Copolymers, low-dielectric substrate compositions, cured products, and electronic devices using the same.

Abstract

To provide a composition for low dielectric substrate, which can be suitably used for next generation communication equipment in which frequency increase continues, radar, and the like and which has low dielectricity and good substrate moldability.SOLUTION: A polymer, which exhibits lower dielectricity and better substrate moldability than the conventional low dielectricity resin, can be realized by our finding of a simple technique of obtaining a prepolymer having an adequate weight average molecular weight by copolymerizing a liquid crystal compound with little conjugation or polar groups and having a polymerizable group with high molecular linearity and symmetry and a polymerizable compound, and further by curing a composition containing the prepolymer.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polymer for low-dielectric substrates made of liquid crystal compounds, a composition for low-dielectric substrates using the polymer, and a cured product using the same. In particular, it relates to a material for high-frequency substrates and related materials, a cured product using the same, and electronic equipment. [Background technology]

[0002] In recent years, with the advent of 5G and beyond-5G and 6G communication equipment, the frequency of electrical signals on electronic circuit boards and the frequency of radio waves transmitted and received by antennas have increased, leading to problems with signal loss in signal processing circuit boards and antenna boards. Therefore, there is a demand for resin materials with low dielectric constant and low dielectric loss tangent used in circuit boards, and resins such as liquid crystal polymer (LCP), polyphenylene ether (PPE), cycloolefin polymer (COP), and fluororesin (PTFE) are beginning to be used instead of conventional polyimide and epoxy resins. In the field of low-dielectric substrates, materials with a relative permittivity of 3.0 or less are currently available, and those containing high thermal conductivity fillers have a relative permittivity of 3.5 or less. There is a growing demand for the development of materials with even lower relative permittivity than these.

[0003] Current materials for high-frequency substrates are thermoplastic resins, which have many drawbacks, such as the need for high-temperature molding and bonding, and poor adhesion between resins themselves and to copper foil electrodes. Patent document 1 focuses on the molecular structure of liquid crystal polymers and investigates ways to further reduce the dielectric constant of liquid crystal polymers. However, liquid crystal polymers have high melting points, requiring processing temperatures of 350°C or higher, making thermal lamination and thermal bonding difficult. Patent Document 2 focuses on the molecular structure of PPE and investigates how to varnish it by increasing its solubility in solvents. Varnishing allows PPE to be formed into a film by coating and used for insulating varnish coating. However, it requires the use of a solvent with high dissolving power, and there are many problems in terms of curing, such as the possibility of redissolution in the solvent when laminating in multiple layers. Therefore, as described in Non-Patent Document 1, there is a need for the development of a low-dielectric substrate composition that can be coated like an insulating varnish and cured easily.

[0004] Polymerizable liquid crystal compounds are thermosetting resins that have the potential to exhibit performance equivalent to or better than liquid crystal polymers. To obtain good substrate moldability with liquid crystal polymers, it is necessary to lower the melt viscosity or make them easily soluble in solvents. To do this, it is necessary to reduce the crystallinity that liquid crystal polymers possess. On the other hand, polymerizable liquid crystal compounds can be cured while maintaining their crystallinity, making it possible to design materials that combine the characteristics of liquid crystal polymers, such as low dielectric properties, with the easy moldability of thermosetting resins. For example, Patent Document 3 discloses that when a polymerizable liquid crystal compound with high linearity is oriented and cured, it exhibits higher thermal conductivity in the orientation direction than conventional thermosetting resins. Furthermore, Patent Document 4 discloses that a thermosetting resin material with even higher thermal conductivity can be formed by compounding a polymerizable liquid crystal compound with a heat dissipation filler. However, these examples focus primarily on increasing thermal conductivity, and low dielectric properties are not considered.

[0005] Low dielectric substrates can be classified into rigid substrates, which are composites of thermosetting resins such as epoxy resins and glass cloth, and flexible substrates, which use resin films such as polyimide. When polymerizable liquid crystal compounds are applied to these substrates, a problem with the former is that polymerizable liquid crystal compounds have a small molecular weight and low melt viscosity, so even if impregnated into glass cloth, they may flow out before curing. In the latter case, a problem is that resin films of polymerizable liquid crystal compounds, when highly crystalline and with a small molecular weight, tend to be brittle and prone to cracking. When polymerizable liquid crystal compounds are combined with heat-dissipating fillers, prepolymerization is possible by pre-kneading at a temperature that does not cause full curing before the main curing (Patent Document 4). However, when using glass cloth, there is a problem in that pre-kneading is not possible in order to maintain the shape of the glass cloth. Also, when polymerizable liquid crystal compounds are formed into films by coating methods, if the viscosity is low, only a thin film can be obtained, making it difficult to use on a substrate. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2019-189734 [Patent Document 2] Japanese Patent Publication No. 2009-67894 [Patent Document 3] Japanese Patent Publication No. 2006-265527 [Patent Document 4] Republished 2015 / 170744 [Non-patent literature]

[0007] [Non-Patent Document 1] RF World No. 40, pp. 97-111, 2017 [Overview of the project] [Problems that the invention aims to solve]

[0008] As described above, the present invention aims to provide copolymers and low-dielectric substrate compositions having low dielectric properties and good substrate moldability, which can be suitably used in next-generation communication equipment with increasing high frequencies, radar, and the like. [Means for solving the problem]

[0009] The inventors of the present invention earnestly studied to solve those problems. As a result, a simple method was found to copolymerize in advance a polymerizable liquid crystal compound having a low dielectric constant and a high thermal conductivity and a polymerizable compound to obtain a prepolymer having an appropriate weight average molecular weight. Furthermore, by curing a composition containing the prepolymer, it was found that a polymer exhibiting a lower dielectric property than conventional low dielectric constant resins and good substrate moldability could be realized, and the present invention was completed.

[0010] [1] A first aspect of the present invention is a copolymer of a liquid crystal compound having a polymerizable group at the terminal represented by formula (1) and a compound having a polymerizable group represented by formula (2). R 1a -Z 1 -A 1 -Z 2 -A 2 -(Z 3 -A 3 ) m1 -Z 4 -R 1b (1) R 1c -(Z 5 -A 4 ) m2 -Y 1 (2) In formula (1), A 1 , A 2 , and A 3 are each independently 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, bicyclo[2.2.2]oct-1,4-diyl, bicyclo[3.1.0]hex-3,6-diyl, or fluorene-2,7-diyl. In these rings, at least one -CH2- may be replaced by -O-, at least one -CH= may be replaced by -N=, and at least one hydrogen is halogen or an alkyl having 1 to 10 carbon atoms in which at least one hydrogen may be replaced by halogen. In this alkyl, at least one -CH2- may be replaced by -O-, -CO-, -COO-, -OCO-, or -C=C-; [[ID=1 , Z 2 , Z 3 , and Z 4 These are independently single-bonded or C1-C22 alkylenes, in which at least one -CH2- may be replaced by -O-, -S-, -CO-, -COO-, -OCO-, -SO2-, -CH=CH-, -CF=CF-, -CH=N-, -N=CH-, or -N=N-, and at least one hydrogen may be replaced by a halogen; m1 is 0, 1, or 2. In the formula, Z 3 Or A 3 If there are multiple items, they may be the same or different. R 1a and R 1b These are independently selected groups from polymerizable groups represented by formulas (PG-1) to (PG-4), TIFF0007838266000001.tif30130 In equations (PG-1) to (PG-4), R b R is hydrogen, halogen, -CF3, or an alkyl group having 1 to 5 carbon atoms, and the formula contains R b If there are multiple instances, they may be identical or different; In formula (2), A 4 is an optionally substituted cycloalkylene, optionally substituted arylene, optionally substituted heterocycloalkylene, or optionally substituted heteroarylene; Z 5 is a single bond or an alkylene having 1 to 22 carbon atoms, wherein at least one -CH2- may be replaced by -O-, -S-, -CO-, -COO-, -OCO-, -SO2-, -CH=CH-, -CF=CF-, -CH=N-, -N=CH-, or -N=N-, and at least one hydrogen may be replaced by a halogen; Y 1 is hydrogen or an alkyl group having 1 to 22 carbon atoms; m2 is an integer from 0 to 4. In the formula, Z5 Or A 4 If there are multiple items, they may be the same or different. R 1c This is a group selected from polymerizable groups represented by formulas (PG-1) to (PG-4), TIFF0007838266000002.tif30130 In equations (PG-1) to (PG-4), R b R is hydrogen, halogen, -CF3, or an alkyl group having 1 to 5 carbon atoms, and the formula contains R b If there are multiple items, they may be the same or different.

[0011] [2] A second aspect of the present invention is: The copolymer according to [1] is one selected from the group consisting of compounds represented by formula (1-1), formula (1-2), and formula (1-3), which is a liquid crystal compound having a polymerizable group at its terminal represented by formula (1). R 1a -Z 1 -A 1 -Z 2 -A 2 -Z 4 -R 1b (1-1) R 1a -Z 1 -A 1 -Z 2 -A 2 -Z 3 -A 3 -Z 4 -R 1b (1-2) R 1a -Z 1 -A 1 -Z 2 -A 2 -Z 3 -A 3 -Z 3 -A 3 -Z 4 -R 1b (1-3) In formulas (1-1) to (1-3), A1 , A 2 , and A 3 These are independently 1,4-cyclohexylene, 1,4-phenylene (where at least one hydrogen may be replaced by a halogen or an alkylene having 1 to 10 carbon atoms), bicyclo[2.2.2]octo-1,4-diyl, bicyclo[3.1.0]hex-3,6-diyl, and fluorene-2,7-diyl (where at least one hydrogen may be replaced by a halogen or an alkylene having 1 to 10 carbon atoms). Z 1 , Z 2 , Z 3 , and Z 4 These are independent, single bonds, -(CH2) a -, -O(CH2) a -,-(CH2) a O-, -O(CH2) a O-, -COO-, -OCO-, -CH=CH-COO-, -OCO-CH=CH-, -(CH2) a -COO-, -OCO-(CH2) a -, -CH=CH-, -SO2-, -OCF2-, or -CF2O-, where a is an integer from 1 to 20. In the formula, Z 3 Or A 3 If there are multiple items, they may be the same or different. R 1a and R 1b This is a polymerizable group represented by formula (PG-1), TIFF0007838266000003.tif3634 In formula (PG-1), R b R is hydrogen, halogen, -CF3, or an alkyl group having 1 to 5 carbon atoms, and the formula contains R b If there are multiple items, they may be the same or different.

[0012] [3] A third aspect of the present invention is: The copolymer according to [1] or [2] is a liquid crystal compound having a polymerizable group at its terminal represented by formula (1), which is at least one selected from the group consisting of formulas (1-1-1), (1-1-2), and (1-1-3). TIFF0007838266000004.tif58106 In formulas (1-1-1) to (1-1-3), Z 1 , Z 2 , and Z 4 are independently a single bond, -(CH2) a -, -O(CH2) a -, -(CH2) a O-, -O(CH2) a O-, -COO-, -OCO-, -CH=CH-COO-, -OCO-CH=CH-, -(CH2) a -COO-, -OCO-(CH2) a -, -CH=CH-, -SO2-, -OCF2-, or -CF2O-, where a is an integer from 1 to 20, X is fluorine or methyl, n is an integer from 0 to 4, including when n is 2 or more, and when there are multiple Xs in the formula, they may be the same or different, R 1a and R 1b are polymerizable groups represented by formula (PG-1), TIFF0007838266000005.tif3331 In formula (PG-1), R b is hydrogen, halogen, -CF3 or alkyl having 1 to 5 carbon atoms, and when there are multiple Rs in the formula, they may be the same or different. b

[0013] [4] The fourth aspect of the present invention is the copolymer according to [1] or [2], wherein the liquid crystal compound having a polymerizable group at the terminal represented by formula (1) is at least one selected from the group consisting of the compounds represented by formulas (1-2-1) to (1-2-6). TIFF0007838266000006.tif115123 In formulas (1-2-1) to (1-2-6), Z 1 , Z 2 , Z 3 and Z4 These are independent, single bonds, -(CH2) a -, -O(CH2) a -,-(CH2) a O-, -O(CH2) a O-, -COO-, -OCO-, -CH=CH-COO-, -OCO-CH=CH-, -CH2CH2-COO-, -OCO-CH2CH2-, -CH=CH-, -SO2-, -OCF2-, or -CF2O-, where a is an integer from 1 to 20. X is either fluorine or methyl, n is an integer between 0 and 4. This includes the case where n is 2 or greater, and if there are multiple X values ​​in the expression, they may be the same or different. R 1a and R 1b This is a polymerizable group represented by formula (PG-1), TIFF0007838266000007.tif3433 In formula (PG-1), R b R is hydrogen, halogen, -CF3, or an alkyl group having 1 to 5 carbon atoms, and the formula contains R b If there are multiple items, they may be identical or different.

[0014] [5] A fifth aspect of the present invention is: The copolymer according to [1] or [2] is one selected from the group consisting of compounds represented by formula (1) to (1-3-9), which is a liquid crystal compound having a polymerizable group at its terminal, represented by formula (1). TIFF0007838266000008.tif182138 In formulas (1-3-1) to (1-3-9), Z 1 , Z 2 , Z 3 and Z 4 These are independent, single bonds, -(CH2) a -, -O(CH2) a -,-(CH2) a O-, -O(CH2) aO-, -COO-, -OCO-, -CH=CH-COO-, -OCO-CH=CH-, -(CH2) a -COO-, -OCO-(CH2) a -, -CH=CH-, -SO2-, -OCF2-, or -CF2O-, where a is an integer from 1 to 20. Z in the formula 3 They may be the same or different. X is either fluorine or methyl, n is an integer between 0 and 4. This includes the case where n is 2 or greater, and if there are multiple X values ​​in the expression, they may be the same or different. R 1a and R 1b This is independently a polymerizable group represented by formula (PG-1), TIFF0007838266000009.tif3634 In formula (PG-1), R b R is hydrogen, halogen, -CF3, or an alkyl group having 1 to 5 carbon atoms, and the formula contains R b If there are multiple items, they may be identical or different.

[0015] [6] A sixth aspect of the present invention is: The copolymer described in [1] or [2] is a liquid crystal compound having a polymerizable group at its terminal represented by formula (1), which is a compound represented by formula (1-1-1a) or formula (1-2-1a). TIFF0007838266000010.tif41137 In equations (1-1-1a) and (1-2-1a), R b These are hydrogen, halogens, -CF3, or alkyl groups having 1 to 5 carbon atoms. Z 2 and Z 3 These are independent, single bonds, -(CH2) a -, -O(CH2) a -,-(CH2) a O-, -O(CH2) aO-, -COO-, -OCO-, -CH=CH-COO-, -OCO-CH=CH-, -(CH2) a -COO-, -OCO-(CH2) a -, -CH=CH-, -SO2-, -OCF2-, or -CF2O-, where a is an integer from 1 to 20. m is an integer between 0 and 20. M is a single bond or oxygen, X is either fluorine or methyl, n is an integer between 0 and 4. This includes the case where n is 2 or greater, and if there are multiple X values ​​in the expression, they may be the same or different. In the formula, R b If there are multiple instances of , m, or M, they may be the same or different.

[0016] [7] A seventh aspect of the present invention is: The copolymer according to [1] or [2] is one selected from the group consisting of compounds represented by formula (1-1-2a), formula (1-1-3a), formula (1-2-5a), and formula (1-2-6a). TIFF0007838266000011.tif87160 In equations (1-1-2a), (1-1-3a), (1-2-5a), and (1-2-6a), R b These are hydrogen, halogens, -CF3, or alkyl groups having 1 to 5 carbon atoms. Z 2 and Z 3 These are independent, single bonds, -(CH2) a -, -O(CH2) a -,-(CH2) a O-, -O(CH2) a O-, -COO-, -OCO-, -CH=CH-COO-, -OCO-CH=CH-, -(CH2) a -COO-, -OCO-(CH2) a-, -CH=CH-, -SO2-, -OCF2-, or -CF2O-, where a is an integer from 1 to 20. m is an integer between 0 and 20. M is a single bond or oxygen, X is either fluorine or methyl, n is an integer between 0 and 4. This includes the case where n is 2 or greater, and if there are multiple X values ​​in the expression, they may be the same or different. In the formula, R b If there are multiple instances of , m, or M, they may be the same or different.

[0017] [8] An eighth aspect of the present invention is: R b However, it is hydrogen, fluorine, -CF3, or methyl, Z 2 and Z 3 These are independent, single bonds, -(CH2) a -, -O(CH2) a -,-(CH2) a O-, -O(CH2) a The copolymer described in [6] or [7] is O-, -COO-, or -OCO-, where a is an integer from 1 to 12 and m is an integer from 0 to 12.

[0018] [9] A ninth aspect of the present invention is: The copolymer is one of any one of [1] to [8], wherein the polymerizable group represented by formula (2) is at least one selected from the group consisting of compounds represented by formulas (2-1), (2-2), (2-3), and (2-4). R 1c -Y 2 (2-1) R 1c -Z 5 -A 4 -Y 3 (2-2) R 1c -Z 5 -A4 -Z 5 -A 4 -Y 3 (2-3) R 1c -Z 5 -A 4 -Z 5 -A 4 -Z 5 -A 4 -Y 3 (2-4) In formulas (2-1) to (2-4), A 4 These are independently 1,4-cyclohexylene, 1,4-phenylene (where at least one hydrogen may be replaced by a halogen or an alkylene having 1 to 10 carbon atoms), bicyclo[2.2.2]octo-1,4-diyl, bicyclo[3.1.0]hex-3,6-diyl, and fluorene-2,7-diyl (where at least one hydrogen may be replaced by a halogen or an alkylene having 1 to 10 carbon atoms). Z 5 These are independent, single bonds, -(CH2) a -, -O(CH2) a -,-(CH2) a O-, -O(CH2) a O-, -COO-, -OCO-, -CH=CH-COO-, -OCO-CH=CH-, -(CH2) a -COO-, -OCO-(CH2) a -, -CH=CH-, -SO2-, -OCF2-, or -CF2O-, where a is an integer from 1 to 20. Y 2 These are alkyl groups with 1 to 20 carbon atoms. Y 3 is hydrogen or an alkyl group having 1 to 20 carbon atoms. In the formula, Z 5 Or A 4 If there are multiple items, they may be the same or different. R 1c This is a polymerizable group represented by formula (PG-1), TIFF0007838266000012.tif3634 In formula (PG-1), R b R is hydrogen, halogen, -CF3, or an alkyl group having 1 to 5 carbon atoms, and the formula contains R b If there are multiple items, they may be identical or different.

[0019]

[10] A tenth aspect of the present invention is: The copolymer described in any one of [1] to [8] is one selected from the group consisting of compounds represented by formula (2-1-1), formula (2-2-1), formula (2-2-2), formula (2-3-1) to (2-3-3), and formula (2-4-1) to (2-4-6). TIFF0007838266000013.tif50107 TIFF0007838266000014.tif62110 TIFF0007838266000015.tif128136 In equations (2-1-1), (2-2-1), (2-2-2), (2-3-1) to (2-3-3), and (2-4-1) to (2-4-6), Z 5 This is a single bond, -(CH2) a -, -O(CH2) a -,-(CH2) a O-, -O(CH2) a O-, -COO-, -OCO-, -CH=CH-COO-, -OCO-CH=CH-, -(CH2) a -COO-, -OCO-(CH2) a -, -CH=CH-, -SO2-, -OCF2-, or -CF2O-, where a is an integer from 1 to 20. X 1 is fluorine or methyl, Y 2 These are alkyl groups with 1 to 12 carbon atoms. Y 3 is hydrogen or an alkyl group having 1 to 12 carbon atoms. n is an integer between 0 and 4. This includes the case where n is 2 or greater, and X in the expression 1If there are multiple items, they may be the same or different. In the formula, Z 5 If there are multiple items, they may be the same or different. R 1c This is a polymerizable group represented by formula (PG-1), TIFF0007838266000016.tif3735 In formula (PG-1), R b R is hydrogen, halogen, -CF3, or an alkyl group having 1 to 5 carbon atoms, and the formula contains R b If there are multiple items, they may be identical or different.

[0020]

[11] An eleventh aspect of the present invention is: The copolymer is one of any one of [1] to [8], wherein the polymerizable group represented by formula (2) is at least one selected from the group consisting of compounds represented by formulas (2-1-1a), (2-2-1a), (2-2-2a), (2-3-1a) to (2-3-3a), (2-4-1a), and (2-4-6a). TIFF0007838266000017.tif209144 In equations (2-1-1a), (2-2-1a), (2-2-2a), (2-3-1a)~(2-3-3a), (2-4-1a), and (2-4-6a), R b These are hydrogen, halogens, -CF3, or alkyl groups having 1 to 5 carbon atoms. Z 5 This is a single bond, -(CH2) a -, -O(CH2) a -,-(CH2) a O-, -O(CH2) a O-, -COO-, -OCO-, -CH=CH-COO-, -OCO-CH=CH-, -(CH2) a -COO-, -OCO-(CH2) a -, -CH=CH-, -SO2-, -OCF2-, or -CF2O-, where a is an integer from 1 to 20. m is an integer between 0 and 20. M is a single bond or oxygen, X 1 is fluorine or methyl, Y 2 These are alkyl groups with 1 to 8 carbon atoms. Y 3 is hydrogen or an alkyl group having 1 to 8 carbon atoms. n is an integer between 0 and 4. This includes the case where n is 2 or greater, and X in the expression 1 If there are multiple items, they may be the same or different. In the formula, Z 5 However, if there are multiple items, they may be identical or different.

[0021]

[12] A twelfth aspect of the present invention is: The copolymer is one of the items described in any one of [1] to

[11] , having a weight-average molecular weight of 300,000 or less.

[0022]

[13] A thirteenth aspect of the present invention is: The copolymer is one of the items described in any one of [1] to

[11] , having a weight-average molecular weight of 50,000 or less.

[0023]

[14] A fourteenth aspect of the present invention is: This is a low-dielectric substrate composition containing the copolymer described in any one of items [1] to

[13] .

[0024]

[15] A fifteenth aspect of the present invention is: The low-dielectric substrate composition described in

[14] further contains a non-polymerizable liquid crystal compound.

[0025]

[16] A sixteenth aspect of the present invention is: The low-dielectric substrate composition according to

[14] or

[15] further contains an inorganic filler.

[0026]

[17] A seventeenth aspect of the present invention is: The low dielectric substrate composition according to

[17] is wherein the inorganic filler is at least one selected from the group consisting of spherical silica, pulverized silica, hollow silica, fumed silica, aluminum nitride, boron nitride, magnesium oxide, aluminum oxide, zinc oxide, titanium oxide, aluminum oxide, magnesium hydroxide, and aluminum hydroxide.

[0027]

[18] An eighteenth aspect of the present invention is: A cured product obtained by curing a low-dielectric substrate composition described in any one of items

[14] to

[17] .

[0028]

[19] A 19th aspect of the present invention is: The cured product is described in

[18] , wherein the relative permittivity at 10 GHz is less than 3.0.

[0029]

[20] A 20th aspect of the present invention is The cured product is one of the products described in

[18] or

[19] , having a thermal conductivity of 1 W / m·K or higher.

[0030]

[21] A 21st aspect of the present invention is: This is an insulating film that uses a cured product as described in any one of items

[18] to

[20] .

[0031]

[22] A 22nd aspect of the present invention is: This film uses a cured product as described in any one of items

[18] to

[20] .

[0032]

[23] A 23rd aspect of the present invention is This sheet uses a cured product as described in any one of items

[18] to

[20] .

[0033]

[24] A 24th aspect of the present invention is: An electronic device using a cured product described in any one of items

[18] to

[20] , an insulating film described in

[21] , a film described in

[22] , or a sheet described in

[23] .

[0034]

[25] A 25th aspect of the present invention is: It is a compound represented by formula (2-3-3a') or formula (2-4-6a'). TIFF0007838266000018.tif48155 In equations (2-3-3a') and (2-4-6a'), R b ' is hydrogen, halogen, -CF3, or alkyl with 1 to 5 carbon atoms. Z 5 ' is a single bond, -(CH2) a -, -O(CH2) a -,-(CH2) a O-, -O(CH2) a O-, -COO-, -OCO-, -CH=CH-COO-, -OCO-CH=CH-, -(CH2) a -COO-, -OCO-(CH2) a -, -CH=CH-, -SO2-, -OCF2-, or -CF2O-, where a is an integer from 1 to 20. m' is an integer between 0 and 20. M' is a single bond or oxygen, Y 3 ' is hydrogen or an alkyl group having 1 to 12 carbon atoms. In the formula, Z 5 If there are multiple instances, they may be identical or different.

[0035]

[26] A 26th aspect of the present invention is: It is a compound represented by formula (2-3-3a''). TIFF0007838266000019.tif18124 In the formula (2-3-3a''), R b '' is hydrogen, halogen, -CF3, or methyl, m'' is an integer between 0 and 10. M'' is a single bond or oxygen, Y 3 '' is either hydrogen or an alkyl group having 1 to 8 carbon atoms.

[0036]

[27] A 27th aspect of the present invention is: It is a compound represented by formula (2-3-3-1). TIFF0007838266000020.tif27103

[0037]

[28] A 28th aspect of the present invention is: It is a compound described in any one of the following

[25] to

[27] used as a raw material monomer for low dielectric resins or low dielectric substrates. [Effects of the Invention]

[0038] The copolymer of the present invention has an optimal weight-average molecular weight as a prepolymer, and a low-dielectric substrate composition containing it as a prepolymer has good substrate moldability, and the cured product has low dielectric properties, making it suitable for, for example, low-dielectric circuit boards, low-dielectric antenna substrates, low-dielectric coatings, and low-dielectric adhesives. Electronic devices using low-dielectric circuit boards, etc., containing the low-dielectric substrate composition of the present invention are excellent in high-speed, high-capacity communication, low power consumption, low latency, and numerous connections. [Modes for carrying out the invention]

[0039] The following describes in detail the methods for producing the polymer, low-dielectric substrate composition, cured product, insulating film, film, and sheet of the present invention. The terms used herein are defined as follows. "Liquid crystal compounds" is a general term for compounds that have liquid crystal phases such as nematic phase and smectic phase, as well as compounds that do not have a liquid crystal phase but possess physical properties unique to liquid crystals, such as dielectric anisotropy, refractive index anisotropy, and magnetic susceptibility anisotropy, and are useful as components of liquid crystal compositions. Furthermore, "(meth)acryloyloxy" means acryloyloxy or methacryloyloxy, "(meth)acrylate" means acrylate or methacrylate, and "(meth)acrylic acid" means acrylic acid or methacrylic acid.

[0040] The meaning of phrases such as "at least one -CH2- in the alkyl group may be replaced with -O-, -CO-, etc." is illustrated with an example. For instance, groups in which at least one -CH2- in C4H9- is replaced with -O- or -CH=CH- include C3H7O-, CH3-O-(CH2)3-, CH3-O-CH2-O-, H2C=CH-(CH2)3-, CH3-CH=CH-(CH2)2-, and CH3-CH=CH-CH2-O-. Thus, the phrase "at least one" means "at least one selected without distinction." Furthermore, considering the stability of the compound, CH3-O-CH2-O-, where oxygen atoms are not adjacent to each other, is preferred over CH3-OO-CH2-, where oxygen atoms are adjacent to each other.

[0041] The copolymer of the present invention is obtained by copolymerizing a liquid crystal compound having a polymerizable group at its terminal end represented by formula (1) with a compound having a polymerizable group represented by formula (2). R 1a -Z 1 -A 1 -Z 2 -A 2 -(Z 3 -A 3 ) m1 -Z 4 -R 1b (1) R 1c -(Z 5 -A 4 ) m2 -Y 1 (2) In formula (1), A 1 , A 2 , and A 3These are independently 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, bicyclo[2.2.2]octo-1,4-diyl, bicyclo[3.1.0]hex-3,6-diyl, or fluorene-2,7-diyl, in which at least one -CH2- may be replaced with -O-, at least one -CH= may be replaced with -N=, at least one hydrogen is a halogen, or a C1-C10 alkyl group in which at least one hydrogen may be replaced with a halogen, in which at least one -CH2- may be replaced with -O-, -CO-, -COO-, -OCO-, or -C=C-, Z 1 , Z 2 , Z 3 , and Z 4 is independently a single bond or an alkylene having 1 to 22 carbon atoms, in which at least one -CH2- may be replaced with -O-, -S-, -CO-, -COO-, -OCO-, -SO2-, -CH=CH-, -CF=CF-, -CH=N-, -N=CH-, or -N=N-, and at least one hydrogen may be replaced with a halogen, m1 is 0, 1, or 2, and in the formula, Z 3 Or A 3 If there are multiple, they may be the same or different, R 1a and R 1b R is independently selected from polymerizable groups represented by formulas (PG-1) to (PG-4), where R b R is hydrogen, halogen, -CF3, or an alkyl group having 1 to 5 carbon atoms, and the formula contains R b If there are multiple items, they may be identical or different. TIFF0007838266000021.tif33141 In formula (2), A 4 is an optionally substituted cycloalkylene, optionally substituted arylene, optionally substituted heterocycloalkylene, or optionally substituted heteroarylene, Z 5is a single bond or an alkylene having 1 to 22 carbon atoms, in which at least one -CH2- may be replaced with -O-, -S-, -CO-, -COO-, -OCO-, -SO2-, -CH=CH-, -CF=CF-, -CH=N-, -N=CH-, or -N=N-, and at least one hydrogen may be replaced with a halogen, Y 1 is hydrogen or an alkyl group having 1 to 22 carbon atoms, m2 is an integer from 0 to 4, and in the formula, Z 5 Or A 4 If there are multiple, they may be the same or different, R 2 R is a group selected from polymerizable groups represented by formulas (PG-1) to (PG-4), where R is a group selected from polymerizable groups represented by formulas (PG-1) to (PG-4). b R is hydrogen, halogen, -CF3, or an alkyl group having 1 to 5 carbon atoms, and the formula contains R b If there are multiple items, they may be identical or different. TIFF0007838266000022.tif33141

[0042] In "cycloalkylenes that may be substituted," "cycloalkylene" refers to a divalent group of atoms formed by removing two hydrogen atoms bonded to different carbon atoms in a cyclic saturated hydrocarbon (cycloalkane). "Cycloalkylene" is not particularly limited, but specific examples include cyclopropylene, cyclobutylene, cyclopentylene, cyclohexylene, norbornylene, adamantylene, bicyclo[2.2.2]octo-1,4-diyl, and bicyclo[3.1.0]hex-3,6-diyl. Preferred cycloalkylenes are 1,4-cyclohexylene, bicyclo[2.2.2]octo-1,4-diyl, and bicyclo[3.1.0]hex-3,6-diyl, with 1,4-cyclohexylene being particularly preferred. Examples of substituents are not particularly limited, but include alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aryloxy, and halogen.

[0043] The "arylene" in "arylene which may be substituted" is, for example, a substituent obtained by removing two hydrogen atoms from the aromatic ring of an aromatic hydrocarbon. The "arylene" is not particularly limited, but specific examples include phenylene, biphenylene, naphthylene, and fluorenylene. Preferred "arylenes" are 1,4-phenylene and fluorene-2,7-diyl, with 1,4-phenylene being particularly preferred. Examples of substituents are not particularly limited, but include alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aryloxy, and halogens.

[0044] In "heterocycloalkylenes that may be substituted," "heterocycloalkylene" refers to a divalent group of atoms formed by removing two hydrogen atoms bonded to opposite carbon atoms in a saturated heterocyclic compound. While "heterocycloalkylene" is not particularly limited, specific examples include oxetanyl, oxolanil, tetrahydropyranil, and oxathiolanil. Examples of substituents are also not particularly limited, but include alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aryloxy, and halogen.

[0045] In "heteroarylenes that may be substituted," "heteroarylene" refers to a substituent obtained by removing two hydrogen atoms from an aromatic heterocyclic compound, for example. "Heteroarylene" is not particularly limited, but specific examples include pyridylene, pyrimidinylene, triazinylene, and dibenzofuranylene. Examples of substituents are not particularly limited, but include alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aryloxy, and halogen.

[0046] "Compound (1)" refers to the liquid crystal compound represented by formula (1) above, and may also refer to at least one of the compounds represented by formula (1). The same applies to "Compound (1-1)," and compounds (1-1) through (1-3) are collectively referred to as "Compound (1)." "Compound (2)" refers to the compound represented by formula (2) above, and may also refer to at least one of the compounds represented by formula (2). The same applies to "Compound (2-1)," and compounds (2-1) through (2-4) are collectively referred to as "Compound (2)." "Composition for low dielectric substrate (1)" means that it contains a copolymer of compound (1) and compound (2). "Copolymer (1)" means a polymer obtained by polymerizing the composition for low dielectric substrate (1). One compound (1) contains multiple A 3 When any two A 3 They may be the same or different. Multiple compounds (1) are A 3 When any two A 3 They may be the same or different. This rule applies to compound (2) and Z. 3 , R b This also applies to other compounds, symbols, groups, etc., such as X.

[0047] [Compound (1)] Compound (1) used in the present invention has a liquid crystal skeleton (rod-shaped mesogenic skeleton) and polymerizable groups, and exhibits high polymerization reactivity, a wide liquid crystal phase temperature range, and good miscibility. When compound (1) is mixed with other liquid crystal compounds or polymerizable compounds, it readily becomes homogeneous.

[0048] Terminal group R of compound (1) 1a or R 1b , ring structure A 1 , A 2 Or A 3 and the binding group Z 1 , Z 2 , Z 3 or Z 4 By appropriately selecting these elements, the physical properties such as reactivity and the liquid crystal phase region can be arbitrarily adjusted. The effects of the terminal groups, ring structure, and types of bonding groups on the reactivity and physical properties of compound (1), as well as preferred examples thereof, are described below.

[0049] <Terminal groupTerminal group R:R 1a and R 1b ) Terminal group of compound (1) 1a and R 1b This is a polymerizable group represented by one of the formulas (PG-1) to (PG-4). TIFF0007838266000023.tif33144 In equations (PG-1) to (PG-4), R b These are hydrogen, halogens, -CF3, or alkyl groups having 1 to 5 carbon atoms. Also R b If there are multiple items, they may be identical or different.

[0050] Preferred examples include polymerizable groups represented by formulas (PG-1a) to (PG-1d), (PG-2a), (PG-3a), and (PG-4a). TIFF0007838266000024.tif63165

[0051] Of these preferred polymerizable groups, (PG-1a) to (PG-1d), (PG-2a), and (PG-4a) have an α,β-unsaturated ketone structure, and can therefore be polymerized by various means to form polymers with larger molecular weights. (PG-3a) has a vinyl group adjacent to an electron-donating group, and can therefore be polymerized by various means to form polymers with larger molecular weights. Of these polymerizable groups, formulas (PG-1a) to (PG-1d) and (PG-2a) are more preferred, and formulas (PG-1a) and (PG-1b) are particularly preferred.

[0052] The polymerizable groups represented by formulas (PG-1) to (PG-4) can be selected appropriately depending on the film manufacturing conditions. For example, when manufacturing a film using commonly used photocuring, the group represented by formula (PG-1) is preferred in terms of high curability, solubility in solvents, and ease of handling, and acrylic groups and methacrylic groups are even more preferred.

[0053] <Ring structure A :A 1 , A 2 and A 3 > Preferred examples of ring structure A of compound (1) are 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2,5-difluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyridine-2,5-diyl, 3-fluoropyridine-2,5-diyl, pyrimidine-2 These include 5-diyl, pyridazine-3,6-diyl, naphthalene-2,6-diyl, tetrahydronaphthalene-2,6-diyl, fluorene-2,7-diyl, 9-methylfluorene-2,7-diyl, 9,9-dimethylfluorene-2,7-diyl, 9-ethylfluorene-2,7-diyl, 9-fluorofluorene-2,7-diyl, and 9,9-difluorofluorene-2,7-diyl. Further preferred examples include 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, and 2-methyl-1,4-phenylene. Particularly preferred examples are 1,4-cyclohexylene or 1,4-phenylene.

[0054] The stereochemistry of 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl, or tetrahydronaphthalene-2,6-diyl is preferred in trans configuration over cis. Since 2-fluoro-1,4-phenylene and 3-fluoro-1,4-phenylene are structurally identical, the latter is not used as an example. This rule also applies to relationships such as that between 2,5-difluoro-1,4-phenylene and 3,6-difluoro-1,4-phenylene.

[0055] When at least one ring in ring structure A is 1,4-phenylene, the orientational order parameter and magnetic anisotropy are large. Also, when at least two rings are 1,4-phenylene, the temperature range of the liquid crystal phase is wide and the transparency point is high. Preferred examples of substitutions where at least one hydrogen atom on the 1,4-phenylene ring may be replaced include fluorine, C1-C5 alkyl groups, -CF3, or -OCF3, resulting in a lower melting point and higher solubility. Furthermore, the molecular polarizability is reduced, leading to a lower dielectric constant. Additionally, the suppression of molecular motion results in lower dielectric loss.

[0056] When at least one ring is 1,4-cyclohexylene, the transparency point is high, the relative permittivity is very low, the dielectric loss is low, and the viscosity is low. Also, when at least two rings are 1,4-cyclohexylene, the transparency point is high, the relative permittivity is very low, the dielectric loss is low, and the viscosity is low. If at least one ring is a fused ring such as a naphthalene ring, decahydronaphthalene ring, or fluorene ring, the molecular volume is large and the relative permittivity is low.

[0057] <Binding group Z :Z 1 , Z 2 , Z 3 and Z 4 > A preferred example of the bonding group Z in compound (1) is a single bond, -(CH2) a -, -O(CH2) a -,-(CH2) a O-, -O(CH2) a O-, -COO-, -OCO-, -CH=CH-COO-, -OCO-CH=CH-, -(CH2) a -COO-, -OCO-(CH2) a -, -CH=CH-, -SO2-, -OCF2-, or -CF2O-, where a is an integer from 1 to 20. A more preferred example is a single bond, -(CH2) a -,-(CH2) a O-, -O(CH2) a -, -O(CH2) a Examples include O-, -COO-, or -OCO-. A particularly preferred example is a single bond, -(CH2) a -,-(CH2) a O-, -O(CH2) a -, or -O(CH2) aThe timescale is O-, where a is an integer between 1 and 22.

[0058] The bonding group Z is a single bond, -(CH2) a -,-(CH2) a O-, -O(CH2) a -, -O(CH2) a When the bond group Z is O-, -CF2O-, or -OCF2-, the viscosity decreases. Also, when the bond group Z is -(CH2) a -,-(CH2) a O-, -O(CH2) a -, or -O(CH2) a When it is O- and a is around 2 to 12, the melting point decreases, solubility in organic solvents increases, the molecular length increases, the temperature range of the liquid crystal phase widens, and the dielectric loss tangent is small.

[0059] When compound (1) has two rings, its viscosity is low, and when it has three or more rings, its transparency point is high. In this specification, a 6-membered ring and fused rings containing a 6-membered ring are generally considered to be rings, while 3-membered rings, 4-membered rings, and 5-membered rings alone are not considered rings. Furthermore, fused rings such as naphthalene rings, decahydronaphthalene rings, and fluorene rings are considered to be a single ring.

[0060] As described above, terminal group R 1 By appropriately selecting the type of ring structure A and bonding group Z, the number of rings, etc., a compound having the desired physical properties can be obtained. Examples of preferred compounds (1) include compounds represented by formulas (1-1-1) to (1-1-3), (1-2-1) to (1-2-6), and (1-3-1) to (1-3-6). TIFF0007838266000025.tif55101 TIFF0007838266000026.tif118125 TIFF0007838266000027.tif122145

[0061] In equations (1-1-1)~(1-1-3), (1-2-1)~(1-2-6), and (1-3-1)~(1-3-6), Z1 , Z 2 , Z 3 and Z 4 These are independent, single bonds, -(CH2) a -, -O(CH2) a -,-(CH2) a O-, -O(CH2) a O-, -COO-, -OCO-, -CH=CH-COO-, -OCO-CH=CH-, -(CH2) a -COO-, -OCO-(CH2) a -, -CH=CH-, -SO2-, -OCF2-, or -CF2O-, where a is an integer from 1 to 20. Z in the formula 3 They may be the same or different. X is either fluorine or methyl, n is an integer between 0 and 4. This includes the case where n is 2 or greater, and if there are multiple X values ​​in the expression, they may be the same or different. R 1a and R 1b This is independently a polymerizable group represented by formula (PG-1), TIFF0007838266000028.tif3230 In formula (PG-1), R b R is hydrogen, halogen, -CF3, or an alkyl group having 1 to 5 carbon atoms, and the formula contains R b If there are multiple items, they may be identical or different.

[0062] A more preferred example of compound (1) is shown below. TIFF0007838266000029.tif129152 In equations (1-1-1a) to (1-1-3a), equation (1-2-1a), equation (1-2-5a), and equation (1-2-6a), R b is hydrogen, fluorine, -CF3, or an alkyl group having 1 to 5 carbon atoms, Z 2 and Z 3 These are independent, single bonds, -(CH2) a -, -O(CH2) a-, -(CH2) a O-, -O(CH2) a O-, -COO-, -OCO-, -CH=CH-COO-, -OCO-CH=CH-, -(CH2) a -COO-, -OCO-(CH2) a -, -CH=CH-, -SO2-, -OCF2-, or -CF2O-, where a is an integer from 1 to 20, m is an integer from 0 to 20, M is a single bond or oxygen, X is fluorine or methyl, n is an integer from 0 to 4, including when n is 2 or more, and when there are multiple Xs in the formula, they may be the same or different, In the formula, R b , m, or M, when there are multiple, they may be the same or different.

[0063] [Compound (2)] Compound (2) used in the present invention has high polymerizability, good miscibility, etc. When this compound (2) is mixed with compound (1), other polymerizable compounds, and liquid crystal compounds, etc., it easily becomes uniform. It is also preferable that compound (2) is a polymerizable liquid crystal compound having a liquid crystal skeleton (rod-shaped mesogen skeleton) and a polymerizable group.

[0064] The terminal group R of compound (2) 1a or R 1b , the ring structure A[[ID=​​​​​​​​​​​​​​​​​​​​​1c is a polymerizable group represented by any one of formulas (PG-1) to (PG-4). TIFF0007838266000030.tif34146 In formulas (PG-1) to (PG-4), R b is hydrogen, a halogen, -CF3, or an alkyl group having 1 to 5 carbon atoms. Also, when there are multiple Rs b they may be the same or different.

[0066] Preferred examples include polymerizable groups represented by formulas (PG-1a) to (PG-1d), (PG-2a), (PG-3a), and (PG-4a). TIFF0007838266000031.tif64167

[0067] Among these preferred polymerizable groups, (PG-1a) to (PG-1d), (PG-2a), and (PG-4a) have the structure of α,β-unsaturated ketone, so they can be polymerized by various means and changed into polymers with larger molecular weights. (PG-3a) has a vinyl group adjacent to an electron-donating group, so it can be polymerized by various means and changed into a polymer with a larger molecular weight. Among these polymerizable groups, formulas (PG-1a) to (PG-1d), and (PG-2a) are more preferred, and formulas (PG-1a), and (PG-1b) are particularly preferred.

[0068] The polymerizable group represented by formulas (PG-1) to (PG-4) can be appropriately selected according to the film production conditions. For example, when producing a film by ordinary photocuring, from the viewpoints of compatibility with compound (1), high curability, solubility in a solvent, and ease of handling, the group represented by formula (PG-1) is preferred, and an acrylic group or a methacrylic group is more preferred.

[0069] <Cyclic structure A :A 4 > Preferred examples of ring structure A of compound (2) are 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2,5-difluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyridine-2,5-diyl, 3-fluoropyridine-2,5-diyl, pyrimidine-2 These include 5-diyl, pyridazine-3,6-diyl, naphthalene-2,6-diyl, tetrahydronaphthalene-2,6-diyl, fluorene-2,7-diyl, 9-methylfluorene-2,7-diyl, 9,9-dimethylfluorene-2,7-diyl, 9-ethylfluorene-2,7-diyl, 9-fluorofluorene-2,7-diyl, and 9,9-difluorofluorene-2,7-diyl. Further preferred examples include 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, and 2-methyl-1,4-phenylene. Particularly preferred examples are 1,4-cyclohexylene or 1,4-phenylene.

[0070] The stereochemistry of 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl, or tetrahydronaphthalene-2,6-diyl is preferred in trans configuration over cis. Since 2-fluoro-1,4-phenylene and 3-fluoro-1,4-phenylene are structurally identical, the latter is not used as an example. This rule also applies to relationships such as that between 2,5-difluoro-1,4-phenylene and 3,6-difluoro-1,4-phenylene.

[0071] When at least one ring in ring structure A is 1,4-phenylene, the orientational order parameter and magnetic anisotropy are large. Also, when at least two rings are 1,4-phenylene, the temperature range of the liquid crystal phase is wide and the transparency point is high. Preferred examples of substitutions where at least one hydrogen atom on the 1,4-phenylene ring may be replaced include fluorine, C1-C5 alkyl groups, -CF3, or -OCF3, resulting in a lower melting point and higher solubility. Furthermore, the molecular polarizability is reduced, leading to a lower dielectric constant. Additionally, the suppression of molecular motion results in lower dielectric loss.

[0072] When at least one ring is 1,4-cyclohexylene, the transparency point is high, the relative permittivity is very low, the dielectric loss is low, and the viscosity is low. Also, when at least two rings are 1,4-cyclohexylene, the transparency point is high, the relative permittivity is very low, the dielectric loss is low, and the viscosity is low. If at least one ring is a fused ring such as a naphthalene ring, decahydronaphthalene ring, or fluorene ring, the molecular volume is large and the relative permittivity is low.

[0073] <Binding group Z :Z 5 > A preferred example of the bonding group Z in compound (2) is a single bond, -(CH2) a -, -O(CH2) a -,-(CH2) a O-, -O(CH2) a O-, -COO-, -OCO-, -CH=CH-COO-, -OCO-CH=CH-, -(CH2) a -COO-, -OCO-(CH2) a -, -CH=CH-, -SO2-, -OCF2-, or -CF2O-, where a is an integer from 1 to 20. A more preferred example is a single bond, -(CH2) a -,-(CH2) a O-, -O(CH2) a -, -O(CH2) a Examples include O-, -COO-, or -OCO-. A particularly preferred example is a single bond, -(CH2) a -,-(CH2) a O-, -O(CH2) a -, or -O(CH2) a The timescale is O-, where a is an integer between 1 and 22.

[0074] The bonding group Z is a single bond, -(CH2) a -,-(CH2) a O-, -O(CH2) a -, -O(CH2) a When the bond group Z is O-, -CF2O-, or -OCF2-, the viscosity decreases. Also, when the bond group Z is -(CH2) a -,-(CH2) a O-, -O(CH2) a -, or -O(CH2) a When it is O- and a is around 2-12, the melting point decreases, solubility in organic solvents increases, and the dielectric loss tangent is small.

[0075] <Substituent Y :Y 1 , Y 2 , and Y 3 > Preferred examples of substituent Y in compound (2) are linear or branched alkyl groups having 1 to 12 carbon atoms, and linear or branched alkyl groups having 1 to 8 carbon atoms are more preferred.

[0076] When compound (2) has two rings, the viscosity is low, and when it has three or more rings, the transparency point is high. In this specification, a 6-membered ring and fused rings containing a 6-membered ring are generally considered to be rings, while 3-membered rings, 4-membered rings, and 5-membered rings alone are not considered rings. Furthermore, fused rings such as naphthalene rings, decahydronaphthalene rings, and fluorene rings are considered to be a single ring.

[0077] As described above, terminal group R 1 By appropriately selecting the type of ring structure A and bonding group Z, the number of rings, etc., a compound having the desired physical properties can be obtained. Examples of preferred compounds (2) include compounds represented by formulas (2-1-1), (2-2-1), (2-2-2), (2-3-1) to (2-3-3), and (2-4-1) to (2-4-6). TIFF0007838266000032.tif50107 TIFF0007838266000033.tif62110 TIFF0007838266000034.tif128136

[0078] In formulas (2-1-1), (2-2-1), (2-2-2), (2-3-1) to (2-3-3), and (2-4-1) to (2-4-6), Z 5 is a single bond, -(CH2) a -, -O(CH2) a -, -(CH2) a O-, -O(CH2) a O-, -COO-, -OCO-, -CH=CH-COO-, -OCO-CH=CH-, -(CH2) a -COO-, -OCO-(CH2) a -, -CH=CH-, -SO2-, -OCF2-, or -CF2O-, where a is an integer from 1 to 20, X 1 is fluorine or methyl, Y 2 is an alkyl having 1 to 12 carbon atoms, Y 3 is hydrogen or an alkyl having 1 to 12 carbon atoms, n is an integer from 0 to 4, including when n is 2 or more, when there are a plurality of Xs in the formula 1 they may be the same or different, in the formula, when there are a plurality of Zs 5 they may be the same or different, R 1c [[ID=4 six]]is a polymerizable group represented by formula (PG-1), TIFF0007838266000035.tif3634 In formula (PG-1), R b is hydrogen, halogen, -CF3 or an alkyl having 1 to 5 carbon atoms, when there are a plurality of Rs in the formula b they may be the same or different.

[0079] More preferred specific examples of compound (2) are shown below. TIFF0007838266000036.tif209144 In equations (2-1-1a), (2-2-1a), (2-2-2a), (2-3-1a)~(2-3-3a), (2-4-1a), and (2-4-6a), R b These are hydrogen, halogens, -CF3, or alkyl groups having 1 to 5 carbon atoms. Z 5 This is a single bond, -(CH2) a -, -O(CH2) a -,-(CH2) a O-, -O(CH2) a O-, -COO-, -OCO-, -CH=CH-COO-, -OCO-CH=CH-, -(CH2) a -COO-, -OCO-(CH2) a -, -CH=CH-, -SO2-, -OCF2-, or -CF2O-, where a is an integer from 1 to 20. m is an integer between 0 and 20. M is a single bond or oxygen, X 1 is fluorine or methyl, Y 2 These are alkyl groups with 1 to 8 carbon atoms. Y 3 is hydrogen or an alkyl group having 1 to 8 carbon atoms. n is an integer between 0 and 4. This includes the case where n is 2 or greater, and X in the expression 1 If there are multiple items, they may be the same or different. In the formula, Z 5 However, if there are multiple items, they may be identical or different.

[0080] In the present invention, "a copolymer of compound (1) and compound (2)" means a polymer obtained by polymerizing monomers containing at least one compound (1) and at least one compound (2), and the polymer only needs to contain monomer units derived from at least one compound (1) and at least one compound (2), and may contain three or more monomer units. That is, a copolymer of compound (1) and compound (2) may be a polymer obtained by copolymerizing two or more compound (1) and one or more compound (2), or a polymer obtained by copolymerizing one or more compound (1) and two or more compound (2), or a copolymer of at least one compound (1) and at least one monomer other than compound (1) and chemical formula (2). Such monomers other than compound (1) and chemical formula (2) (hereinafter also referred to as "other polymerizable compounds") are not particularly limited.

[0081] <Other polymerizable compounds> The polymer obtained by polymerizing compound (1) may be copolymerized with other polymerizable compounds. Preferred polymerizable compounds are those that do not reduce film-forming properties and mechanical strength. These polymerizable compounds are classified into those that are not liquid crystalline and those that are liquid crystalline. Examples of non-liquid crystalline polymerizable compounds include vinyl derivatives, styrene derivatives, (meth)acrylic acid derivatives, sorbic acid derivatives, fumaric acid derivatives, and itaconic acid derivatives. Preferred examples of these derivatives are shown below.

[0082] Preferred vinyl derivatives include, for example, vinyl chloride, vinyl fluoride, vinyl acetate, vinyl pivalate, vinyl 2,2-dimethylbutanoate, vinyl 2,2-dimethylpentanoate, vinyl 2-methyl-2-butanoate, vinyl propionate, vinyl stearate, vinyl 2-ethyl-2-methylbutanoate, N-vinylacetamide, pt-butyl benzoate, vinyl N,N-dimethylaminobenzoate, vinyl benzoate, ethyl vinyl ether, hydroxybutyl monovinyl ether, t-amyl vinyl ether, cyclohexanedimethanol methyl vinyl ether, α,β-vinylnaphthalene, methyl vinyl ketone, and isobutyl vinyl ketone.

[0083] Preferred styrene derivatives include, for example, styrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, o-chloromethylstyrene, m-chloromethylstyrene, p-chloromethylstyrene, and α-methylstyrene.

[0084] Preferred (meth)acrylic acid derivatives include, for example, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, neopentyl glycol diacrylate, triethylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, tetraethylene glycol diacrylate, trimethylolpropane triacrylate, trimethylol EO-added triacrylate, pentaerythritol triacrylate, trisacryloyloxyethyl phosphate, bisphenol A EO-added diacrylate, bisphenol A glycidyl diacrylate (trade name: "Viscoat 700" manufactured by Osaka Organic Chemical Co., Ltd.), polyethylene glycol diacrylate dimethyl itaconate, and the like.

[0085] Preferred sorbic acid derivatives include, for example, sodium sorbate, potassium sorbate, lithium sorbate, 1-naphthylmethylammonium sorbate, benzylammonium sorbate, dodecylammonium sorbate, octadecylammonium sorbate, methyl sorbate, ethyl sorbate, propyl sorbate, isopropyl sorbate, butyl sorbate, t-butyl sorbate, hexyl sorbate, octyl sorbate, octadecyl sorbate, cyclopentyl sorbate, cyclohexyl sorbate, vinyl sorbate, allyl sorbate, and propagyl sorbate.

[0086] Preferred fumaric acid derivatives include, for example, dimethyl fumarate, diethyl fumarate, diisopropyl fumarate, dibutyl fumarate, dicyclopentyl fumarate, and dicyclohexyl fumarate.

[0087] Preferred itaconic acid derivatives include, for example, diethyl itaconate, dibutyl itaconate, and diisopropyl itaconate. In addition to these, many other polymerizable compounds can be used, such as butadiene, isoprene, and maleimide.

[0088] <Other polymerizable liquid crystal compounds> The copolymer of compound (1) and compound (2) may contain polymerizable liquid crystal compounds other than compounds (1) and (2) as constituent elements. The low-dielectric substrate composition (1) may contain polymerizable liquid crystal compounds other than compounds (1) and (2), and polymers obtained by polymerizing these compounds. From the viewpoint of compatibility between the copolymer of compound (1) and compound (2) and organic solvents, compounds represented by formula (M1), formula (M2), or formula (M3) are preferred as the polymerizable liquid crystal compounds.

[0089] TIFF0007838266000037.tif73146

[0090] In equations (M1), (M2), and (M3), A M This is independently a divalent group selected from 1,4-phenylene, 1,4-cyclohexylene, 1,4-cyclohexenylene, pyridine-2,5-diyl, 1,3-dioxane-2,5-diyl, naphthalene-2,6-diyl, or fluorene-2,7-diyl, wherein at least one hydrogen in the divalent group may be replaced with fluorine, chlorine, cyano, hydroxyl, formyl, trifluoroacetyl, difluoromethyl, trifluoromethyl, C1-C5 alkyl, C1-C5 alkoxy, C1-C5 alkoxycarbonyl, or C1-C5 alkanoyl. Z M These are independently single bonds, -OCH2-, -CH2O-, -COO-, -OCO-, -COS-, -SCO-, -OCOO-, -CONH-, -NHCO-, -CF2O-, -OCF2-, -CH2CH2-, -CF2CF2-, -CH=CHCOO-, -OCOCH=CH-, -CH2CH2COO-, -OCOCH2CH2-, -COOCH2CH2-, -CH2CH2OCO-, -CH=CH-, -N=CH-, -CH=N-, -N=C(CH3)-, -C(CH3)=N-, -N=N-, -C≡C-, -CH=NN=CH-, or -C(CH3)=NN=C(CH3)-. X M These are hydrogen, fluorine, chlorine, trifluoromethyl, trifluoromethoxy, cyano, C1-C20 alkyl, C1-C20 alkenyl, C1-C20 alkoxy, or C1-C20 alkoxycarbonyl. Y M These are independently single bonds, -O-, -COO-, -OCO-, or -OCOO-, Q M These are single bonds, -O-, -COO-, or -OCO-, q is an integer from 1 to 6, c and d are independent integers between 0 and 3, and the relationship 1 ≤ c + d ≤ 6, and a is an integer between 0 and 20. R M It is hydrogen or methyl.

[0091] A copolymer of compound (1) and compound (2) can be used as a prepolymer for low-dielectric substrates. A prepolymer is an intermediate product obtained by stopping the polymerization reaction of monomers at an intermediate stage, and is a preliminary step before it becomes a polymer. Polymerization and crosslinking reactions can be easily induced in this prepolymer by heating, etc.

[0092] The weight-average molecular weight (Mw) of the copolymer of compound (1) and compound (2) is not particularly limited, but is preferably 300,000 or less, more preferably 150,000 or less, even more preferably 50,000 or less, even more preferably 30,000 or less, even more preferably 10,000 or less, and particularly preferably 6,000 or less. It is also preferably 500 or more, more preferably 2,000 or more, even more preferably 3,000 or more, and particularly preferably 4,000 or more. When the polymer is used as a prepolymer for a low-dielectric substrate, when the weight-average molecular weight (Mw) is preferably 300,000 or less, it has a suitable melt viscosity and therefore exhibits excellent moldability. When the polymer is used as a prepolymer, residual monomers may be present, and monomers may coexist in the composition.

[0093] The molecular weight of the copolymer of compound (1) and compound (2) was measured using gel permeation chromatography (GPC) with the "Nexera GPC system" (a test device from Shimadzu Corporation), with tetrahydrofuran or dimethyl sulfoxide (containing lithium bromide as an additive) as the carrier and polystyrene or pullulan as the molecular weight standard.

[0094] The copolymer of compound (1) and compound (2) of the present invention can be produced by polymerizing the monomer compound (1) by a conventional method such as radical polymerization. For example, it can be produced by the method described in the 4th edition of Experimental Chemistry, Volume 28, Polymer Synthesis (edited by the Chemical Society of Japan).

[0095] Examples of solvents for radical polymerization reactions include ethers, esters, ketones, amides, sulfoxides, alcohols, and hydrocarbons. More specifically, ethers include linear ethers such as diethyl ether, and cyclic ethers such as tetrahydrofuran and dioxane. Esters include methyl acetate, ethyl acetate, butyl acetate, and ethyl lactate. Ketones include acetone, methyl ethyl ketone, and methyl isobutyl ketone. Amides include N,N-dimethylacetamide and N,N-dimethylformamide. Sulfoxides include dimethyl sulfoxide. Alcohols include methanol, ethanol, and propanol. Hydrocarbons include aromatic hydrocarbons such as benzene, toluene, and xylene, aliphatic hydrocarbons such as hexane, and alicyclic hydrocarbons such as cyclohexane.

[0096] A mixed solvent, obtained by mixing the solvents for the above polymerization reactions, may be used as the solvent for the radical polymerization reaction. Known polymerization initiators can be used as the polymerization initiator. The polymerization reaction temperature can be appropriately selected within a range of, for example, 30 to 150°C.

[0097] In the method for producing a copolymer of compound (1) and compound (2) of the present invention by radical polymerization, examples of preferred polymerization initiators include organic azo polymerization initiators such as 2,2'-azobis(4-methoxy2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), dimethyl2,2'-azobis(2-methylpropionate), 2,2'-azobis[N-(2-propyl)-2-methylpropionamide], and 2,2-azobis[2-(2-imidazolin-2-yl)propane], as well as organic peroxides such as benzoyl peroxide, t-butylperoxy-2-ethylhexanoate, and t-butylperoxybenzoate. These polymerization initiators may be used individually or in mixtures of two or more types.

[0098] In the method for producing a copolymer of compound (1) and compound (2) of the present invention by radical polymerization, organic azo polymerization initiators such as 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, and 2,2'-azobis(2-methylbutyronitrile) can preferably be used. By using organic azo polymerization initiators, safety during polymer production is ensured, and polymers with controlled weight-average molecular weights tend to be produced.

[0099] In the method for producing a copolymer of compound (1) and compound (2) of the present invention by radical polymerization, in order to control the appropriate weight-average molecular weight, it is desirable to use 0.5 to 100 parts by weight of polymerization initiator per 100 parts by weight of monomer, preferably 2 to 50 parts by weight, and more preferably 5 to 30 parts by weight.

[0100] In the present invention's method for producing a copolymer of compound (1) and compound (2) by radical polymerization, a chain transfer agent can be used as needed. While the chain transfer agent is not particularly limited, mercaptan compounds can be suitably used to control the weight-average molecular weight of the polymer and to improve the adhesion of the resin to copper foil or the like. Examples of mercaptan compounds include primary, secondary, and tertiary mercaptans having alkyl groups or substituted alkyl groups such as n-butyl, isobutyl, n-octyl, n-dodecyl, sec-butyl, sec-dodecyl, and tert-butyl mercaptan; aromatic mercaptans such as phenyl mercaptan, thiocresol, and 4-tert-butyl-o-thiocresol; mercaptan compounds containing carboxyl groups such as mercaptoacetic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, and mercaptosuccinic acid; mercaptan compounds containing ester groups such as ethyl mercapto, cyclohexyl 3-mercaptopropionate, and tridecyl 3-mercaptopropionate; and mercaptan compounds containing hydroxyl groups such as 2-mercaptoethanol and 3-mercapto-1,2-propanediol. These can be used individually or in combination of two or more types. Among these mercaptan compounds, mercaptoacetic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, and mercaptosuccinic acid, which contain carboxyl groups, are more preferred in order to improve the adhesion of the resin to copper foil and the like. Furthermore, it is desirable to use 0.5 to 200 parts by weight of a chain transfer agent per 100 parts by weight of the above monomer, preferably 5 to 100 parts by weight, and more preferably 30 to 100 parts by weight.

[0101] [Synthesis methods for compounds (1) and (2)] Compounds (1) and (2) can be synthesized by combining known techniques in organic synthesis. Methods for introducing desired terminal groups, ring structures, and bonding groups into starting materials are described, for example, in textbooks such as Houben-Wyle (Methods of Organic Chemistry, Georg Thieme Verlag, Stuttgart), Organic Syntheses (John Wily & Sons, Inc.), Organic Reactions (John Wily & Sons, Inc.), Comprehensive Organic Synthesis (Pergamon Press), and New Experimental Chemistry Series (Maruzen).

[0102] The method for introducing the binding group Z is explained in schemes 1 to 9 below. In these schemes, MSG 1 and MSG 2 represents a monovalent organic group having at least one ring, and Hal represents a halogen. Multiple MSGs used in the scheme below 1 (or MSG) 2 The compounds (1A) to (1M) in the following scheme correspond to compounds (1) and (2) above. These methods can be applied to the synthesis of optically active compounds (1) and (2) and optically inert compounds (1) and (2).

[0103] (Scheme 1) Compounds in which Z is a single bond As shown below, MSG is produced by reacting arylboric acid (S1) with a compound (S2) synthesized by a known method in the presence of an aqueous carbonate solution and a catalyst such as tetrakis(triphenylphosphine)palladium. 1 and MSG 2Compound (1A) can be synthesized in which a single bond is introduced between the two. This compound (1A) can also be synthesized by reacting compound (S3), which is synthesized by known methods, with n-butyllithium, then zinc chloride, and then further reacting it with compound (S2) in the presence of a catalyst such as dichlorobis(triphenylphosphine)palladium.

[0104] TIFF0007838266000038.tif52137

[0105] (Scheme 2) Compounds where Z is -CH=CH- As shown below, MSG is produced by reacting a phosphorus ylide generated by reacting a phosphonium salt (S5), synthesized by a known method, with a base such as potassium t-butoxide, with an aldehyde (S4). 1 and MSG 2 Compound (1B) in which -CH=CH- is introduced between the two isomers can be synthesized. Depending on the reaction conditions and substrate, the cis isomer may be produced, so the cis isomer can be isomerized to the trans isomer by known methods as needed.

[0106] TIFF0007838266000039.tif33122

[0107] (Scheme 3) Compounds where Z is -(CH2)2- As shown below, by hydrogenating the compound (1B) obtained as described above in the presence of a catalyst such as palladium carbon, MSG is produced. 1 and MSG 2 A compound (1C) having -(CH2)2- can be synthesized between them.

[0108] TIFF0007838266000040.tif25130

[0109] (Scheme 4) Compounds where Z is -(CF2)2- As shown below, MSG is produced by fluorinating diketone (S6) with sulfur tetrafluoride in the presence of a hydrogen fluoride catalyst, according to the method described in J. Am. Chem. Soc., 2001, 123, 5414. 1 and MSG 2 A compound (1D) having -(CF2)2- between the two can be synthesized.

[0110] TIFF0007838266000041.tif35122

[0111] (Scheme 5) Compounds where Z is -(CH2)4- As shown below, a compound having -(CH2)2-CH=CH- is synthesized using the phosphonium salt (S7) instead of the phosphonium salt (S5) according to the method of Scheme 2, and then catalytically hydrogenated in the same manner as in Scheme 3 to obtain MSG 1 and MSG 2 Compound (1E) can be synthesized in which -(CH2)4- is introduced between the two.

[0112] TIFF0007838266000042.tif34151

[0113] (Scheme 6) Compounds where Z is -CH2O- or -OCH2- As shown below, compound (S4) is reduced with a reducing agent such as sodium borohydride to obtain compound (S8). This is halogenated with hydrobromic acid or the like to obtain compound (S9). By reacting this compound (S9) with compound (S10) in the presence of potassium carbonate, MSG is produced. 1 and MSG 2 Compounds (1F) can be synthesized in which -OCH2- (or -CH2O-) is introduced between the two.

[0114] TIFF0007838266000043.tif55147

[0115] (Scheme 7) Compounds where Z is -COO- or -OCO- As shown below, compound (S3) is reacted with n-butyllithium, followed by carbon dioxide, to obtain a carboxylic acid (S11). This compound (S11) and phenol (S10) are dehydrated in the presence of DCC (1,3-dicyclohexylcarbodiimide) and DMAP (4-dimethylaminopyridine) to obtain MSG. 1 and MSG 2 A compound (1G) can be synthesized in which -COO- (or -OCO-) is introduced between the two.

[0116] TIFF0007838266000044.tif34151

[0117] (Scheme 8) Compounds where Z is -CF=CF- As shown below, compound (S3) is treated with n-butyllithium and then reacted with tetrafluoroethylene to obtain compound (S12). Subsequently, compound (S2) is treated with n-butyllithium and then reacted with compound (S12) to obtain MSG. 1 and MSG 2 A compound (1H) in which -CF=CF- is introduced between the two isomers can be synthesized. By selecting the synthesis conditions, it is also possible to produce the cis isomer.

[0118] TIFF0007838266000045.tif37146

[0119] (Scheme 9) Compounds in which Z is -CF2O- or -OCF2- As shown below, compound (1G) obtained by the method described in Scheme 7 above is treated with a sulfurizing agent such as Lawson's reagent to obtain compound (S16). This compound (S16) is fluorinated with a pyridine hydrogen fluoride complex and N-bromosuccinimide (NBS) to obtain MSG 1 and MSG 2Compound (1M) having -CF2O- (or -OCF2-) between the two can be synthesized. Compound (1M) can also be synthesized by fluorinating compound (S16) with (diethylamino)sulfate trifluoride (DAST). Furthermore, the method described in P. Kirsch et al., Angew. Chem. Int. Ed. 2001, 40, 1480. It is also possible to generate these bonding groups by [method / action].

[0120] TIFF0007838266000046.tif55119

[0121] [Liquid crystal composition] The low-dielectric substrate composition (1) in the present invention may contain a copolymer of compound (1) and compound (2), and may also contain at least one compound other than compound (1) other than the copolymer of compound (1) and compound (2). Such components other than the copolymer of compound (1) and compound (2) are not particularly limited, but examples include polymerizable compounds other than compounds (1) and (2) (hereinafter also referred to as "other polymerizable compounds"), non-polymerizable liquid crystal compounds, optically active compounds, polymerization initiators, solvents, and fillers.

[0122] <Other polymerizable compounds> The low-dielectric substrate composition (1) may also contain other polymerizable compounds as components. Preferred polymerizable compounds are those that do not reduce film-forming properties and mechanical strength. These polymerizable compounds are classified into those that are not liquid crystalline and those that are liquid crystalline. Examples of non-liquid crystalline polymerizable compounds include vinyl derivatives, styrene derivatives, (meth)acrylic acid derivatives, sorbic acid derivatives, fumaric acid derivatives, and itaconic acid derivatives. Preferred examples of these derivatives are the same compounds as described above for copolymers of compound (1) and compound (2).

[0123] <Other polymerizable liquid crystal compounds> The low-dielectric substrate composition (1) may contain a polymer obtained by polymerizing polymerizable liquid crystal compounds other than copolymers of compound (1) and compound (2). From the viewpoint of the expression of the liquid crystal phase of the polymerizable liquid crystal composition and compatibility with the copolymer and organic solvents, the compounds represented by the above formulas (M1), (M2), or (M3) are preferred as the polymerizable liquid crystal compounds.

[0124] <Non-polymerizable liquid crystal compounds> The low-dielectric substrate composition (1) may also contain a liquid crystal compound that does not have polymerizable groups as a component. Examples of such non-polymerizable liquid crystal compounds are listed in the liquid crystal compound database LiqCryst (LCI Publisher GmbH, Hamburg, Germany), etc. By polymerizing the low-dielectric substrate composition (1) containing the non-polymerizable liquid crystal compound, composite materials can be obtained of a copolymer of compound (1) and compound (2) and the liquid crystal compound. In such composite materials, for example, the non-polymerizable liquid crystal compound is present in a polymer network such as a polymer-dispersed liquid crystal.

[0125] <Polymerization initiator> The low-dielectric substrate composition (1) may also contain a polymerization initiator as a component. Depending on the polymerization method of the low-dielectric substrate composition (1), the polymerization initiator may be, for example, a photoradical polymerization initiator, a photocationic polymerization initiator, or a thermal radical polymerization initiator.

[0126] The photoradical polymerization initiator is not particularly limited and any known one can be used. Examples include 4-methoxyphenyl-2,4-bis(trichloromethyl)triazine, 2-(4-butoxystyryl)-5-trichloromethyl-1,3,4-oxadiazole, 9-phenylacrididine, 9,10-benzphenazine, benzophenone / Michlar's ketone mixture, hexaarylbiimidazole / mercaptobenzimidazole mixture, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, benzyldimethyl ketal, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2,4-diethylxanthone / p-dimethylaminobenzoate methyl mixture, and benzophenone / methyltriethanolamine mixture. Examples of commercially available products include the "Darocure Series 1173, 4265" and the "IrgaCure Series 184, 369, 500, 651, 784, 819, 907, 1300, 1700, 1800, 1850, 2959" manufactured by Chiba Specialty Co., Ltd.

[0127] The photocationic polymerization initiator is not particularly limited and any known one can be used, for example, "Sylacure UVI-6990, 6974" manufactured by UCC Corporation, "Adeka Optomer SP-150, 152, 170, 172" manufactured by Asahi Denka Co., Ltd., "Photoinitiator 2074" manufactured by Rhodia Corporation, "Irga Cure 250" manufactured by Ciba Specialty Co., Ltd., and "DTS-102" manufactured by Midori Chemical Co., Ltd.

[0128] Preferred initiators for thermal radical polymerization include, for example, benzoyl peroxide, diisopropyl peroxydicarbonate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxypivalate, di-t-butyl peroxide (DTBPO), t-butyl peroxydiisobutyrate, lauroyl peroxide, dimethyl 2,2'-azobisisobutyrate (MAIB), azobisisobutyronitrile (AIBN), and azobiscyclohexanecarbonilate (ACN).

[0129] <Inorganic fillers as fillers> In the low dielectric substrate composition (1), fillers (inorganic fillers) can be added to improve mechanical strength, reduce dielectric loss, improve thermal conductivity, and adjust viscosity. For example, by adding silica powder, especially hollow silica powder, a hardened product with a low dielectric loss tangent can be obtained. Furthermore, by adding metal fillers such as metal nitrides like aluminum nitride, boron nitride, and silicon nitride; carbides like diamond, graphite, and silicon carbide; metal oxides like magnesium oxide, aluminum oxide, zinc oxide, titanium oxide, tin oxide, holmium oxide, and calcium oxide; metal hydroxides like magnesium hydroxide and aluminum hydroxide; silicate compounds such as cordierite or mullite; gold, silver, copper, platinum, iron, tin, lead, nickel, aluminum, magnesium, tungsten, molybdenum, and stainless steel, high thermal conductivity can be achieved. Preferably, hollow silica and boron nitride, which have low dielectric constants, are preferred. While thermal conductivity and other properties increase with higher inorganic filler content, inorganic fillers generally have a higher relative permittivity and lower dielectric loss tangent compared to resin components. Therefore, increasing the amount of filler increases the dielectric constant. Consequently, it is preferable to fill only the required amount, within a range that does not exceed the desired dielectric constant.

[0130] Examples of filler shapes include spherical, amorphous, fibrous, rod-shaped, cylindrical, and plate-shaped. The filler shape is preferably one that does not hinder the orientation of the polymerizable liquid crystal compound when it forms the liquid crystal phase. The type, shape, size, and amount of filler can be appropriately selected according to the purpose. If the resulting low-dielectric constant molded body requires insulation, the filler may be conductive as long as the desired insulation, dielectric constant, and dielectric loss are maintained. Preferably, hollow silica is used to obtain a hardened product with low dielectric constant and low dielectric loss tangent, while plate-shaped crystalline boron nitride has a low dielectric constant, allowing for both high thermal conductivity and low dielectric properties. Using polymerizable liquid crystal compounds and fine-particle spherical silicon oxide can increase the viscosity of the molten material or solution, and using silicate compounds is preferable because it can reduce the thermal expansion coefficient of the molded body.

[0131] The average particle size of spherical or irregularly shaped fillers is preferably 0.1 to 200 μm, more preferably 1 to 100 μm. A particle size of 0.1 μm or more provides good thermal conductivity, while a particle size of 200 μm or less allows for increased packing efficiency. For fibrous fillers, longer fiber lengths improve tensile strength, but kneading and dispersion become impossible, so selection is preferable depending on the application. When dispersion is required, using whisker-shaped short fibers is preferable because it facilitates uniform dispersion and improves the strength of the low dielectric constant molded body. In this specification, the average particle size is based on particle size distribution measurement by laser diffraction and scattering. Specifically, using analysis based on Fraunhofer diffraction theory and Mie scattering theory, the median diameter is defined as the diameter at which the larger and smaller sides are equal in volume when the powder is divided into two parts from a certain particle size using a wet method. The amount of filler is preferably such that the low dielectric constant molded body contains 20 to 95% by weight of filler after curing. More preferably, it is 50 to 95% by weight. A filler of 20% by weight or more is preferable because it increases thermal conductivity. A filler of 95% by weight or less is preferable because it prevents the low dielectric constant molded body from becoming brittle. As the filler, commercially available products that have undergone surface treatment such as dispersion treatment or waterproofing treatment may be used as is, or the surface treatment agent may be removed from the commercially available product. Alternatively, untreated fillers may be treated with silane coupling agents, affinity agents, surface tension modifiers, settling inhibitors, coagulation inhibitors, etc., before use.

[0132] <glass cloth> The low-dielectric substrate composition (1) may be compounded with glass cloth and cured to obtain excellent mechanical strength, dielectric properties, and thermal conductivity. Commercially available glass cloth can be used, and low-dielectric glass cloth is preferred because it can achieve mechanical strength and dielectric properties suitable for printed circuit boards used at high frequencies. Glass cloth that has been surface-treated to increase its affinity with the low-dielectric substrate composition (1) can also be used. It is preferable to use glass cloth with fiber thickness and density that are necessary for the properties of the target substrate. By impregnating the cloth with a solution of polymer dissolved in a solvent, evaporating the solvent, and then heating under pressure, a substrate with smoothness and mechanical strength suitable for printed circuit boards can be realized.

[0133] <Solvent> The low-dielectric substrate composition (1) may contain a solvent. Polymerization of the low-dielectric substrate composition (1) may be carried out in or without a solvent. The low-dielectric substrate composition (1) containing a solvent may be applied to a substrate, for example by a spin coating method, and then the solvent may be removed before photopolymerization. Alternatively, after photocuring, post-treatment may be performed by heating to an appropriate temperature and thermal curing.

[0134] Preferred solvents include, for example, benzene, toluene, xylene, mesitylene, hexane, heptane, octane, nonane, decane, tetrahydrofuran, γ-butyrolactone, N-methylpyrrolidone, dimethylformamide, dimethyl sulfoxide, cyclohexane, methylcyclohexane, cyclopentanone, cyclohexanone, and PGMEA. These solvents may be used individually or in combination of two or more. Furthermore, there is little point in limiting the proportion of solvent used during polymerization; it should be determined on a case-by-case basis, taking into account polymerization efficiency, solvent costs, energy costs, etc.

[0135] <Other additives> The low-dielectric substrate composition (1), comprising compound (1), compound (2), a copolymer of compound (1) and compound (2), and a copolymer of compound (1) and compound (2), is polymerizable, and therefore a stabilizer may be added to facilitate handling. The copolymer of compound (1) and compound (2) retains polymerizable groups and can therefore be used as a prepolymer. Any known stabilizer can be used without limitation for this purpose, such as hydroquinone, 4-ethoxyphenol, and 3,5-di-t-butyl-4-hydroxytoluene (BHT). For applications requiring a low dielectric loss tangent (low tanδ) and a high glass transition temperature, it is preferable to add a crosslinking agent. The crosslinking agent is preferably one that chemically bonds with the polymerizable groups of the liquid crystal compound having polymerizable groups at the ends of the present invention, thereby forming a three-dimensional crosslink.

[0136] [Low dielectric resin] Another embodiment of the present invention, the low dielectric constant resin, is a cured product of the low dielectric substrate composition described above. It can be used in sheet-like, film-like, plate-like, fibrous, and three-dimensional shaped components (such as the insulating portion of a connector), and can also be used as a coating agent, adhesive, or filler. Because the low dielectric constant resin is a cured product of the above-described composition, it has a low dielectric constant, and because it uses a polymerizable liquid crystal compound as the polymer, it also exhibits excellent thermal conductivity, heat resistance, rigidity, elasticity, moldability, chemical resistance, and dimensional stability.

[0137] When a low-dielectric resin exhibits liquid crystalline properties, molecular orientation can be controlled by orientation treatment before curing. Relative permittivity and thermal conductivity exhibit anisotropy depending on the molecular orientation. For example, in dielectric and thermal design of electronic substrates, it becomes possible to design the substrate so that the area directly beneath a heat-generating IC has high thermal conductivity in the thickness direction, while other areas are oriented laterally to spread heat over a wider area, enabling more advanced material design. The orientation method can be controlled by the following methods.

[0138] Methods for controlling the orientation of mesogenic moieties of liquid crystal molecules in a low-dielectric substrate composition include treating the filler surface with a silane coupling agent or orientation agent having orientation capabilities, and aligning the molecules using the self-orientation-regulating force of the composition itself. These methods may be performed individually or in combination of two or more. Examples of orientation states controlled by such orientation control methods include homogeneous, twisted, homeotropic, hybrid, bent, and spray orientation, which can be appropriately determined depending on the application and the orientation control method. Furthermore, during film formation or molding, shear stress can be applied to the liquid crystal state before curing to physically align the molecules.

[0139] The orientation temperature is in the range of room temperature to 250°C, preferably room temperature to 200°C, and more preferably room temperature to 180°C. The heat treatment time is in the range of 5 seconds to 2 hours, preferably 10 seconds to 60 minutes, and more preferably 20 seconds to 30 minutes. If the heat treatment time is shorter than the above range, the temperature of the layer made of the low dielectric substrate composition (1) may not be raised to the predetermined temperature, and if it is longer than the above range, productivity may decrease. Note that the above heat treatment conditions vary depending on the type and composition ratio of the compounds used in the low dielectric substrate composition (1), the presence and content of polymerization initiators, etc., and therefore these are only approximate ranges. In particular, if the temperature is higher than the polymerization initiation temperature, the resin will harden before orientation can occur, and a low dielectric resin with molecular chains oriented in a specific direction cannot be obtained.

[0140] Examples of polymerization methods for the low-dielectric substrate composition (1) include radical polymerization, cationic polymerization, anionic polymerization, and coordination polymerization. However, to immobilize molecular arrangements or helical structures, thermal polymerization or photopolymerization using light or heat, such as electron beams, ultraviolet light, visible light, or infrared light (heat rays), is suitable. Thermal polymerization is preferably carried out in the presence of a radical polymerization initiator, and photopolymerization is preferably carried out in the presence of a photo-radical polymerization initiator. For example, a polymer in which the arrangement of liquid crystal molecules is immobilized can be obtained by polymerization using irradiation with ultraviolet light or an electron beam in the presence of a photo-radical polymerization initiator. The resulting polymer (1) may be a homopolymer, a random copolymer, an alternating copolymer, a block copolymer, or a graft copolymer, and can be appropriately selected depending on the application.

[0141] When fixing the orientation of the low-dielectric substrate composition (1) by photopolymerization, ultraviolet light or visible light is usually used. The wavelength of the light used for irradiation is in the range of 150 to 500 nm, preferably 250 to 450 nm, and more preferably 300 to 400 nm. Examples of light sources for irradiation include low-pressure mercury lamps (germicidal lamps, fluorescent chemical lamps, black lights), high-pressure discharge lamps (high-pressure mercury lamps, metal halide lamps), and short-arc discharge lamps (ultra-high-pressure mercury lamps, xenon lamps, mercury xenon lamps), and ultraviolet light-emitting diodes. Among these, metal halide lamps, xenon lamps, ultraviolet light-emitting diodes, and high-pressure mercury lamps are preferred.

[0142] The wavelength range of the light source can be selected by installing a filter or the like between the light source and the low-dielectric substrate composition (1) to allow only a specific wavelength range to pass through. The amount of light emitted from the light source is 2 to 5000 mJ / cm². 2 Preferably 10 to 3000 mJ / cm² 2 more preferably 100-2000 mJ / cm² 2 This is within the specified range. The temperature conditions during light irradiation are preferably set in the same way as the heat treatment temperature described above.

[0143] The conditions for fixing the orientation of the low-dielectric substrate composition (1) by thermal polymerization are as follows: the curing temperature is in the range of room temperature to 350°C, preferably room temperature to 250°C, more preferably 50°C to 200°C; and the curing time is in the range of 5 seconds to 10 hours, preferably 1 minute to 5 hours, more preferably 5 minutes to 1 hour. After polymerization, slow cooling is preferable to suppress stress and strain. Alternatively, reheating may be performed to alleviate strain.

[0144] The polymer whose orientation has been controlled as described above, or the polymer in the polymerization process, may be further oriented in any desired direction by mechanical operations such as stretching. The isolated polymer (1) may be dissolved in a solvent and oriented on an orientation-treated substrate to be processed into a film or the like, or two polymers may be mixed and processed, or multiple polymers may be laminated. Preferred solvents include, for example, N-methyl-2-pyrrolidone, dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide, N,N-dimethylacetamide dimethylacetal, tetrahydrofuran, chloroform, 1,4-dioxane, bis(methoxyethyl) ether, γ-butyrolactone, tetramethylurea, trifluoroacetic acid, trifluoroethyl acetate, hexafluoro-2-propanol, 2-methoxyethyl acetate, methyl ethyl ketone, cyclopentanone, and cyclohexanone. These may also be used in combination with common organic solvents such as acetone, benzene, toluene, heptane, and methylene chloride.

[0145] Even if a highly linear low-dielectric substrate composition does not exhibit liquid crystalline properties or exhibits a very narrow liquid crystalline phase, if it has high crystallinity, it forms domains with axes aligned in a certain direction, resulting in higher thermal conductivity compared to polymerizable compounds such as bisphenol A structures. Furthermore, orientation and crystallinity can be controlled by slowly curing the material from an isotropic liquid state while a polymer sheet surface with aligned orientation or a crystalline resin filler is present as a core for crystal growth. However, excessively high crystallinity tends to reduce flexibility, so it is necessary to use a polymerizable composition with appropriate crystalline properties.

[0146] The low dielectric constant molded article of the present invention consists of the low dielectric substrate composition (1) described above and is used in the form of a sheet, film, thin film, fiber, molded article, coated film, etc. Preferred forms are film and thin film. Film and thin film are obtained by polymerizing the low dielectric substrate composition (1) while it is applied to a substrate or release film, or while it is sandwiched between flat plates such as a substrate or mold. Alternatively, it can also be obtained by applying the low dielectric substrate composition (1) containing a solvent to an oriented substrate and then removing the solvent. Furthermore, sheets, films, and thin films can also be obtained by press molding the polymer. In this specification, the film thickness of a sheet is 1 mm or more, preferably 5 mm or less. The film thickness of a film is 5 μm or more and less than 1 mm, preferably 10 to 500 μm, more preferably 20 to 300 μm, and the film thickness of a thin film is less than 5 μm, preferably 0.1 μm or more.

[0147] The following describes in detail a method for producing a film, which is a low dielectric constant molded body, using a low dielectric substrate composition (1) containing a solvent. First, a low-dielectric substrate composition (1) is applied to a mold-released substrate, and the solvent is dried and removed to form a coating layer with a uniform thickness. Examples of application methods include spin coating, roll coating, curtain coating, flow coating, printing, microgravure coating, gravure coating, wire bar coating, dip coating, spray coating, and meniscus coating.

[0148] The solvent can be removed by drying, for example, by air drying at room temperature, drying on a hot plate, drying in a drying oven, or by blowing warm or hot air. The conditions for solvent removal are not particularly limited; it is sufficient to dry the coating layer until the solvent is mostly removed and the coating layer loses its fluidity. Depending on the type and composition ratio of the compounds used in the low-dielectric substrate composition (1), the molecular orientation of the liquid crystal molecules in the coating layer may be completed during the drying process. In such cases, the coating layer that has gone through the drying process can be subjected to the polymerization process without going through the heat treatment process described above. However, in order to make the orientation of the liquid crystal molecules in the coating layer more uniform, it is preferable to heat the coating layer that has gone through the drying process to the liquid crystal phase emergence temperature to orient it in the liquid crystal state, and then fix the orientation by photopolymerization or thermal polymerization treatment.

[0149] Furthermore, when the low-dielectric substrate composition (1) is cured and used as a low-dielectric constant insulating film, it is also preferable to perform an orientation treatment on the substrate surface before applying the low-dielectric substrate composition (1) to the substrate. Prepolymers with large molecular weights are difficult to orient with orientation agents, but if unreacted monomers are left behind or monomers are added later, these monomers can be oriented by the orientation treatment. As for orientation treatment methods, for example, one may simply form an orientation film on the substrate, or form an orientation film on the substrate and then perform a rubbing treatment with a rayon cloth or the like, or directly rub the substrate with a rayon cloth or the like, or even obliquely deposit silicon dioxide, or perform rubbing-free orientation using a stretched film, photo-alignment film or ion beam, etc. In addition, it is sometimes possible to form a desired orientation state without treating the substrate surface. For example, when forming homeotropic orientation, surface treatments such as rubbing are often not performed, but rubbing treatment may be performed to achieve higher orientation.

[0150] The orientation film is not particularly limited as long as it can control the orientation of the low-dielectric substrate composition (1), and known orientation films can be used. For example, polyimide, polyamide, polyvinyl alcohol, alkylsilane, alkylamine, or lecithin-based orientation films are preferred. Silane coupling agents are also preferred when vertical orientation is required.

[0151] Any method can be used for the rubbing process described above. Typically, a rubbing cloth made of materials such as rayon, cotton, and polyamide is wrapped around a metal roll or the like, and the roll is rotated and moved while in contact with the substrate or alignment film, or the substrate is moved while the roll is fixed.

[0152] Furthermore, to obtain a more uniform orientation, an orientation control additive may be included in the low-dielectric substrate composition (1). Examples of such orientation-controlling additives include imidazolines, quaternary ammonium salts, alkylamine oxides, polyamine derivatives, polyoxyethylene-polyoxypropylene condensates, polyethylene glycol and its esters, sodium lauryl sulfate, ammonium lauryl sulfate, lauryl sulfate amines, alkyl-substituted aromatic sulfonates, alkyl phosphates, aliphatic or aromatic sulfonic acid formalin condensates, laurylamidopropyl betaine, laurylaminoacetic acid betaine, polyethylene glycol fatty acid esters, polyoxyethylene alkylamines, perfluoroalkyl sulfonates, perfluoroalkyl carboxylates, perfluoroalkylethylene oxide adducts, perfluoroalkyltrimethylammonium salts, oligomers having a perfluoroalkyl group and a hydrophilic group, oligomers having a perfluoroalkyl group and a lipophilic group, urethanes having a perfluoroalkyl group, and organosilicon compounds having a primary amino group (e.g., alkoxysilane type, linear siloxane type, and three-dimensional condensation type silsesquioxane type organosilicon compounds).

[0153] Examples of the above-mentioned substrates include plastic film substrates such as polyimide, polyamideimide, polyamide, polyetherimide, polyetheretherketone, polyetherketone, polyketone sulfide, polyethersulfone, polysulfone, polyphenylene sulfide, polyphenylene oxide, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyacetal, polycarbonate, polyarylate, acrylic resin, polyvinyl alcohol, polypropylene, cellulose, triacetylcellulose or partially saponified thereof, epoxy resin, phenolic resin, norbornene resin, as well as glass-reinforced resin substrates, glass substrates such as alkali glass, borosilicate glass, and flint glass; metal substrates such as aluminum, iron, and copper; and inorganic substrates such as silicon.

[0154] The above-mentioned film substrate may be a uniaxially oriented film or a biaxially oriented film. The above-mentioned film substrate may be subjected to a surface treatment such as saponification, corona treatment, or plasma treatment in advance. A protective layer that is not affected by the solvent contained in the above-mentioned low-dielectric substrate composition (1) may be formed on these film substrates. Examples of materials that can be used as a protective layer include polyvinyl alcohol. Furthermore, an anchor coat layer may be formed to improve the adhesion between the protective layer and the substrate. Such an anchor coat layer may be made of either inorganic or organic material, as long as it improves the adhesion between the protective layer and the substrate. The low-dielectric substrate composition of the present invention is useful for low-dielectric substrates, low-dielectric sheets, low-dielectric coatings, low-dielectric adhesives, low-dielectric molded products, and the like.

[0155] <Manufacturing method> The following describes in detail a method for producing a low-dielectric substrate composition, and a method for producing a low-dielectric-constant, high-heat-resistant substrate and a low-dielectric-constant, high-heat-resistant insulating layer from the composition.

[0156] The low-dielectric substrate composition of the present invention can be used as a liquid resin raw material in the temperature range in which the liquid crystal phase or isotropic phase is exhibited, or it can be used after being dissolved in a solvent. To prepare the solution, the polymerizable liquid crystal composition, the necessary solvent, filler, and additives are added, and the mixture is stirred and degassed using a stirrer until the composition is uniform. For example, a rotation-orbit mixer is used, and the mixture is stirred at 2000 rpm for 10 minutes, followed by degassing at 2200 rpm for 10 minutes. In addition to a rotation-orbit mixer, dispersion can be carried out using a stirring motor, a swivel, a three-roll mill, a ball mill, a rotation-orbit mill, a planetary mill, a bead mill, a jet mill, etc.

[0157] For the coating method, a wet coating method is preferable to uniformly coat the low-dielectric substrate composition. Among wet coating methods, the spin coating method is preferred for small quantities as it is simple and allows for homogeneous film formation. When productivity is a priority, gravure coating, die coating, bar coating, reverse coating, roll coating, slit coating, dipping, spray coating, kiss coating, reverse kiss coating, air knife coating, curtain coating, inkjet, flexographic printing, screen printing, and rod coating methods are preferred. The wet coating method can be appropriately selected from these methods depending on the required film thickness, viscosity, curing conditions, etc.

[0158] When manufacturing sheets, a casting method is used in which a low-dielectric substrate composition is coated onto a release-treated substrate using the method described above and then peeled off. When manufacturing structures, a mold can be used, and resin molding methods such as press molding, injection molding, and various 3D printer molding methods (extrusion deposition) can be employed. After molding, it is possible to remove the mold and perform final curing, or to perform final curing while still in the mold. Furthermore, when manufacturing composite sheets with glass cloth, it is possible to impregnate the glass cloth with raw materials dissolved in a solvent, dry the solvent, and then cure by applying pressure and heating. [Examples]

[0159] The present invention will be described in more detail by way of examples (including production examples of compounds, compositions, polymers, resins, etc.). The present invention is not limited by these examples.

[0160] [Synthesis Example of Compound (1)] Compound (1) was synthesized according to the procedures shown in Examples such as Synthesis Example 1. Unless otherwise specified, the reaction was carried out under a nitrogen atmosphere. The synthesized compound was identified by methods such as NMR analysis. The device characteristics of Compound (1), compositions, polymers, resins, etc. were measured by the following methods.

[0161] [NMR Analysis] For the measurement, JNM-ECZR manufactured by JEOL Ltd. was used. 1 For the measurement of 1H-NMR, the sample was dissolved in a deuterated solvent such as CDCl3, and the measurement was carried out at room temperature under the conditions of 500 MHz and 16 integration times. Tetramethylsilane was used as an internal standard. 19 For the measurement of 19F-NMR, CFCl3 was used as an internal standard, and the measurement was carried out with 32 integration times. In the description of the nuclear magnetic resonance spectrum, s means singlet, d means doublet, t means triplet, q means quartet, quin means quintet, sex means sextet, m means multiplet, and br means broad.

[0162] [Gas Chromatography Analysis] For the measurement, a GC-2014 type gas chromatograph manufactured by Shimadzu Corporation was used. The column used was a capillary column DB-1 manufactured by Agilent Technologies Inc. (length 30 m or 15 m, inner diameter 0.25 mm, film thickness 0.25 μm). Nitrogen (1 ml / min) was used as the carrier gas. The temperature of the sample vaporization chamber was set to 300 °C, and the temperature of the detector (FID) part was set to 300 °C. The sample was dissolved in an appropriate solvent such as acetone and prepared into a 1 wt% solution, and 1 μl of the obtained solution was injected into the sample vaporization chamber. For the recorder, a GCSolution system manufactured by Shimadzu Corporation, etc. was used.

[0163] [HPLC Analysis] For the measurements, a Prominence (LC-20AD; SPD-20A) manufactured by Shimadzu Corporation was used. The column used was a YMC-Pack ODS-A (length 150 mm, inner diameter 4.6 mm, particle size 5 μm) manufactured by YMC Corporation. The eluent was a mixture of acetonitrile and water as appropriate. As detectors, UV detectors, RI detectors, CORONA detectors, etc. were used as appropriate. When using a UV detector, the detection wavelength was set to 254 nm. The sample was dissolved in acetonitrile to prepare a 0.1 wt% solution, and 1 μL of this solution was introduced into the sample chamber. A Shimadzu C-R7Aplus was used as the recorder.

[0164] <UV-visible spectroscopy> A PharmaSpec UV-1700 manufactured by Shimadzu Corporation was used for the measurements. The detection wavelength was set from 190 nm to 700 nm. The sample was dissolved in acetonitrile to prepare a 0.01 mmol / L solution, which was then placed in a quartz cell (optical path length 1 cm) for measurement.

[0165] <Measurement sample> When measuring the phase structure and transition temperature (transparency point, melting point, polymerization initiation temperature, etc.), the compound itself was used as the sample. (1) Phase structure The sample was placed on a hot plate (Mettler FP-52 hot stage) of a melting point analyzer equipped with a polarizing microscope. The phase state and its changes were observed using a polarizing microscope while the sample was heated at a rate of 3°C / min, and the type of phase was identified.

[0166] (2) Transition temperature (°C) A high-sensitivity differential scanning calorimeter, X-DSC7000, manufactured by SSI Nanotechnology Co., Ltd., was used for the measurements. The sample was heated and cooled at a rate of 3-5°C / min, and the transition temperature was determined by extrapolating the starting point of the endothermic or exothermic peak associated with the phase change of the sample. The melting point and polymerization initiation temperature of the compounds were also measured using this instrument. The temperature at which a compound transitions from solid to liquid crystal phases such as the smectic phase and nematic phase is sometimes abbreviated as the "lower limit temperature of the liquid crystal phase." The temperature at which a compound transitions from the liquid crystal phase to liquid is sometimes abbreviated as the "transparency point."

[0167] Crystals were represented by C. When different types of crystals could be distinguished, they were represented as C1, C2, etc. Smectic phases were represented by S, and nematic phases by N. Within the smectic phase, when smectic A, smectic B, smectic C, or smectic F phases could be distinguished, they were represented as S. A S B S C , or S F This was expressed as follows. Liquid (isotropic) was represented as I. The transition temperature was expressed as, for example, "C 50.0 N 100.0 I". This indicates that the transition temperature from crystal to nematic phase is 50.0°C, and the transition temperature from nematic phase to liquid is 100.0°C.

[0168] [Synthesis Example 1] Compound (S01: Compound (1-1-1a) with R b Both are CH3, n=0, m=0, M and Z 2 Synthesis of compounds in which the bond is a single bond. TIFF0007838266000047.tif2476 4,4'-biphenyldiol (S01-a) is commercially available, for example, from Fujifilm Wako Pure Chemical Corporation.

[0169] TIFF0007838266000048.tif25166 Under a nitrogen atmosphere, a solution of 4,4'-biphenyldiol (S01-a) (10.0 g, 53.70 mmol), N,N'-dicyclohexylcarbodiimide (DCC) (24.4 g, 118.2 mmol), and 4-dimethylaminopyridine (DMAP) (3.94 g, 32.22 mmol) in dichloromethane (100 mL) was cooled to -10°C and stirred. Methacrylic acid (9.71 g, 112.8 mmol) was added dropwise to the resulting solution, and the temperature was gradually raised to room temperature while stirring for 6 hours. Dichloromethane (100 mL) was added to the reaction mixture, filtered, washed three times with water, and the organic layer was concentrated under reduced pressure at 40°C. The resulting residue was isolated by silica gel column chromatography (solvent: toluene / ethyl acetate = 5 / 1 (volume ratio)) and concentrated under reduced pressure at 40°C. The compound was then purified by recrystallization filtration (heptane / ethyl acetate = 3 / 3v) and further dried under reduced pressure to obtain compound (S01) (11.8 g, 36.52 mmol). The transition temperature of compound (S01) was C 150.9 I (°C). The polymerization initiation temperature was 171.9°C.

[0170] Also, compounds 1 The H-NMR signals were as follows: δ(ppm;CDCl3):7.58-7.56(d,4H), 7.19-7.18(d,4H), 6.37(qd,2H), 6.21(qd,2H), 2.07(dd,6H)

[0171] [Synthesis Example 2] Compound (S02: Compound (1-1-3a) with R b Both are CH3, n=0, m=0, M and Z 2 Synthesis of compounds in which the bond is a single bond. TIFF0007838266000049.tif2578 4,4'-Bicyclohexyldiol (S02-a) is commercially available, for example, from Fujifilm Wako Pure Chemical Industries, Ltd. This raw material was purified using common methods such as recrystallization filtration, and the trans isomer was isolated.

[0172] TIFF0007838266000050.tif25166 Compound (S02) (3.60 g, 10.76 mmol) was obtained by using 4,4'-bicyclohexyldiol (S02-a) instead of 4,4'-biphenyldiol (S01-a) in the same manner as described in Synthesis Example 1 of Example 1. The transition temperature of this compound (S01) was C 113.0 I (°C). The polymerization initiation temperature was 118.8°C.

[0173] Also, compounds 1 The H-NMR signals were as follows: δ(ppm;CDCl3):6.06(qd,2H), 5.52-5.51(qd,2H), 4.71-4.65(tt,2H), 2.05-2.00( m, 4H), 1.92-1.91(dd,6H), 1.80-1.77(m,4H), 1.38-1.36(m,4H), 1.15-1.08(m,6H)

[0174] [Synthesis Example 3] Compound (S03: Compound (1-1-1a) with R b Both are CH3, n=0, m=6, M is oxygen, Z 2 Synthesis of compounds in which the bond is a single bond. TIFF0007838266000051.tif22117 4,4'-biphenyldiol (S03-a) is commercially available, for example, from Fujifilm Wako Pure Chemical Corporation. TIFF0007838266000052.tif46166

[0175] (1st stage) Under a nitrogen atmosphere, a solution of 4,4'-biphenyldiol (S01-a) (10.0 g, 53.70 mmol), sodium hydroxide (4.51 g, 112.8 mmol), and 6-bromo-1-hexanol (20.4 g, 112.8 mmol) in N,N-dimethylformamide (100 mL) was heated and stirred at 60°C for 6 hours. The reaction mixture was filtered, the crystals were washed three times with ethanol, and then dried under reduced pressure to obtain compound (S03-b) (14.0 g, 36.22 mmol).

[0176] (Second stage) Compound (S03) (2.90 g, 5.55 mmol) was obtained by using the compound (S03-b) and 4,4'-bicyclohexyldiol (S02-a) obtained in the previous step instead of 4,4'-biphenyldiol (S01-a) in the same manner as described in Synthesis Example 1 of Example 1. The transition temperature of this compound (S03) was C 61.9 I (°C). The polymerization initiation temperature was 163.3°C.

[0177] Also, compounds 1 The H-NMR signals were as follows: δ(ppm;CDCl3):7.45-7.43(d,4H), 6.94-6.91(d,4H), 6.09(qd,2H), 5.54-5.53(qd,2H), 4.17-4.14 (t,4H), 3.99-3.97(t,4H), 1.93(dd,6H), 1.84-1.78(tt,4H), 1.74-1.68(tt,4H), 1.55-1.42(m,8H)

[0178] [Synthesis Example 4] Compound (S04: Compound (1-1-3a), R b Both are CH3, n=0, m=6, M is a single bond, Z 2 Synthesis of compounds in which the bond is a single bond. TIFF0007838266000053.tif22107 4,4'-dicyclohexanone (S04-a) is commercially available, for example, from Tokyo Chemical Industry Co., Ltd.

[0179] TIFF0007838266000054.tif94166

[0180] (1st stage) 1-Bromo-7-methoxyheptane can be easily prepared using general organic synthesis methods. Under a nitrogen atmosphere, 1-bromo-7-methoxyheptane is added to a mixture of magnesium and THF to prepare the Grignard reagent. To the prepared Grignard reagent, a THF solution of 4,4'-bicyclohexanone (S04-a) is added at 30°C and the mixture is stirred for 1 hour. The reaction mixture is slowly added to a (1N)HCl solution and extracted with toluene, and the organic layer is washed three times with water. The resulting organic layer is concentrated under reduced pressure to obtain compound (S04-b).

[0181] (Second stage) Under a nitrogen atmosphere, the toluene solution of compound (S04-b) obtained in the previous step and p-toluenesulfonic acid monohydrate is heated and stirred at 110°C for 1 hour while removing the water generated using a Dane stack trap. Toluene is added to the reaction mixture, and the organic layer is washed three times with water and concentrated under reduced pressure at 40°C. The resulting residue is purified by silica gel column chromatography (solvent: toluene) and recrystallization filtration (heptane / ethanol) to obtain compound (S04-c).

[0182] (3rd stage) The compound (S04-c) obtained in the previous step and palladium / carbon are added to a toluene / iso-propyl alcohol (IPA) mixed solution with H2 at room temperature and stirred under an H2 atmosphere for 6 hours. The reaction mixture is filtered and concentrated under reduced pressure at 40°C. The resulting residue is purified by silica gel column chromatography (solvent: toluene) and recrystallization filtration (solvent: heptane / ethanol) to obtain compound (S04-d).

[0183] (4th stage) To the acetone solution of compound (S04-d) obtained in the previous step, (3N)HCl is added at room temperature and the mixture is stirred for 2 hours. The reaction mixture is extracted with toluene, washed three times with water, and then concentrated under reduced pressure at 40°C. The resulting residue is washed with ethanol and dried under reduced pressure to obtain compound (S04-e).

[0184] (5th paragraph) Compound (S04) is obtained by using compound (S04-e) instead of 4,4'-biphenyldiol (S01-a) in the same manner as described in Synthesis Example 1 of Example 1.

[0185] [Synthesis Example 5] Synthesis of compound (S05): compound (2-3-3-1) TIFF0007838266000055.tif4472 4'-Pentyl-[1,1'-bi(cyclohexane)]-4-ol (S05-a) is commercially available, for example, from Tokyo Chemical Industry Co., Ltd.

[0186] TIFF0007838266000056.tif30160 Compound (S05) (4.83 g, 15.07 mmol) was obtained by using 4'-pentyl-[1,1'-bi(cyclohexane)]-4-ol (S05-a) instead of 4,4'-biphenyldiol (S01-a) in the same manner as described in Synthesis Example 1 of Example 1. Mass spectrometry confirmed that the obtained compound was compound (2-3-3-1). EI-MS: m / z = 321.

[0187] [Example of synthesis of a copolymer of compound (1) and compound (2)] Copolymers of compound (1) and compound (2) were synthesized according to the procedures shown in Synthesis Examples 6-19. Unless otherwise specified, the reactions were carried out under a nitrogen atmosphere. The weight-average molecular weight (Mw) and number-average molecular weight (Mn) of the polymers were measured by the following methods.

[0188] <Gel Permeation Chromatography (GPC) Analysis> The weight-average molecular weight (Mw) and number-average molecular weight (Mn) were determined by gel permeation chromatography (GPC) analysis. The "Nexera GPC System" (Shimadzu Corporation) was used as the measurement instrument. GPC columns included PLgel 5μm MIXED-D (Agilent, Inc.), GPC KF-804 (Showa Denko K.K.), GPC KF-805 (Showa Denko K.K.), and TSKgel α-3000 (Tosoh Corporation). Carriers included tetrahydrofuran, N,N-dimethylformamide, dimethyl sulfoxide, or dimethyl sulfoxide (containing lithium bromide as an additive). Polystyrene or pullulan were used as molecular weight standards. The polydispersity of the polymer (Mw / Mn) was calculated from the Mw and Mn measurement results.

[0189] [Synthesis Example 6] Synthesis of copolymer (SS02-1); compound (S02) and cyclohexyl methacrylate (S06: compound (2-2-2a), R b CH3, n=0, m=0, M is a single bond, Y 3 Copolymerization with a compound in which hydrogen is present. Compound (S02) (1.50 g, 50 parts by weight), cyclohexyl methacrylate (S06; manufactured by Tokyo Chemical Industry Co., Ltd.) (1.50 g, 50 parts by weight), and toluene (70 g) were added to a 300 mL three-necked round-bottom flask equipped with a reflux condenser, and the mixture was stirred at 100°C for 30 minutes. Next, 2,2'-azobis(2,4-dimethylvaleronitrile) (0.90 g, 30 parts by weight) was added to the flask, and the mixture was stirred at 100°C for 2 hours. After the reaction mixture was cooled to room temperature, the organic solvent was removed by distillation under reduced pressure to obtain the crude copolymer product (SS02-1c) (3.56 g). The crude copolymer product was diluted with toluene (20 mL) and added to heptane (350 mL). The resulting precipitate was filtered off and purified by drying under reduced pressure to obtain 0.36 g of copolymer (SS02-1) as a white powder. GPC analysis of the copolymer revealed that the crude copolymer product (SS02-1c) had a Mn content of 264, a Mw content of 1,594, and an Mw / Mn ratio of 6.03, while the purified copolymer (SS02-1) had a Mn content of 2,921, a Mw content of 6,512, and an Mw / Mn ratio of 2.23.

[0190] [Synthesis Example 7] Synthesis of copolymer (SS02-2); Copolymerization of compound (S02) and cyclohexyl methacrylate (S06) 2 Compound (S02) (1.95 g, 65 parts by weight), cyclohexyl methacrylate (S06; manufactured by Tokyo Chemical Industry Co., Ltd.) (1.05 g, 35 parts by weight), and toluene (70 g) were added to a 300 mL three-necked round-bottom flask equipped with a reflux condenser, and the mixture was stirred at 100°C for 30 minutes. Next, 2,2'-azobis(2,4-dimethylvaleronitrile) (0.90 g, 30 parts by weight) was added to the flask, and the mixture was stirred at 100°C for 2 hours. After the reaction mixture was cooled to room temperature, the organic solvent was removed by distillation under reduced pressure to obtain the crude copolymer product (SS02-2c) (3.61 g). The crude copolymer product was diluted with toluene (20 mL) and added to heptane (350 mL). The resulting precipitate was filtered off and purified by drying under reduced pressure to obtain 0.54 g of copolymer (SS02-2) as a white powder. GPC analysis of the copolymer revealed that the crude copolymer product (SS02-2c) had a Mn of 315, an Mw of 4,010, and an Mw / Mn ratio of 12.75, while the purified copolymer (SS02-2) had a Mn of 4,044, an Mw of 7,724, and an Mw / Mn ratio of 1.91.

[0191] [Synthesis Example 8] Synthesis of copolymer (SS02-3); Copolymerization of compound (S02) and cyclohexyl methacrylate (S06) 3 Compound (S02) (2.25 g, 75 parts by weight), cyclohexyl methacrylate (S06; manufactured by Tokyo Chemical Industry Co., Ltd.) (0.75 g, 25 parts by weight), and toluene (70 g) were added to a 300 mL three-necked round-bottom flask equipped with a reflux tubing, and the mixture was stirred at 100°C for 30 minutes. Next, 2,2'-azobis(2,4-dimethylvaleronitrile) (0.90 g, 30 parts by weight) was added to the flask, and the mixture was stirred at 100°C for 2 hours. After the reaction mixture was cooled to room temperature, the organic solvent was removed by distillation under reduced pressure to obtain the crude copolymer product (SS02-3c) (3.48 g). The crude copolymer product was diluted with toluene (20 mL), added to heptane (350 mL), and the resulting precipitate was filtered off and purified by drying under reduced pressure to obtain 0.93 g of copolymer (SS02-3) as a white powder. GPC analysis of the copolymer revealed that the crude copolymer product (SS02-3c) had a Mn of 354, Mw of 5,060, and an Mw / Mn ratio of 14.26, while the purified copolymer (SS02-3) had a Mn of 2,983, Mw of 10,416, and an Mw / Mn ratio of 3.49.

[0192] [Synthesis Example 9] Synthesis of copolymer (SS02-4); Copolymerization of compound (S02) and cyclohexyl methacrylate (S06) 4 Compound (S02) (2.55 g, 85 parts by weight), cyclohexyl methacrylate (S06; manufactured by Tokyo Chemical Industry Co., Ltd.) (0.45 g, 15 parts by weight), and toluene (70 g) were added to a 300 mL three-necked round-bottom flask equipped with a reflux condenser, and the mixture was stirred at 100°C for 30 minutes. Next, 2,2'-azobis(2,4-dimethylvaleronitrile) (0.90 g, 30 parts by weight) was added to the flask, and the mixture was stirred at 100°C for 2 hours. After the reaction mixture was cooled to room temperature, the organic solvent was removed by distillation under reduced pressure to obtain the crude copolymer product (SS02-4c) (3.65 g). The crude copolymer product was diluted with toluene (20 mL) and added to heptane (350 mL). The resulting precipitate was filtered off and purified by drying under reduced pressure to obtain 1.05 g of copolymer (SS02-4) as a white powder. GPC analysis of the copolymer revealed that the crude copolymer product (SS02-4c) had a Mn content of 369, Mw content of 6,477, and an Mw / Mn ratio of 17.56, while the purified copolymer (SS02-4) had a Mn content of 4,461, Mw content of 13,948, and an Mw / Mn ratio of 3.13.

[0193] [Synthesis Example 10] Synthesis of copolymer (SS02-5); Copolymerization of compound (S02) and cyclohexyl methacrylate (S06) 5 Compound (S02) (1.50 g, 50 parts by weight), cyclohexyl methacrylate (S06; manufactured by Tokyo Chemical Industry Co., Ltd.) (1.50 g, 50 parts by weight), and toluene (70 g) were added to a 300 mL three-necked round-bottom flask equipped with a reflux tubing, and the mixture was heated under reflux for 30 minutes. Next, 2,2'-azobisisobutyronitrile (0.90 g, 30 parts by weight) was added to the flask, and the mixture was heated under reflux for 2 hours. After the reaction mixture was cooled to room temperature, the organic solvent was removed by distillation under reduced pressure to obtain the crude copolymer product (SS02-5c) (3.70 g). The crude copolymer product was diluted with toluene (20 mL) and added to heptane (350 mL). The resulting precipitate was filtered off and purified by drying under reduced pressure to obtain 1.26 g of copolymer (SS02-5) as a white powder. GPC analysis of the copolymer revealed that the crude copolymer product (SS02-5c) had a Mn of 400, Mw of 4,551, and an Mw / Mn ratio of 11.38, while the purified copolymer (SS02-5) had a Mn of 2,476, Mw of 8,861, and an Mw / Mn ratio of 3.58.

[0194] [Synthesis Example 11] Synthesis of copolymer (SS02-6); Copolymerization of compound (S02) and cyclohexyl methacrylate (S06) 6 Compound (S02) (1.95 g, 65 parts by weight), cyclohexyl methacrylate (S06; manufactured by Tokyo Chemical Industry Co., Ltd.) (1.05 g, 35 parts by weight), and toluene (70 g) were added to a 300 mL three-necked round-bottom flask equipped with a reflux tubing, and the mixture was heated under reflux for 30 minutes. Next, 2,2'-azobisisobutyronitrile (0.90 g, 30 parts by weight) was added to the flask, and the mixture was heated under reflux for 2 hours. After the reaction mixture was cooled to room temperature, the organic solvent was removed by distillation under reduced pressure to obtain the crude copolymer product (SS02-6c) (3.47 g). The crude copolymer product was diluted with toluene (20 mL) and added to heptane (350 mL). The resulting precipitate was filtered off and purified by drying under reduced pressure to obtain 1.29 g of copolymer (SS02-6) as a white powder. GPC analysis of the copolymer revealed that the crude copolymer product (SS02-6c) had a Mn content of 456, a Mw content of 7,533, and an Mw / Mn ratio of 16.52, while the purified copolymer (SS02-6) had a Mn content of 2,405, a Mw content of 12,063, and an Mw / Mn ratio of 5.01.

[0195] [Synthesis Example 12] Synthesis of copolymer (SS02-7); Copolymerization of compound (S02) and cyclohexyl methacrylate (S06) 7 Compound (S02) (2.25 g, 75 parts by weight), cyclohexyl methacrylate (S06; manufactured by Tokyo Chemical Industry Co., Ltd.) (0.75 g, 25 parts by weight), and toluene (70 g) were added to a 300 mL three-necked round-bottom flask equipped with a reflux tubing, and the mixture was heated under reflux for 30 minutes. Next, 2,2'-azobisisobutyronitrile (0.90 g, 30 parts by weight) was added to the flask, and the mixture was heated under reflux for 2 hours. After the reaction mixture was cooled to room temperature, the organic solvent was removed by distillation under reduced pressure to obtain the crude copolymer product (SS02-7c) (3.54 g). The crude copolymer product was diluted with toluene (20 mL) and added to heptane (350 mL). The resulting precipitate was filtered off and purified by drying under reduced pressure to obtain 1.59 g of copolymer (SS02-7) as a white powder. GPC analysis of the copolymer revealed that the crude copolymer product (SS02-7c) had a Mn content of 579, a Mw content of 12,863, and an Mw / Mn ratio of 22.21, while the purified copolymer (SS02-7) had a Mn content of 4,044, a Mw content of 20,060, and an Mw / Mn ratio of 4.96.

[0196] [Synthesis Example 13] Synthesis of copolymer (SS02-8); Copolymerization of compound (S02) and cyclohexyl methacrylate (S06) 8 Compound (S02) (1.50 g, 50 parts by weight), cyclohexyl methacrylate (S06; manufactured by Tokyo Chemical Industry Co., Ltd.) (1.50 g, 50 parts by weight), and toluene (70 g) were added to a 300 mL three-necked round-bottom flask equipped with a reflux tubing, and the mixture was heated under reflux at 100 °C for 30 minutes. Next, 2,2'-azobisisobutyronitrile (1.50 g, 50 parts by weight) was added to the flask, and the mixture was heated under reflux for 2 hours. After the reaction mixture was cooled to room temperature, the organic solvent was removed by distillation under reduced pressure to obtain the crude copolymer product (SS02-8c) (4.29 g). The crude copolymer product was diluted with toluene (20 mL) and added to heptane (350 mL). The resulting precipitate was filtered off and purified by drying under reduced pressure to obtain 1.11 g of copolymer (SS02-8) as a white powder. GPC analysis of the copolymer revealed that the crude copolymer product (SS02-8c) had a Mn of 361, Mw of 2,502, and an Mw / Mn ratio of 6.93, while the purified copolymer (SS02-8) had a Mn of 2,608, Mw of 4,801, and an Mw / Mn ratio of 2.32.

[0197] [Synthesis Example 14] Synthesis of copolymer (SS02-9); Copolymerization of compound (S02) and cyclohexyl methacrylate (S06) 9 Compound (S02) (1.95 g, 65 parts by weight), cyclohexyl methacrylate (S06; manufactured by Tokyo Chemical Industry Co., Ltd.) (1.05 g, 35 parts by weight), and toluene (70 g) were added to a 300 mL three-necked round-bottom flask equipped with a reflux tubing, and the mixture was heated under reflux for 30 minutes. Next, 2,2'-azobisisobutyronitrile (1.50 g, 50 parts by weight) was added to the flask, and the mixture was heated under reflux for 2 hours. After the reaction mixture was cooled to room temperature, the organic solvent was removed by distillation under reduced pressure to obtain the crude copolymer product (SS02-9c) (4.30 g). The crude copolymer product was diluted with toluene (20 mL) and added to heptane (350 mL). The resulting precipitate was filtered off and purified by drying under reduced pressure to obtain 1.14 g of copolymer (SS02-9) as a white powder. GPC analysis of the copolymer revealed that the crude copolymer product (SS02-9c) had a Mn of 477, Mw of 4,054, and an Mw / Mn ratio of 8.50, while the purified copolymer (SS02-9) had a Mn of 1,840, Mw of 6,515, and an Mw / Mn ratio of 3.54.

[0198] [Synthesis Example 15] Synthesis of copolymer (SS02-10); copolymerization of compound (S02) and cyclohexyl methacrylate (S06) 10 Compound (S02) (2.25 g, 75 parts by weight), cyclohexyl methacrylate (S06; manufactured by Tokyo Chemical Industry Co., Ltd.) (0.75 g, 25 parts by weight), and toluene (70 g) were added to a 300 mL three-necked round-bottom flask equipped with a reflux tubing, and the mixture was heated under reflux for 30 minutes. Next, 2,2'-azobisisobutyronitrile (1.50 g, 50 parts by weight) was added to the flask, and the mixture was heated under reflux for 2 hours. After the reaction mixture was cooled to room temperature, the organic solvent was removed by distillation under reduced pressure to obtain the crude copolymer product (SS02-10c) (4.19 g). The crude copolymer product was diluted with toluene (20 mL), added to heptane (350 mL), and the resulting precipitate was filtered off and purified by drying under reduced pressure to obtain 1.80 g of copolymer (SS02-10) as a white powder. GPC analysis of the copolymer revealed that the crude copolymer product (SS02-10c) had a Mn content of 561, a Mw content of 6,858, and an Mw / Mn ratio of 12.23, while the purified copolymer (SS02-10) had a Mn content of 2,156, a Mw content of 10,297, and an Mw / Mn ratio of 4.78.

[0199] [Synthesis Example 16] Synthesis of copolymer (SS02-11); Copolymerization of compound (S02) and compound (S05; 2-3-3-1) 1 Compound (S02) (2.25 g, 75 parts by weight), compound (S05; 2-3-3-1) (0.75 g, 25 parts by weight), and toluene (70 g) were added to a 300 mL three-necked round-bottom flask equipped with a reflux tubing, and the mixture was stirred at 100°C for 30 minutes. Next, 2,2'-azobis(2,4-dimethylvaleronitrile) (0.90 g, 30 parts by weight) was added to the flask, and the mixture was stirred at 100°C for 2 hours. After the reaction mixture was cooled to room temperature, the organic solvent was removed by distillation under reduced pressure to obtain the crude copolymer product (SS02-11c) (3.63 g). The crude copolymer product was diluted with toluene (20 mL), added to heptane (350 mL), and the resulting precipitate was filtered off and purified by drying under reduced pressure to obtain 0.96 g of copolymer (SS02-11) as a white powder. GPC analysis of the copolymer revealed that the crude copolymer product (SS02-11c) had a Mn of 450, Mw of 4,389, and an Mw / Mn ratio of 9.76, while the purified copolymer (SS02-11) had a Mn of 5,197, Mw of 11,875, and an Mw / Mn ratio of 2.29.

[0200] [Synthesis Example 17] Synthesis of copolymer (SS02-12); Copolymerization of compound (S02) and compound (S05; 2-3-3-1) 2 Compound (S02) (1.50 g, 50 parts by weight), compound (S05; 2-3-3-1) (1.50 g, 50 parts by weight), and toluene (70 g) were added to a 300 mL three-necked round-bottom flask equipped with a reflux tubing, and the mixture was heated under reflux for 30 minutes. Next, 2,2'-azobisisobutyronitrile (1.50 g, 50 parts by weight) was added to the flask, and the mixture was heated under reflux for 2 hours. After the reaction mixture was cooled to room temperature, the organic solvent was removed by distillation under reduced pressure to obtain the crude copolymer product (SS02-12c) (4.37 g). The crude copolymer product was diluted with toluene (20 mL) and added to heptane (350 mL). The resulting precipitate was filtered off and purified by drying under reduced pressure to obtain 0.87 g of copolymer (SS02-12) as a white powder. GPC analysis of the copolymer revealed that the crude copolymer product (SS02-12c) had a Mn of 588, Mw of 2,562, and an Mw / Mn ratio of 4.36, while the purified copolymer (SS02-12) had a Mn of 2,525, Mw of 5,589, and an Mw / Mn ratio of 1.54.

[0201] [Synthesis Example 18] Synthesis of copolymer (SS02-13); Copolymerization of compound (S02) and compound (S05; 2-3-3-1) 3 Compound (S02) (2.25 g, 75 parts by weight), compound (S05; 2-3-3-1) (0.75 g, 25 parts by weight), and toluene (70 g) were added to a 300 mL three-necked round-bottom flask equipped with a reflux tubing, and the mixture was heated under reflux for 30 minutes. Next, 2,2'-azobisisobutyronitrile (1.50 g, 50 parts by weight) was added to the flask, and the mixture was heated under reflux for 2 hours. After the reaction mixture was cooled to room temperature, the organic solvent was removed by distillation under reduced pressure to obtain the crude copolymer product (SS02-13c) (4.08 g). The crude copolymer product was diluted with toluene (20 mL), added to heptane (350 mL), and the resulting precipitate was filtered off and purified by drying under reduced pressure to obtain 1.98 g of copolymer (SS02-13) as a white powder. GPC analysis of the copolymer revealed that the crude copolymer product (SS02-13c) had a Mn content of 708, a Mw content of 7,864, and an Mw / Mn ratio of 11.11, while the purified copolymer (SS02-13) had a Mn content of 2,193, a Mw content of 11,406, and an Mw / Mn ratio of 5.20.

[0202] [Synthesis Example 19] Synthesis of copolymer (SS02-14); Copolymerization of compound (S01) and cyclohexyl methacrylate (S06) 1 Compound (S01) (1.50 g, 50 parts by weight), cyclohexyl methacrylate (S06; manufactured by Tokyo Chemical Industry Co., Ltd.) (1.50 g, 50 parts by weight), and toluene (70 g) were added to a 300 mL three-necked round-bottom flask equipped with a reflux tubing, and the mixture was heated under reflux for 30 minutes. Next, 2,2'-azobisisobutyronitrile (1.50 g, 50 parts by weight) was added to the flask, and the mixture was heated under reflux for 2 hours. After the reaction mixture was cooled to room temperature, the organic solvent was removed by distillation under reduced pressure to obtain the crude copolymer product (SS02-14c) (4.20 g). GPC analysis of the copolymer revealed that the crude copolymer product (SS02-14c) had a Mn of 186, a Mw of 2,281, and an Mw / Mn ratio of 12.23.

[0203] [Comparative examples of polymer synthesis of compound (1)] Polymers of compound (1) were synthesized according to the procedures shown in Comparative Synthesis Examples 1-3. Unless otherwise specified, the reactions were carried out under a nitrogen atmosphere. The weight-average molecular weight (Mw) and number-average molecular weight (Mn) of the polymers were measured using the same method as in the synthesis examples of copolymers of compound (1) and compound (2).

[0204] [Comparative Example 1 of Synthesis] Synthesis of polymer (S02-1); polymerization of compound (S02) 1 Compound (S02) (3.00 g, 100 parts by weight) and toluene (70 g) were added to a 300 mL three-necked round-bottom flask equipped with a reflux condenser, and the mixture was stirred at 100°C for 30 minutes. Next, 2,2'-azobis(2,4-dimethylvaleronitrile) (0.90 g, 30 parts by weight) was added to the flask, and the mixture was stirred at 100°C for 2 hours. After the reaction mixture was cooled to room temperature, the organic solvent was removed by distillation under reduced pressure to obtain the crude polymer product (S02-1c) (3.42 g). The crude polymer product was diluted with toluene (20 mL) and added to heptane (350 mL). The resulting precipitate was filtered off and purified by drying under reduced pressure to obtain 0.96 g of polymer (S02-1) as a white powder. GPC analysis of the polymer revealed that the crude polymer product (S02-1c) had a Mn of 447, Mw of 22,467, and an Mw / Mn ratio of 50.24, while the purified copolymer (S02-1) had a Mn of 4,317, Mw of 27,784, and an Mw / Mn ratio of 6.49.

[0205] [Comparative Example 2 of Synthesis] Synthesis of polymer (S02-2); polymerization of compound (S02) 2 Compound (S02) (3.00 g, 100 parts by weight) and toluene (70 g) were added to a 300 mL three-necked round-bottom flask equipped with a reflux tubing, and the mixture was heated under reflux for 30 minutes. Then, 2,2'-azobisisobutyronitrile (1.50 g, 50 parts by weight) was added to the flask, and the mixture was heated under reflux for 2 hours, at which point the reaction solution gelled.

[0206] [Comparative Example 3 of Synthesis] Synthesis of polymer (S01-1); polymerization of compound (S01) 1 Compound (S01) (3.00 g, 100 parts by weight) and toluene (70 g) were added to a 300 mL three-necked round-bottom flask equipped with a reflux tubing, and the mixture was heated under reflux for 30 minutes. Then, 2,2'-azobisisobutyronitrile (1.50 g, 50 parts by weight) was added to the flask, and the mixture was heated under reflux for 2 hours, at which point the reaction solution gelled.

[0207] Comparisons of synthesis examples 6-9 and 16 with comparative example 1, and comparisons of synthesis examples 10-15 and 17-19 with comparative examples 2 and 3 demonstrate that the technology of the present invention makes it possible to synthesize polymers with appropriate molecular weights as prepolymers in high yield.

[0208] [Examples 1-16; Evaluation of physical properties of copolymers of compound (1) and compound (2)] The physical properties of polymers (SS02-1), (SS02-2), (SS02-3), (SS02-4), (SS02-5), (SS02-5c), (SS02-6), (SS02-7), (SS02-8), (SS02-9), (SS02-9c), (SS02-10), (SS02-11), (SS02-12), and (SS02-13c) were evaluated according to the following procedure.

[0209] <Exudation test from glass cloth> 0.2 g of the synthesized polymer was dissolved by gradually adding 1-methyl-2-pyrrolidone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., 97%) (NMP), and this solution was soaked into a 3 cm square piece of glass cloth (Nitto Boseki Co., Ltd. NE Glass 2116). This sample was dried on a hot plate set to 120°C. After measuring the weight after drying, it was placed again on a hot plate heated to 160°C and heat-treated for 1 hour. The weight change (%) was calculated as (weight after heat treatment) - (weight before heat treatment) × 100. The amount of weight loss in the weight change is the amount of leaching, and a smaller amount of leaching indicates a superior resin for substrates.

[0210] <Preparation of samples for relative permittivity measurement> A polymer solution, prepared in the same manner as in the exudation test, was coated onto a polyimide film (Panac Co., Ltd., Kapton 200H) to a thickness of approximately 60 μm, and two layers of sample were obtained in the same manner. From the film-forming samples, 50 mm x 50 mm samples for dielectric constant evaluation were cut out and evaluated.

[0211] <Method for evaluating relative permittivity> Samples cut into 50mm squares were measured using a cavity resonator (TE mode 10GHz and 28GHz) manufactured by AET Corporation, connected to a vector network analyzer (MS46522B-043, manufactured by Anritsu Corporation). The resonant frequency shift and attenuation were measured, and the relative permittivity was calculated using AET's software. Since the measured values ​​represent a two-layer structure of polyimide film and cured film, the dielectric constant of only the cured film was calculated using the values ​​measured for the polyimide film alone, using AET's calculation sheet. To minimize the influence of moisture content in the samples when comparing data, the samples were formed the day before measurement, and the relative permittivity evaluation was started after the samples were allowed to stand for at least 60 minutes in a laboratory at a temperature of 20°C and relative humidity of 48%.

[0212] [Comparative Example 1] Evaluation samples were prepared using the compound (S02; the compound used as a raw material for the polymer) in the same manner as in Examples 1 to 16, and the weight change before and after heat treatment was determined. We also attempted to prepare samples for dielectric constant preparation, but the film was brittle and warped during curing, so we were unable to obtain a 5 cm square sample that could be placed in the measuring instrument without cracks.

[0213] [Comparative Example 2] 6.92 g of bisphenol F type epoxy (manufactured by Mitsubishi Chemical Corporation, 807), 4,4'-methylenedianiline (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., 98%), and 2.0 g of NMP were mixed until a clear liquid was obtained. Comparative samples were then prepared using the same method as in Examples 1-16, and the weight change was evaluated in the same manner as in Examples 1-16. The dielectric constant was also measured by preparing a cured film in the form of a polyimide film.

[0214] Table 1 shows the weight change and dielectric constant before and after heat treatment obtained in Examples 1-16 and Comparative Examples 1 and 2.

[0215] TIFF0007838266000057.tif170170

[0216] Table 1 shows that when the copolymer of the present invention is used as a prepolymer, there is less seepage from the glass cloth compared to when compound (1) used as a raw material for the copolymer, indicating improved substrate moldability. Furthermore, since the polymer of the present invention has a lower dielectric constant compared to general-purpose epoxy resins, it is suitable as a raw material for low-dielectric substrates for high-frequency equipment such as high-speed communication devices and high-speed data servers. [Industrial applicability]

[0217] The low-dielectric substrate composition of the present invention can be suitably used in next-generation communication equipment and radar, which are increasingly operating at high frequencies.

Claims

1. A composition for low dielectric substrates containing a copolymer of a liquid crystal compound having a polymerizable group at its terminal end, represented by formula (1), and a compound having a polymerizable group, represented by formula (2). R １ａ -Z １ -A １ -Z ２ -A ２ -(Z ３ -A ３ ) ｍ１ -Z ４ -R １ｂ (1) R １ｃ -(Z ５ -A ４ ) ｍ２ -Y １ (2) In formula (1), A １ A ２ , and A ３ It is 1,4-cyclohexylene; Z １ Z ２ Z ３ , and Z ４ These are independently single-bonded or C1-C22 alkylenes, and in this alkylene, at least one -CH ２ The dash can be replaced with -O-; m1 is 0, 1, or 2. In the formula, Z ３ If there are multiple items, they may be the same or different. R １ａ and R １ｂ These are independently selected groups from polymerizable groups represented by formulas (PG-1) to (PG-4), In formulas (PG-1) to (PG-4), R ｂ is hydrogen or an alkyl group having 1 to 5 carbon atoms, and the formula contains R ｂ If there are multiple of them, they may be the same or different; In formula (2), A ４ It is a cycloalkylene; Z ５ This is a single bond or an alkylene having 1 to 22 carbon atoms, and in this alkylene, at least one -CH ２ The dash can be replaced with -O-; Y １ is hydrogen or an alkyl group having 1 to 22 carbon atoms; m² is an integer between 0 and 4. In the formula, Z ５ Or A ４ If there are multiple items, they may be the same or different. R １ｃ This is a group selected from polymerizable groups represented by formulas (PG-1) to (PG-4), In formulas (PG-1) to (PG-4), R ｂ is hydrogen or an alkyl group having 1 to 5 carbon atoms, and the formula contains R ｂ If there are multiple items, they may be identical or different.

2. The low-dielectric substrate composition according to claim 1, wherein the liquid crystal compound having a polymerizable group at its terminus, represented by formula (1), is at least one selected from the group consisting of compounds represented by formulas (1-1), (1-2), and (1-3). R １ａ -Z １ -A １ -Z ２ -A ２ -Z ４ -R １ｂ (1-1) R １ａ -Z １ -A １ -Z ２ -A ２ -Z ３ -A ３ -Z ４ -R １ｂ (1-2) R １ａ -Z １ -A １ -Z ２ -A ２ -Z ３ -A ３ -Z ３ -A ３ -Z ４ -R １ｂ (1-3) In formulas (1-1) to (1-3), A １ A ２ , and A ３ It is 1,4-cyclohexylene, Z １ Z ２ Z ３ , and Z ４ These are independently single bonds, -(CH ２ ) ａ -, -O(CH ２ ) ａ -, - (CH ２ ) ａ O-, or -O(CH ２ ) ａ O-, where a is an integer from 1 to 20. In the formula, Z ３ If there are multiple items, they may be the same or different. R １a and R １ｂ This is a polymerizable group represented by formula (PG-1), In formula (PG-1), R ｂ is hydrogen or an alkyl group having 1 to 5 carbon atoms, and the formula contains R ｂ If there are multiple items, they may be identical or different.

3. The low-dielectric substrate composition according to claim 1 or 2, wherein the liquid crystal compound having a polymerizable group at its terminal, represented by formula (1), is at least one selected from the group consisting of formula (1-1-3). In formula (1-1-3), Z １ 、Z ２ 、and Z ４ are independently a single bond, -(CH ２ ), ａ -, -O(CH ２ ), ａ -, -(CH ２ ), ａ O -, or -O(CH ２ ), ａ O -, where a is an integer from 1 to 20, n is an integer between 0 and 4. R １ａ and R １ｂ are polymerizable groups represented by formula (PG-1), In formula (PG-1), R ｂ is hydrogen or an alkyl group having 1 to 5 carbon atoms, and the formula contains R ｂ If there are multiple items, they may be identical or different.

4. The low-dielectric substrate composition according to claim 1 or 2, wherein the liquid crystal compound having a polymerizable group at its terminal, represented by formula (1), is at least one selected from the group consisting of compounds represented by formula (1-2-6). In formula (1-2-6), Z １ Z ２ Z ３ and Z ４ These are independently single bonds, -(CH ２ ) ａ -, -O(CH ２ ) ａ -, - (CH ２ ) ａ O-, or -O(CH ２ ) ａ O-, where a is an integer from 1 to 20. n is an integer between 0 and 4. R １ａ and R １ｂ This is a polymerizable group represented by formula (PG-1), In formula (PG-1), R ｂ is hydrogen or an alkyl group having 1 to 5 carbon atoms, and the formula contains R ｂ If there are multiple items, they may be identical or different.

5. The low-dielectric substrate composition according to claim 1 or 2, wherein the liquid crystal compound having a polymerizable group at its terminal, represented by formula (1), is at least one selected from the group consisting of compounds represented by formula (1-3-9). In formula (1-3-9), Z １ Z ２ Z ３ and Z ４ These are independently single bonds, -(CH ２ ) ａ -, -O(CH ２ ) ａ -, - (CH ２ ) ａ O-, or -O(CH ２ ) ａ O-, where a is an integer from 1 to 20. Z in the formula ３ They may be the same or different. n is an integer between 0 and 4. R １ａ and R １ｂ This is independently a polymerizable group represented by formula (PG-1), In formula (PG-1), R ｂ is hydrogen or an alkyl group having 1 to 5 carbon atoms, and the formula contains R ｂ If there are multiple items, they may be identical or different.

6. The low-dielectric substrate composition according to claim 1 or 2, wherein the liquid crystal compound having a polymerizable group at its terminal, represented by formula (1), is at least one selected from the group consisting of compounds represented by formulas (1-1-3a) and (1-2-6a). In equations (1-1-3a) and (1-2-6a), R ｂ is hydrogen, or an alkyl group having 1 to 5 carbon atoms. Z ２ and Z ３ These are independently single bonds, -(CH ２ ) ａ -, -O(CH ２ ) ａ -, - (CH ２ ) ａ O-, or -O(CH ２ ) ａ O-, where a is an integer from 1 to 20. m is an integer between 0 and 20. M is a single bond or oxygen, n is an integer between 0 and 4. In the formula, R ｂ If there are multiple instances of , m, or M, they may be the same or different.

7. R ｂ However, it is hydrogen or methyl, Z ２ and Z ３ These are independent, single bonds, -(CH ２ ) ａ -, -O(CH ２ ) ａ -, - (CH ２ ) ａ O-, or -O(CH ２ ) ａ The low dielectric composition for substrates according to claim 5 or 6, wherein the ratio is O-, where a is an integer from 1 to 12 and m is an integer from 0 to 12.

8. The low-dielectric substrate composition according to any one of claims 1 to 7, wherein the compound having a polymerizable group represented by formula (2) is at least one selected from the group consisting of compounds represented by formula (2-1), formula (2-2), formula (2-3), and formula (2-4). R １ｃ -Y ２ (2-1) R １ｃ -Z ５ -A ４ -Y ３ (2-2) R １ｃ -Z ５ -A ４ -Z ５ -A ４ -Y ３ (2-3) R １ｃ -Z ５ -A ４ -Z ５ -A ４ -Z ５ -A ４ -Y ３ (2-4) In formulas (2-1) to (2-4), A ４ It is 1,4-cyclohexylene, Z ５ These are independently single bonds, -(CH ２ ) ａ -, -O(CH ２ ) ａ -, - (CH ２ ) ａ O-, or -O(CH ２ ) ａ O-, where a is an integer from 1 to 20. Y ２ These are alkyl groups having 1 to 20 carbon atoms. Y ３ is hydrogen or an alkyl group having 1 to 20 carbon atoms. In the formula, Z ５ If there are multiple items, they may be the same or different. R １ｃ This is a polymerizable group represented by formula (PG-1), In formula (PG-1), R ｂ is hydrogen or an alkyl group having 1 to 5 carbon atoms, and the formula contains R ｂ If there are multiple items, they may be identical or different.

9. The low dielectric substrate composition according to any one of claims 1 to 8, wherein the compound having a polymerizable group represented by formula (2) is at least one selected from the group consisting of compounds represented by (2-1-1), formula (2-2-2), formula (2-3-3), and formula (2-4-6). In equations (2-1-1), (2-2-2), (2-3-3), and (2-4-6), Z ５ is a single bond, -(CH ２ ) ａ -, -O(CH ２ ) ａ -, - (CH ２ ) ａ O-, or -O(CH ２ ) ａ O-, where a is an integer from 1 to 20. Y ２ These are alkyl groups having 1 to 12 carbon atoms. Y ３ is hydrogen or an alkyl group having 1 to 12 carbon atoms. n is an integer between 0 and 4. In the formula, Z ５ If there are multiple items, they may be the same or different. R １ｃ This is a polymerizable group represented by formula (PG-1), In formula (PG-1), R ｂ is hydrogen or an alkyl group having 1 to 5 carbon atoms, and the formula contains R ｂ If there are multiple items, they may be identical or different.

10. The low dielectric substrate composition according to any one of claims 1 to 8, wherein the compound having a polymerizable group represented by formula (2) is at least one selected from the group consisting of compounds represented by formula (2-1-1a), formula (2-2-2a), formula (2-3-3a), and formula (2-4-6a). In equations (2-1-1a), (2-2-2a), (2-3-3a), and (2-4-6a), R ｂ is hydrogen or an alkyl group having 1 to 5 carbon atoms. Z ５ is a single bond, -(CH ２ ) ａ -, -O(CH ２ ) ａ -, - (CH ２ ) ａ O-, or -O(CH ２ ) ａ O-, where a is an integer from 1 to 20. M is a single bond or oxygen, Y ２ These are alkyl groups having 1 to 8 carbon atoms. Y ３ is hydrogen or an alkyl group having 1 to 8 carbon atoms. In the formula, Z ５ However, if there are multiple items, they may be identical or different.

11. A low-dielectric substrate composition according to any one of claims 1 to 10, comprising the copolymer according to claim 1, wherein the weight-average molecular weight is 300,000 or less.

12. A low-dielectric substrate composition according to any one of claims 1 to 10, comprising the copolymer according to claim 1, wherein the weight-average molecular weight is 50,000 or less.

13. The low-dielectric substrate composition according to claim 12, further comprising a non-polymerizable liquid crystal compound.

14. The low-dielectric substrate composition according to claim 12 or 13, further comprising an inorganic filler.

15. The low-dielectric substrate composition according to claim 14, wherein the inorganic filler is at least one selected from the group consisting of spherical silica, pulverized silica, hollow silica, fumed silica, aluminum nitride, boron nitride, magnesium oxide, aluminum oxide, zinc oxide, titanium oxide, aluminum oxide, magnesium hydroxide, and aluminum hydroxide.

16. A cured product obtained by curing the low-dielectric substrate composition according to any one of claims 12 to 15.

17. The cured product according to claim 16, wherein the relative permittivity at 10 GHz is less than 3.

0.

18. The cured product according to claim 16 or 17, wherein the thermal conductivity is 1 W / m·K or more.

19. An insulating film using the cured product according to any one of claims 16 to 18.

20. A film using the cured product described in any one of claims 16 to 18.

21. Sheet using the cured product described in any one of claims 16 to 18

22. An electronic device using a cured product according to any one of claims 16 to 18, an insulating film according to claim 19, a film according to claim 20, or a sheet according to claim 21.

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