] FIG. 1 is a cross-sectional view showing a schematic example of the structure of an optoelectronic composite substrate according to this embodiment. As shown in FIG. 1, an optical / electrical composite substrate 200 has an optical waveguide 100 provided on a substrate 110. The optical waveguide 100 includes a first cladding layer 20, a core layer 30, and a second cladding layer 40 laminated in this order. A mirror 50 on the light-emitting element side and a mirror 60 on the light-receiving element side are formed on the optical waveguide 100. Vias 140 (140a, 140b) are formed in the substrate 110 (note that the via 140 shown in FIG. 1 is buried in the first cladding layer 20). A light-emitting element 120 and a light-receiving element 130 are provided on the side of the substrate 110 opposite the optical waveguide 100 side.

[0013] The propagation path of light in the optical / electrical composite substrate 200 will be specifically described using Figure 1. Light emitted from the light-emitting portion of the light-emitting element 120 passes through via 140a formed in the substrate 110, enters mirror 50 on the light-emitting element side, and after being transmitted through the core layer 30, enters mirror 60 on the light-receiving element side, passes through via 140b formed in the substrate 110, and enters light-receiving element 130. The arrows in Figure 1 are a schematic representation of the propagation of light.

[0014] A method for providing the optical waveguide 100 on the substrate 110 includes, for example, a method including a step of laminating the substrate 110 having the via 140 formed therein and a film for forming the first cladding layer 20, and integrating them by heating and pressurizing. That is, resin compositions that can be used for optical waveguide cladding are required to have coatability because they may be formed into a film.

[0015] Furthermore, the optical waveguide is required to suppress optical loss.

[0016] The present invention provides a resin composition that can improve coatability and suppress optical loss in an optical waveguide.

[0017] In addition, in the above-mentioned integration step, the via 140 needs to be filled with the first cladding layer 20. According to the inventors' investigations, it was found that conventional materials for forming optical waveguide claddings cannot sufficiently fill the optical waveguide claddings in the vias formed in the substrate, and that this can result in depressions on the surface of the optical waveguide cladding opposite the substrate side (i.e., the core layer side of the optical waveguide cladding) or voids in the vias. It was also found that when the above-mentioned depressions or voids occur in the optoelectronic composite substrate, optical loss occurs at the interfaces of the depressions or voids. In other words, a resin composition that can be used for the clad of an optical waveguide is required to have properties that enable the resin composition for the clad to be sufficiently embedded in vias.

[0018] According to the resin composition of this embodiment, embeddability can be further improved.

[0019] [Resin composition] The resin composition of the present embodiment is a resin composition that can be used for an optical waveguide clad, and comprises a cyclic olefin resin (A). The cyclic olefin resin (A) comprises a structural unit (a) and a structural unit (b). The structural unit (a) comprises, on a polymer side chain, at least one structural unit selected from the group consisting of a linear alkyl group having from 4 to 20 carbon atoms, a group in which one or more hydrogen atoms contained in the linear alkyl group having from 4 to 20 carbon atoms are substituted with halogen atoms, and a group in which one or more methylene groups contained in the linear alkyl group having from 4 to 20 carbon atoms are substituted with oxygen atoms, and the structural unit (b) comprises a structural unit derived from a maleimide compound.

[0020] From the viewpoint of further improving the light propagation efficiency of the optical waveguide, the refractive index of the resin composition of this embodiment is preferably 1.55 or less, more preferably 1.54 or less, even more preferably 1.53 or less, and even more preferably 1.52 or less, and the lower limit is not particularly limited, but may be, for example, 1.47 or more, or 1.48 or more. Furthermore, from the viewpoint of further improving the light propagation efficiency of the optical waveguide, the refractive index of the resin composition of this embodiment is preferably 1.47 or more and 1.55 or less, more preferably 1.47 or more and 1.54 or less, even more preferably 1.47 or more and 1.53 or less, and even more preferably 1.48 or more and 1.52 or less. The refractive index of the resin composition means the refractive index measured for a resin film made of the resin composition using an Abbe refractometer under conditions of 23° C. and 589 nm. A resin film made of the resin composition can be produced, for example, by applying the resin composition onto a substrate film and drying it, as in the method described in the Examples.

[0021] From the viewpoint of further improving the light propagation efficiency of the optical waveguide, the light transmittance of the resin composition of this embodiment at a wavelength of 850 nm is preferably 85% or more and 100% or less, more preferably 90% or more and 100% or less, even more preferably 95% or more and 100% or less, even more preferably 97% or more and 100% or less, and even more preferably 98% or more and 100% or less. The light transmittance of the resin composition at a wavelength of 850 nm means the light transmittance value measured by an ultraviolet-visible spectrophotometer for a resin film made of the resin composition and having a thickness of 25 μm. A resin film made of a resin composition having a thickness of 25 μm can be produced, for example, by applying the resin composition onto a substrate film and drying it, as in the method described in the Examples.

[0022] The shape of the resin composition of the present embodiment is not particularly limited, and examples thereof include a film, membrane, varnish, and sheet.

[0023] Hereinafter, each of the constituent components of the resin composition of this embodiment will be described.

[0024] <Cyclic olefin resin (A)> The resin composition of the present embodiment contains a cyclic olefin resin (A).

[0025] The cyclic olefin resin (A) of this embodiment contains a structural unit (a) and a structural unit (b). The cyclic olefin resin (A) of the present embodiment contains a structural unit derived from a cyclic olefin compound. At least one structural unit selected from the group consisting of the structural unit (a) and the structural unit (c) may contain a structural unit derived from a cyclic olefin compound, or a structural unit other than the structural unit (a) and the structural unit (c) may contain a structural unit derived from a cyclic olefin compound. The cyclic olefin-based compound includes, for example, at least one selected from the group consisting of norbornene-based compounds and dicyclopentadiene-based compounds, and preferably includes a norbornene-based compound.

[0026] Hereinafter, each structural unit contained in the cyclic olefin resin (A) will be specifically explained.

[0027] (Structural unit (a)) The cyclic olefin resin (A) contains a structural unit (a). By including the structural unit (a), the cyclic olefin resin (A) can improve the balance of coating properties and embeddability.

[0028] The structural unit (a) contains, in a polymer side chain, a structural unit containing at least one selected from the group consisting of a linear alkyl group having from 4 to 20 carbon atoms, a group in which one or more hydrogen atoms contained in a linear alkyl group having from 4 to 20 carbon atoms are substituted with halogen atoms, and a group in which one or more methylene groups contained in a linear alkyl group having from 4 to 20 carbon atoms are substituted with oxygen atoms. The structural unit (a) preferably includes a structural unit having a linear alkyl group having from 4 to 20 carbon atoms in the polymer side chain, and more preferably includes a structural unit having a linear alkyl group having from 4 to 15 carbon atoms in the polymer side chain.

[0029] Examples of the linear alkyl group having 4 to 20 carbon atoms include at least one selected from the group consisting of an n-butyl group, a hexyl group, an octyl group, a decyl group, and a dodecyl group. In a group in which one or more hydrogen atoms contained in a linear alkyl group having from 4 to 20 carbon atoms are substituted with halogen atoms, the halogen atoms include at least one selected from the group consisting of, for example, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0030] The structural unit (a) preferably includes at least one selected from the group consisting of a structural unit represented by formula (a-1), a structural unit represented by formula (a-2), and a structural unit represented by formula (a-3).

[0031] [ka]

[0032] In formula (a-1), R 31 represents any one selected from the group consisting of a linear alkyl group having from 4 to 20 carbon atoms, a group in which one or more hydrogen atoms contained in a linear alkyl group having from 4 to 20 carbon atoms are substituted with halogen atoms, and a group in which one or more methylene groups contained in a linear alkyl group having from 4 to 20 carbon atoms are substituted with oxygen atoms. In formula (a-1), R 31 is preferably a linear alkyl group having 4 to 20 carbon atoms, more preferably a linear alkyl group having 6 to 18 carbon atoms, even more preferably a linear alkyl group having 8 to 16 carbon atoms, even more preferably a linear alkyl group having 10 to 14 carbon atoms, and even more preferably a linear alkyl group having 12 carbon atoms (dodecyl group).

[0033] [ka]

[0034] In formula (a-2), R41 represents any one selected from the group consisting of a linear alkyl group having 4 to 20 carbon atoms, a group in which one or more hydrogen atoms contained in a linear alkyl group having 4 to 20 carbon atoms are substituted with a halogen atom, and a group in which one or more methylene groups contained in a linear alkyl group having 4 to 20 carbon atoms are substituted with an oxygen atom, and R 42 are each independently any one selected from the group consisting of a hydrogen atom, a methyl group, and an ethyl group. In formula (a-2), R 41 is preferably a linear alkyl group having 4 to 20 carbon atoms, more preferably a linear alkyl group having 4 to 15 carbon atoms, more preferably a linear alkyl group having 5 to 10 carbon atoms, and even more preferably a linear alkyl group having 6 to 8 carbon atoms. In formula (a-2), R 42 is preferably a hydrogen atom.

[0035] [ka]

[0036] In formula (a-3), R 51 represents any one selected from the group consisting of a linear alkyl group having from 4 to 20 carbon atoms, a group in which one or more hydrogen atoms contained in a linear alkyl group having from 4 to 20 carbon atoms are substituted with halogen atoms, and a group in which one or more methylene groups contained in a linear alkyl group having from 4 to 20 carbon atoms are substituted with oxygen atoms. In formula (a-3), R 51 is preferably a linear alkyl group having 4 to 20 carbon atoms, more preferably a linear alkyl group having 4 to 15 carbon atoms, more preferably a linear alkyl group having 5 to 10 carbon atoms, even more preferably a linear alkyl group having 6 to 8 carbon atoms, and even more preferably a linear alkyl group having 6 carbon atoms (hexyl group).

[0037] (Structural unit (b)) The cyclic olefin resin (A) contains a structural unit (b). The structural unit (b) includes a structural unit derived from a maleimide compound. By including the structural unit (b), the cyclic olefin resin (A) can improve the coatability and suppress the optical loss of the optical waveguide.

[0038] The structural unit (b) preferably includes a structural unit represented by formula (b-1).

[0039] [ka]

[0040] In formula (b-1), R 21 represents any one selected from the group consisting of a hydrogen atom, a hydroxyl group, and an organic group having 1 to 30 carbon atoms.

[0041] In formula (b-1), R 21 The organic group constituting the formula (I) may be, for example, at least one selected from the group consisting of a chain alkyl group, a cyclic alkyl group, an alkenyl group, an alkynyl group, an alkylidene group, an aryl group, an aralkyl group, and an alkaryl group.

[0042] The chain alkyl group includes both a straight-chain alkyl group and a branched-chain alkyl group, and examples thereof include at least one selected from the group consisting of a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and the like. The cyclic alkyl group may be, for example, at least one selected from the group consisting of a cyclohexyl group, a cyclooctyl group, a cyclopentyl group, an adamantyl group, and the like. The alkenyl group may be, for example, at least one selected from the group consisting of an allyl group, a pentenyl group, a vinyl group, and the like. Examples of the alkynyl group include an ethynyl group. The alkylidene group may be, for example, at least one selected from the group consisting of a methylidene group, an ethylidene group, and the like. The aryl group may be, for example, at least one selected from the group consisting of a phenyl group, a naphthyl group, an anthracenyl group, and the like. The aralkyl group may be, for example, at least one selected from the group consisting of a benzyl group, a phenethyl group, and the like. The alkaryl group may be, for example, at least one selected from the group consisting of a tolyl group, a xylyl group, and the like.

[0043] In formula (b-1), R 21 is preferably any one selected from the group consisting of a hydrogen atom, a hydroxyl group, and a cyclic alkyl group having from 4 to 20 carbon atoms, more preferably a cyclic alkyl group having from 4 to 20 carbon atoms, even more preferably a cyclic alkyl group having from 4 to 10 carbon atoms, and even more preferably a cyclic alkyl group having 6 carbon atoms (cyclohexyl group).

[0044] (Structural unit (c)) The cyclic olefin resin (A) preferably further contains a structural unit (c). The structural unit (c) includes a structural unit containing at least one selected from the group consisting of a crosslinkable group and a group reactive with a crosslinkable group, and preferably includes a structural unit containing a crosslinkable group. By including the structural unit (c), the cyclic olefin resin (A) can improve the heat resistance, mechanical properties, etc. of the resulting cured product.

[0045] In the structural unit (c), the crosslinkable group includes, for example, at least one selected from the group consisting of an epoxy group, an oxetanyl group, and a group having a diene structure, and preferably includes at least one selected from the group consisting of an epoxy group and an oxetanyl group.

[0046] In the structural unit (c), the group reactive with a crosslinkable group means a group capable of reacting with a crosslinkable group in a compound having a crosslinkable group to form a crosslinked structure. The group reactive with a crosslinkable group includes, for example, at least one selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group, etc., and preferably includes a hydroxyl group.

[0047] The structural unit (c) preferably includes a structural unit represented by formula (c-1).

[0048] [ka]

[0049] In formula (c-1), R 11 represents a group containing at least one selected from the group consisting of an epoxy group, an oxetanyl group, and a hydroxyl group. In formula (c-1), R 11 preferably represents a group containing at least one selected from the group consisting of an epoxy group and an oxetanyl group. In formula (c-1), R 11 The group containing at least one selected from the group consisting of an epoxy group, an oxetanyl group, and a hydroxyl group in the above formula is a concept that also includes an epoxy group, an oxetanyl group, and a hydroxyl group themselves. In formula (c-1), R 11 The number of carbon atoms is not particularly limited, but may be, for example, 2 or more and 30 or less, or 3 or more and 20 or less.

[0050] The structural unit represented by formula (c-1) preferably includes at least one selected from the group consisting of a structural unit represented by formula (c-1-1), a structural unit represented by formula (c-1-2), and a structural unit represented by formula (c-1-3), and more preferably includes at least one selected from the group consisting of a structural unit represented by formula (c-1-1) and a structural unit represented by formula (c-1-2).

[0051] [ka]

[0052] In formula (c-1-1), a represents an integer of 0 or more and 3 or less, and b represents an integer of 1 or more and 3 or less. In formula (c-1-1), a is preferably 1 or 2, and more preferably 1. In formula (c-1-1), b is preferably 1 or 2, and more preferably 1.

[0053] [ka]

[0054] In formula (c-1-2), R 12 is any one selected from the group consisting of a hydrogen atom and an alkyl group having 1 to 4 carbon atoms, and c is an integer of 1 to 3. In formula (c-1-2), R 12 is preferably an alkyl group having 1 to 3 carbon atoms, more preferably any group selected from the group consisting of a methyl group and an ethyl group, and even more preferably an ethyl group. In formula (c-1-2), c is preferably 1 or 2, and more preferably 1.

[0055] [ka]

[0056] In formula (c-1-3), d represents an integer of 1 or more and 10 or less. In formula (c-1-3), d is preferably an integer of 1 or more and 8 or less, more preferably an integer of 1 or more and 7 or less, and even more preferably an integer of 2 or more and 5 or less.

[0057] The content of the structural unit (a) in the cyclic olefin resin (A) is preferably 5 mol % or more and 40 mol % or less, more preferably 7 mol % or more and 35 mol % or less, and even more preferably 10 mol % or more and 30 mol % or less, when the total of the structural units in the cyclic olefin resin (A) is 100 mol %.

[0058] The content of the structural unit (b) in the cyclic olefin resin (A) is preferably 30 mol % or more and 85 mol % or less, more preferably 35 mol % or more and 80 mol % or less, and even more preferably 40 mol % or more and 75 mol % or less, when the total of the structural units in the cyclic olefin resin (A) is 100 mol %.

[0059] The content of the structural unit (c) in the cyclic olefin resin (A) is preferably 5 mol % or more and 40 mol % or less, more preferably 7 mol % or more and 35 mol % or less, and even more preferably 10 mol % or more and 30 mol % or less, when the total of the structural units in the cyclic olefin resin (A) is 100 mol %.

[0060] The total content of the structural units (a), (b) and (c) in the cyclic olefin resin (A) is preferably 80 mol% or more and 100 mol% or less, more preferably 90 mol% or more and 100 mol% or less, and even more preferably 95 mol% or more and 100 mol% or less, when the total amount of the structural units in the cyclic olefin resin (A) is taken as 100 mol%.

[0061] The cyclic olefin resin (A) preferably includes at least one selected from the group consisting of a cyclic olefin resin (A1), a cyclic olefin resin (A2), and a cyclic olefin resin (A3). Here, the cyclic olefin resin (A1) contains a structural unit represented by formula (a-1), a structural unit (b), and a structural unit (c). The cyclic olefin resin (A2) contains a structural unit represented by formula (a-2), a structural unit (b), and a structural unit (c). The cyclic olefin resin (A3) contains a structural unit represented by formula (a-3), a structural unit (b), and a structural unit (c).

[0062] Here, the structural unit (b) contained in the cyclic olefin resin (A1) excludes those corresponding to the structural unit represented by formula (a-1). In the cyclic olefin resin (A) other than the cyclic olefin resin (A1), the structural unit (b) may contain a structural unit represented by formula (a-1).

[0063] From the viewpoint of further improving coatability, the weight average molecular weight (Mw) of the cyclic olefin resin (A) is preferably 5,000 or more and 50,000 or less, more preferably 6,000 or more and 40,000 or less, even more preferably 7,500 or more and 30,000 or less, and even more preferably 10,000 or more and 25,000 or less.

[0064] From the viewpoint of further improving coatability, the polydispersity (Mw / Mn) of the cyclic olefin resin (A) is preferably 1.1 or more and 3.5 or less, more preferably 1.2 or more and 3.0 or less, and even more preferably 1.3 or more and 2.8 or less.

[0065] The weight average molecular weight (Mw) and polydispersity (Mw / Mn) of the cyclic olefin resin refer to values ​​determined by gel permeation chromatography (GPC) using polystyrene as a standard substance.

[0066] From the viewpoint of further improving heat resistance, the 5% mass loss temperature of the cyclic olefin resin (A) is preferably 300° C. or higher, more preferably 330° C. or higher, and even more preferably 350° C. or higher, and the upper limit is not particularly limited, but may be, for example, 420° C. or lower or 410° C. or lower. Furthermore, from the viewpoint of further improving heat resistance, the 5% mass loss temperature of the cyclic olefin resin (A) is preferably 300° C. or higher and 420° C. or lower, more preferably 330° C. or higher and 410° C. or lower, and even more preferably 350° C. or higher and 410° C. or lower. The 5% mass loss temperature of a cyclic olefin resin means the temperature at which the mass of the cyclic olefin resin decreases by 5% based on the mass of the cyclic olefin resin at the start of measurement when the cyclic olefin resin is heated from 30°C to 500°C at a heating rate of 10°C / min in a nitrogen atmosphere using a thermogravimetric and differential thermal analyzer.

[0067] The softening point of the cyclic olefin resin (A) of this embodiment is preferably 100°C or higher and 300°C or lower, more preferably 110°C or higher and 280°C or lower, and even more preferably 120°C or higher and 250°C or lower, from the viewpoint of further improving the balance of coating property and embeddability. The softening point of the cyclic olefin resin is a value obtained using a thermomechanical analyzer. Specifically, the cyclic olefin resin is heated using a thermomechanical analyzer under a nitrogen atmosphere under the following conditions: measurement mode: compression, load: 30 mN, temperature range: 30°C to 300°C, and heating rate: 3°C / min, and a temperature-displacement graph is created. The softening point of the cyclic olefin resin is determined as the extension of the linear portion without displacement on the low-temperature side or the intersection of the tangent to the minimum displacement rate and the tangent to the maximum displacement rate.

[0068] From the viewpoint of further improving the light propagation efficiency of the optical waveguide, the refractive index of the cyclic olefin resin (A) is preferably 1.55 or less, more preferably 1.54 or less, and even more preferably 1.53 or less, and the lower limit is not particularly limited, but may be, for example, 1.45 or more, 1.46 or more, or 1.47 or more. Furthermore, from the viewpoint of further improving the light propagation efficiency of the optical waveguide, the refractive index of the cyclic olefin resin (A) is preferably 1.45 or more and 1.55 or less, more preferably 1.46 or more and 1.54 or less, and even more preferably 1.47 or more and 1.53 or less. The refractive index of the cyclic olefin resin means the refractive index measured with an Abbe refractometer under the conditions of 23° C. and 589 nm.

[0069] The content of the cyclic olefin resin (A) in the resin composition of this embodiment is preferably 20% by mass or more and 90% by mass or less, more preferably 30% by mass or more and 80% by mass or less, and even more preferably 35% by mass or more and 75% by mass or less, from the viewpoint of further improving the coatability and further suppressing the optical loss of the optical waveguide, when the total content of the non-volatile components in the resin composition is taken as 100% by mass.

[0070] The method for producing the cyclic olefin resin (A) is not particularly limited, and it can be produced, for example, by polymerizing monomers capable of forming each structural unit by any method. The polymerization conditions are not particularly limited, but for example, the polymerization temperature can be 60° C. or higher and 90° C. or lower, and the polymerization time can be 1 hour or higher and 8 hours or lower.

[0071] In the method for producing the cyclic olefin resin (A), raw material monomers may be polymerized to obtain a polymer, and then the obtained polymer may be purified by any method.

[0072] The purification method is not particularly limited, and examples thereof include reprecipitation. In the method for producing a polymer of the present embodiment, the polymer may be purified by carrying out a reprecipitation operation two or more times. Examples of good solvents used in the reprecipitation purification include tetrahydrofuran, etc. Examples of poor solvents used in the reprecipitation purification include at least one solvent selected from the group consisting of methanol, isopropanol, etc.

[0073] The cyclic olefin resin (A) may be a single cyclic olefin resin, or may contain two or more cyclic olefin resins.

[0074] <Compound (B) Having a Cyclic Ether Structure> From the viewpoint of further improving embeddability, the resin composition of the present embodiment preferably further contains a compound (B) having a cyclic ether structure.

[0075] The compound (B) having a cyclic ether structure preferably includes at least one selected from the group consisting of epoxy compounds and oxetane compounds.

[0076] The compound (B) having a cyclic ether structure preferably contains an alicyclic structure in the molecule. Here, the compound (B) having a cyclic ether structure containing an alicyclic structure in the molecule means that it contains an alicyclic structure in addition to the cyclic ether structure. However, the alicyclic structure in this embodiment includes a fused ring structure in which a cyclic ether and an aliphatic ring are fused, and a spiro ring structure in which a cyclic ether and an aliphatic ring are bonded via a spiro bond atom. The number of ring members in the alicyclic structure is not particularly limited, but is preferably a 4- to 10-membered ring, more preferably a 4- to 8-membered ring, even more preferably a 5- or 6-membered ring, and even more preferably a 6-membered ring.

[0077] The compound (B) having a cyclic ether structure preferably contains two or more cyclic ether structures in the molecule, and more preferably contains two or three cyclic ether structures in the molecule.

[0078] The compound (B) having a cyclic ether structure is preferably liquid at 23° C., from the viewpoint of further improving embeddability and further improving handleability when producing a resin composition.

[0079] From the viewpoint of further improving the light propagation efficiency of the optical waveguide, the refractive index of the compound (B) having a cyclic ether structure is preferably 1.55 or less, more preferably 1.53 or less, and even more preferably 1.52 or less, and the lower limit is not particularly limited, but may be, for example, 1.43 or more or 1.44 or more. Furthermore, from the viewpoint of further improving the light propagation efficiency of the optical waveguide, the refractive index of the compound (B) having a cyclic ether structure is preferably 1.43 or more and 1.55 or less, more preferably 1.43 or more and 1.53 or less, and even more preferably 1.44 or more and 1.52 or less. The refractive index of the compound having a cyclic ether structure means the refractive index measured with an Abbe refractometer under the conditions of 23° C. and 589 nm.

[0080] The content of the compound (B) having a cyclic ether structure in the resin composition of this embodiment is preferably 10% by mass or more and 80% by mass or less, more preferably 20% by mass or more and 70% by mass or less, and even more preferably 25% by mass or more and 65% by mass or less, from the viewpoint of further improving embeddability, when the total content of non-volatile components in the resin composition is taken as 100% by mass.

[0081] The compound (B) having a cyclic ether structure may be a compound having one type of cyclic ether structure, or may contain compounds having two or more types of cyclic ether structures.

[0082] <Curing agent (C)> The resin composition of the present embodiment preferably further contains a curing agent (C). The curing agent (C) may be, for example, at least one selected from the group consisting of a thermal polymerization initiator, a photopolymerization initiator, an amine compound, and the like.

[0083] The curing agent (C) preferably contains a cationic polymerization initiator, and more preferably contains a photocationic polymerization initiator.

[0084] The photocationic polymerization initiator includes, for example, at least one selected from the group consisting of sulfonium salt-type polymerization initiators and iodonium salt-type polymerization initiators, and preferably includes a sulfonium salt-type polymerization initiator, more preferably includes a triarylsulfonium salt-type polymerization initiator, and even more preferably includes a triphenylsulfonium salt-type polymerization initiator.

[0085] The curing agent (C) more preferably includes a photocationic polymerization initiator and a thermal cationic polymerization initiator. The thermal cationic polymerization initiator includes, for example, at least one selected from the group consisting of sulfonium salt type polymerization initiators and iodonium salt type polymerization initiators, and preferably includes a sulfonium salt type polymerization initiator.

[0086] The amine compound preferably includes an imidazole compound. The imidazole compound means a compound containing an imidazole ring structure, and includes, for example, a compound in which hydrogen atoms of imidazole are substituted with hydrocarbon groups or the like.

[0087] The content of the curing agent (C) in the resin composition of this embodiment is preferably 0.01 parts by mass or more and 1.0 parts by mass or less, more preferably 0.05 parts by mass or more and 0.7 parts by mass or less, and even more preferably 0.1 parts by mass or more and 0.5 parts by mass or less, when the total content of the cyclic olefin resin (A) and the compound having a cyclic ether structure (B) in the resin composition is 100 parts by mass. The content of the curing agent (C) in the resin composition of this embodiment is preferably 0.01 parts by mass or more and 1.0 parts by mass or less, more preferably 0.05 parts by mass or more and 0.7 parts by mass or less, and even more preferably 0.1 parts by mass or more and 0.5 parts by mass or less, when the total content of the resin components in the resin composition is 100 parts by mass. Herein, the resin components in the resin composition include the polymer (A) and the compound (B) having a cyclic ether structure. When the resin composition contains a polymer other than the polymer (A) and the compound (B) having a cyclic ether structure, the polymer other than the polymer (A) and the compound (B) having a cyclic ether structure is also included in the resin components in the resin composition.

[0088] The curing agent (C) of the present embodiment may contain one type of curing agent, or may contain two or more types of curing agents.

[0089] <Antioxidant (D)> The resin composition of the present embodiment preferably further contains an antioxidant (D). The antioxidant (D) is not particularly limited and includes, for example, at least one selected from the group consisting of phenol-type antioxidants, amine-type antioxidants, phosphorus-type antioxidants, and thioether-type antioxidants, and preferably includes a phenol-type antioxidant. The antioxidant (D) of the present embodiment may contain one type of antioxidant, or may contain two or more types of antioxidants.

[0090] The content of the antioxidant (D) in the resin composition of this embodiment is preferably 0.01 parts by mass or more and 10.0 parts by mass or less, more preferably 0.1 parts by mass or more and 5.0 parts by mass or less, and even more preferably 0.5 parts by mass or more and 3 parts by mass or less, relative to 100 parts by mass of the total content of the cyclic olefin resin (A) and the compound having a cyclic ether structure (B) in the resin composition. The content of the antioxidant (D) in the resin composition of the present embodiment is preferably 0.01 parts by mass or more and 10.0 parts by mass or less, more preferably 0.1 parts by mass or more and 5.0 parts by mass or less, and even more preferably 0.5 parts by mass or more and 3 parts by mass or less, when the total content of the resin components in the resin composition is 100 parts by mass.

[0091] <Surfactant (E)> From the viewpoint of further improving embeddability, the resin composition of the present embodiment preferably further contains a surfactant (E). The surfactant (E) includes, for example, at least one selected from the group consisting of silicone surfactants and fluorine-based surfactants, and preferably includes a silicone surfactant. The surfactant (E) of the present embodiment may be a single surfactant or may contain two or more surfactants.

[0092] The content of the surfactant (E) in the resin composition of this embodiment is preferably 0.01 parts by mass or more and 3.0 parts by mass or less, more preferably 0.05 parts by mass or more and 1.0 parts by mass or less, and even more preferably 0.1 parts by mass or more and 0.5 parts by mass or less, when the total content of the cyclic olefin resin (A) and the compound (B) having a cyclic ether structure in the resin composition is 100 parts by mass. The content of the surfactant (E) in the resin composition of this embodiment is preferably 0.01 parts by mass or more and 3.0 parts by mass or less, more preferably 0.05 parts by mass or more and 1.0 parts by mass or less, and even more preferably 0.1 parts by mass or more and 0.5 parts by mass or less, when the total content of the resin components in the resin composition is 100 parts by mass.

[0093] <Organic solvent (F)> The resin composition of the present embodiment may contain an organic solvent (F). When the resin composition of the present embodiment contains an organic solvent (F), it can be made into a varnish-like resin composition.

[0094] The organic solvent (F) of the present embodiment includes at least one selected from the group consisting of, for example, acetone, methyl ethyl ketone, methyl amyl ketone, toluene, propylene glycol monomethyl ether, propylene glycol methyl ethyl ether, propylene glycol dimethyl ether, propylene glycol 1-monomethyl ether 2-acetate, diethylene glycol ethyl methyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, benzyl alcohol, propylene carbonate, ethylene glycol diacetate, propylene glycol diacetate, propylene glycol monomethyl ether acetate, dipropylene glycol methyl-n-propyl ether, butyl acetate, γ-butyrolactone, methyl lactate, ethyl lactate, and butyl lactate. The organic solvent (F) of the present embodiment may be a single organic solvent, or may contain two or more organic solvents.

[0095] When the resin composition of the present embodiment contains an organic solvent (F), the concentration of the total solids (non-volatile components) in the resin composition is preferably 10% by mass or more and 60% by mass or less, more preferably 20% by mass or more and 55% by mass or less, and even more preferably 30% by mass or more and 50% by mass or less, from the viewpoint of appropriately controlling the viscosity of the resin composition and sufficiently dissolving each component in the resin composition.

[0096] <Other ingredients> The resin composition of the present embodiment may further contain, for example, a curing aid, a leveling agent, a colorant, a storage stabilizer, a plasticizer, a filler, inorganic particles, an antidegradant, a wettability improver, an antistatic agent, etc. The content of other components is an appropriate amount.

[0097] The total content of the cyclic olefin resin (A) and the compound (B) having a cyclic ether structure in the resin composition of this embodiment is preferably 80% by mass or more and less than 100% by mass, more preferably 90% by mass or more and less than 100% by mass, and even more preferably 95% by mass or more and less than 100% by mass, from the viewpoint of further improving coatability and further suppressing optical loss in the optical waveguide, when the total content of non-volatile components in the resin composition is taken as 100% by mass. The total content of the resin (A) having a norbornene structure and the compound (B) having a cyclic ether structure in the resin composition of the present embodiment, when the total content of all components in the resin composition is taken as 100% by mass, is preferably 10% by mass or more and less than 100% by mass, more preferably 20% by mass or more and less than 100% by mass, even more preferably 30% by mass or more and less than 100% by mass, even more preferably 35% by mass or more and less than 100% by mass, even more preferably 50% by mass or more and less than 100% by mass, even more preferably 70% by mass or more and less than 100% by mass, even more preferably 80% by mass or more and less than 100% by mass, even more preferably 85% by mass or more and less than 100% by mass, even more preferably 90% by mass or more and less than 100% by mass, and even more preferably 95% by mass or more and less than 100% by mass, from the viewpoint of further improving coatability and further suppressing optical loss in the optical waveguide.

[0098] The resin composition of the present embodiment can be obtained, for example, by mixing the components. The film-like resin composition of this embodiment can be obtained, for example, by applying a varnish-like resin composition onto a substrate film and drying it.

[0099] [Resin film] The resin film of this embodiment is made of the resin composition of this embodiment. The resin film of this embodiment includes not only a resin film alone but also a resin film formed on a substrate film.

[0100] From the viewpoint of further improving the light propagation efficiency of the optical waveguide, the light transmittance of the resin film of this embodiment at a wavelength of 850 nm is preferably 85% or more and 100% or less, more preferably 90% or more and 100% or less, even more preferably 95% or more and 100% or less, even more preferably 97% or more and 100% or less, and even more preferably 98% or more and 100% or less. The light transmittance of the resin film at a wavelength of 850 nm means the value of the light transmittance measured by an ultraviolet-visible spectrophotometer.

[0101] The thickness of the resin film in this embodiment is preferably 1 μm or more, more preferably 3 μm or more, even more preferably 5 μm or more, and even more preferably 8 μm or more, from the viewpoint of further improving embeddability, and is preferably 150 μm or less, more preferably 130 μm or less, even more preferably 100 μm or less, even more preferably 70 μm or less, even more preferably 50 μm or less, and even more preferably 30 μm or less, from the viewpoint of further improving embeddability and light propagation efficiency of the optical waveguide, and is preferably 1 μm or more and 150 μm or less, more preferably 3 μm or more and 130 μm or less, even more preferably 5 μm or more and 100 μm or less, even more preferably 8 μm or more and 70 μm or less, even more preferably 8 μm or more and 50 μm or less, and even more preferably 8 μm or more and 30 μm or less.

[0102] The resin film of this embodiment can be obtained by a known method for forming a coating film using, for example, the varnish-like resin composition of this embodiment as a raw material.

[0103] [film] The film of this embodiment includes a resin layer formed from the resin composition of this embodiment. The film of this embodiment is preferably a dry film.

[0104] The resin composition forming the resin layer of the present embodiment may be an uncured product, a semi-cured product, or a cured product, but is preferably a semi-cured product.

[0105] From the viewpoint of further improving the handleability of the film, the thickness of the film of this embodiment is preferably 10 μm or more and 250 μm or less, more preferably 30 μm or more and 200 μm or less, even more preferably 40 μm or more and 150 μm or less, even more preferably 60 μm or more and 140 μm or less, and even more preferably 80 μm or more and 130 μm or less.

[0106] The thickness of the resin layer in this embodiment is preferably 1 μm or more, more preferably 3 μm or more, even more preferably 5 μm or more, and even more preferably 8 μm or more, from the viewpoint of further improving embeddability, and is preferably 150 μm or less, more preferably 130 μm or less, even more preferably 100 μm or less, even more preferably 70 μm or less, even more preferably 50 μm or less, and even more preferably 30 μm or less, from the viewpoint of further improving embeddability and light propagation efficiency of the optical waveguide, and is preferably 1 μm or more and 150 μm or less, more preferably 3 μm or more and 130 μm or less, even more preferably 5 μm or more and 100 μm or less, even more preferably 8 μm or more and 70 μm or less, even more preferably 8 μm or more and 50 μm or less, and even more preferably 8 μm or more and 30 μm or less.

[0107] The film of the present embodiment preferably further includes a substrate film and has a resin layer on the substrate film. The base film may be, for example, a resin film. The resin constituting the base film is not particularly limited, but preferably contains at least one selected from the group consisting of polyimide and polyethylene terephthalate.

[0108] From the viewpoint of further improving the handleability of the film, the thickness of the base film of this embodiment is preferably 10 μm or more and 100 μm or less, more preferably 15 μm or more and 80 μm or less, even more preferably 20 μm or more and 60 μm or less, and even more preferably 20 μm or more and 40 μm or less.

[0109] The substrate film of the present embodiment may be subjected to a surface treatment such as an antistatic treatment or a release treatment.

[0110] The film of this embodiment may further include a cover film, which is preferably provided so as to be in direct contact with the resin layer. When the film of this embodiment includes a base film, the cover film is preferably provided on the surface of the resin layer opposite to the base film. The cover film is not particularly limited, but for example, an OPP cover film can be used.

[0111] The film of this embodiment can be obtained, for example, by applying the varnish-like resin composition of this embodiment to a substrate film and drying it. Examples of the application method include direct application using various coater devices such as a pin coater, a die coater, a comma coater, and a curtain coater, and printing methods such as screen printing.

[0112] [Film Set] The film set of this embodiment includes a first film and a second film, and at least one of the first film and the second film is the film of this embodiment.

[0113] In the film set of this embodiment, when the first film is a film that can be used for the first clad layer 20 in Figure 1 and the second film is a film that can be used for the second clad layer 40 in Figure 1, preferably the first film is a film of this embodiment, and more preferably both the first film and the second film are films of this embodiment.

[0114] [Optical waveguide] The optical waveguide of this embodiment will be described with reference to FIG. The optical waveguide 100 of this embodiment is an optical waveguide in which a first clad layer 20, a core layer 30, and a second clad layer 40 are stacked in this order, and at least one of the first clad layer 20 and the second clad layer 40 contains the resin composition of this embodiment. In this specification, when the optical waveguide 100 is provided on the substrate 110, the cladding layer located on the substrate 110 side is referred to as the first cladding layer 20. Furthermore, hereinafter, when simply referring to a "cladding layer," this concept includes both the first cladding layer 20 and the second cladding layer 40.

[0115] In the optical waveguide 100 of this embodiment, the first clad layer 20 preferably contains the resin composition of this embodiment, and more preferably both the first clad layer 20 and the second clad layer 40 contain the resin composition of this embodiment.

[0116] The resin composition contained in the cladding layer of this embodiment may be an uncured product, a semi-cured product, or a cured product, but is preferably a cured product.

[0117] From the viewpoint of further improving embeddability, the thickness of the first cladding layer 20 is preferably 1 μm or more, more preferably 3 μm or more, even more preferably 5 μm or more, even more preferably 8 μm or more, even more preferably 10 μm or more, even more preferably 15 μm or more, and even more preferably 20 μm or more; from the viewpoint of further improving the light propagation efficiency of the optical waveguide, the thickness is preferably 150 μm or less, more preferably 100 μm or less, even more preferably 70 μm or less, even more preferably 50 μm or less, even more preferably 40 μm or less, and even more preferably 30 μm or less; and from the viewpoint of further improving embeddability and the light propagation efficiency of the optical waveguide, the thickness is preferably 1 μm or more and 150 μm or less, more preferably 3 μm or more and 100 μm or less, even more preferably 5 μm or more and 70 μm or less, even more preferably 8 μm or more and 50 μm or less, even more preferably 10 μm or more and 40 μm or less, even more preferably 15 μm or more and 30 μm or less.

[0118] From the viewpoint of further suppressing thermal deformation of the optical waveguide, the thickness of the second cladding layer 40 is preferably 1 μm or more and 150 μm or less, more preferably 3 μm or more and 100 μm or less, even more preferably 5 μm or more and 70 μm or less, even more preferably 8 μm or more and 50 μm or less, and even more preferably 8 μm or more and 20 μm or less.

[0119] The material for forming the core layer 30 is not particularly limited, but may be formed from, for example, a resin composition. The resin for forming the core layer 30 includes, for example, a resin used for the core of a known optical waveguide, preferably a cyclic olefin resin, and more preferably a norbornene resin. The resin composition for forming the core layer 30 may contain an antioxidant, a photocationic polymerization initiator, and the like.

[0120] The thickness of the core layer 30 is preferably 1 μm or more and 100 μm or less, more preferably 5 μm or more and 80 μm or less, even more preferably 10 μm or more and 60 μm or less, and even more preferably 30 μm or more and 50 μm or less.

[0121] A waveguide pattern may be formed in the core layer 30. Methods for forming the waveguide pattern include, for example, exposure, etching, and replication.

[0122] The optical waveguide 100 may have a mirror formed thereon, and may have a mirror 50 on the light-emitting element side and a mirror 60 on the light-receiving element side. The mirrors may be formed, for example, by forming an inclined surface by laser processing or the like.

[0123] The optical waveguide 100 may include other layers in addition to the first cladding layer 20, the core layer 30, and the second cladding layer 40, as long as the excellent performance of the optical waveguide 100 is not affected.

[0124] [Optical / electrical composite substrate] The optical and electrical composite substrate of this embodiment will be described with reference to FIG. The optical / electrical composite substrate 200 includes a substrate 110 and an optical waveguide 100 provided on the substrate 110 .

[0125] The substrate 110 may be, for example, a printed circuit board or a flexible substrate, and is preferably a flexible substrate. The substrate 110 may have vias 140 formed therein.

[0126] The optical / electrical composite substrate 200 may further include a polyimide base material (not shown) on the surface of the second cladding layer 40 opposite to the core layer 30 side.

[0127] The optical / electrical composite substrate 200 may include a light emitting element 120, a light receiving element 130, and the like.

[0128] The optical-electrical composite substrate 200 can be obtained, for example, by (i) forming a first clad layer 20 on the substrate 110, (ii) forming a core layer 30 on the first clad layer 20, and (iii) forming a second clad layer 40 on the core layer 30. Examples of methods for forming each layer include methods in which films for forming each layer are laminated in order by roll lamination, vacuum roll lamination, flat plate lamination, vacuum flat plate lamination, atmospheric pressing, vacuum pressing, etc.

[0129] [Electronic Components] The electronic component of this embodiment includes the optical / electrical composite substrate of this embodiment. Examples of the electronic component of this embodiment include electronic components in electronic devices such as mobile phones, game machines, router devices, WDM devices, personal computers, televisions, and home servers.

[0130] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations can also be adopted. Furthermore, the present invention is not limited to the above-described embodiment, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention. [Example]

[0131] The present embodiment will be described in detail below based on examples and comparative examples, but the present embodiment is not limited to the descriptions of these examples.

[0132] [Raw materials] First, the raw materials used in the examples and comparative examples will be described.

[0133] <Synthesis of Polymer (A-1)> (polymerization) In a reactor equipped with a stirrer, reflux condenser, and thermometer, 34.0 g (188 mmol) of methyl glycidyl ether norbornene, 23.6 g (132 mmol) of cyclohexylmaleimide, 15.0 g (56.5 mmol) of dodecylmaleimide, 17 g of methyl ethyl ketone, and 41 g of heptane were weighed and stirred to dissolve. The mixture was heated and stirred under a nitrogen flow until the temperature reached 70 °C. In a separate vessel, 4.34 g of dimethyl 2,2'-azobis(2-methylpropionate) was weighed as an initiator and dissolved in 10 g of methyl ethyl ketone. After the temperature inside the reactor stabilized, the entire amount was added all at once. The reaction was allowed to proceed for 4 hours with heating and stirring, starting from the moment the addition began. The polymer solution after the reaction was completed was used as the synthesized polymer.

[0134] (purification) After the reaction was completed, the polymer solution was cooled to room temperature, diluted with 40 g of tetrahydrofuran, and then added dropwise to 1,100 g of isopropanol to cause reprecipitation. The residue was redissolved in 120 g of tetrahydrofuran and then added dropwise to 800 g of isopropanol to cause reprecipitation. The mixture was further dried overnight in a vacuum dryer at 40 °C to obtain polymer (A-1) (purified polymer).

[0135] <Synthesis of Polymer (A-2)> (polymerization) In a reactor equipped with a stirrer, reflux condenser, and thermometer, 23.8 g (132 mmol) of methyl glycidyl ether norbornene, 30.4 g (170 mmol) of cyclohexylmaleimide, 20.0 g (75.4 mmol) of dodecylmaleimide, 32 g of methyl ethyl ketone, and 28 g of heptane were weighed and dissolved by stirring. The mixture was heated and stirred under a nitrogen flow until the temperature reached 70 °C. In a separate vessel, 4.34 g of dimethyl 2,2'-azobis(2-methylpropionate) was weighed as an initiator and dissolved in 10 g of methyl ethyl ketone. After the temperature inside the reactor stabilized, the entire amount was added all at once. The reaction was allowed to proceed for 4 hours with heating and stirring, starting from the moment the addition began. The polymer solution after the reaction was completed was used as the synthesized polymer.

[0136] (purification) After the reaction was completed, the polymer solution was cooled to room temperature and added dropwise to 1,000 g of methanol for reprecipitation. The residue was redissolved in 120 g of tetrahydrofuran and then added dropwise to 1,200 g of methanol for reprecipitation. The mixture was further dried overnight in a vacuum dryer at 40 °C to obtain polymer (A-2) (purified polymer).

[0137] <Synthesis of Polymer (A-3)> (polymerization) In a reactor equipped with a stirrer, reflux condenser, and thermometer, 16.1 g (89.1 mmol) of methyl glycidyl ether norbornene, 37.5 g (209 mmol) of cyclohexylmaleimide, 10.0 g (89.1 mmol) of 1-octene, 13 g of methyl ethyl ketone, and 36 g of heptane were weighed and stirred to dissolve. The mixture was heated and stirred under a nitrogen flow until the temperature reached 70 °C. In a separate vessel, 4.46 g of dimethyl 2,2'-azobis(2-methylpropionate) was weighed as an initiator and dissolved in 10 g of methyl ethyl ketone. After the temperature inside the reactor stabilized, the entire amount was added all at once. The reaction was allowed to proceed for 3 hours with heating and stirring, starting from the moment the addition began. The polymer solution after the reaction was completed was used as the synthesized polymer.

[0138] (purification) After the reaction was completed, the polymer solution was cooled to room temperature and added dropwise to 1000 g of methanol for reprecipitation. The residue was redissolved in 100 g of tetrahydrofuran and then added dropwise to 1000 g of methanol for reprecipitation. The mixture was further dried overnight in a vacuum dryer at 40 °C to obtain polymer (A-3) (purified polymer).

[0139] <Synthesis of Polymer (A-4)> (polymerization) In a reactor equipped with a stirrer, reflux condenser, and thermometer, 15.4 g (85.5 mmol) of methyl glycidyl ether norbornene, 36.0 g (201 mmol) of cyclohexylmaleimide, 12.0 g (85.5 mmol) of 1-decene, 14 g of methyl ethyl ketone, and 36 g of heptane were weighed and stirred to dissolve. The mixture was heated and stirred under a nitrogen flow until the temperature reached 70 °C. In a separate vessel, 4.28 g of dimethyl 2,2'-azobis(2-methylpropionate) was weighed as an initiator and dissolved in 10 g of methyl ethyl ketone. After the temperature inside the reactor stabilized, the entire amount was added all at once. The reaction was allowed to proceed for 3 hours with heating and stirring, starting from the moment the addition began. The polymer solution after the reaction was completed was used as the synthesized polymer.

[0140] (purification) After the reaction was completed, the polymer solution was cooled to room temperature and added dropwise to 1000 g of methanol for reprecipitation. The residue was redissolved in 100 g of tetrahydrofuran and then added dropwise to 1000 g of methanol for reprecipitation. The mixture was further dried overnight in a vacuum dryer at 40 °C to obtain polymer (A-4) (purified polymer).

[0141] <Synthesis of Polymer (A-5)> (polymerization) In a reactor equipped with a stirrer, reflux condenser, and thermometer, 20.2 g (85.5 mmol) of (3-ethyloxetan-3-yl)methyl bicyclo[2.2.1]hept-5-ene-2-carboxylate, 36.0 g (201 mmol), 12.0 g (85.5 mmol), 14 g of methyl ethyl ketone, and 36 g of heptane were weighed and stirred to dissolve. The mixture was heated and stirred under a nitrogen flow until the temperature reached 70 °C. In a separate vessel, 4.28 g of dimethyl 2,2'-azobis(2-methylpropionate) was weighed as an initiator and dissolved in 10 g of methyl ethyl ketone. After the temperature inside the reactor stabilized, the entire amount was added all at once. The reaction was continued for 3 hours with heating and stirring, starting from the moment the addition began. The polymer solution after the reaction was completed was used as the synthesized polymer.

[0142] (purification) After the reaction was completed, the polymer solution was cooled to room temperature and added dropwise to 1000 g of methanol for reprecipitation. The residue was redissolved in 100 g of tetrahydrofuran and then added dropwise to 1000 g of methanol for reprecipitation. The mixture was further dried overnight in a vacuum dryer at 40 °C to obtain polymer (A-5) (purified polymer).

[0143] <Synthesis of Polymer (A-6)> (polymerization) In a reactor equipped with a stirrer, reflux condenser, and thermometer, 16.2 g (89.7 mmol) of methyl glycidyl ether norbornene, 32.2 g (179 mmol) of cyclohexylmaleimide, 16.0 g (89.7 mmol) of hexylnorbornene, 14 g of methyl ethyl ketone, and 36 g of heptane were weighed and stirred to dissolve. The mixture was heated and stirred under a nitrogen flow until the temperature reached 70 °C. In a separate vessel, 4.13 g (17.9 mmol) of dimethyl 2,2'-azobis(2-methylpropionate) was weighed as an initiator and dissolved in 10 g of methyl ethyl ketone. After the temperature inside the reactor stabilized, the entire amount was added all at once. The reaction was allowed to proceed for 3 hours with heating and stirring, starting from the moment the addition began. The polymer solution after the reaction was completed was used as the synthesized polymer.

[0144] (purification) After the reaction was completed, the polymer solution was cooled to room temperature, diluted with 30 g of tetrahydrofuran, and then added dropwise to 1,000 g of isopropanol to cause reprecipitation. The residue was redissolved in 170 g of tetrahydrofuran and then added dropwise to 1,200 g of isopropanol to cause reprecipitation. The mixture was then dried overnight in a vacuum dryer at 40 °C to obtain polymer (A-6) (purified polymer).

[0145] <Synthesis of Polymer (A-7)> (synthesis) The inside of a reaction vessel equipped with a stirrer and a condenser was first thoroughly purged with nitrogen, and then 164 g (0.7 mol) of decylnorbornene, 54.1 g (0.3 mol) of methoxyglycidyl ether norbornene, and 800 g of toluene were charged and heated to 50 °C in an oil bath while stirring. A solution of 26.9 g (0.014 mol) of (toluene)Ni(CF) in 5 g of toluene was added, and the reaction was continued for another 3 hours at 50 °C. The polymer solution after the reaction was completed was used as the synthesized polymer.

[0146] (purification) The resulting polymer solution was reprecipitated in a large amount of methanol to obtain a polymer precipitate, which was then filtered using a suction filter to obtain a polymer powder. The resulting polymer powder was vacuum dried at 60°C for 16 hours to obtain polymer (A-7) (purified polymer).

[0147] <Synthesis of Polymer (A-9)> (polymerization) In a reactor equipped with a stirrer, reflux condenser, and thermometer, 10.3 g (57.0 mmol) of methyl glycidyl ether norbornene, 44.3 g (247 mmol) of cyclohexylmaleimide, 24.0 g (171 mmol) of 1-decene, 13 g of methyl ethyl ketone, and 23 g of heptane were weighed and stirred to dissolve. The mixture was heated and stirred under a nitrogen flow until the temperature reached 75°C. In a separate vessel, 0.63 g of dimethyl 2,2'-azobis(2-methylpropionate) was weighed as an initiator and dissolved in 6 g of methyl ethyl ketone. After the temperature inside the reactor stabilized, the entire amount was added all at once. The reaction was allowed to proceed for 5 hours with heating and stirring, starting from the moment the addition began. The polymer solution after the reaction was completed was used as the synthesized polymer.

[0148] (purification) After the reaction was completed, the polymer solution was cooled to room temperature, diluted with 50 g of tetrahydrofuran, and then added dropwise to 1,200 g of methanol for reprecipitation. The residue was redissolved in 120 g of tetrahydrofuran and then added dropwise to 1,200 g of methanol for reprecipitation. The residue was further dried overnight in a vacuum dryer at 40 °C to obtain polymer (A-9) (purified polymer).

[0149] <Synthesis of Polymer (A-10)> (polymerization) In a reactor equipped with a stirrer, reflux condenser, and thermometer, 35.6 g (197.8 mmol) of methyl glycidyl ether norbornene, 30.6 g (170 mmol) of cyclohexylmaleimide, 44.0 g (314 mmol) of 1-decene, and 13 g of methyl ethyl ketone were weighed and stirred to dissolve. The mixture was heated and stirred under a nitrogen flow until the temperature reached 75°C. In a separate vessel, 0.63 g of dimethyl 2,2'-azobis(2-methylpropionate) was weighed as an initiator and dissolved in 6 g of methyl ethyl ketone. After the temperature inside the reactor stabilized, the entire amount was added all at once. The reaction was allowed to proceed for 5 hours with heating and stirring, starting from the moment the addition began. The polymer solution after the reaction was completed was used as the synthesized polymer.

[0150] (purification) After the reaction was completed, the polymer solution was cooled to room temperature, diluted with 60 g of tetrahydrofuran, and then added dropwise to 1,300 g of methanol for reprecipitation. The residue was redissolved in 130 g of tetrahydrofuran and then added dropwise to 1,300 g of methanol for reprecipitation. The residue was further dried overnight in a vacuum dryer at 40 °C to obtain polymer (A-10) (purified polymer).

[0151] <Synthesis of Polymer (A-11)> (polymerization) In a reactor equipped with a stirrer, reflux condenser, and thermometer, 24.2 g (134 mmol) of methyl glycidyl ether norbornene, 29.3 g (164 mmol) of cyclohexylmaleimide, 50.0 g (356 mmol) of 1-decene, and 12 g of methyl ethyl ketone were weighed and stirred to dissolve. The mixture was heated and stirred under a nitrogen flow until the temperature reached 75°C. In a separate vessel, 0.60 g of dimethyl 2,2'-azobis(2-methylpropionate) was weighed as an initiator and dissolved in 5.5 g of methyl ethyl ketone. After the temperature inside the reactor stabilized, the entire amount was added all at once. The reaction was allowed to proceed for 5 hours with heating and stirring, starting from the moment the addition began. The polymer solution after the reaction was completed was used as the synthesized polymer.

[0152] (purification) After the reaction was completed, the polymer solution was cooled to room temperature, diluted with 50 g of tetrahydrofuran, and then added dropwise to 1,200 g of methanol for reprecipitation. The residue was redissolved in 120 g of tetrahydrofuran and then added dropwise to 1,200 g of methanol for reprecipitation. The residue was further dried overnight in a vacuum dryer at 40 °C to obtain polymer (A-11) (purified polymer).

[0153] <Synthesis of Polymer (A-12)> (polymerization) In a reactor equipped with a stirrer, reflux condenser, and thermometer, 32.9 g (198 mmol) of norbornene butanol, 30.6 g (170 mmol) of cyclohexylmaleimide, 44.0 g (314 mmol) of 1-decene, and 13 g of methyl ethyl ketone were weighed and stirred to dissolve. The mixture was heated and stirred under a nitrogen flow until the temperature reached 75°C. In a separate vessel, 0.63 g of dimethyl 2,2'-azobis(2-methylpropionate) was weighed as an initiator and dissolved in 6 g of methyl ethyl ketone. After the temperature inside the reactor stabilized, the entire amount was added all at once. The reaction was allowed to proceed for 5 hours with heating and stirring, starting from the moment the addition began. The polymer solution after the reaction was completed was used as the synthesized polymer.

[0154] (purification) After the reaction was completed, the polymer solution was cooled to room temperature, diluted with 60 g of tetrahydrofuran, and then added dropwise to 1,300 g of methanol for reprecipitation. The residue was redissolved in 130 g of tetrahydrofuran and then added dropwise to 1,300 g of methanol for reprecipitation. The residue was further dried overnight in a vacuum dryer at 40 °C to obtain polymer (A-12) (purified polymer).

[0155] The physical properties of the polymers (A-1) to (A-7) and (A-9) to (A-12) are shown in Table 1. The methods for measuring the physical properties of the polymers (A-1) to (A-7) and (A-9) to (A-12) will be described later.

[0156] The details of the raw materials for each component in Table 2 are as follows:

[0157] <Polymer (A)> (A-1) Polymer synthesized above (A-2) Polymer synthesized above (A-3) Polymer synthesized above (A-4) Polymer synthesized above (A-5) Polymer synthesized above (A-6) Polymer synthesized above (A-7) Polymer synthesized above (for comparison) (A-8) JER-1256 (Mitsubishi Chemical Corporation, phenoxy resin) (for comparison) (A-9) Polymer synthesized above (A-10) Polymer synthesized above (A-11) Polymer synthesized above (A-12) Polymer synthesized above

[0158] [ka]

[0159] <Compound (B) Having a Cyclic Ether Structure> (B-1) JER-YX8034 (manufactured by Mitsubishi Chemical Corporation, epoxy compound, liquid at 23°C, refractive index 1.51) (B-2)OXT-221 (manufactured by Toagosei Co., Ltd., oxetane compound, liquid at 23°C, refractive index 1.45)

[0160] [ka]

[0161] <Curing agent (C)> (C-1) CPI-310B (San-Apro Co., Ltd., photocationic polymerization initiator)

[0162] <Antioxidant (D)> (D-1) Irganox 1076 (BASF, hindered phenol type antioxidant)

[0163] <Surfactant (E)> (E-1) BYK-333 (BYK Japan Co., Ltd., silicone surfactant)

[0164] <Organic solvent (F)> (F-1) Toluene (F-2) Propylene glycol monomethyl ether-2-acetate

[0165] [Examples 1 to 10 and Comparative Examples 1 and 2] (Preparation of Resin Composition) The raw materials formulated according to Table 2 were stirred at room temperature until the raw materials were completely dissolved to obtain a solution, which was then filtered through a PTFE filter with a pore size of 0.2 μm to obtain varnish-like resin compositions of Examples 1 to 10 and Comparative Examples 1 and 2, respectively.

[0166] (Film Preparation) The resin compositions of Examples 1 to 10 and Comparative Examples 1 to 2 obtained by preparing the resin compositions described above were applied as a varnish using an applicator onto a 38 μm thick antistatic treated polyethylene terephthalate substrate so that the dried thickness would be 25 μm.Then, the substrate was dried at 100°C for 10 minutes, and finally, an OPP cover film was attached to the surface of the resin layer formed by the resin composition to create a film, thereby obtaining the films of Examples 1 to 10 and Comparative Examples 1 to 2 (films for forming the first clad layer), respectively.

[0167] (Preparation of dry film for core layer formation) (Synthesis of polymer for forming core layer) In a reactor equipped with a stirrer, reflux condenser, and thermometer, 36.0 g (202 mmol) of hexylnorbornene, 64.7 g (202 mmol) of diphenylmethylnorbornenemethoxysilane, 13.6 g of 1-octene, and 380 g of methylcyclohexane were weighed and stirred under a nitrogen flow until the temperature reached 80 °C. In a separate vessel, 0.02 g of palladium(II) (acetonitrile) bis(triisopropylphosphine) acetate tetrakis(2,3,4,5,6-pentafluorophenyl)borate and 0.01 g of N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate were weighed and dissolved in 4.0 g of ethyl acetate. After the temperature inside the reactor stabilized, the entire amount was added all at once. The moment the addition began was considered the starting time, and 40 minutes later, an additional 10.8 g (60.6 mmol) of hexylnorbornene was added. The reaction was then continued for 3 hours with heating and stirring. After the reaction was complete, the polymer solution was reprecipitated in a large amount of methanol to obtain a polymer precipitate, which was then filtered using a suction filter to obtain a polymer powder. The obtained powder was dissolved in 350 g of THF and reprecipitated again in a large amount of methanol to obtain a polymer precipitate, which was then filtered using a suction filter to obtain a polymer powder. The obtained polymer powder was vacuum dried at 60°C for 16 hours to obtain a powder of the polymer for forming the core layer. The weight-average molecular weight of the obtained polymer measured by GPC was 140,000.

[0168] (Preparation of Resin Composition for Forming Core Layer) 10 g of the core layer-forming polymer powder was weighed into a 100 mL glass container, and 30 g of toluene, 2.4 g of an oxetane compound (manufactured by Toagosei Co., Ltd., product name: OXT-213), 0.8 g of an epoxy compound having an alicyclic structure (manufactured by Daicel Corporation, product name: CELLOXIDE 2021P), 0.06 g of a photocationic polymerization initiator (manufactured by San-Apro Co., Ltd., product name: CPI-310B), and 0.1 g of an antioxidant (manufactured by BASF, product name: Irganox1076) were added thereto and dissolved uniformly. The mixture was then filtered through a 0.2 μm PTFE filter to obtain a core layer-forming resin composition.

[0169] (Preparation of dry film for core layer formation) The obtained core layer-forming resin composition was applied to a release-treated PET film using an applicator so that the film thickness after drying would be 40 μm. After coating, the film was placed in a dryer at 45°C for 5 minutes to completely remove the solvent, forming a coating. Finally, an OPP cover film was attached to the surface of the resin layer formed by the resin composition, thereby producing a dry film for forming a core layer.

[0170] (Preparation of dry film for forming second cladding layer) (Preparation of Resin Composition for Forming Second Clad Layer) 5.0 g of polymer (A-3), 5.0 g of JER-YX8034 (B-1), 0.1 g of Irganox1076 (D-1), 0.03 g of BYK-333 (E-1), and 0.5 g of Curesol C11z (Shikoku Kasei Corporation, imidazole compound) were weighed out, and 30 g of propylene glycol monomethyl ether-2-acetate was added and completely dissolved, followed by filtration through a 0.2 μm PTFE filter to obtain a resin composition for forming a second cladding layer.

[0171] (Preparation of dry film for forming second cladding layer) The obtained resin composition for forming the second cladding layer was applied as a varnish using an applicator onto a 25 μm thick polyimide substrate so that the dried thickness would be 10 μm, and then dried at 100°C for 10 minutes.Finally, an OPP cover film was attached to the surface of the resin layer formed by the resin composition to create a film, and a dry film for forming the second cladding layer was obtained.

[0172] (Fabrication of photoelectric composite substrate) A double-sided copper-clad laminate measuring 80 mm in width, 120 mm in length, and 50 μm in thickness was placed on a stainless steel plate. After peeling off the OPP cover film from the film for forming the first clad layer, the film was laminated using a vacuum laminator (manufactured by Nikko Materials Co., Ltd., device name: CVP-600) under conditions of temperature: 100°C, pressure: 5.0 MPa, and time: 120 seconds so that the resin layer for forming the clad layer of the film for forming the first clad layer came into contact with the double-sided copper-clad laminate. Then, a high-pressure mercury lamp was used to expose the entire film for forming the first clad layer to a dose of 1000 mJ / cm. 2 The exposure was carried out under the conditions of (a) to (c) to obtain Laminate A having a layer structure of "double-sided copper-clad laminate / first clad layer / PET substrate." Here, the PET substrate is a PET substrate derived from the film for forming the first clad layer.

[0173] Next, the PET substrate of laminate A was peeled off, and the OPP cover film of the dry film for core layer formation was peeled off. The first clad layer of laminate A was then bonded to the core layer of the dry film for core layer formation using a vacuum laminator (Nikko Materials Co., Ltd., CVP-300) at 60°C, pressure of 0.5 MPa, and time of 30 seconds. Next, a direct imaging exposure machine (SCREEN Co., Ltd., LI-9000) was used to create 20 lines and spaces, each 9 cm long, 10 μm in exposed area, and 50 μm in unexposed area. The PET substrate from the dry film for core layer formation was then peeled off, and the resulting laminate was heated in an atmospheric oven at 120°C for 1 hour to obtain laminate B, which had a layer structure of "double-sided copper-clad laminate / first clad layer / core layer."

[0174] Next, the OPP cover film of the dry film for forming the second cladding layer was peeled off, and the core layer in Laminate B was laminated with the resin layer (a resin layer composed of the resin composition for forming the cladding layer) in the dry film for forming the second cladding layer using a vacuum laminator (manufactured by Nikko Materials Co., Ltd., model CVP-300) at a temperature of 140°C, a pressure of 0.5 MPa, and a time of 120 seconds, followed by heating in an atmospheric oven at 160°C for 2 hours to obtain the optoelectronic composite substrates of Examples 1 to 10 and Comparative Examples 1 and 2. The layer structure of the optoelectronic composite substrates was "double-sided copper-clad laminate / first cladding layer / core layer / second cladding layer / polyimide substrate."

[0175] [Evaluation and Measurement] First, the methods for measuring the physical properties of polymers (A-1) to (A-7) and (A-9) to (A-12) are described. The results are shown in Table 1.

[0176] <Monomer reaction rate, composition ratio> The mixed solution of raw material monomers before polymerization of polymers (A-1) to (A-7) and (A-9) to (A-12) and the polymer solution after the reaction were subjected to GC measurement using a gas chromatograph mass spectrometer (Shimadzu Corporation, product name: Nexis GC-2030). From the obtained spectra, the amount of monomer reduction before and after polymerization was calculated. The amount of monomer reduction was taken as the amount of monomer involved in the reaction and was used as the reaction rate of each monomer. The composition ratio was calculated from the product of the charge ratio and the reaction rate of each monomer.

[0177] Polymers (A-1) to (A-7) and (A-9) to (A-12) were also analyzed by NMR, but the peaks overlapped, making it difficult to identify the composition ratios by NMR.

[0178] <Yield> For the polymers (A-1) to (A-7) and (A-9) to (A-12), the yield was calculated from the ratio of the mass of the obtained polymer to the total mass of the raw material monomers.

[0179] <Molecular weight, polydispersity> The weight-average molecular weight (Mw) and polydispersity (Mw / Mn) of polymers (A-1) to (A-7) and (A-9) to (A-12) were determined by gel permeation chromatography (GPC). The weight-average molecular weight (Mw) and polydispersity (Mw / Mn) of the polymers were determined using polystyrene equivalent values ​​obtained from a calibration curve of standard polystyrene obtained by GPC measurement. In Table 1, "after polymerization" refers to the measured value for the polymer after polymerization, and "after purification" refers to the measured value for the polymer after purification. The measurement conditions are as follows. Measurement device: HLC-8420GPC EcoSEC Elite (Tosoh Corporation, a measurement device with an integrated detector) Column: TSKgel SuperMultiporeXZ-M (Tosoh Corporation) Measurement temperature: 40℃ Measurement sample: A solution diluted with tetrahydrofuran (THF) so that the polymer concentration was 0.2 to 0.5% by mass was filtered through a 0.2 μm filter to prepare a measurement sample.

[0180] <5% mass loss temperature of polymer> Using a thermogravimetric and differential thermal analyzer (manufactured by Hitachi High-Tech Science Corporation, product name: STA7200RV), polymers (A-1) to (A-7) and (A-9) to (A-12) were heated from 30°C to 500°C under a nitrogen atmosphere at a heating rate of 10°C / min. The temperature at which the polymer's mass decreased by 5% based on the mass at the start of the measurement was defined as the 5% mass loss temperature of the polymer.

[0181] <Refractive index of polymer> The refractive index of polymers (A-1) to (A-7) and (A-9) to (A-12) was measured using an Abbe refractometer (manufactured by Atago Co., Ltd., product name: NAR-1T SOLID) under conditions of 23°C and 589 nm.

[0182] <Softening point of polymer> 1 mg of polymers (A-1) to (A-7) and (A-9) to (A-12) were placed in an aluminum sample pan, and the softening points were measured under a nitrogen atmosphere using a thermomechanical analyzer (Hitachi High-Tech Science Corporation, product name: TMA / SS6100). The measurement conditions were: measurement mode: compression, load: 30 mN, temperature range: 30°C to 300°C, and heating rate: 3°C / min. When the polymer softens due to heating, it deforms and the amount of displacement is detected. A temperature-displacement graph was created, and the softening point was determined as the extension of the straight line with no displacement on the low-temperature side, or the intersection of the tangent to the minimum displacement rate and the tangent to the maximum displacement rate.

[0183] Next, there will be described the methods for evaluating and measuring the resin compositions, etc. of Examples 1 to 10 and Comparative Examples 1 and 2. Table 2 shows the results of the measurements and evaluations of the resin compositions, etc.

[0184] <Coatability of resin composition> The appearance of the films of Examples 1 to 10 and Comparative Examples 1 and 2 was observed, and samples with no appearance abnormalities such as those of standard B were rated as A, and samples with appearance abnormalities (uneven coating, cloudiness, repelling, cracks, etc.) were rated as B.

[0185] <Refractive Index of Resin Composition> The OPP cover film was peeled off from the films of Examples 1 to 10 and Comparative Examples 1 and 2, and the refractive index was measured at 23° C. and 589 nm using an Abbe refractometer (manufactured by Atago Co., Ltd., product name: NAR-1T SOLID).

[0186] <Light transmittance for a wavelength of 850 nm> For the films of Examples 1 to 10 and Comparative Examples 1 and 2, the OPP cover film was peeled off, and the resin layer formed from the resin composition was laminated onto a glass slide at a temperature of 100°C, a pressure of 0.5 MPa, and a time of 2 minutes, with the resin layer facing the glass slide. The substrate film was then peeled off to obtain a sample for transmittance measurement (a glass slide with the resin composition). Subsequently, a 100% calibration was performed using a UV-visible spectrophotometer (manufactured by JASCO Corporation, product name: V-670) with glass slides inserted into both the background slot and the sample slot. The glass slide on the measurement slot side was replaced with the transmittance measurement sample, and the light transmittance [%] at a wavelength of 850 nm was measured in transmittance measurement mode.

[0187] <Embeddability evaluation> A 50 μm-thick double-sided copper-clad laminate (CCL) with a 100 μm diameter through-hole was prepared. The OPP cover film of each of the films in Examples 1 to 10 and Comparative Examples 1 and 2 was peeled off, and the film was attached to the CCL so that the resin layer formed from the resin composition faced the CCL. The film was then laminated using a laminator (manufactured by Nikko Materials, product name: CVP-600) at a temperature of 100°C, a pressure of 5.0 MPa, and a time of 2 minutes. The through-holes in the substrate were observed under a microscope, and samples that were filled without voids were rated as A, samples with insufficient filling were rated as B, and samples with poor filling, such as voids or bleeding, were rated as C.

[0188] <Optical loss evaluation> The optoelectronic composite substrates of Examples 1 to 10 and Comparative Examples 1 and 2 were cut by dicing on both sides so that the length of the patterned portion was 7 cm, to obtain samples for evaluating optical loss. The propagation loss of the optical loss evaluation samples was measured in accordance with 4.6.2.1 Cutback Method in "Test Methods for Polymer Optical Waveguides (JPCA-PE02-05-01S-2008)." The measurement was performed using light with a wavelength of 850 nm. Based on the results, samples with a propagation loss of less than 1 dB were rated as A, samples with a propagation loss of 1 dB to 3 dB as B, and samples with a propagation loss of more than 3 dB as C.

[0189] [Table 1]

[0190] In Table 1, l, m, and n correspond to l, m, and n of each structural unit described in the structural formula of the polymer, respectively.

[0191] [Table 2]

[0192] It can be seen from Table 2 that the coating properties of all the examples were good. Furthermore, the optical loss evaluation results of all the examples were good. That is, the resin composition of this embodiment can improve the coating properties and suppress the optical loss of the optical waveguide. Furthermore, the evaluation results of embeddability were all good in all of the examples. That is, the resin composition of this embodiment can further improve embeddability. [Explanation of symbols]

[0193] 20 First cladding layer 30 Core Layer 40 Second cladding layer 50 Mirror on the light-emitting element side 60 Mirror on the light receiving element side 100 optical waveguide 110 Substrate 120 Light-emitting element 130 Photodetector 140a, 140b vias 200 Optical and electrical composite substrate

Claims

1. A resin composition that can be used for an optical waveguide clad, Contains a cyclic olefin resin (A), The cyclic olefin resin (A) contains a structural unit (a) and a structural unit (b), the structural unit (a) comprises, in a polymer side chain, a structural unit containing at least one selected from the group consisting of a linear alkyl group having from 4 to 20 carbon atoms, a group in which one or more hydrogen atoms contained in a linear alkyl group having from 4 to 20 carbon atoms are substituted with halogen atoms, and a group in which one or more methylene groups contained in a linear alkyl group having from 4 to 20 carbon atoms are substituted with oxygen atoms; The resin composition, wherein the structural unit (b) includes a structural unit derived from a maleimide compound.

2. The structural unit (a) includes at least one selected from the group consisting of a structural unit represented by the following formula (a-1), a structural unit represented by the following formula (a-2), and a structural unit represented by the following formula (a-3): The resin composition according to claim 1. 【Chemical 1】 (In the formula (a-1), R ３１ represents any one selected from the group consisting of a linear alkyl group having from 4 to 20 carbon atoms, a group in which one or more hydrogen atoms contained in a linear alkyl group having from 4 to 20 carbon atoms are substituted with a halogen atom, and a group in which one or more methylene groups contained in a linear alkyl group having from 4 to 20 carbon atoms are substituted with an oxygen atom) 【Chemistry 2】 (In the formula (a-2), R ４１ represents any one selected from the group consisting of a linear alkyl group having from 4 to 20 carbon atoms, a group in which one or more hydrogen atoms contained in a linear alkyl group having from 4 to 20 carbon atoms are substituted with halogen atoms, and a group in which one or more methylene groups contained in a linear alkyl group having from 4 to 20 carbon atoms are substituted with oxygen atoms, and R ４２ each independently represents one selected from the group consisting of a hydrogen atom, a methyl group, and an ethyl group. 【Chemistry 3】 (In the formula (a-3), R ５１ represents any one selected from the group consisting of a linear alkyl group having from 4 to 20 carbon atoms, a group in which one or more hydrogen atoms contained in a linear alkyl group having from 4 to 20 carbon atoms are substituted with a halogen atom, and a group in which one or more methylene groups contained in a linear alkyl group having from 4 to 20 carbon atoms are substituted with an oxygen atom)

3. 3. The resin composition according to claim 1, wherein the content of the structural unit (a) in the cyclic olefin resin (A) is 5 mol % or more and 40 mol % or less, when the total of all structural units in the cyclic olefin resin (A) is 100 mol %.

4. The resin composition according to claim 1 or 2, wherein the structural unit (b) includes a structural unit represented by the following formula (b-1): 【Chemistry 4】 (In the formula (b-1), R ２１ represents any one selected from the group consisting of a hydrogen atom, a hydroxyl group, and an organic group having 1 to 30 carbon atoms.

5. The cyclic olefin resin (A) further contains a structural unit (c), The resin composition according to claim 1 or 2, wherein the structural unit (c) includes a structural unit containing at least one selected from the group consisting of a crosslinkable group and a group reactive with a crosslinkable group.

6. The resin composition according to claim 5, wherein the structural unit (c) includes a structural unit represented by the following formula (c-1): 【Chemistry 5】 (In the formula (c-1), R １１ represents a group containing at least one selected from the group consisting of an epoxy group, an oxetanyl group, and a hydroxyl group.

7. The resin composition according to claim 1 or 2, wherein the cyclic olefin resin (A) has a weight average molecular weight (Mw) of 5,000 or more and 50,000 or less.

8. The resin composition according to claim 1 or 2, wherein the cyclic olefin resin (A) has a polydispersity (Mw / Mn) of 1.1 or more and 3.5 or less.

9. The resin composition according to claim 1 or 2, wherein the 5% mass loss temperature of the cyclic olefin resin (A) is 300°C or higher.

10. The resin composition according to claim 1 or 2, wherein the softening point of the cyclic olefin resin (A) is 100°C or higher and 300°C or lower.

11. The resin composition according to claim 1 or 2, wherein the refractive index of the cyclic olefin resin (A) is 1.45 or more and 1.55 or less.

12. 3. The resin composition according to claim 1, wherein the content of the cyclic olefin resin (A) in the resin composition is 20% by mass or more and 90% by mass or less, when the total content of non-volatile components in the resin composition is 100% by mass.

13. The resin composition according to claim 1 or 2, further comprising a compound (B) having a cyclic ether structure.

14. The resin composition according to claim 1 or 2, having a refractive index of 1.47 or more and 1.55 or less.

15. A resin film made of the resin composition according to claim 1 or 2, The resin film has a light transmittance of 85% or more for a wavelength of 850 nm.

16. A film comprising a resin layer formed from the resin composition according to claim 1 or 2.

17. a first film and a second film; 17. A film set, wherein at least one of the first film and the second film is the film of claim 16.

18. An optical waveguide in which a first clad layer, a core layer, and a second clad layer are laminated in this order, An optical waveguide, wherein at least one of the first clad layer and the second clad layer comprises the resin composition according to claim 1 or 2.

19. A substrate; An optical / electrical composite substrate comprising: the optical waveguide according to claim 18 provided on the substrate.

20. An electronic component comprising the optical-electrical composite substrate according to claim 19.

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