Polymers, compositions, dry films, optical waveguides, optoelectronic composite substrates, and electronic components

Abstract

The present invention provides a novel polymer capable of reducing the warping of the resulting dry film. [Solution] A polymer comprising the structural unit represented by formula (1) and norbornene structural units other than those represented by formula (1). TIFF2026071529000014.tif48153 (In equation (1), a represents an integer between 0 and 6, and R 11 (This indicates an aryl group.)

Description

[Technical Field]

[0001] The present invention relates to polymers, compositions, dry films, optical waveguides, optoelectronic composite substrates, and electronic components. [Background technology]

[0002] Polymers are included in components used in various fields such as electrical engineering, electronics, optics, information technology, and communications. An example of polymer technology is the technology described in Patent Document 1.

[0003] Patent Document 1 describes a copolymer comprising aromatic vinyl monomer units, crosslinking group-containing monomer units, and monomer units that give a homopolymer with a glass transition temperature of 150°C or higher. According to the technology described in Patent Document 1, it is possible to provide a copolymer that is excellent in solvent solubility and low dielectric loss tangent. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-27753 [Overview of the project] [Problems that the invention aims to solve]

[0005] This invention provides a novel polymer capable of reducing the warping of the resulting dry film. [Means for solving the problem]

[0006] The present invention provides polymers, compositions, dry films, optical waveguides, optoelectronic composite substrates, and electronic components as described below.

[0007] [1] A polymer comprising a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2). [ka] (In formula (1) above, a represents an integer between 0 and 6, and R 11 (This indicates an aryl group.) [ka] (In formula (2) above, b represents an integer between 1 and 6, c represents an integer between 1 and 6, R 21 (This indicates an alkyl group with 1 to 3 carbon atoms.) [2] The polymer according to [1], wherein the content of the structural unit represented by formula (1) in the polymer is 50 mol% or more and 90 mol% or less when the total amount of structural units in the polymer is 100 mol%. [3] The polymer according to [1] or [2], wherein the content of the structural unit represented by formula (2) in the polymer is 1 mol% or more and 20 mol% or less when the total amount of structural units in the polymer is 100 mol%. [4] The polymer according to any one of [1] to [3], further comprising the structural unit shown by the following formula (3). [ka] (In formula (3) above, d represents an integer between 0 and 15.) [5] The polymer according to [4], wherein the content of the structural unit represented by formula (3) in the polymer is 5 mol% or more and 45 mol% or less, when the total amount of structural units in the polymer is 100 mol%. [6] A polymer according to any one of the above [1] to [5], having a refractive index of 1.50 or more and 1.60 or less. [7] A polymer according to any one of the above [1] to [6], wherein the weight-average molecular weight (Mw) is 50,000 or more and 200,000 or less. [8] The polymer according to any one of [1] to [7], having a glass transition temperature of 150°C or higher and 250°C or lower. [9] The polymer according to any one of [1] to [8], having a storage elastic modulus E' at 30°C of 500 MPa or higher and 2000 MPa or lower.

[10] The polymer according to any one of [1] to [9], which can be used for the core layer of an optical waveguide.

[11] A composition comprising the polymer according to any one of [1] to

[10] .

[12] The composition according to

[11] , further comprising a compound having a cyclic ether structure.

[13] The composition according to

[11] or

[12] , further comprising a photoacid generator.

[14] A dry film comprising a layer made of the composition according to any one of

[11] to

[13] .

[15] An optical waveguide comprising a core layer and a cladding layer, wherein the core layer contains the polymer according to any one of [1] to

[10] .

[16] A substrate, and the optical waveguide according to

[15] provided on the substrate, comprising an optoelectronic composite substrate.

[17] An electronic component comprising the optoelectronic composite substrate according to

[16] . [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a novel polymer capable of reducing the warpage of the obtained dry film. [Brief Description of the Drawings]

[0009] [Figure 1] It is a cross-sectional view schematically showing an example of the structure of the optoelectronic composite substrate of the present embodiment. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below with reference to the drawings. Note that the drawings are simplified diagrams and do not correspond to the actual dimensional ratios. Unless otherwise specified, the numerical range "A~B" represents A or greater and B or less.

[0011] Polymers are included in components used in various fields such as electrical engineering, electronics, optics, information technology, and communications. Furthermore, in the manufacturing process of such components, it is known that dry films comprising a layer of polymer-containing composition are used. Such dry films require reduced warping to further improve handling. The present invention provides a novel polymer capable of reducing the warping of the resulting dry film.

[0012] [polymer] The polymer of this embodiment includes a structural unit represented by formula (1) and a structural unit represented by formula (2).

[0013] The structural units contained in the polymer of this embodiment will be described below.

[0014] The polymer of this embodiment contains structural units represented by formula (1). If the polymer of this embodiment contains the structural unit shown in formula (1), the refractive index of the polymer can be adjusted to a suitable range for use as a core layer in an optical waveguide.

[0015] [ka]

[0016] In equation (1), a represents an integer between 0 and 6, and R 11 This indicates an aryl group.

[0017] In formula (1), a preferably represents an integer of 1 or more and 5 or less, more preferably represents an integer of 1 or more and 3 or less, and even more preferably is 2. In formula (1), R 11 is a group selected from the group consisting of, for example, a phenyl group, a tolyl group, a naphthyl group, an anthracenyl group, etc., and is preferably a phenyl group.

[0018] In formula (1), a represents an integer of 1 or more and 3 or less, and R 11 preferably represents a phenyl group, a is 2, and R 11 more preferably represents a phenyl group.

[0019] The polymer of this embodiment contains a structural unit represented by formula (2). When the polymer of this embodiment contains a structural unit represented by formula (2), the warpage of the obtained dry film can be reduced.

[0020]

Chemical formula

[0021] In formula (2), b represents an integer of 1 or more and 6 or less, c represents an integer of 1 or more and 6 or less, and R 21 represents an alkyl group having 1 to 3 carbon atoms.

[0022] In formula (2), b preferably represents an integer of 1 or more and 4 or less, more preferably represents 1 or 2, and even more preferably represents 1. In formula (2), c preferably represents an integer of 1 or more and 4 or less, more preferably represents an integer of 1 or more and 3 or less, and even more preferably represents 2. In formula (2), R 21 is preferably a methyl group or an ethyl group, and more preferably a methyl group.

[0023] In formula (2), b represents an integer of 1 or more and 4 or less, c represents an integer of 1 or more and 4 or less, and R 21b is preferably a methyl group or an ethyl group, b is 1 or 2, c is an integer between 1 and 3, and R 21 It is more preferably a methyl group or an ethyl group, where b indicates 1, c indicates 2, and R 21 It is even more preferable that it exhibits a methyl group.

[0024] The polymer of this embodiment preferably further comprises structural units represented by formula (3).

[0025] [ka]

[0026] In equation (3), d represents an integer between 0 and 15, inclusive. In formula (3), d is preferably an integer between 1 and 10, more preferably an integer between 3 and 8, even more preferably an integer between 4 and 6, and even more preferably 5.

[0027] The content of the structural unit represented by formula (1) in the polymer of this embodiment is preferably 50 mol% to 90 mol%, more preferably 55 mol% to 88 mol%, even more preferably 60 mol% to 85 mol%, and even more preferably 70 mol% to 80 mol%, when the total amount of structural units in the polymer is 100 mol%. If the content of the structural unit represented by formula (1) in the polymer of this embodiment is within the above numerical range, the refractive index of the polymer can be adjusted to a range more suitable for use as a core layer of an optical waveguide.

[0028] The content of the structural unit represented by formula (2) in the polymer of this embodiment is preferably 1 mol% to 20 mol%, more preferably 2 mol% to 15 mol%, and even more preferably 3 mol% to 8 mol%, from the viewpoint of further reducing the warpage of the resulting dry film, when the total amount of structural units in the polymer is 100 mol%.

[0029] The content of the structural unit represented by formula (3) in the polymer of this embodiment is preferably 5 mol% to 45 mol%, more preferably 8 mol% to 40 mol%, even more preferably 10 mol% to 35 mol%, and even more preferably 15 mol% to 25 mol%, when the total amount of structural units in the polymer is 100 mol%.

[0030] The total content of the structural units represented by formula (1), formula (2), and formula (3) in the polymer of this embodiment is preferably 60 mol% to 100 mol%, more preferably 80 mol% to 100 mol%, even more preferably 90 mol% to 100 mol%, and even more preferably 95 mol% to 100 mol%, from the viewpoint of further reducing the warping of the resulting dry film.

[0031] The refractive index of the polymer in this embodiment is preferably 1.50 or more and 1.60 or less, more preferably 1.52 or more and 1.59 or less, and even more preferably 1.54 or more and 1.58 or less. If the refractive index of the polymer in this embodiment is within the above range, it can be suitably used as the core layer of an optical waveguide. The refractive index of a polymer is measured using a prism coupler, and refers to the refractive index at a measurement temperature of 25°C and a measurement wavelength of 632 nm.

[0032] The weight-average molecular weight (Mw) of the polymer in this embodiment is preferably 50,000 to 200,000, more preferably 70,000 to 200,000, even more preferably 100,000 to 195,000, and even more preferably 150,000 to 190,000.

[0033] The polydispersity (PDI) of the polymer in this embodiment is preferably 1.5 to 3.5, more preferably 1.8 to 3.0, and even more preferably 2.0 to 2.7.

[0034] The weight-average molecular weight (Mw) and polydispersity (PDI) of the polymer are values ​​determined by gel permeation chromatography (GPC) using polystyrene as a standard substance. The specific measurement conditions are those described in the examples.

[0035] The glass transition temperature of the polymer in this embodiment is preferably 150°C to 250°C, more preferably 180°C to 230°C, and even more preferably 190°C to 220°C.

[0036] The storage modulus E' of the polymer in this embodiment at 30°C is preferably 500 MPa to 2000 MPa, more preferably 700 MPa to 1500 MPa, and even more preferably 900 MPa to 1200 MPa. If the storage modulus E' of the polymer at 30°C is below the above upper limit, the warping of the resulting dry film can be further reduced.

[0037] The storage modulus E' of a polymer at 30°C is determined by cutting a 10mm x 40mm test piece from a polymer coating film with a thickness of 60μm, heating the test piece from 30°C to 250°C using a dynamic viscoelasticity analyzer under the conditions of a heating rate of 5°C / min, tensile mode, and frequency of 1Hz, and measuring the storage modulus E' with respect to temperature. Furthermore, the glass transition temperature of a polymer refers to the temperature at which the loss tangent tanδ, obtained when measuring the storage modulus E' using the method described above, shows its maximum value.

[0038] [Method for producing polymers] The method for producing the polymer of this embodiment is not particularly limited, and for example, it can be produced by polymerizing monomers capable of forming each structural unit in any way.

[0039] Monomers capable of forming the structural unit shown in formula (1) include, for example, phenethylnorbornene. Monomers capable of forming the structural unit shown in formula (2) include, for example, norbornenetrioxanonanane. Monomers capable of forming the structural unit shown in formula (3) include, for example, hexylnorbornene.

[0040] [Applications of polymers] The polymer of this embodiment is preferably a polymer that can be used in optical waveguides, and more preferably a polymer that can be used in the core layer of an optical waveguide.

[0041] [Composition] The composition of this embodiment comprises the polymer of this embodiment.

[0042] The content of the polymer of this embodiment in the composition of this embodiment is preferably 40% by mass or more and 95% by mass or less, more preferably 50% by mass or more and 85% by mass or less, and even more preferably 60% by mass or more and 80% by mass or less, when the total amount of nonvolatile components in the composition is 100% by mass.

[0043] The composition of this embodiment preferably further comprises a compound having a cyclic ether structure. The compound having a cyclic ether structure in this embodiment preferably includes a low molecular weight compound. The low molecular weight compound is, for example, a compound with a molecular weight of 1000 or less.

[0044] The compound having a cyclic ether structure preferably includes at least one selected from the group consisting of epoxy compounds and oxetane compounds.

[0045] Compounds having a cyclic ether structure preferably include compounds with a lower refractive index than the polymer of this embodiment.

[0046] The content of the compound having a cyclic ether structure in the composition of this embodiment is preferably 10 parts by mass or more and 100 parts by mass or less, more preferably 20 parts by mass or more and 70 parts by mass or less, and even more preferably 25 parts by mass or more and 45 parts by mass or less, when the content of the polymer of this embodiment in the composition is 100 parts by mass.

[0047] The composition of this embodiment preferably further comprises a photoacid generator. The photoacid generator 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.

[0048] The content of the photoacid generator in the composition of this embodiment is preferably 0.05 parts by mass or more and 3 parts by mass or less, more preferably 0.1 parts by mass or more and 2 parts by mass or less, and even more preferably 0.3 parts by mass or more and 1 part by mass or less, when the content of the polymer of this embodiment in the composition is 100 parts by mass.

[0049] The composition of this embodiment may further contain, for example, antioxidants, quenchers, organic solvents, surfactants, curing aids, leveling agents, colorants, preservatives, plasticizers, fillers, inorganic particles, degradation inhibitors, wettability improvers, antistatic agents, etc. The content of other components is appropriate.

[0050] The shape of the composition of this embodiment is not particularly limited and may be in the form of a film, membrane, varnish, sheet, or the like.

[0051] The composition of this embodiment can be obtained, for example, by mixing each component.

[0052] [Dry film] The dry film of this embodiment comprises a layer made of the composition of this embodiment. The composition forming the layer of this embodiment may be an uncured product, a semi-cured product, or a cured product, but it is preferably a semi-cured product.

[0053] The thickness of the layer made of the composition of this embodiment is preferably 1 μm to 100 μm, more preferably 5 μm to 80 μm, even more preferably 10 μm to 60 μm, and even more preferably 30 μm to 50 μm.

[0054] The dry film of this embodiment preferably further comprises a base film and has a layer made of the composition on the base film. For example, a resin film can be used as the base film. The resin constituting the base film is not particularly limited and includes, for example, at least one selected from the group consisting of polyethylene terephthalate and polyimide, and preferably contains polyethylene terephthalate.

[0055] The base film of this embodiment may be subjected to surface treatments such as antistatic treatment and mold release treatment.

[0056] The dry film of this embodiment may further include a cover film. Preferably, the cover film is provided in direct contact with the layer made of the composition.

[0057] The dry film of this embodiment can be obtained, for example, by applying the varnish-like composition of this embodiment onto a base film and drying it. Methods of application include, for example, direct application using various coating devices such as pin coaters, die coaters, comma coaters, and curtain coaters, as well as printing methods such as screen printing.

[0058] [Optical waveguide] The optical waveguide of this embodiment comprises a core layer and a cladding layer, wherein the core layer contains the polymer of this embodiment.

[0059] Figure 1 is a schematic cross-sectional view showing an example of the structure of the optoelectronic composite substrate of this embodiment. The optical waveguide of this embodiment will be explained using Figure 1. In Figure 1, the optical waveguide 100 comprises a first cladding layer 20, a core layer 30, and a second cladding layer 40 in this order. In this specification, when the optical waveguide 100 is provided on a substrate 110, the cladding layer located on the substrate 110 side is referred to as the first cladding layer 20. Furthermore, hereafter, when simply referred to as "cladding layer," the concept includes both the first cladding layer 20 and the second cladding layer 40.

[0060] The core layer 30 is a layer containing the polymer of this embodiment, and preferably a layer containing the composition of this embodiment. The composition contained in the core layer 30 may be an uncured product, a semi-cured product, or a cured product, but it is preferably a cured product.

[0061] The preferred numerical range for the thickness of the core layer 30 is the same as the preferred numerical range for the thickness of the layer made up of the dry film composition of this embodiment.

[0062] The core layer 30 may have a waveguide pattern formed on it. Examples of methods for forming the waveguide pattern include exposure, etching, and replication.

[0063] The cladding layer of this embodiment is preferably a layer containing a resin composition that can be used as a cladding layer. The resin composition contained in the cladding layer of this embodiment may be uncured, semi-cured, or cured, but is preferably cured.

[0064] The thickness of the first cladding layer 20 is preferably 1 μm to 150 μm, more preferably 5 μm to 100 μm, even more preferably 10 μm to 50 μm, and even more preferably 15 μm to 35 μm, from the viewpoint of further improving the optical propagation efficiency of the optical waveguide. The thickness of the second cladding layer 40 is preferably 1 μm to 150 μm, more preferably 3 μm to 100 μm, even more preferably 5 μm to 70 μm, even more preferably 8 μm to 50 μm, and even more preferably 8 μm to 20 μm, from the viewpoint of further suppressing thermal deformation of the optical waveguide.

[0065] The optical waveguide 100 may have mirrors formed on it. One method for forming the mirrors is to create an inclined surface by laser processing or the like.

[0066] In addition to the first cladding layer 20, the core layer 30, and the second cladding layer 40, the optical waveguide 100 may also include other layers, provided that they do not affect the good performance of the optical waveguide 100.

[0067] [Optoelectric composite substrate] The optoelectronic composite substrate of this embodiment will be described with reference to Figure 1. The optoelectronic composite substrate 200 comprises a substrate 110 and an optical waveguide 100 provided on the substrate 110.

[0068] The substrate 110 can be, for example, a printed circuit board or a flexible circuit board, and is preferably a flexible circuit board. The substrate 110 may have vias formed on it.

[0069] The optoelectronic composite substrate 200 may further include a polyimide substrate on the side of the second cladding layer 40 opposite to the core layer 30.

[0070] The photoelectric composite substrate 200 may include light-emitting elements, light-receiving elements, and the like.

[0071] The optoelectronic composite substrate 200 can be obtained, for example, by (i) forming a first cladding layer 20 on a substrate 110, (ii) forming a core layer 30 on the first cladding layer 20, and (iii) forming a second cladding layer 40 on the core layer 30. Methods for forming each layer include, for example, laminating each layer sequentially by rolling a dry film to form each layer using methods such as roll lamination, vacuum roll lamination, flat lamination, vacuum flat lamination, atmospheric pressure pressing, and vacuum pressing.

[0072] [Electronic components] The electronic component of this embodiment includes the photoelectric composite substrate of this embodiment. Examples of electronic components in this embodiment include those found in electronic devices such as mobile phones, game consoles, routers, WDM devices, personal computers, televisions, and home servers.

[0073] The embodiments of the present invention have been described above, but these are merely examples, and various other configurations can also be adopted. Furthermore, the present invention is not limited to the embodiments described above, and any modifications, improvements, etc., that can achieve the objectives of the present invention are included in the present invention. [Examples]

[0074] The embodiment will be described in detail below based on examples and comparative examples. However, this embodiment is not limited in any way to the descriptions of these examples.

[0075] [Example 1] <Polymer synthesis> Ethyl acetate (16.8 g), toluene (151.5 g), phenethylnorbornene (33.36 g, 0.168 mol), norbornenetrioxanonanane (2.54 g, 0.011 mol), and hexylnorbornene (8.0 g, 0.045 mol) were added to the reaction vessel. Oxygen was removed from the reaction medium by passing dry N2 through the solution for 30 minutes. After purging was complete, the reaction solution was brought to 40°C and 0.364 g (0.71 mmol) of bis(mesitylene)bis(perfluorophenyl)nickel dissolved in 6.9 g of toluene was injected into the reactor. The reaction mixture was stirred for 10 minutes, then treated with a peracetic acid solution (a mixture of 0.085 times the weight of the reaction solution in acetic acid, 0.17 times the weight in 30% hydrogen peroxide solution, and 0.29 times the weight in deionized water), and stirred for a further 30 minutes. Stirring was stopped and the mixture was allowed to stand to separate the aqueous layer from the solvent layer. The aqueous layer was then removed, and the solvent layer was reprecipitation in 2100 g of methanol. The recovered solid was dissolved in 350 g of THF and reprecipitation again in 2100 g of methanol. The recovered solid was then dissolved in 234 g of toluene, and solvent replacement was performed under reduced pressure at 60°C to remove methanol and THF, yielding 120 g of a toluene solution of the polymer from Example 1 (solid content 31%, yield 90%). The polymer of Example 1 is the polymer represented by the following formula (A-1).

[0076] [ka]

[0077] The polymer of Example 1 has the following ratio in formula (A-1): l:m:n = 75:20:5. GC measurements were performed on the mixed solution of raw material monomers before polymerization and the polymer solution after the reaction was completed, 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 defined as the amount of monomer involved in the reaction and as the reaction rate of each monomer. The composition ratio was determined by the product of the charge ratio and the reaction rate of each monomer.

[0078] <Preparation of the composition> In Example 1, 100 parts by mass of the polymer (solids), 24 parts by mass of low refractive index monomer (oxetane compound, EHOX, manufactured by Toagosei Co., Ltd.), 8 parts by mass of low refractive index monomer (epoxy compound, CEL2021P, manufactured by Daicel Corporation), 0.6 parts by mass of photoacid generator (CPI-310B, manufactured by Sunapro Co., Ltd.), 1 part by mass of antioxidant (Irganox 1076, manufactured by BASF), 0.25 parts by mass of antioxidant (Irgafos 168, manufactured by BASF), and 213 parts by mass of toluene were stirred at room temperature until the raw materials were completely dissolved to obtain a solution. The solution was then filtered through a PTFE filter with a pore size of 0.2 μm to obtain the composition. Note that the parts by mass of toluene in the composition include the parts by mass of toluene in the toluene solution of the polymer in Example 1.

[0079] <Preparation of dry film> The composition was coated onto a release-treated PET film using an applicator to achieve a dry film thickness of 40 μm. After coating, the film was placed in a 45°C dryer for 5 minutes to completely remove the solvent and form a coating. Finally, a PET cover film was attached to the surface of the layer containing the composition of Example 1 to obtain the dry film of Example 1.

[0080] <Fabrication of optical waveguides> (Preparation of film for the core) The dry film of Example 1 was irradiated with ultraviolet light through a mask having an opening to form the desired pattern and obtain a core film. Hereinafter, the layer in the core film consisting of the composition of Example 1 will also be referred to as the layer consisting of the core composition.

[0081] (Synthesis of copolymers for cladding) Decyl norbornene (DeNB, CAS number 22094-85-5) (16.4 g, 0.07 mol), methyl glycidyl ether norbornene (MGENB, CAS number 3188-75-8) (5.41 g, 0.03 mol), and toluene (58.0 g) were mixed in a 500 mL sealant bottle in a dry box, and then heated in an oil bath at 80°C while stirring to form a solution. To this solution, (η 6 A toluene solution (5 g) of -toluene)Ni(C6F5)2 (0.69 g, 0.0014 mol) was added. The mixture was stirred with a magnetic stirrer at room temperature for 4 hours. To this mixture, toluene (87.0 g) was added and stirred vigorously. The reaction mixture (toluene solution) was then transferred to a larger beaker, and methanol (1 L), a poor solvent, was added dropwise, causing a fibrous white solid to precipitate. The solid was filtered and collected, and vacuum-dried in an oven at 60°C, yielding a product with a dry mass of 17.00 g (yield 87%). The molecular weight of the product was measured by GPC (THF solvent, polystyrene equivalent), and the results were Mw = 75,000 and Mn = 30,000. 1 The copolymer was identified as a DeNB / MGENB copolymer by 1H-NMR. The refractive index of this copolymer was measured by prism coupling and found to be 1.5153 in the TE mode and 1.5151 in the TM mode at a wavelength of 633 nm.

[0082] (Preparation of cladding composition) Under yellow light, 10 g of the copolymer for cladding was dissolved in dehydrated toluene to prepare a 20 wt% copolymer solution (50 g). To this solution, antioxidants (Irganox 1076, 0.01 g), antioxidant (Irgafos 168, 0.0025 g), and photoacid generator (Toyo Ink Mfg. Co., Ltd., product name: TAG-382, 0.2 g) were added and uniformly dissolved. The solution was then filtered through a 0.2 μm pore size filter to prepare the cladding composition.

[0083] (Preparation of cladding film) After filling a syringe of a coating machine with 200 g of the cladding composition, the cladding composition was applied to a polyimide (PI) film (12.5 μm thick) support substrate using a nozzle with controllable discharge to form a uniform 60 μm liquid cladding coating on the support substrate. Subsequently, this coating was placed in a dryer together with the PI film and heated at 45°C for 10 minutes to evaporate the solvent, thereby obtaining a cladding film containing a 5 μm thick layer of the cladding composition.

[0084] (First cladding layer lamination process) A PI film from the cladding film was bonded to a laminated substrate (stainless steel plate) via a protective sheet. Next, a layer consisting of the cladding composition from the cladding film was adsorbed and fixed to a bonding device via the PI film, protective sheet, and laminated substrate in that order. The PET cover film was peeled off from the core film, the layer consisting of the core composition was subjected to corona treatment, and then it was adsorbed and fixed to a lamination device via the PET film in the core film. Subsequently, an automatic roller was used to temporarily bond the layer made of the cladding composition and the layer made of the core composition. After removing the bonding device, a protective sheet was placed on the layer made of the core composition via a PET film, and the layer made of the cladding composition and the layer made of the core composition were heat-pressed together using a laminator to obtain laminate A. The heat-pressure bonding conditions were 140°C, 0.3 MPa, and 210 seconds under vacuum conditions. The layer structure of laminate A consists of "laminated substrate / protective sheet / PI film / layer made of cladding composition / layer made of core composition / PET film".

[0085] After heat-pressing, the laminator's air cooling system was used to cool each layer of laminate A to room temperature. Then, a highly adhesive tape was applied to the PET film in laminate A, and the PET film was peeled off while removing the tape.

[0086] (Second cladding layer lamination process) A layer consisting of a cladding composition within a cladding film was adsorbed and fixed to a laminating device via a PI film. After corona treatment was applied to the layer consisting of the core composition in laminate A, the layer consisting of the cladding composition, PI film, protective sheet, and laminate substrate were attached to a bonding device in this order. Subsequently, an automatic roller was used to temporarily bond the layer made of the cladding composition and the layer made of the core composition. Furthermore, a protective sheet was placed on the layer made of the cladding composition via a PI film, and the layer made of the cladding composition and the layer made of the core composition were heat-pressed together using a laminator to obtain laminate B. The heat-pressure bonding conditions were 140°C, 0.3 MPa, and 210 seconds under vacuum conditions.

[0087] The resulting laminate B was fixed to a support substrate (stainless steel plate) with magnets and placed in an oven, where it was heated at 160°C for 2 hours to cure the core composition and the cladding composition. Thus, the optical waveguide of Example 1 was obtained.

[0088] [Example 2] <Polymer synthesis> In the synthesis of the polymer in Example 1, phenethylnorbornene (33.36 g, 0.168 mol), norbornenetrioxanonanane (2.54 g, 0.011 mol), and hexylnorbornene (8.0 g, 0.045 mol) were replaced with phenethylnorbornene (26.69 g, 0.135 mol), norbornenetrioxanonanane (2.54 g, 0.011 mol), and hexylnorbornene (14.0 g, 0.079 mol) in the same manner as in Example 1 to obtain a toluene solution of the polymer of Example 2 (solids content 30%, yield 88%). The polymer in Example 2 is the polymer represented by the following formula (A-1).

[0089] [ka]

[0090] The polymer of Example 2 has a composition ratio of l:m:n = 60:35:5 in formula (A-1). The composition ratio was determined by the same method as for the polymer of Example 1.

[0091] The composition and dry film of Example 2 were obtained in the same manner as in Example 1, except that the polymer of Example 2 was used instead of the polymer of Example 1. Note that no optical waveguide was fabricated in Example 2.

[0092] [Comparative Example 1] <Polymer synthesis> Ethyl acetate (16.8 g), toluene (151.5 g), phenethylnorbornene (31.14 g, 0.157 mol), and hexylnorbornene (12.0 g, 0.067 mol) were added to the reaction vessel. Oxygen was removed from the reaction medium by passing dry N2 through the solution for 30 minutes. After purging was complete, the reaction solution was brought to 40°C, and 0.364 g (0.71 mmol) of bis(mesitylene)bis(perfluorophenyl)nickel dissolved in 6.9 g of toluene was injected into the reactor. The reaction mixture was stirred for 10 minutes, then treated with a peracetic acid solution (a mixture of 0.085 times the weight of the reaction solution in acetic acid, 0.17 times the weight in 30% hydrogen peroxide solution, and 0.29 times the weight in deionized water), and stirred for a further 30 minutes. The stirring was stopped and the mixture was allowed to stand to separate the aqueous layer from the solvent layer. The aqueous layer was then removed, and the solvent layer was reprecipitation in 2100 g of methanol. The recovered solid was dissolved in 350 g of THF and reprecipitation again in 2100 g of methanol. The recovered solid was then dissolved in 234 g of toluene, and solvent replacement was performed under reduced pressure at 60°C to remove methanol and THF, yielding 113 g of a toluene solution of the polymer of Comparative Example 1 (solid content 32%, yield 84%). The polymer of Comparative Example 1 is the polymer represented by the following formula (A-2).

[0093] [ka]

[0094] In formula (A-2), m:n = 70:30. The composition ratio was determined by the same method as for the polymer in Example 1.

[0095] The composition, dry film, and optical waveguide of Comparative Example 1 were obtained in the same manner as in Example 1, except that the polymer of Comparative Example 1 was used instead of the polymer of Example 1.

[0096] [Measurement and Evaluation] The following measurements and evaluations were performed on Examples 1 and 2 and Comparative Example 1. The measurement and evaluation results are shown in Table 1. In Table 1, "-" indicates that no measurement was performed.

[0097] <Weight-average molecular weight (Mw) and polydispersity (PDI)> The weight-average molecular weight (Mw) and polydispersity (PDI) of the polymers in Examples 1-2 and Comparative Example 1 were measured by GPC using a polystyrene standard. The measurement conditions were as follows: • Equipment: Tosoh Corporation, Gel Permeation Chromatography System HLC-8320GPC • Column: TSK-GEL Supermultipore HZ-M, manufactured by Tosoh Corporation. • Detector: RI detector for liquid chromatography ·Measurement temperature: 40℃ • Solvent: THF • Sample concentration: 2.0 mg / ml

[0098] <Refractive index> (Preparation of polymer evaluation films) Toluene solutions of the polymers from Example 1 and Comparative Example 1 were applied to a base film using a coating apparatus to achieve a dry film thickness of 60 μm. After heating at 90°C for 30 minutes, and then further heating at 120°C for 30 minutes, polymer evaluation films containing coated films made of the polymers from Example 1 and Comparative Example 1 were obtained.

[0099] The refractive index of a polymer coating film in a polymer evaluation film was measured at a measurement temperature of 25°C and a measurement wavelength of 632 nm using a prism coupler (Metricon, USA, part number: Model 2010).

[0100] <Storage modulus E' and glass transition temperature at 30°C> (Preparation of polymer evaluation films) A polymer evaluation film was prepared using the same method as described in <Refractive Index> (Preparation of Polymer Evaluation Film). The evaluations described below were performed on the polymer coating film after peeling the substrate film from the polymer evaluation film.

[0101] A 10mm x 40mm test piece was cut from a polymer coating film. This test piece was heated from 30°C to 250°C using a dynamic viscoelasticity analyzer (DMA Q800, manufactured by T.A. Instruments Japan Co., Ltd.) under the conditions of heating rate 5°C / min, tensile mode, and frequency 1Hz. The storage modulus E' with respect to temperature was measured, and the storage modulus E' [MPa] at 30°C was calculated. The temperature at which the loss tangent tanδ showed its maximum value was defined as the glass transition temperature [°C].

[0102] <Evaluation of dry film warpage> The dry films from Examples 1 and 2 and Comparative Example 1 were cut into 3cm x 10cm sections and used as samples for evaluating the amount of warping. After removing the PET cover film from the sample used for evaluating warpage, the sample was placed on a flat surface for 5 minutes with the composition layer facing upwards, and the vertical distance between the vertices of the sample and the surface was measured. The vertical distance from the surface was measured at each of the four vertices of the sample, and the average value was evaluated as the amount of warpage of the dry film. Here, since the sample used for evaluating warpage is rectangular, the four vertices of the sample refer to the four corners of the rectangle. Samples with a dry film curvature of 5 mm or less were evaluated as A, and samples with a curvature greater than 5 mm were evaluated as B.

[0103] <Linear loss> For the optical waveguides of Example 1 and Comparative Example 1, both sides were cut by dicing so that the pattern section length was 7 cm, thereby obtaining a straight pattern. For a linear pattern, the linear loss [dB] was measured using a cutback method, in which light with a wavelength of 850 nm was input through an optical fiber from one end of the core layer and the output from the other end was measured.

[0104] <Bending loss> For the optical waveguides of Example 1 and Comparative Example 1, both sides were cut by dicing so that the length of the pattern portion was 7 cm, and then a bent pattern having a curve along a circle with a radius of 10 mm was obtained. The insertion loss [dB] of the bent pattern was measured using a cutback method, in which light with a wavelength of 850 nm was input to the bent pattern through an optical fiber from one end of the core layer and the output from the other end was measured. The bending loss [dB] value was obtained from the following formula. Bending loss [dB] = Insertion loss of bending pattern [dB] - Linear loss [dB]

[0105] <Peel strength> For the optical waveguides of Example 1 and Comparative Example 1, the 90° peel strength [N / cm] between the first cladding layer and the core layer, and the 90° peel strength [N / cm] between the second cladding layer and the core layer were measured using a tensile testing machine (A&D Co., Ltd., product name: STA-1150) with 5 mm wide test specimens at a rate of 50 mm / min. The 90° peel strength [N / cm] between the first cladding layer and the core layer was defined as "peel strength (front)," and the 90° peel strength [N / cm] between the second cladding layer and the core layer was defined as "peel strength (back)."

[0106] [Table 1]

[0107] Table 1 shows that the dry film of the example had a better warpage evaluation compared to the dry film of the comparative example. In other words, the polymer of this embodiment can reduce the warpage of the resulting dry film.

[0108] Furthermore, the optical waveguide of the embodiment showed improved peel strength compared to the optical waveguide of the comparative example. In other words, the polymer of this embodiment can improve the interlayer adhesion of the resulting optical waveguide. [Explanation of symbols]

[0109] 20. First cladding layer 30 core layers 40. Second cladding layer 100 optical waveguide 110 circuit boards 200 Optoelectronic composite substrate

Claims

1. A polymer comprising a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2). 【Chemistry 1】 (In formula (1) above, a represents an integer between 0 and 6, and R １１ (This indicates an aryl group.) 【Chemistry 2】 (In formula (2) above, b represents an integer between 1 and 6, c represents an integer between 1 and 6, R ２１ (This indicates an alkyl group with 1 to 3 carbon atoms.)

2. The polymer according to claim 1, wherein the content of the structural unit represented by formula (1) in the polymer is 50 mol% or more and 90 mol% or less, when the total amount of structural units in the polymer is 100 mol%.

3. The polymer according to claim 1 or 2, wherein the content of the structural unit represented by formula (2) in the polymer is 1 mol% or more and 20 mol% or less, when the total amount of structural units in the polymer is 100 mol%.

4. The polymer according to claim 1 or 2, further comprising a structural unit represented by the following formula (3). 【Transformation 3】 (In formula (3) above, d represents an integer between 0 and 15.)

5. The polymer according to claim 4, wherein the content of the structural unit represented by formula (3) in the polymer is 5 mol% or more and 45 mol% or less, when the total amount of structural units in the polymer is 100 mol%.

6. The polymer according to claim 1 or 2, wherein the refractive index is 1.50 or more and 1.60 or less.

7. The polymer according to claim 1 or 2, wherein the weight-average molecular weight (Mw) is 50,000 or more and 200,000 or less.

8. The polymer according to claim 1 or 2, wherein the glass transition temperature is 150°C or higher and 250°C or lower.

9. The polymer according to claim 1 or 2, wherein the storage modulus E' at 30°C is 500 MPa or more and 2000 MPa or less.

10. The polymer according to claim 1 or 2, which is a polymer that can be used in the core layer of an optical waveguide.

11. A composition comprising the polymer according to claim 1 or 2.

12. The composition according to claim 11, further comprising a compound having a cyclic ether structure.

13. The composition according to claim 11, further comprising a photoacid generator.

14. A dry film comprising a layer made of the composition described in claim 11.

15. An optical waveguide comprising a core layer and a cladding layer, An optical waveguide comprising the polymer described in claim 1 or 2 in the core layer.

16. circuit board and An optoelectronic composite substrate comprising an optical waveguide according to claim 15 provided on the substrate.

17. An electronic component comprising the optoelectronic composite substrate described in claim 16.

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