Composition, liquid crystal polymer sheet, low dielectric substrate material, and printed circuit substrate

Abstract

The present application relates to a composition characterized by containing a liquid crystal polymer comprising a structural unit represented by formula (1), a structural unit represented by formula (2), and a structural unit represented by formula (3), the liquid crystal polymer has at least one of a polymerizable unsaturated group, a structure after a reaction of the polymerizable unsaturated group, and an imide bond. # imgabs0 # (In formula (1), Ar1 represents a specific group. In formula (2), Ar2 represents a specific group. In formula (3), Ar3 represents a specific group, X represents-NH-or-O-, and Y represents-NH-or-O-. And * represents a binding bond).

Description

Technical Field

[0001] The invention relates to a composition, a liquid crystal polymer sheet, a low dielectric substrate material and a wiring circuit substrate. Background Art

[0002] Liquid crystal polymers have low moisture absorption and low dielectric constant. Therefore, the use of liquid crystal polymer sheets using liquid crystal polymers, for example, as insulating layers of FPCs (Flexible printed circuits) is advancing.

[0003] As a liquid crystal polymer, for example, a liquid crystal polyester having a specific structural unit is known (for example, see Patent Document 1). The liquid crystal polyester described in Patent Document 1, for example, has repeating units represented by the following general formulas (X1), (X2) and (X3), and has 30 to 45 mol% of the repeating unit represented by the following general formula (X1), 27.5 to 35 mol% of the repeating unit represented by the following general formula (X2), and 27.5 to 35 mol% of the repeating unit represented by the following general formula (X3), relative to the total amount of all repeating units constituting the liquid crystal polyester.

[0004] (X1)-O-Ar1-CO-

[0005] (X2)-CO-Ar2-CO-

[0006] (X3)-X-Ar3-Y-

[0007] (In the formula, Ar1 is phenylene, naphthylene or biphenylene; Ar2 and Ar3 are each independently phenylene, naphthylene, biphenylene or a group represented by the following general formula (X4); X and Y are each independently an oxygen atom or an imino group; and one or more hydrogen atoms in Ar1, Ar2 and Ar3 may each independently be replaced by a halogen atom, an alkyl group or an aryl group.)

[0008] (X4)-Ar4-Z-Ar5-

[0009] (In the formula, Ar4 and Ar5 are each independently a phenylene group or a naphthylene group; and Z is an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group or an alkylene group.)

[0010] Prior art literature

[0011] Patent Literature

[0012] Patent Document 1: Japanese Patent Application Publication No. 2012-201835 Summary of the invention

[0013] Technical problem to be solved by the invention

[0014] However, as described above, the film-forming property of liquid crystal polymers is low, and particularly when an attempt is made to produce a liquid crystal polymer sheet from a liquid composition containing a liquid crystal polymer and a solvent, film-forming defects are likely to occur.

[0015] An object of the present invention is to provide a liquid crystal polymer sheet having good film-forming properties and a low dielectric constant, a composition that can be suitably used to produce the liquid crystal polymer sheet, and a low dielectric substrate material and a wiring circuit substrate using the liquid crystal polymer sheet.

[0016] Technical solutions for solving technical problems

[0017] Therefore, in order to achieve the above-mentioned purpose, the inventors conducted intensive research and invented a liquid crystal polymer sheet with good film-forming properties and a low dielectric constant by introducing at least one of a polymerizable unsaturated group, a structure after the reaction of the polymerizable unsaturated group, and an imide bond into a liquid crystal polymer.

[0018] That is, the present invention includes the following contents.

[0019] [1] A composition comprising a liquid crystal polymer, wherein the liquid crystal polymer comprises a structural unit represented by the following formula (1), a structural unit represented by the following formula (2), and a structural unit represented by the following formula (3),

[0020] The liquid crystal polymer has at least any one of a polymerizable unsaturated group, a structure after a reaction of the polymerizable unsaturated group, and an imide bond.

[0021] [Chemistry 1]

[0022]

[0023] (In the formula (1), Ar1 represents 1,4-phenylene, 2,6-naphthylene or 4,4′-biphenylene.

[0024] In the formula (2), Ar2 represents a 1,4-phenylene group, a 1,3-phenylene group, a 4,4′-biphenylene group, a 2,6-naphthylene group or a group represented by the following formula (Q).

[0025] In formula (3), Ar3 represents 1,4-phenylene, 1,3-phenylene, 2,6-naphthylene or a group represented by the following formula (Q), X represents -NH- or -O-, and Y represents -NH- or -O-.

[0026] * indicates a bond. )

[0027] [Chemistry 2]

[0028]

[0029] (In formula (Q), Ar 11 ,Ar 12 and Ar 13 Each independently represents a phenylene group or a naphthylene group, and Q1 and Q2 each independently represent -O-, -C(=O)-, -C(R 11 )(R 12 )-(R 11 and R 12 Each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms which may be substituted with a halogen atom. ) or -S(=O)2-. n represents 0 or 1. * represents a bond. )

[0030] [2] The composition according to [1], wherein the liquid crystal polymer has the polymerizable unsaturated group at a terminal.

[0031] [3] The composition according to [1], wherein the liquid crystal polymer has the imide bond in the middle of a molecular chain or at a terminal of a molecular chain.

[0032] [4] The composition according to [1], wherein in the formula (3), X represents -NH-, Y represents -O-, or X and Y represent -O-.

[0033] [5] A liquid crystal polymer sheet obtained from the composition described in any one of [1] to [4].

[0034] [6] A low dielectric substrate material comprising the liquid crystal polymer sheet described in [5] and a metal layer in this order in the thickness direction.

[0035] [7] A wired circuit board comprising the liquid crystal polymer sheet according to [5] and a conductor layer in this order in the thickness direction.

[0036] Effects of the Invention

[0037] According to the present invention, a liquid crystal polymer sheet having good film-forming properties and a low dielectric constant, a composition suitable for producing the liquid crystal polymer sheet, and a low dielectric substrate material and a wiring circuit board using the liquid crystal polymer sheet can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic cross-sectional view of one embodiment of the low dielectric substrate material of the present invention.

[0039] Figure 2 This is a schematic cross-sectional view of another embodiment of the low dielectric substrate material of the present invention.

[0040] Figure 3 This is a schematic cross-sectional view of one embodiment of the wired circuit board of the present invention. DETAILED DESCRIPTION

[0041] (Composition and Liquid Crystal Polymer Sheet)

[0042] The composition of the present invention contains a liquid crystal polymer.

[0043] The liquid crystal polymer sheet of the present invention is obtained from a composition containing a liquid crystal polymer.

[0044] The composition may contain only the liquid crystal polymer, or may contain other components in addition to the liquid crystal polymer.

[0045] <Liquid Crystal Polymer>

[0046] The liquid crystal polymer includes a structural unit represented by the following formula (1), a structural unit represented by the following formula (2), and a structural unit represented by the following formula (3).

[0047] In one embodiment, the liquid crystal polymer has a polymerizable unsaturated group. Alternatively, in other embodiments, the liquid crystal polymer has a structure after the reaction of the polymerizable unsaturated group. Alternatively, in other embodiments, the liquid crystal polymer has an imido bond. The liquid crystal polymer may have two or more of a polymerizable unsaturated group, a structure after the reaction of the polymerizable unsaturated group, and an imido bond.

[0048] [Chemistry 3]

[0049]

[0050] (In the formula (1), Ar1 represents 1,4-phenylene, 2,6-naphthylene or 4,4′-biphenylene.

[0051] In the formula (2), Ar2 represents a 1,4-phenylene group, a 1,3-phenylene group, a 4,4′-biphenylene group, a 2,6-naphthylene group or a group represented by the following formula (Q).

[0052] In formula (3), Ar3 represents 1,4-phenylene, 1,3-phenylene, 2,6-naphthylene or a group represented by the following formula (Q), X represents -NH- or -O-, and Y represents -NH- or -O-.

[0053] * indicates a bond. )

[0054] [Chemistry 4]

[0055]

[0056] (In formula (Q), Ar 11 ,Ar 12 and Ar 13 Each independently represents a phenylene group or a naphthylene group, and Q1 and Q2 each independently represent -O-, -C(=O)-, -C(R11 )(R 12 )-(R 11 and R 12 Each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms which may be substituted with a halogen atom. ) or -S(=O)2-. n represents 0 or 1. * represents a bond. )

[0057] As Ar 11 ,Ar 12 and Ar 13 The phenylene group in the above-mentioned group is preferably 1,4-phenylene or 1,3-phenylene.

[0058] As Ar 11 ,Ar 12 and Ar 13 The naphthylene in the embodiment is preferably 2,6-naphthylene.

[0059] As R 11 and R 12 The alkyl group having 1 to 4 carbon atoms which may be substituted with a halogen atom in the group may include an alkyl group having 1 to 4 carbon atoms and a halogenated alkyl group having 1 to 4 carbon atoms. The halogenated alkyl group may be a fully halogenated alkyl group or a partially halogenated alkyl group.

[0060] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, among which a fluorine atom is preferred.

[0061] As R 11 and R 12 , preferably a hydrogen atom, a methyl group or a trifluoromethyl group.

[0062] The structural unit represented by the formula (1) (hereinafter, sometimes referred to as "structural unit (1)") is a structural unit derived from a predetermined aromatic hydroxycarboxylic acid.

[0063] As the structural unit (1), the following structural units are preferred.

[0064] [Chemistry 5]

[0065]

[0066] (* indicates a bond.)

[0067] The structural unit represented by the formula (2) (hereinafter, sometimes referred to as "structural unit (2)") is a structural unit derived from a predetermined aromatic dicarboxylic acid.

[0068] As the structural unit (2), the following structural units are preferred.

[0069] [Chemistry 6]

[0070]

[0071] (* indicates a bond.)

[0072] The structural unit represented by formula (3) (hereinafter, sometimes referred to as "structural unit (3)") is a structural unit derived from a predetermined aromatic diol, aromatic hydroxyamine or aromatic diamine.

[0073] As the structural unit (3), the following structural units are preferred.

[0074] [Chemistry 7]

[0075]

[0076] (* indicates a bond.)

[0077] Since the liquid crystal polymer has a polymerizable unsaturated group or a structure after the reaction of the polymerizable unsaturated group, the liquid crystal polymer is given structural flexibility, and the film-forming property of the liquid crystal polymer sheet is improved compared with the case where the liquid crystal polymer does not have a polymerizable unsaturated group or a structure after the reaction of the polymerizable unsaturated group.

[0078] In addition, since the liquid crystal polymer has a polymerizable unsaturated group or a structure after the reaction of the polymerizable unsaturated group, the polarity of the liquid crystal polymer decreases, and thus the dielectric constant of the liquid crystal polymer sheet decreases compared to the case where the liquid crystal polymer does not have a polymerizable unsaturated group or a structure after the reaction of the polymerizable unsaturated group.

[0079] Examples of the polymerizable unsaturated group include a vinyl group, a vinylphenyl group, an acryloyl group, a methacryloyl group, etc. Among them, an acryloyl group and a methacryloyl group are preferred from the viewpoint of providing a liquid crystal polymer with better film-forming properties and a lower dielectric constant.

[0080] The liquid crystal polymer may have a polymerizable unsaturated group in a side chain of the molecular chain or at a terminal of the molecular chain. However, the liquid crystal polymer preferably has a polymerizable unsaturated group at a terminal of the molecular chain.

[0081] The structure after the reaction of the polymerizable unsaturated group refers to the structure after the polymerizable unsaturated bond possessed by the polymerizable unsaturated group undergoes an addition reaction. As such a structure, when the polymerizable unsaturated group is a methacryloyl group, it can be represented by the following structure. As an addition reaction, for example, free radical addition polymerization can be cited.

[0082] [Chemistry 8]

[0083]

[0084] (In the structure, * indicates a bond.)

[0085] When the liquid crystal polymer has imide bonds, the liquid crystal polymer is given rigidity due to the strong intermolecular force of the imide bonds, and the film-forming property of the liquid crystal polymer sheet is improved compared with the case where the liquid crystal polymer has no imide bonds.

[0086] Furthermore, since the liquid crystal polymer has an imide bond, the dipole is fixed, and thus the dielectric constant of the liquid crystal polymer sheet is lowered compared to a case where the liquid crystal polymer has no imide bond.

[0087] The liquid crystal polymer may have an imide bond in the middle of the molecular chain or at the terminal of the molecular chain.

[0088] As an embodiment having an imide bond in the middle of a molecular chain, an embodiment having an imide bond in a main chain and an embodiment having an imide bond in a side chain are mentioned.

[0089] When the liquid crystal polymer has an imide bond, the liquid crystal polymer preferably further has a structural unit represented by the following formula (4).

[0090] [Chemistry 9]

[0091]

[0092] (In formula (4), Ar3 has the same meaning as Ar3 in formula (3). Y represents -NH- or -O-. *1 represents a bond to the nitrogen atom of the imide bond. * represents a bond.)

[0093] The liquid crystal polymer preferably has a structural unit represented by the following formula (5A) (hereinafter, sometimes referred to as “structural unit (5A)”) as a structure having a polymerizable unsaturated group.

[0094] [Chemistry 10]

[0095]

[0096] (In formula (5A), Z1 represents a polymerizable unsaturated group. * represents a bonding bond.)

[0097] In the liquid crystal polymer, the bonding bond in the formula (5A) is bonded to, for example, the oxygen atom of "-O-" in the formula (1).

[0098] Examples of Z1 include a vinyl group, a vinylphenyl group, an acryloyl group, and a methacryloyl group. Among them, an acryloyl group and a methacryloyl group are preferred.

[0099] The liquid crystal polymer preferably has a structural unit represented by the following formula (5B) (hereinafter, sometimes referred to as “structural unit (5B)”) as a structure after reaction having a polymerizable unsaturated group.

[0100] [Chemistry 11]

[0101]

[0102] (In formula (5B), Z 11 It represents the structure after the reaction of the polymerizable unsaturated group. *1 and * represent the bonding bond.

[0103] In the liquid crystal polymer, the bonding bond *1 in the formula (5B) is bonded to, for example, the oxygen atom of "-O-" in the formula (1).

[0104] As Z 11 For example, a structure in which the polymerizable unsaturated bond possessed by Z1 in formula (5A) undergoes an addition reaction can be mentioned.

[0105] The liquid crystal polymer preferably has a structural unit represented by the following formula (6-1) (hereinafter, sometimes referred to as "structural unit (6-1)"), a structural unit represented by the following formula (6-2) (hereinafter, sometimes referred to as "structural unit (6-2)"), a structural unit represented by the following formula (6-3) (hereinafter, sometimes referred to as "structural unit (6-3)"), and a structural unit represented by the following formula (6-4) (hereinafter, sometimes referred to as "structural unit (6-4)") as a structure having an imide bond.

[0106] [Chemistry 12]

[0107]

[0108] (In formula (6-1), R1 to R4 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 20 carbon atoms. * represents a bond.

[0109] In formula (6-2), R5 to R8 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 20 carbon atoms. * represents a bond.

[0110] In formula (6-3) and formula (6-4), * represents a bonding bond.

[0111] The maleimide group represented by the formula (6-3) has a structure having an imide bond and is also a polymerizable unsaturated group.

[0112] The structural unit represented by the formula (6-4) represents a structure after the reaction of a maleimide group.

[0113] As R1 to R4 in the formula (6-1), a hydrogen atom is preferred.

[0114] As R5 to R8 in the formula (6-2), a hydrogen atom is preferred.

[0115] In the liquid crystal polymer, the bonding bond in the formula (6-1) bonds to, for example, Ar3 in the formula (4).

[0116] In the liquid crystal polymer, the bonding bond in the formula (6-2) bonds to, for example, Ar3 in the formula (4).

[0117] In the liquid crystal polymer, the bonding bond in the formula (6-3) bonds to, for example, Ar3 in the formula (4).

[0118] In the liquid crystal polymer, the bond to the nitrogen atom in the formula (6-4) is bonded to, for example, Ar3 in the formula (4).

[0119] The liquid crystal polymer preferably has a structural unit represented by the following formula (7) (hereinafter, sometimes referred to as “structural unit (7)”) as a structure having an imide bond.

[0120] [Chemistry 13]

[0121]

[0122] (In formula (7), Z2 represents a tetravalent organic group represented by the following formulas (X3-1) to (X3-2). * represents a bonding bond.)

[0123] [Chemistry 14]

[0124]

[0125] (In formula (X3-1) and formula (X3-2), x and y each independently represent a single bond, -O-, -C(=O)-, -COO-, 1,4-phenylene, -SO2- or -CONH-. j and k each independently represent 0 or 1. * represents a bonding bond.)

[0126] In the liquid crystal polymer, the bonding bonds in the formula (7) are each bonded to, for example, Ar3 in the formula (4).

[0127] The content of the structural unit (1) in the liquid crystal polymer is not particularly limited, but is preferably 30 mol % or more, more preferably 30 to 70 mol %, further preferably 35 to 65 mol %, and particularly preferably 40 to 60 mol %, relative to the total amount of all structural units constituting the liquid crystal polymer (the value obtained by dividing the mass of each structural unit constituting the liquid crystal polymer by the formula weight of each structural unit to determine the equivalent amount (molar) of each structural unit, and adding them together).

[0128] The content of the structural unit (2) in the liquid crystal polymer is not particularly limited, but is preferably 35 mol% or less, more preferably 5 to 35 mol%, further preferably 10 to 35 mol%, and particularly preferably 20 to 30 mol%, relative to the total amount of all structural units constituting the liquid crystal polymer.

[0129] The content of the structural unit (3) in the liquid crystal polymer is not particularly limited, but is preferably 35 mol% or less, more preferably 5 to 35 mol%, further preferably 10 to 35 mol%, and particularly preferably 20 to 30 mol%, relative to the total amount of all structural units constituting the liquid crystal polymer.

[0130] The ratio of the content of structural unit (1) to the content of structural unit (2) in the liquid crystal polymer is not particularly limited, and is preferably 1.1 to 3, more preferably 1.4 to 2.6, and particularly preferably 1.7 to 2.3, expressed as [content of structural unit (1)] / [content of structural unit (2)] (mol / mol).

[0131] The ratio of the content of the structural unit (1) to the content of the structural unit (3) in the liquid crystal polymer is not particularly limited, and is preferably 1.1 to 3, more preferably 1.4 to 2.6, and particularly preferably 1.7 to 2.3, expressed as [content of the structural unit (1)] / [content of the structural unit (3)] (mol / mol).

[0132] The ratio of the content of the structural unit (2) to the content of the structural unit (3) in the liquid crystal polymer is not particularly limited, and is preferably 0.7 / 1 to 1 / 0.7, and more preferably 0.8 / 1 to 1 / 0.8, expressed as [content of the structural unit (2)] / [content of the structural unit (3)] (mol / mol).

[0133] The ratio of the content of structural unit (1) to the total content of structural unit (2) and structural unit (3) in the liquid crystal polymer is not particularly limited and is expressed as [content of structural unit (1)] / [content of structural unit (2)+content of structural unit (3)] (mol / mol). It is preferably 0.7 / 1 to 1 / 0.7, more preferably 0.8 / 1 to 1 / 0.8, and particularly preferably 0.9 / 1 to 1 / 0.9.

[0134] The content of the structural unit (4) in the liquid crystal polymer is not particularly limited, but is preferably 15 mol% or less, more preferably 0.5 to 15 mol%, further preferably 1 to 10 mol%, and particularly preferably 1.5 to 6 mol%, relative to the total amount of all structural units constituting the liquid crystal polymer.

[0135] The ratio of the content of the structural unit (4) to the content of the structural unit (3) in the liquid crystal polymer is not particularly limited, and is preferably 0.01 / 1 to 0.5 / 1, more preferably 0.05 / 1 to 0.3 / 1, expressed as [content of the structural unit (4)] / [content of the structural unit (3)] (mol / mol).

[0136] The total content of structural units (5A) and structural units (5B) in the liquid crystal polymer is not particularly limited, but is preferably 20 mol% or less, more preferably 0.5 to 20 mol%, further preferably 1 to 15 mol%, and particularly preferably 5 to 15 mol%, relative to the total amount of all structural units constituting the liquid crystal polymer.

[0137] The content of at least any one of the structural units (6-1) to (6-4) in the liquid crystal polymer is not particularly limited, but is preferably 15 mol % or less, more preferably 0.5 to 15 mol %, further preferably 1 to 10 mol %, and particularly preferably 1.5 to 6 mol %, relative to the total amount of all structural units constituting the liquid crystal polymer.

[0138] The content of the structural unit (7) in the liquid crystal polymer is not particularly limited, but is preferably 15 mol% or less, more preferably 0.5 to 15 mol%, further preferably 1 to 10 mol%, and particularly preferably 1.5 to 6 mol%, relative to the total amount of all structural units constituting the liquid crystal polymer.

[0139] <<Method for producing liquid crystal polymer>>

[0140] In the production of a liquid crystal polymer, for example, a compound represented by the following formula (1A), a compound represented by the following formula (2A), and a compound represented by the following formula (3A) are used.

[0141] [Chemistry 15]

[0142] HO-Ar1-CO-OH (1A)

[0143] HO-CO-Ar2-CO-OH (2A)

[0144] HX-Ar3-YH (3A)

[0145] (In formula (1A), Ar1 represents 1,4-phenylene, 2,6-naphthylene or 4,4′-biphenylene.

[0146] In the formula (2A), Ar2 represents a 1,4-phenylene group, a 1,3-phenylene group, a 4,4′-biphenylene group, a 2,6-naphthylene group or a group represented by the formula (Q).

[0147] In formula (3A), Ar3 represents 1,4-phenylene, 1,3-phenylene, 2,6-naphthylene or a group represented by formula (Q), X represents -NH- or -O-, and Y represents -NH- or -O-.)

[0148] First, the manufacture method of the liquid crystal polymer under the condition of not having polymerizable unsaturated groups, the reacted structure of polymerizable unsaturated groups and imido bonds is described. This manufacture method is, for example, the manufacture method of the liquid crystal polyester described in Japanese Patent Application Laid-Open No. 2004-315678. This manufacture method is the following method: utilizing excessive fatty acid anhydride to acylate the phenolic hydroxyl group and the amino group of the compound shown in the formula (1A) and the compound shown in the formula (3A), and the obtained acylate is subjected to transesterification (polycondensation) and melt polymerization (hereinafter, sometimes referred to as "basic manufacture method") with the compound shown in the acylated formula (1A) and the compound shown in the formula (2A). As acylate, the fatty acid ester obtained by pre-acylation can be used.

[0149] The amount of the fatty acid anhydride added in the acylation reaction is preferably 1.0 to 1.2 equivalents, more preferably 1.05 to 1.1 equivalents, based on the total amount of the phenolic hydroxyl group and the amino group.

[0150] The acylation reaction is preferably carried out at 130 to 180° C. for 5 minutes to 10 hours, and more preferably at 140 to 160° C. for 10 minutes to 3 hours.

[0151] The fatty acid anhydride used in the acylation reaction is not particularly limited, and examples thereof include acetic anhydride, propionic anhydride, butyric anhydride, isobutyric anhydride, valeric anhydride, pivalic anhydride, 2-ethylhexanoic anhydride, monochloroacetic anhydride, dichloroacetic anhydride, trichloroacetic anhydride, monobromoacetic anhydride, dibromoacetic anhydride, tribromoacetic anhydride, monofluoroacetic anhydride, difluoroacetic anhydride, trifluoroacetic anhydride, glutaric anhydride, maleic anhydride, succinic anhydride, and β-bromopropionic anhydride.

[0152] These may be used in combination of two or more types.

[0153] From the viewpoint of price and handling properties, acetic anhydride, propionic anhydride, butyric anhydride, and isobutyric anhydride are preferred, and acetic anhydride is more preferred.

[0154] In the transesterification, the acyl group of the acylated product is preferably 0.8 to 1.2 times the equivalent of the carboxyl group.

[0155] The transesterification is preferably performed at 130 to 400° C. while increasing the temperature at a rate of 0.1 to 50° C. / min, and more preferably performed at 150 to 350° C. while increasing the temperature at a rate of 0.3 to 5° C. / min.

[0156] When the fatty acid ester obtained by acylation is transesterified with a carboxylic acid, in order to shift the equilibrium, it is preferred to remove by-produced fatty acid and unreacted fatty acid anhydride to the outside of the system by evaporation or the like.

[0157] In addition, the acylation reaction and the transesterification can be performed in the presence of a catalyst.

[0158] In the basic manufacturing method, for example, the compound shown in formula (1A), the compound shown in formula (2A), the compound shown in formula (3A) and fatty acid anhydride are mixed, heated to carry out acylation reaction, and then, while distilling off the by-product and unreacted fatty acid anhydride, transesterification reaction is carried out. As a specific example, comparative synthesis example 1 described in the embodiments described later can be cited.

[0159] In one embodiment of the production of the liquid crystal polymer used in the present invention, in addition to the compound represented by formula (1A), the compound represented by formula (2A) and the compound represented by formula (3A), a compound that imparts a polymerizable unsaturated group to the liquid crystal polymer and at least any one of the structures after the reaction of the polymerizable unsaturated group, and any one of the compounds that impart an imide bond to the liquid crystal polymer are also used.

[0160] Examples of the compound that imparts at least one of a polymerizable unsaturated group and a structure after the reaction of the polymerizable unsaturated group to the liquid crystal polymer include an acid anhydride having a polymerizable unsaturated group. Examples of the acid anhydride having a polymerizable unsaturated group include acrylic anhydride and methacrylic anhydride.

[0161] As a method for manufacturing a liquid crystal polymer having at least any one of the structures after the reaction of a polymerizable unsaturated group and a polymerizable unsaturated group, for example, the following method can be cited: a compound represented by formula (1A), a compound represented by formula (2A), a compound represented by formula (3A), an acid anhydride having a polymerizable unsaturated group, and a fatty acid anhydride are mixed, heated to carry out an acylation reaction, and then, while distilling off the by-products and unreacted fatty acid anhydride, an ester exchange reaction is carried out. As a specific example, Synthesis Example 1 described in the embodiments described later can be cited.

[0162] As a compound which provides an imide bond to a liquid crystal polymer, dicarboxylic acid anhydride and tetracarboxylic acid dianhydride are mentioned, for example.

[0163] As dicarboxylic anhydride, for example, aromatic dicarboxylic anhydride can be mentioned. As aromatic dicarboxylic anhydride, for example, the compound represented by the following formula (6A-1) is preferred. As other dicarboxylic anhydride, for example, the compound represented by the following formula (6A-2) and the compound represented by the following formula (6A-3) are preferred.

[0164] [Chemistry 16]

[0165]

[0166] (In formula (6A-1), R1 to R4 have the same meanings as R1 to R4 in formula (6-1), respectively.

[0167] In formula (6A-2), R5 to R8 have the same meanings as R5 to R8 in formula (6-2).

[0168] Examples of the compound represented by formula (6A-1) include phthalic anhydride.

[0169] Examples of tetracarboxylic dianhydride include aromatic tetracarboxylic dianhydride. Here, aromatic tetracarboxylic dianhydride refers to an acid dianhydride obtained by intramolecular dehydration of a carboxyl group bonded to an aromatic ring such as a benzene ring or a naphthalene ring.

[0170] As an aromatic tetracarboxylic dianhydride, the compound represented by following formula (7A) is mentioned, for example.

[0171] [Chemistry 17]

[0172]

[0173] (In formula (7A), Z2 has the same meaning as Z2 in formula (7).)

[0174] In the production of a liquid crystal polymer, an imide bond can be introduced into the terminal of the liquid crystal polymer by using a dicarboxylic anhydride and a compound represented by formula (3A) (wherein one of X and Y represents -NH- and the other represents -O-).

[0175] In the production of a liquid crystal polymer, an imide bond can be introduced in the middle of the main chain of the liquid crystal polymer by using tetracarboxylic dianhydride and a compound represented by formula (3A) (wherein one of X and Y represents -NH- and the other represents -O-).

[0176] As a method for manufacturing a liquid crystal polymer having an imide bond at the end of the molecular chain of the liquid crystal polymer, for example, the following method can be cited: after reacting dicarboxylic anhydride with an excess of a compound represented by formula (3A) (wherein one of X and Y represents -NH- and the other represents -O-), the compound represented by formula (1A), the compound represented by formula (2A) and a fatty acid anhydride are mixed, heated to perform an acylation reaction, and then, while distilling off the by-products and unreacted fatty acid anhydride, an ester exchange reaction is performed. As a specific example, Synthesis Example 3 described in the embodiments described later can be cited.

[0177] As a method for manufacturing a liquid crystal polymer having an imide bond in the middle of the main chain of the liquid crystal polymer, for example, the following method can be cited: tetracarboxylic dianhydride and an excess of a compound represented by formula (3A) (wherein one of X and Y represents -NH- and the other represents -O-). After reacting, the compound represented by formula (1A), the compound represented by formula (2A) and a fatty acid anhydride are mixed, heated to perform an acylation reaction, and then, while distilling off the by-products and unreacted fatty acid anhydride, an ester exchange reaction is performed. As a specific example, Synthesis Example 2 described in the embodiments described later can be cited.

[0178] The content of the liquid crystal polymer in the composition is not particularly limited, but is preferably 5.0% by mass or more, more preferably 8.0 to 30.0% by mass, and particularly preferably 10.0 to 25.0% by mass.

[0179] The content of the liquid crystal polymer in the liquid crystal polymer sheet is not particularly limited, but is preferably 70% by mass or more, and more preferably 80% by mass or more, based on the liquid crystal polymer sheet.

[0180] <Other ingredients>

[0181] Examples of other components include fillers, additives, and resins other than liquid crystal polymers.

[0182] Examples of the filler include inorganic fillers such as silica, alumina, titanium oxide, barium titanate, strontium titanate, aluminum hydroxide, and calcium carbonate; and organic fillers such as cured epoxy resins, cross-linked benzoguanamine resins, and cross-linked acrylic resins.

[0183] The content of the filler in the liquid crystal polymer sheet is not particularly limited, but is preferably 0 to 100 parts by mass based on 100 parts by mass of the liquid crystal polymer.

[0184] Examples of the additive include a leveling agent, a defoaming agent, an antioxidant, an ultraviolet absorber, a flame retardant, and a colorant.

[0185] The content of the additive in the liquid crystal polymer sheet is not particularly limited, but is preferably 0 to 5 parts by mass based on 100 parts by mass of the liquid crystal polymer.

[0186] Examples of resins other than liquid crystal polymers include thermoplastic resins such as polypropylene, polyamide, amorphous polyester, polyphenylene sulfide, polyether ketone, polycarbonate, polyether sulfone, polyphenylene ether, and polyether imide; and thermosetting resins such as phenolic resins, epoxy resins, polyimide resins, and cyanate resins.

[0187] The content of resin other than the liquid crystal polymer in the liquid crystal polymer sheet is not particularly limited, but is preferably 0 to 20 parts by mass based on 100 parts by mass of the liquid crystal polymer.

[0188] <Method for producing liquid crystal polymer sheet>

[0189] The liquid crystal polymer sheet is obtained from the above composition.

[0190] The method for producing the liquid crystal polymer sheet is not particularly limited, and an example thereof includes a method of applying a liquid composition containing a liquid crystal polymer, a solvent, and any other components and then drying the composition.

[0191] The content of the liquid crystal polymer in the liquid composition is not particularly limited, but is preferably 5.0% by mass or more, more preferably 8.0 to 30.0% by mass, and particularly preferably 10.0 to 25.0% by mass.

[0192] Examples of the solvent include halogenated hydrocarbons such as dichloromethane, chloroform, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, and o-dichlorobenzene; halogenated phenols such as p-chlorophenol, pentachlorophenol, and pentafluorophenol; ethers such as diethyl ether, tetrahydrofuran, and 1,4-dioxane; ketones such as acetone and cyclohexanone; esters such as ethyl acetate and γ-butyrolactone; carbonates such as ethylene carbonate and propylene carbonate; amines such as triethylamine; nitrogen-containing heterocyclic aromatic compounds such as pyridine; nitriles such as acetonitrile and succinonitrile; amide compounds (compounds having an amide bond) such as N-methyl-2-pyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide; urea compounds such as tetramethylurea; nitro compounds such as nitromethane and nitrobenzene; sulfur compounds such as dimethyl sulfoxide and cyclopentane; and phosphorus compounds such as hexamethylphosphoramide and tri-n-butyl phosphate.

[0193] These solvents can be used alone or in combination of two or more.

[0194] Among them, N-methyl-2-pyrrolidone is preferred.

[0195] The content of the solvent in the liquid composition is not particularly limited, but is preferably 95.0% by mass or less, more preferably 70.0 to 92.0% by mass, and particularly preferably 75.0 to 90.0% by mass.

[0196] The coating method is not particularly limited, and examples thereof include a roll coating method, a bar coating method, a screen printing method, a die coating method, and a comma coating method.

[0197] In addition, coating can be either continuous or single-sheet.

[0198] The drying method, i.e., the method of removing the solvent of the liquid composition, is not particularly limited, but preferably the method of removing the solvent by evaporation. It should be noted that, herein, "removing the solvent" does not necessarily mean "removing all the solvent", and for example, the solvent can be sufficiently removed to the extent that no significant weight change of the object occurs.

[0199] The removal of the solvent is preferably performed while heating, and the heating temperature (drying temperature) at this time is preferably 50 to 180°C.

[0200] After drying, heating may be performed. Heating is performed for the purpose of, for example, removing residual components or promoting crystallization.

[0201] The heating temperature is not particularly limited, and may be, for example, 300 to 400°C.

[0202] The heating time is not particularly limited, and examples thereof include 1 to 24 hours.

[0203] When a liquid crystal polymer sheet is obtained from a composition containing a liquid crystal polymer, the liquid crystal polymer may or may not react. For example, when the liquid crystal polymer has a polymerizable unsaturated group, an addition reaction utilizing a polymerizable unsaturated bond can be mentioned.

[0204] The thickness of the liquid crystal polymer sheet is, for example, 2 μm or more, preferably 5 μm or more, and, for example, 1000 μm or less, preferably 500 μm or less.

[0205] (Low dielectric substrate material)

[0206] The low dielectric substrate material of the present invention comprises the liquid crystal polymer sheet of the present invention and a metal layer in this order in the thickness direction.

[0207] The low dielectric substrate material includes, for example, an adhesive layer as another structure.

[0208] In the low dielectric substrate material, the liquid crystal polymer sheet is the insulating layer.

[0209] <Metal layer>

[0210] The metal layer has a sheet (plate) shape.

[0211] The material of the metal layer is not particularly limited, and examples thereof include copper, iron, silver, gold, aluminum, nickel, and alloys thereof (stainless steel, bronze), etc. Preferably, copper is used.

[0212] The thickness of the metal layer is, for example, 0.1 μm or more, preferably 1 μm or more, and, for example, 100 μm or less, preferably 50 μm or less.

[0213] <Adhesive layer>

[0214] For example, the adhesive layer has a sheet shape along the surface direction of one surface in the thickness direction of the liquid crystal polymer sheet.

[0215] The material of the adhesive layer is not particularly limited, and various types of adhesives such as hot melt adhesives and thermosetting adhesives may be used, and specific examples include acrylic adhesives, epoxy adhesives, silicone adhesives, etc. Preferably, an acrylic adhesive is used.

[0216] The thickness of the adhesive layer is, for example, 2 μm or more, preferably 5 μm or more, and, for example, 50 μm or less, preferably 25 μm or less.

[0217] The thickness of the low dielectric substrate material is, for example, 10 μm or more, preferably 20 μm or more, and, for example, 5000 μm or less, preferably 2000 μm or less.

[0218] Low dielectric substrate materials are used for various purposes, and are preferably used for manufacturing high-frequency antennas and high-speed transmission substrates (high-speed transmission FPC, etc.) that meet the fifth generation (5G) standard. Specifically, low dielectric substrate materials are used as substrate materials for high-frequency antennas and high-speed FPCs.

[0219] An example of a low dielectric substrate material will be described using the drawings.

[0220] Figure 1 This is a schematic cross-sectional view of one embodiment of the low dielectric substrate material of the present invention.

[0221] Figure 1 The low dielectric substrate material 1 shown has one surface and the other surface facing each other in the thickness direction, and has a shape extending in a surface direction perpendicular to the thickness direction.

[0222] The low dielectric substrate material 1 includes a first metal layer 2, a liquid crystal polymer sheet 3 disposed on one side in the thickness direction of the first metal layer 2, an adhesive layer 4 disposed on one side in the thickness direction of the liquid crystal polymer sheet 3, and a second metal layer 5 disposed on one side in the thickness direction of the adhesive layer 4. That is, the low dielectric substrate material 1 includes the first metal layer 2, the liquid crystal polymer sheet 3, the adhesive layer 4, and the second metal layer 5 in order from the other side to the one side in the thickness direction. It is preferred that the low dielectric substrate material 1 includes only the first metal layer 2, the liquid crystal polymer sheet 3, the adhesive layer 4, and the second metal layer 5.

[0223] <Method for producing low dielectric substrate material>

[0224] Next, explain Figure 1 The manufacturing method of the low dielectric substrate material 1 is shown.

[0225] In the production of the low dielectric substrate material 1 in one embodiment, for example, each member is stacked (formed) while being conveyed by a roll-to-roll method.

[0226] Specifically, first, the first metal layer 2 is prepared. For example, a foil (metal foil) made of the above-mentioned material is prepared as the first metal layer 2.

[0227] Next, the liquid crystal polymer sheet 3 is formed on one side of the first metal layer 2. For example, the liquid crystal polymer sheet 3 is formed (installed) on one side of the first metal layer 2.

[0228] The liquid crystal polymer sheet 3 is produced, for example, by a method in which a liquid composition containing a liquid crystal polymer, a solvent, and any other components is applied onto the first metal layer 2 and then dried.

[0229] Then, the adhesive layer 4 is disposed on one side of the liquid crystal polymer sheet 3. For example, an adhesive is applied on one side of the liquid crystal polymer sheet 3, or the adhesive layer 4 formed in advance into a sheet shape by an adhesive is attached to one side of the liquid crystal polymer sheet 3.

[0230] Next, the second metal layer 5 is disposed on one side of the adhesive layer 4. For example, a foil (metal foil) made of the above-mentioned material is attached to one side of the adhesive layer 4.

[0231] Through the above, it is possible to produce Figure 1 The low dielectric substrate material 1 is shown.

[0232] In other embodiments of low dielectric substrate materials, such as Figure 2 As shown, the low dielectric substrate material 1 includes a liquid crystal polymer sheet 3 and a metal layer 6 in this order on one side in the thickness direction.

[0233] (wiring circuit board)

[0234] The wired circuit board of the present invention comprises the liquid crystal polymer sheet of the present invention and a conductor layer in this order in the thickness direction.

[0235] The wired circuit board includes, for example, an adhesive layer as another structure.

[0236] In the wiring circuit board, the liquid crystal polymer sheet is an insulating layer.

[0237] The wiring circuit board has wiring as a conductor layer, for example. Examples of the wiring include signal wiring, antenna wiring, ground wiring, etc. The wiring can be formed by patterning a metal layer using photolithography (eg, subtractive method), for example.

[0238] An example of a printed circuit board will be described using the drawings.

[0239] Figure 3 This is a schematic cross-sectional view of one embodiment of the wired circuit board of the present invention.

[0240] Figure 3 The wiring circuit board 10 shown extends in the plane direction. The wiring circuit board 10 has a sheet shape. The wiring circuit board 10 has a liquid crystal polymer sheet 3 and a conductor layer 7 in this order on one side facing the thickness direction. The conductor layer 7 is in contact with one side of the liquid crystal polymer sheet 3 in the thickness direction. The conductor layer 7 has a predetermined wiring pattern.

[0241] Figure 3 The wired circuit board 10 shown can be produced, for example, as follows.

[0242] First, prepare Figure 2 The low dielectric substrate material 1 is shown.

[0243] Next, by using photolithography Figure 2 The metal layer 6 of the low dielectric substrate material 1 shown is patterned, thereby forming a conductor layer 7 on the liquid crystal polymer sheet 3 .

[0244] Example

[0245] The present invention will be described in more detail below by showing examples and comparative examples. However, the present invention is not limited to any of the examples and comparative examples.

[0246] The compounds used in the following synthesis examples and comparative synthesis examples are shown below.

[0247] Monomer 1-1: 6-Hydroxy-2-naphthoic acid

[0248] [Chemistry 18]

[0249]

[0250] Monomer A-1: ​​Isophthalic acid

[0251] Monomer A-2: 4,4′-dicarboxy diphenyl ether

[0252] Monomer A-3: Terephthalic acid

[0253] Monomer A-4: 2,2-bis(4-carboxyphenyl)hexafluoropropane

[0254] [Chemistry 19]

[0255]

[0256] Monomer B-1: 4-aminophenol

[0257] Monomer B-2: 1,4-dihydroxybenzene

[0258] Monomer B-3: 1,4-bis(4-aminophenoxy)benzene Monomer B-4: α,α′-bis(4-aminophenyl)-1,4-diisopropylbenzene Monomer B-5: 4,4′-diaminodiphenylmethane Monomer B-6: 1,3-bis(4-aminophenoxy)benzene Monomer B-7: 3-aminophenol

[0259] [Chemistry 20]

[0260]

[0261] Compound C-1: Methacrylic Anhydride

[0262] Compound C-2: TAHQ (1,4-phenylenebis(1,3-dioxy-1,3-dihydroisobenzofuran-5-carboxylate))

[0263] Compound C-3: Phthalic anhydride

[0264] [Chemistry 21]

[0265]

[0266] <Comparative Synthesis Example 1>

[0267] In a reactor equipped with a stirring device, a nitrogen inlet pipe, a thermometer and a reflux cooler, 6-hydroxy-2-naphthoic acid (11.6 g, 0.062 mol), 4-aminophenol (3.37 g, 0.031 mol), isophthalic acid (5.13 g, 0.031 mol) and acetic anhydride (15.1 g, 0.15 mol) were added, and the gas in the reactor was replaced with nitrogen. Then, while stirring under a nitrogen stream, the temperature was raised from room temperature to 150° C. in 15 minutes, and the temperature (150° C.) was maintained and refluxed for 3 hours. Then, while distilling off the by-product acetic acid and unreacted acetic anhydride, the temperature was raised to 300° C. in 2 hours and 30 minutes, and after being maintained at 300° C. for 30 minutes, the content was taken out from the reactor. The content was cooled to room temperature, and the obtained solid was pulverized with a pulverizer to obtain a powdery liquid crystal polyester.

[0268] <Synthesis example 1>

[0269] In a reactor equipped with a stirring device, a nitrogen inlet pipe, a thermometer and a reflux cooler, 6-hydroxy-2-naphthoic acid (17.1 g, 0.091 mol), 4-aminophenol (4.96 g, 0.045 mol), isophthalic acid (7.55 g, 0.045 mol), acetic anhydride (22.3 g, 0.22 mol) and methacrylic anhydride (1.40 g, 0.0091 mol) were added, and the gas in the reactor was replaced with nitrogen. Then, while stirring under a nitrogen flow, the temperature was raised from room temperature to 150° C. in 15 minutes, and the temperature (150° C.) was maintained and refluxed for 3 hours. Then, while distilling off the distilled by-product acetic acid and unreacted acetic anhydride, the temperature was raised to 300° C. in 2 hours and 30 minutes, and after being maintained at 300° C. for 30 minutes, the content was taken out from the reactor. The content was cooled to room temperature, and the obtained solid was pulverized with a pulverizer to obtain a powdery liquid crystal polyester.

[0270] <Synthesis example 2>

[0271] 4-Aminophenol (4.20 g, 0.038 mole) and N-methyl-2-pyrrolidone (9.01 g) were added to a reactor equipped with a stirring device, a nitrogen inlet pipe, a thermometer, and a reflux cooler. After replacing the gas in the reactor with nitrogen, the mixture was stirred under a nitrogen flow. After 4-aminophenol was dissolved, TAHQ (1,4-phenylenebis(1,3-dioxy-1,3-dihydroisobenzofuran-5-carboxylate)), 1.76 g, 0.0038 mole) was added. After stirring at room temperature for 2 hours, 6-hydroxy-2-naphthoic acid (14.5 g, 0.077 mole), isophthalic acid (6.39 g, 0.038 mole), and acetic anhydride (18.9 g, 0.18 mole) were added, and the temperature was raised from room temperature to 150°C over 15 minutes, and the temperature (150°C) was maintained and refluxed for 3 hours. Next, the temperature was raised to 300° C. over 2 hours and 30 minutes while distilling off the by-product acetic acid, unreacted acetic anhydride and N-methyl-2-pyrrolidone, and after being kept at 300° C. for 30 minutes, the contents were taken out from the reactor. The contents were cooled to room temperature, and the obtained solid matter was pulverized with a pulverizer to obtain a powdered liquid crystal polyester.

[0272] <Synthesis example 3>

[0273] 4-Aminophenol (5.46 g, 0.050 mole) and N-methyl-2-pyrrolidone (12.0 g) were added to a reactor equipped with a stirring device, a nitrogen inlet pipe, a thermometer and a reflux cooler. After the gas in the reactor was replaced with nitrogen, the mixture was stirred under a nitrogen stream. After the 4-aminophenol was dissolved, phthalic anhydride (0.74 g, 0.0050 mole) was added. After stirring at room temperature for 2 hours, 6-hydroxy-2-naphthoic acid (18.8 g, 0.10 mole), isophthalic acid (8.31 g, 0.050 mole) and acetic anhydride (24.5 g, 0.24 mole) were added, and the temperature was raised from room temperature to 150° C. in 15 minutes, and the temperature (150° C.) was maintained and refluxed for 3 hours. Next, the temperature was raised to 300° C. over 2 hours and 30 minutes while distilling off the by-product acetic acid, unreacted acetic anhydride and N-methyl-2-pyrrolidone, and after being kept at 300° C. for 30 minutes, the contents were taken out from the reactor. The contents were cooled to room temperature, and the obtained solid matter was pulverized with a pulverizer to obtain a powdered liquid crystal polyester.

[0274] <Comparative Synthesis Example 2>

[0275] In a reactor equipped with a stirring device, a nitrogen inlet pipe, a thermometer and a reflux cooler, 6-hydroxy-2-naphthoic acid (10.5 g, 0.056 mole), 4,4'-dicarboxy diphenyl ether (7.17 g, 0.028 mole), 1,4-dihydroxybenzene (3.06 g, 0.028 mole) and acetic anhydride (13.6 g, 0.13 mole) were added, and the gas in the reactor was replaced with nitrogen. Then, the temperature was raised from room temperature to 150°C in 15 minutes while stirring under a nitrogen flow, and the temperature (150°C) was maintained and refluxed for 3 hours. Then, while distilling off the by-product acetic acid and unreacted acetic anhydride, the temperature was raised to 300°C in 2 hours and 30 minutes, and after being maintained at 300°C for 30 minutes, the content was taken out from the reactor. The content was cooled to room temperature, and the obtained solid was pulverized with a pulverizer to obtain a powdery liquid crystal polyester.

[0276] <Synthesis example 4>

[0277] In a reactor equipped with a stirring device, a nitrogen inlet pipe, a thermometer and a reflux cooler, 6-hydroxy-2-naphthoic acid (10.5 g, 0.056 mol), 4,4'-dicarboxydiphenyl ether (7.17 g, 0.028 mol), 1,4-dihydroxybenzene (3.06 g, 0.028 mol), acetic anhydride (13.6 g, 0.13 mol) and methacrylic anhydride (0.82 g, 0.0056 mol) were added, and after replacing the gas in the reactor with nitrogen, the temperature was raised from room temperature to 150°C over 15 minutes while stirring under a nitrogen flow, and the temperature (150°C) was maintained and refluxed for 3 hours. Then, while distilling off the by-product acetic acid and unreacted acetic anhydride, the temperature was raised to 300°C over 2 hours and 30 minutes, and after maintaining at 300°C for 30 minutes, the content was taken out from the reactor. The contents were cooled to room temperature, and the obtained solid matter was pulverized with a pulverizer to obtain a powdery liquid crystal polyester.

[0278] <Comparative Synthesis Example 3 to Comparative Synthesis Example 9>

[0279] In Comparative Synthesis Example 1, the blending amount of 6-hydroxy-2-naphthoic acid was changed to the blending amount of 6-hydroxy-2-naphthoic acid described in Table 1-1.

[0280] Furthermore, in Comparative Synthesis Example 1, 4-aminophenol (3.37 g, 0.031 mol), isophthalic acid (5.13 g, 0.031 mol) and acetic anhydride (15.1 g, 0.15 mol) were changed to the type and amount of monomer A, the type and amount of monomer B, and the amount of acetic anhydride described in Table 1-1.

[0281] Except for the above, the same operation as in Comparative Synthesis Example 1 was carried out to obtain a powdery liquid crystal polyester.

[0282] [Table 1-1]

[0283]

[0284] <Synthesis Example 5 to Synthesis Example 11>

[0285] In Synthesis Example 1, the blending amount of 6-hydroxy-2-naphthoic acid was changed to the blending amount of 6-hydroxy-2-naphthoic acid described in Table 1-2.

[0286] Furthermore, in Synthesis Example 1, 4-aminophenol (4.96 g, 0.045 mol), isophthalic acid (7.55 g, 0.045 mol), acetic anhydride (22.3 g, 0.22 mol) and methacrylic anhydride (1.40 g, 0.0091 mol) were changed to the type and amount of monomer A, the type and amount of monomer B, the amount of acetic anhydride, and the amount of methacrylic anhydride described in Table 1-2.

[0287] A powdery liquid crystal polyester was obtained in the same manner as in Synthesis Example 1 except for the above.

[0288] [Table 1-2]

[0289]

[0290] <Synthesis Example 12>

[0291] In Synthesis Example 2, 4-aminophenol (4.20 g, 0.038 mol) and N-methyl-2-pyrrolidone (NMP, 9.01 g) were changed to the type and blending amount of Monomer B and the blending amount of NMP described in Table 1-3.

[0292] Furthermore, in Synthesis Example 2, TAHQ (1.76 g, 0.0038 mol) was changed to the blending amount of TAHQ described in Table 1-3.

[0293] Furthermore, in Synthesis Example 2, 6-hydroxy-2-naphthoic acid (14.5 g, 0.077 mol), isophthalic acid (6.39 g, 0.038 mol) and acetic anhydride (18.9 g, 0.18 mol) were changed to the amount of 6-hydroxy-2-naphthoic acid, the type and amount of monomer A, and the amount of acetic anhydride recorded in Table 1-3.

[0294] Except for the above, the same operation as in Synthesis Example 2 was carried out to obtain a powdery liquid crystal polyester.

[0295] [Table 1-3]

[0296]

[0297] <Comparative Example 1>

[0298] 2.0 g of the liquid crystal polyester produced in Comparative Synthesis Example 1 was added to 18.0 g of N-methyl-2-pyrrolidone, and the mixture was heated to 160° C. to obtain a liquid crystal polyester solution.

[0299] The obtained liquid crystal polyester solution was coated on a copper foil by a bar coating method.

[0300] The temperature was raised from 40°C to 80°C over 2 hours, and dried at 80°C for 1 hour to obtain a dried sheet.

[0301] The obtained dried sheet was further subjected to the following heating process under vacuum to promote the removal of residual components and crystallization, thereby obtaining a liquid crystal polymer sheet on a copper foil.

[0302] Heating process (1) to (3):

[0303] (1) Heating from room temperature to 350°C in 10 hours

[0304] (2) Maintain at 350°C for 3 hours

[0305] (3) Let cool to room temperature

[0306] <Example 1 to Example 12, and Comparative Example 2 to Comparative Example 9>

[0307] A liquid crystal polymer sheet was formed on a copper foil in the same manner as in Comparative Example 1, except that the liquid crystal polyester used in Comparative Example 1 was changed to a liquid crystal polyester described in Table 2.

[0308] <Film thickness>

[0309] The thickness of the liquid crystal polymer sheet was measured using a contact film thickness meter (model R1-205) manufactured by Peacock.

[0310] <Film-forming property>

[0311] The quality of the film-forming property can be judged by whether the liquid crystal polymer sheet can be separated from the copper foil.

[0312] The case where separation was possible was evaluated as “good”, and the case where separation was not possible was evaluated as “bad”.

[0313] <Dielectric constant>

[0314] The relative dielectric constant (Dk) and dielectric loss tangent (Df) of the liquid crystal polymer sheet at 10 GHz were measured by the SPDR method (split dielectric resonance method) according to ASTM D150 using a "10 GHz SPDR resonator" manufactured by QWED.

[0315] [Table 2]

[0316]

[0317] Description of Reference Numerals

[0318] 1 Low dielectric substrate materials

[0319] 2. First metal layer

[0320] 3 Liquid crystal polymer sheet

[0321] 4 Adhesive layer

[0322] 5 Second Metal Layer

[0323] 6 Metal Layer

[0324] 7 Conductor layer

[0325] 10 Wiring circuit substrate.

Claims

1. A composition, characterized in that A liquid crystal polymer comprising a structural unit represented by the following formula (1), a structural unit represented by the following formula (2), and a structural unit represented by the following formula (3), The liquid crystal polymer has at least one of a polymerizable unsaturated group, a structure after reaction of the polymerizable unsaturated group, and an imide bond. In formula (1), Ar1 represents 1,4-phenylene, 2,6-naphthylene or 4,4′-biphenylene; In formula (2), Ar2 represents 1,4-phenylene, 1,3-phenylene, 4,4′-biphenylene, 2,6-naphthylene or a group represented by the following formula (Q); In formula (3), Ar3 represents 1,4-phenylene, 1,3-phenylene, 2,6-naphthylene or a group represented by the following formula (Q), X represents -NH- or -O-, and Y represents -NH- or -O-; * indicates a bond, In formula (Q), Ar 11 ,Ar 12 and Ar 13 Each independently represents a phenylene group or a naphthylene group, and Q1 and Q2 each independently represent -O-, -C(=O)-, -C(R 11 )(R 12 )- or -S(=O)2-, wherein R 11 and R 12 Each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms which may be substituted with a halogen atom, n represents 0 or 1, and * represents a bond.

2. The composition according to claim 1, wherein The liquid crystal polymer has the polymerizable unsaturated group at a terminal.

3. The composition according to claim 1, wherein The liquid crystal polymer has the imide bond in the middle of a molecular chain or at a terminal of a molecular chain.

4. The composition according to claim 1, wherein In the formula (3), X represents -NH-, Y represents -O-, or X and Y represent -O-.

5. A liquid crystal polymer sheet, characterized in that: Obtained from the composition according to any one of claims 1 to 4.

6. A low dielectric substrate material, characterized in that: The liquid crystal polymer sheet according to claim 5 and a metal layer are provided in this order in the thickness direction.

7. A wiring circuit substrate, characterized in that: The liquid crystal polymer sheet according to claim 5 and a conductor layer are provided in this order in the thickness direction.

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