Polymers

Abstract

To provide a new polymer capable of improving the performance balance of moldability and flexibility.SOLUTION: Provided is a polymer selected from the group consisting of a polymer (A1) and a polymer (A2), wherein the polymer (A1) contains a structural unit including at least one selected from the group consisting of a structural unit represented by formula (1a) and a structural unit represented by formula (1b), a structural unit represented by formula (2), and a structural unit represented by formula (3), and the polymer (A2) contains a structural unit including at least one selected from the group consisting of a structural unit represented by formula (1a) and a structural unit represented by formula (1b), a structural unit represented by formula (2), and a structural unit represented by formula (4).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to polymers. [Background technology]

[0002] Some polymers are known to be used in optical components, electronic components, etc. Patent Document 1 discloses an example of a technology relating to polymers.

[0003] Patent Document 1 describes a copolymer containing an aromatic vinyl monomer unit, a crosslinking group-containing monomer unit, and a monomer unit that gives a homopolymer having a glass transition temperature of 150° C. or higher. According to the technology described in Patent Document 1, it is stated that a copolymer excellent in solvent solubility and low dielectric loss tangent can be provided. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-27753 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention provides a novel polymer that can improve the performance balance between moldability and flexibility. [Means for solving the problem]

[0006] According to the present invention, there is provided the following polymer:

[0007] [1] A polymer selected from the group consisting of polymer (A1) and polymer (A2), The polymer (A1) comprises a structural unit including at least one selected from the group consisting of a structural unit represented by the following formula (1a) and a structural unit represented by the following formula (1b), a structural unit represented by the following formula (2), and a structural unit represented by the following formula (3): The polymer (A2) is a polymer comprising a structural unit containing at least one selected from the group consisting of a structural unit represented by the following formula (1a) and a structural unit represented by the following formula (1b), a structural unit represented by the following formula (2), and a structural unit represented by the following formula (4): [ka] (In the formula (1a), 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.) [ka] (In the above formula (1b), 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. [ka] (In the formula (2), R 21 represents 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. [ka] (In the formula (3), R 31 indicates a straight-chain alkyl group having 4 to 20 carbon atoms. [ka] (In the formula (4), R 41 represents a linear alkyl group having 4 to 20 carbon atoms, and R 42 each independently represents one selected from the group consisting of a hydrogen atom, a methyl group, and an ethyl group. [2] The polymer according to [1] above, having a weight average molecular weight (Mw) of 5,000 or more and 50,000 or less. [3] The polymer according to [1] or [2] above, having a polydispersity (Mw / Mn) of 1.1 or more and 3.5 or less. [4] The polymer according to any one of the above [1] to [3], which has a 5% mass loss temperature of 300°C or higher. [5] The polymer according to any one of the above [1] to [4], which has a softening point of 100°C or higher and 300°C or lower. [6] The polymer according to any one of the above [1] to [5], which has a refractive index of 1.45 or more and 1.55 or less. [7] The polymer according to any one of [1] to [6] above, wherein the total content of the structural units represented by the formula (1a) and the structural units represented by the formula (1b) in the polymer (A1) is 10 mol % or more and 40 mol % or less, when the total amount of the structural units in the polymer (A1) is 100 mol %. [8] The polymer according to any one of [1] to [7] above, wherein the content of the structural unit represented by the formula (2) in the polymer (A1) is 30 mol % or more and 80 mol % or less, when the total amount of the structural units in the polymer (A1) is 100 mol %. [9] The polymer according to any one of [1] to [8] above, wherein the content of the structural unit represented by the formula (3) in the polymer (A1) is 10 mol % or more and 40 mol % or less, when the total amount of the structural units in the polymer (A1) is 100 mol %.

[10] The polymer according to any one of [1] to [6] above, wherein the total content of the structural unit represented by formula (1a) and the structural unit represented by formula (1b) in the polymer (A2) is 5 mol % or more and 40 mol % or less, when the total amount of the structural units in the polymer (A2) is 100 mol %.

[11] The polymer according to any one of [1] to [6] and

[10] above, wherein the content of the structural unit represented by the formula (2) in the polymer (A2) is 40 mol % or more and 85 mol % or less, when the total amount of the structural units in the polymer (A2) is 100 mol %.

[12] The polymer according to any one of [1] to [6] and

[10] to

[11] above, wherein the content of the structural unit represented by the formula (4) in the polymer (A2) is 5 mol % or more and 40 mol % or less, when the total amount of the structural units in the polymer (A2) is 100 mol %. [Effects of the Invention]

[0008] According to the present invention, a novel polymer can be provided that can improve the balance of moldability and flexibility. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described. Unless otherwise specified, the numerical range "A to B" indicates A or more and B or less.

[0010] Resin members are used in various fields such as electrical, electronic, optical, information, and communications fields. Furthermore, such resin members are required to have properties such as moldability and flexibility. The present invention provides a novel polymer that can improve the performance balance between moldability and flexibility.

[0011] [polymer] The polymer of this embodiment is any polymer selected from the group consisting of polymer (A1) and polymer (A2). Polymer (A1) contains structural units containing at least one selected from the group consisting of structural units represented by formula (1a) and structural units represented by formula (1b), structural units represented by formula (2), and structural units represented by formula (3). Polymer (A2) contains structural units containing at least one selected from the group consisting of structural units represented by formula (1a) and structural units represented by formula (1b), structural units represented by formula (2), and structural units represented by formula (4).

[0012] Preferred embodiments of the polymers (A1) and (A2) will be described below.

[0013] <Polymer (A1)> The polymer (A1) contains a structural unit including at least one selected from the group consisting of a structural unit represented by formula (1a) and a structural unit represented by formula (1b), a structural unit represented by formula (2), and a structural unit represented by formula (3).

[0014] The polymer (A1) contains at least one structural unit selected from the group consisting of a structural unit represented by formula (1a) and a structural unit represented by formula (1b), and preferably contains a structural unit represented by formula (1a).

[0015] [ka]

[0016] In formula (1a), 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 (1a), a is preferably 1 or 2, and more preferably 1. In formula (1a), b is preferably 1 or 2, and more preferably 1.

[0017] [ka]

[0018] In formula (1b), 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 (1b), 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 (1b), c is preferably 1 or 2, and more preferably 1.

[0019] The epoxy group in formula (1a) and the oxetanyl group in formula (1b) function as crosslinking groups. Therefore, the polymer of this embodiment contains at least one structural unit selected from the group consisting of the structural unit represented by formula (1a) and the structural unit represented by formula (1b), thereby improving the heat resistance, mechanical properties, etc. of the resulting cured product.

[0020] The polymer (A1) contains a structural unit represented by formula (2). The polymer of this embodiment contains the structural unit represented by formula (2), thereby improving the balance of moldability and flexibility.

[0021] [ka]

[0022] In formula (2), R 21 represents any one selected from the group consisting of a hydrogen atom, a hydroxyl group, and a cyclic alkyl group having 4 to 20 carbon atoms.

[0023] In formula (2), examples of the cyclic alkyl group having 4 to 20 carbon atoms include at least one selected from the group consisting of a cyclohexyl group, a cyclooctyl group, a cyclopentyl group, an adamantyl group, and the like.

[0024] In formula (2), R 21 is preferably a cyclic alkyl group having 4 to 20 carbon atoms, more preferably a cyclic alkyl group having 4 to 10 carbon atoms, and even more preferably a cyclic alkyl group having 6 carbon atoms (cyclohexyl group).

[0025] The polymer (A1) contains a structural unit represented by formula (3). By including the structural unit represented by formula (3), the polymer (A1) can improve the balance of moldability and flexibility.

[0026] [ka]

[0027] In formula (3), R 31 represents a straight-chain alkyl group having 4 to 20 carbon atoms. In formula (3), R 31 is preferably a linear alkyl group having 6 to 18 carbon atoms, 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).

[0028] The total content of the structural units represented by formula (1a) and the structural units represented by formula (1b) in polymer (A1) is preferably 10 mol % or more and 40 mol % or less, more preferably 15 mol % or more and 35 mol % or less, and even more preferably 18 mol % or more and 30 mol % or less, when the total amount of the structural units in polymer (A1) is taken as 100 mol %.

[0029] The content of the structural unit represented by formula (2) in polymer (A1) is preferably 30 mol % or more and 80 mol % or less, more preferably 35 mol % or more and 65 mol % or less, and even more preferably 40 mol % or more and 60 mol % or less, when the total amount of structural units in polymer (A1) is taken as 100 mol %.

[0030] The content of the structural unit represented by formula (3) in polymer (A1) is preferably 10 mol % or more and 40 mol % or less, more preferably 15 mol % or more and 35 mol % or less, and even more preferably 18 mol % or more and 30 mol % or less, when the total amount of structural units in polymer (A1) is taken as 100 mol %.

[0031] The total content of the structural units represented by formula (1a), (1b), (2), and (3) in polymer (A1) 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 polymer (A1) is taken as 100 mol %.

[0032] <Polymer (A2)> The polymer (A2) contains a structural unit including at least one selected from the group consisting of a structural unit represented by formula (1a) and a structural unit represented by formula (1b), a structural unit represented by formula (2), and a structural unit represented by formula (4).

[0033] The structural units represented by formula (1a), (1b), and (2) contained in polymer (A2) are similar to the structural units represented by formula (1a), (1b), and (2) contained in polymer (A1).

[0034] The polymer (A2) contains a structural unit represented by formula (4). By including the structural unit represented by formula (4), the polymer (A2) can improve the balance of moldability and flexibility.

[0035] [ka]

[0036] In formula (4), R 41represents a linear alkyl group having 4 to 20 carbon atoms, 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 (4), R 41 is 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 (4), R 42 is preferably a hydrogen atom.

[0037] The total content of the structural units represented by formula (1a) and the structural units represented by formula (1b) in polymer (A2) is preferably 5 mol % or more and 40 mol % or less, more preferably 7 mol % or more and 30 mol % or less, and even more preferably 10 mol % or more and 25 mol % or less, when the total amount of the structural units in polymer (A2) is taken as 100 mol %.

[0038] The content of the structural unit represented by formula (2) in polymer (A2) is preferably 40 mol % or more and 85 mol % or less, more preferably 45 mol % or more and 83 mol % or less, even more preferably 50 mol % or more and 80 mol % or less, and even more preferably 60 mol % or more and 75 mol % or less, when the total amount of structural units in polymer (A2) is taken as 100 mol %.

[0039] The content of the structural unit represented by formula (4) in polymer (A2), when the total of the structural units in polymer (A2) is taken as 100 mol %, is preferably 5 mol % or more and 40 mol % or less, more preferably 7 mol % or more and 38 mol % or less, even more preferably 7 mol % or more and 36 mol % or less, even more preferably 7 mol % or more and 30 mol % or less, even more preferably 7 mol % or more and 25 mol % or less, and even more preferably 10 mol % or more and 20 mol % or less.

[0040] The total content of the structural units represented by formula (1a), (1b), (2), and (4) in polymer (A2) 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 polymer (A2) is taken as 100 mol %.

[0041] Hereinafter, preferred aspects of the physical property values ​​of the polymer of this embodiment will be described.

[0042] From the viewpoint of further improving moldability, the weight average molecular weight (Mw) of the polymer of this embodiment 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 still more preferably 10,000 or more and 25,000 or less.

[0043] From the viewpoint of further improving moldability, the polydispersity (Mw / Mn) of the polymer of this embodiment 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.

[0044] The weight average molecular weight (Mw) and polydispersity (Mw / Mn) of a polymer refer to values ​​determined by gel permeation chromatography (GPC) using polystyrene as a standard substance.

[0045] From the viewpoint of further improving heat resistance, the 5% mass loss temperature of the polymer of this embodiment 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 polymer of this embodiment 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 polymer refers to the temperature at which the mass of the polymer decreases by 5% based on the mass at the start of measurement when the polymer 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 scanning calorimeter.

[0046] From the viewpoint of further improving the balance of moldability and flexibility, the softening point of the polymer 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. The softening point of a polymer refers to a value obtained using a thermomechanical analyzer. Specifically, a polymer is heated using a thermomechanical analyzer under conditions of measurement mode: compression, load: 30 mN, temperature range: 30°C to 300°C, and heating rate: 3°C / min in a nitrogen atmosphere, and a temperature-displacement graph is created. The softening point of the polymer 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.

[0047] The refractive index of the polymer of this embodiment 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. When the refractive index of the polymer of this embodiment is within the above range, it can be suitably used as a clad for an optical waveguide. The refractive index of the polymer means the refractive index measured with an Abbe refractometer under the conditions of 23° C. and 589 nm.

[0048] The light transmittance of the polymer 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. When the polymer of this embodiment has a light transmittance at a wavelength of 850 nm within the above range, the optical properties of the optical member can be further improved, and therefore the polymer can be suitably used as an optical member. The light transmittance of the polymer of this embodiment at a wavelength of 850 nm means the light transmittance value measured by an ultraviolet-visible spectrophotometer for a resin film made of the polymer and having a thickness of 25 μm. A resin film made of a polymer can be produced, for example, by applying a polymer solution dissolved in an arbitrary solvent onto a substrate film and drying it.

[0049] [Polymer applications] The use of the polymer of this embodiment is not particularly limited. The polymer of the present embodiment is a polymer that can be used for at least one selected from the group consisting of, for example, optical components, electronic components, films, tapes, and the like, and is preferably a polymer that can be used for optical components. The optical member is not particularly limited, but is, for example, at least one member selected from the group consisting of an optical waveguide, an optical fiber, an optical lens, an optical filter, and the like. The polymer of this embodiment is preferably a polymer that can be used in an optical waveguide, and more preferably a polymer that can be used in the cladding of an optical waveguide.

[0050] [Polymer manufacturing method] The method for producing the polymer of this embodiment is not particularly limited, and the polymer 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.

[0051] Monomers capable of forming the structural unit represented by formula (1a) include, for example, methyl glycidyl ether norbornene. Examples of monomers capable of forming the structural unit represented by formula (1b) include (3-ethyloxetan-3-yl)methyl bicyclo[2.2.1]hept-5-ene-2-carboxylate. The monomer capable of forming the structural unit represented by formula (2) includes, for example, at least one selected from the group consisting of cyclohexylmaleimide, methylmaleimide, and maleimide. Monomers capable of forming the structural unit represented by formula (3) include, for example, dodecylmaleimide. The monomer capable of forming the structural unit represented by formula (4) includes, for example, at least one selected from the group consisting of 1-octene, 1-decene, and the like.

[0052] In the method for producing a polymer according to the present embodiment, after the raw material monomers are polymerized to obtain a polymer, the obtained polymer may be purified by any method.

[0053] 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.

[0054] 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]

[0055] 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.

[0056] [Example 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.

[0057] (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 resulting solution was further dried overnight in a vacuum dryer at 40°C to obtain the polymer of Example 1 (purified polymer). Hereinafter, the polymer of Example 1 will also be referred to as polymer (A-1).

[0058] [Example 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.

[0059] (purification) After the reaction was completed, the polymer solution was cooled to room temperature and added dropwise to 1000 g of methanol to cause reprecipitation. The residue was redissolved in 120 g of tetrahydrofuran and then added dropwise to 1200 g of methanol to cause reprecipitation. The resulting solution was further dried overnight in a vacuum dryer at 40°C to obtain the polymer of Example 2 (purified polymer). Hereinafter, the polymer of Example 2 will also be referred to as polymer (A-2).

[0060] [Example 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.

[0061] (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 resulting solution was further dried overnight in a vacuum dryer at 40°C to obtain the polymer of Example 3 (purified polymer). Hereinafter, the polymer of Example 3 will also be referred to as polymer (A-3).

[0062] [Example 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.

[0063] (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 resulting solution was further dried overnight in a vacuum dryer at 40°C to obtain the polymer of Example 4 (purified polymer). Hereinafter, the polymer of Example 4 will also be referred to as polymer (A-4).

[0064] [Example 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.

[0065] (purification) After the reaction was completed, the polymer solution was cooled to room temperature and added dropwise to 1000 g of methanol to cause reprecipitation. The residue was redissolved in 100 g of tetrahydrofuran and then added dropwise to 1000 g of methanol to cause reprecipitation. The resulting solution was further dried overnight in a vacuum dryer at 40°C to obtain the polymer of Example 5 (purified polymer). Hereinafter, the polymer of Example 5 will also be referred to as polymer (A-5).

[0066] [Example 6] (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.

[0067] (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 1200 g of methanol to cause reprecipitation. The residue was redissolved in 120 g of tetrahydrofuran and then added dropwise to 1200 g of methanol to cause reprecipitation. The resultant was further dried overnight in a vacuum dryer at 40°C to obtain the polymer of Example 6 (purified polymer). Hereinafter, the polymer of Example 6 will also be referred to as polymer (A-8).

[0068] [Example 7] (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.

[0069] (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 1300 g of methanol to cause reprecipitation. The residue was redissolved in 130 g of tetrahydrofuran and then added dropwise to 1300 g of methanol to cause reprecipitation. The resultant was further dried overnight in a vacuum dryer at 40°C to obtain the polymer of Example 7 (purified polymer). Hereinafter, the polymer of Example 7 will also be referred to as polymer (A-9).

[0070] [Example 8] (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.

[0071] (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 1200 g of methanol for reprecipitation. The residue was redissolved in 120 g of tetrahydrofuran and then added dropwise to 1200 g of methanol for reprecipitation. The resultant was further dried overnight in a vacuum dryer at 40°C to obtain the polymer of Example 8 (purified polymer). Hereinafter, the polymer of Example 8 will also be referred to as polymer (A-10).

[0072] [Comparative Example 1] (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.

[0073] (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 dried in vacuum at 60°C for 16 hours to obtain the polymer of Comparative Example 1 (purified polymer). Hereinafter, the polymer of Comparative Example 1 will also be referred to as polymer (A-6).

[0074] Comparative Example 2 JER-1256 (phenoxy resin, manufactured by Mitsubishi Chemical Corporation) was used as the polymer of Comparative Example 2. Hereinafter, the polymer of Comparative Example 2 will also be referred to as polymer (A-7).

[0075] The structural formulas of the polymers in each of the examples and comparative examples are as follows:

[0076] [ka]

[0077] Resin compositions and photoelectric composite substrates were prepared using the polymers of each of the examples and comparative examples.

[0078] In Table 2, polymer (A) corresponds to the polymer of each example and each comparative example. Details of the raw materials of each component other than polymer (A) in Table 2 are as follows.

[0079] <Compound (B) Having a Cyclic Ether Structure> (B-1) JER-YX8034 (manufactured by Mitsubishi Chemical Corporation, epoxy compound) (B-2)OXT-221 (manufactured by Toagosei Co., Ltd., oxetane compound)

[0080] [ka]

[0081] <Curing agent (C)> (C-1) CPI-310B (San-Apro Co., Ltd., photocationic polymerization initiator)

[0082] <Antioxidant (D)> (D-1) Irganox 1076 (BASF, hindered phenol type antioxidant)

[0083] <Surfactant (E)> (E-1) BYK-333 (BYK Japan Co., Ltd., silicone surfactant)

[0084] <Organic solvent (F)> (F-1) Toluene (F-2) Propylene glycol monomethyl ether-2-acetate

[0085] [Examples 1 to 8 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 8 and Comparative Examples 1 and 2, respectively.

[0086] (Film Preparation) The resin compositions of Examples 1 to 8 and Comparative Examples 1 and 2 obtained by preparing the above resin compositions 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, 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, thereby obtaining the films of Examples 1 to 8 and Comparative Examples 1 and 2 (films for forming the first clad layer), respectively.

[0087] (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.

[0088] (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.

[0089] (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.

[0090] (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.

[0091] (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.

[0092] (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.

[0093] 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."

[0094] 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 to 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 8 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.

[0095] [Evaluation and Measurement] First, the evaluation and measurement methods for the polymers of Examples 1 to 8 and Comparative Example 1 will be described. The results of measurement and evaluation for the polymers are shown in Table 1. Note that the polymer of Comparative Example 2 was not evaluated or measured.

[0096] <Monomer reaction rate, composition ratio> For the mixed solutions of raw material monomers before polymerization and the polymer solutions after the completion of the reaction in Examples 1 to 8 and Comparative Example 1, GC measurements were performed 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.

[0097] The polymers of Examples 1 to 8 and Comparative Example 1 were also analyzed by NMR, but the peaks overlapped, making it difficult to identify the composition ratios by NMR.

[0098] <Yield> For Examples 1 to 8 and Comparative Example 1, the yield was calculated as the ratio of the mass of the obtained polymer to the total mass of the raw material monomers.

[0099] <Molecular weight, polydispersity> The weight-average molecular weight (Mw) and polydispersity (Mw / Mn) of the polymers of Examples 1 to 8 and Comparative Example 1 were determined by gel permeation chromatography (GPC). The weight-average molecular weight (Mw) and polydispersity (Mw / Mn) of the polymer were determined as polystyrene equivalent values ​​from a calibration curve of standard polystyrene obtained by GPC measurement. Here, in Table 1, "after polymerization" means the measured value for the polymer after polymerization, and "after purification" means 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.

[0100] <5% mass loss temperature of polymer> Using a thermogravimetric and differential thermal analyzer (manufactured by Hitachi High-Tech Science Corporation, product name: STA7200RV), the polymers of Examples 1 to 8 and Comparative Example 1 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 mass of the polymer decreased by 5% based on the mass at the start of the measurement was defined as the 5% mass loss temperature of the polymer.

[0101] <Refractive index of polymer> The refractive index of the polymers of Examples 1 to 8 and Comparative Example 1 was measured using an Abbe refractometer (manufactured by Atago Co., Ltd., product name: NAR-1T SOLID) under conditions of 23° C. and 589 nm.

[0102] <Softening point of polymer> 1 mg of the polymers of Examples 1 to 8 and Comparative Example 1 was placed in an aluminum sample pan, and the softening points were measured under a nitrogen atmosphere using a thermomechanical analyzer (product name: TMA / SS6100, manufactured by Hitachi High-Tech Science Corporation). 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.

[0103] Next, there will be described the evaluation and measurement methods for the resin compositions, etc. of Examples 1 to 8 and Comparative Examples 1 and 2. Table 2 shows the results of the measurement and evaluation of the resin compositions, etc.

[0104] <Coatability of resin composition> The appearance of the films of Examples 1 to 8 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.

[0105] <Refractive index of resin composition> The OPP cover film was peeled off from the films of Examples 1 to 8 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).

[0106] <Light transmittance for a wavelength of 850 nm> The OPP cover film was peeled off from the films of Examples 1 to 8 and Comparative Examples 1 and 2, 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.

[0107] <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 8 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.

[0108] <Optical loss evaluation> The optoelectronic composite substrates of Examples 1 to 8 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.

[0109] [Table 1]

[0110] 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.

[0111] [Table 2]

[0112] From Table 2, it can be seen that all of the Examples had good evaluation results for coatability, meaning that moldability could be improved. Also, all of the Examples had good evaluation results for embeddability, meaning that flexibility could be improved. Therefore, it can be seen from each example and each comparative example that the polymer of this embodiment can improve the balance of moldability and flexibility.

[0113] Furthermore, it can be seen from Table 2 that the evaluation results of the refractive index, light transmittance, and optical loss of all of the examples were good. That is, it can be seen that the polymer of this embodiment can improve the performance balance of moldability, flexibility, and optical properties.

Claims

1. A polymer selected from the group consisting of polymer (A1) and polymer (A2), The polymer (A1) comprises a structural unit including at least one selected from the group consisting of a structural unit represented by the following formula (1a) and a structural unit represented by the following formula (1b), a structural unit represented by the following formula (2), and a structural unit represented by the following formula (3): The polymer (A2) is a polymer comprising a structural unit including at least one selected from the group consisting of a structural unit represented by the following formula (1a) and a structural unit represented by the following formula (1b), a structural unit represented by the following formula (2), and a structural unit represented by the following formula (4): 【Chemical 1】 (In the formula (1a), 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.) 【Chemistry 2】 (In the above formula (1b), 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. 【Chemistry 3】 (In the formula (2), R ２１ represents 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. 【Chemistry 4】 (In the formula (3), R ３１ represents a linear alkyl group having 4 to 20 carbon atoms) 【Chemistry 5】 (In the formula (4), R ４１ represents a linear alkyl group having 4 to 20 carbon atoms, and R ４２ each independently represents one selected from the group consisting of a hydrogen atom, a methyl group, and an ethyl group.

2. 2. The polymer according to claim 1, having a weight average molecular weight (Mw) of 5,000 or more and 50,000 or less.

3. 3. The polymer according to claim 1, wherein the polydispersity (Mw / Mn) is 1.1 or more and 3.5 or less.

4. The polymer according to claim 1 or 2, which has a 5% mass loss temperature of 300°C or higher.

5. The polymer according to claim 1 or 2, having a softening point of 100°C or higher and 300°C or lower.

6. 3. The polymer according to claim 1, having a refractive index of 1.45 or more and 1.55 or less.

7. 3. The polymer according to claim 1, wherein the total content of the structural units represented by formula (1a) and the structural units represented by formula (1b) in the polymer (A1) is 10 mol % or more and 40 mol % or less, when the total amount of the structural units in the polymer (A1) is 100 mol %.

8. 3. The polymer according to claim 1, wherein the content of the structural unit represented by formula (2) in the polymer (A1) is 30 mol % or more and 80 mol % or less, when the total amount of structural units in the polymer (A1) is 100 mol %.

9. 3. The polymer according to claim 1, wherein the content of the structural unit represented by formula (3) in the polymer (A1) is 10 mol % or more and 40 mol % or less, when the total amount of structural units in the polymer (A1) is 100 mol %.

10. 3. The polymer according to claim 1, wherein the total content of the structural unit represented by formula (1a) and the structural unit represented by formula (1b) in the polymer (A2) is 5 mol % or more and 40 mol % or less, when the total amount of the structural units in the polymer (A2) is 100 mol %.

11. 3. The polymer according to claim 1, wherein the content of the structural unit represented by formula (2) in the polymer (A2) is 40 mol % or more and 85 mol % or less, when the total amount of structural units in the polymer (A2) is 100 mol %.

12. 3. The polymer according to claim 1, wherein the content of the structural unit represented by formula (4) in the polymer (A2) is 5 mol % or more and 40 mol % or less, when the total amount of structural units in the polymer (A2) is 100 mol %.

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