Cured product of thermosetting resin composition, laminate, multilayer printed wiring board and semiconductor package

Abstract

To provide a polymer that can give a novel substrate material; a thermosetting resin composition containing the polymer; and a metal foil with resin, a prepreg, a laminate, a multilayer printed wiring board and a semiconductor package, each of which is prepared using the thermosetting resin composition; and a method for producing the polymer.SOLUTION: A siloxane-modified liquid crystal polymer has a siloxane polymer-derived constitutional unit (1), a liquid crystal polymer-derived constitutional unit (2), and a constitutional unit (3) having an ethylenically unsaturated bond-containing group.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a siloxane-modified liquid crystal polymer, a thermosetting resin composition, a resin-coated metal foil, a prepreg, a laminate, a multilayer printed wiring board, and a semiconductor package, as well as a method for producing the siloxane-modified liquid crystal polymer. [Background technology]

[0002] In recent years, as information terminal devices such as smartphones and tablet PCs have become more sophisticated, the semiconductor packages they are equipped with have rapidly become smaller, thinner, and denser. In addition, the fifth generation mobile information communication (hereinafter sometimes referred to as 5G), which began to be introduced in 2019, has dramatically improved functions such as higher speed, larger capacity, multiple simultaneous connections, and ultra-low latency, and is expected to usher in a full-scale IoT (Internet of Things) era in which all things will be connected. In the next generation of information and communication systems, such as 5G, higher frequency bands are used for transmitting signals. In the high frequency bands, the amount of information that can be transmitted per unit time increases, and while it is possible to realize high speed and large capacity, problems such as increased transmission loss arise (see, for example, Patent Document 1). Therefore, while there is a strong demand for low transmission loss in substrate materials, various characteristics such as low warpage are also required in substrate materials, and the balance of these various characteristics is also important. Therefore, the reality is that research and development of substrate materials has become extremely complex and diverse. Therefore, in the current situation, the development of as many new substrate materials as possible is itself one of the important themes. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Excerpt from JP2020-045385A, paragraph

[0003] Summary of the Invention [Problem to be solved by the invention]

[0004] Therefore, an object of the present disclosure is to provide a polymer that can provide a new substrate material, a thermosetting resin composition containing the polymer, a resin-coated metal foil, a prepreg, a laminate, a multilayer printed wiring board, and a semiconductor package that use the thermosetting resin composition, and a method for producing the polymer. [Means for solving the problem]

[0005] As a result of extensive research, the present inventors have found that a specific siloxane-modified liquid crystal polymer and a thermosetting resin composition containing the siloxane-modified liquid crystal polymer can achieve the above object.

[0006] That is, one aspect of this embodiment includes the following [1] to

[15] . [1] A siloxane-modified liquid crystal polymer having a structural unit (1) derived from a siloxane polymer, a structural unit (2) derived from a liquid crystal polymer, and a structural unit (3) having an ethylenically unsaturated bond-containing group. [2] The siloxane-modified liquid crystal polymer according to the above [1], wherein the content of the structural unit (1) is 0.1 to 35 mass %. [3] The siloxane-modified liquid crystal polymer according to the above [1] or [2], wherein the content of the structural unit (2) is 10 to 98 mass %. [4] The liquid crystal polymer constituting the structural unit (2) has a structural unit derived from one or more polymerizable compounds selected from the group consisting of aromatic hydroxycarboxylic acids, acylated aromatic hydroxycarboxylic acids, esterified aromatic hydroxycarboxylic acids, aromatic hydroxycarboxylic acid halides, aromatic dicarboxylic acids, esterified aromatic dicarboxylic acids, aromatic dicarboxylic acid dihalides, aromatic diols, acylated aromatic diols, aromatic aminocarboxylic acids, acylated aromatic aminocarboxylic acids, esterified aromatic aminocarboxylic acids, aromatic aminocarboxylic acid halides, aromatic hydroxyamines, acylated aromatic hydroxyamines, aromatic diamines, acylated aromatic diamines, aliphatic diols, acylated aliphatic diols, aliphatic dicarboxylic acids, esterified aliphatic dicarboxylic acids, and aliphatic dicarboxylic acid dihalides. [5] The siloxane-modified liquid crystal polymer according to any one of the above [1] to [4], which has a structural unit (3) having an ethylenically unsaturated bond-containing group at a molecular terminal. [6] The siloxane-modified liquid crystal polymer according to any one of the above [1] to [5], wherein the ethylenically unsaturated bond is one or more selected from the group consisting of unsaturated aliphatic hydrocarbon groups (3-i) and groups containing a hetero atom and an ethylenically unsaturated bond (3-ii). [7] The siloxane-modified liquid crystal polymer according to any one of the above [1] to [6], wherein the ethylenically unsaturated bond-containing group is a (meth)acryloyl group. [8] A thermosetting resin composition comprising the siloxane-modified liquid crystal polymer according to any one of [1] to [7] above. [9] A resin-coated metal foil having a layer of the thermosetting resin composition described in [8] above on the metal foil.

[10] A prepreg comprising the thermosetting resin composition according to [8] above and a sheet-like fiber reinforcing substrate.

[11] A laminate comprising (i) the resin-coated metal foil described in [9] above or (ii) the prepreg and metal foil described in

[10] above.

[12] A multilayer printed wiring board comprising: (i) the resin-coated metal foil according to [9] above; (ii) the prepreg according to

[10] above; or (iii) the laminate according to

[11] above.

[13] A semiconductor package comprising the multilayer printed wiring board according to

[12] above and a semiconductor element mounted thereon.

[14] Siloxanediol (1-a), one or more polymerizable compounds (2-a) selected from the group consisting of aromatic diols, aliphatic diols, aromatic hydroxyamines, and aromatic diamines; one or more polymerizable compounds (2-b) selected from the group consisting of aromatic hydroxycarboxylic acid halides, aromatic dicarboxylic acid dihalides, aromatic aminocarboxylic acid halides, and aliphatic dicarboxylic acid dihalides; (Meth)acrylic acid halide (3-a) is mixed in an organic solvent, Furthermore, the present invention provides a method for producing a siloxane-modified liquid crystal polymer by reacting the compound by adding a base having a pKa of 9 or more.

[15] The method for producing a siloxane-modified liquid crystal polymer according to

[14] above, wherein the base having a pKa of 9 or higher is one or more selected from the group consisting of 4-dimethylaminopyridine, trimethylamine, triethylamine, N,N-diisopropylethylamine, diazabicyclononene, and diazabicycloundecene. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a siloxane-modified liquid crystal polymer that can provide a novel substrate material, and also to provide a thermosetting resin composition containing the siloxane-modified liquid crystal polymer, a resin-coated metal foil, a prepreg, a laminate, a multilayer printed wiring board, and a semiconductor package using the thermosetting resin composition, and a method for producing the polymer. [Brief description of the drawings]

[0008] [Figure 1] 1 shows the results of 1H NMR measurement of the siloxane-modified liquid crystal polymer produced in Example 1. [Diagram 2]FIG. 2 is an enlarged view of the peaks shown in FIG. 1 from 7.5 to 6.8 ppm. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In the numerical ranges described in this specification, the upper or lower limit of the numerical range may be replaced with the values ​​shown in the examples. In addition, the lower and upper limits of a numerical range may be arbitrarily combined with the lower or upper limit of another numerical range. In the expression of a numerical range "AA to BB", the numerical values ​​AA and BB at both ends are included in the numerical range as the lower and upper limits, respectively. In addition, each component and material exemplified in this specification may be used alone or in combination of two or more types, unless otherwise specified. In this specification, the content of each component in the composition means the total amount of the multiple substances present in the composition when multiple substances corresponding to each component are present in the composition, unless otherwise specified. In this specification, for example, the expression "10 or more" means 10 or a numerical value exceeding 10, and the same applies when the numerical values ​​are different. In addition, for example, the expression "10 or less" means 10 or a numerical value less than 10, and the same applies when the numerical values ​​are different. In this specification, the term "structural unit derived from CC" refers to a structural unit that constitutes compound CC when compound CC is used as a raw material and reacted. Any combination of the descriptions in this specification is also included in this embodiment.

[0010] In this specification, the solid content refers to components in a resin composition other than water, volatile substances such as the solvent described below, etc. In other words, the solid content includes those that are liquid, syrup-like, or wax-like at room temperature around 25° C., and does not necessarily mean that they are solid.

[0011] [Siloxane modified liquid crystal polymer] One of the present embodiments is a siloxane-modified liquid crystal polymer having a structural unit (1) derived from a siloxane polymer [hereinafter, sometimes abbreviated as "structural unit (1)"], a structural unit (2) derived from a liquid crystal polymer [hereinafter, sometimes abbreviated as "structural unit (2)"], and a structural unit (3) having an ethylenically unsaturated bond-containing group [hereinafter, sometimes abbreviated as "structural unit (3)"]. The structural units contained in the siloxane-modified liquid crystal polymer of this embodiment will be described below in order.

[0012] (Structural unit derived from siloxane polymer (1)) The siloxane polymer constituting the structural unit (1) is not particularly limited as long as it contains a siloxane skeleton. In other words, the siloxane polymer may be one that contains a structural unit represented by the following general formula (1-1). [ka] (In the formula, R a1 and R a2 each independently represents an alkyl group having 1 to 5 carbon atoms, a phenyl group, or a phenyl group having a substituent.

[0013] Each group in the general formula (1-1) will be described below. R a1 and R a2 Examples of the alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, etc. As the alkyl group, an alkyl group having 1 to 3 carbon atoms is preferable, and a methyl group is more preferable. In the "phenyl group having a substituent", examples of the substituent on the phenyl group include an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, and an alkynyl group having 2 to 5 carbon atoms. Examples of the alkyl group having 1 to 5 carbon atoms include the same as those mentioned above. Examples of the alkenyl group having 2 to 5 carbon atoms include a vinyl group, an allyl group, and the like. Examples of the alkynyl group having 2 to 5 carbon atoms include an ethynyl group, a propargyl group, and the like. R a1 and R a2 is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group.

[0014] Examples of the siloxane polymer include siloxane diols and siloxane diamines. The siloxane diols preferably have hydroxy groups at the molecular terminals. The siloxane diamines preferably have amino groups at the molecular terminals. From the viewpoint of achieving low transmission loss, the siloxane polymer is preferably a siloxane diol, and more preferably a siloxane diol represented by the following general formula (1-1'). [ka] (In the formula, R a1 and R a2 is the same as in general formula (1-1). a3 and R a4 R each independently represents an alkyl group having 1 to 5 carbon atoms, a phenyl group, or a phenyl group having a substituent. a5 and R a6 each independently represents a divalent organic group, and m1 is an integer of 2 to 100.

[0015] Each group in the general formula (1-1') will be explained below. R a3 and R a4 The alkyl group having 1 to 5 carbon atoms, the phenyl group, and the phenyl group having a substituent are represented by R a1 and R a2The explanation is the same as in R. a3 and R a4 As the alkyl group, a methyl group is preferable. R a5 and R a6 Examples of the divalent organic group represented by include an alkylene group, an alkenylene group, an alkynylene group, an arylene group, -O-, or a divalent linking group formed by combining these groups. Examples of the alkylene group include alkylene groups having 1 to 10 carbon atoms, such as a methylene group, an ethylene group, or a propylene group. Examples of the alkenylene group include alkenylene groups having 2 to 10 carbon atoms. Examples of the alkynylene group include alkynylene groups having 2 to 10 carbon atoms. Examples of the arylene group include arylene groups having 6 to 20 carbon atoms, such as a phenylene group or a naphthylene group. The "divalent linking group in which these are combined" refers to a divalent linking group in which one or more selected from the group consisting of an alkylene group, an alkenylene group, an alkynylene group, an arylene group, and -O- are combined. Examples include a combination of an alkylene group and an arylene group, a combination of an alkylene group and -O-, a combination of an alkenylene group and an arylene group, a combination of an alkynylene group and an arylene group, and a combination of an arylene group and -O-. Among the above, R a5 and R a6 As the alkyl group, an alkylene group or an arylene group is preferable. m1 is preferably an integer of 2 to 50, more preferably an integer of 3 to 40, further preferably an integer of 5 to 30, and further preferably an integer of 7 to 30.

[0016] The functional group equivalent of the siloxane polymer is not particularly limited, but is preferably 50 to 4,000 g / mol, more preferably 100 to 3,000 g / mol, further preferably 150 to 1,800 g / mol, particularly preferably 200 to 1,300 g / mol, and may be 500 to 1,300 g / mol. As the siloxane polymer, commercially available products can be used. Examples of commercially available products include "KF-6000" (functional group equivalent: 470 g / mol), "KF-6001" (functional group equivalent: 900 g / mol), "KF-6002" (functional group equivalent: 1,600 g / mol), "KF-6003" (functional group equivalent: 2,500 g / mol), "X-21-5841" (functional group equivalent: 500 g / mol), and "KF-9701" (functional group equivalent: 1,500 g / mol) [all from Shin-Etsu Chemical Co., Ltd.]. Momentive Performance Materials Japan, LLC]; "XC96-723" (functional group equivalent: 200 g / mol), "XF42-B0970" (functional group equivalent: 900 g / mol) [all manufactured by Momentive Performance Materials Japan, LLC]; "SF8427" (functional group equivalent: 1,200 g / mol), "BY16-201" (functional group equivalent: 1,600 g / mol), "SF8428" (functional group equivalent: 1,600 g / mol) l) [All of the above are manufactured by Dow Corning Toray Co., Ltd.]; "DMS-S12" (functional group equivalent: 300 g / mol), "DMS-S14" (functional group equivalent: 600 g / mol), "DMS-S15" (functional group equivalent: 1,400 g / mol), "DMS-S21" (functional group equivalent: 2,100 g / mol) [All of the above are manufactured by Gelest Co., Ltd.]; "KF-8010" (functional group equivalent: 430 g / mol), "X-22-161A" (functional group equivalent: equivalent: 800 g / mol), "X-22-161B" (functional group equivalent: 1,500 g / mol), "KF-8012" (functional group equivalent: 2,200 g / mol), "KF-8008" (functional group equivalent: 5,700 g / mol), "X-22-9409" (functional group equivalent: 670 g / mol), "X-22-1660B-3" (functional group equivalent: 2,200 g / mol) [all manufactured by Shin-Etsu Chemical Co., Ltd.] and the like.

[0017] (Structural unit derived from liquid crystal polymer (2)) The liquid crystal polymer constituting the structural unit (2) is not particularly limited, and any liquid crystal polymer (liquid crystal polyester) can be used. The liquid crystal polymer is preferably one or more structural units derived from a polymerizable compound selected from the group consisting of aromatic hydroxycarboxylic acids, acylated aromatic hydroxycarboxylic acids, esterified aromatic hydroxycarboxylic acids, aromatic hydroxycarboxylic acid halides, aromatic dicarboxylic acids, esterified aromatic dicarboxylic acids, aromatic dicarboxylic acid dihalides, aromatic diols, acylated aromatic diols, aromatic aminocarboxylic acids, acylated aromatic aminocarboxylic acids, esterified aromatic aminocarboxylic acids, aromatic aminocarboxylic acid halides, aromatic hydroxyamines, acylated aromatic hydroxyamines, aromatic diamines, acylated aromatic diamines, aliphatic diols, acylated aliphatic diols, aliphatic dicarboxylic acids, esterified aliphatic dicarboxylic acids, and aliphatic dicarboxylic acid dihalides. From the viewpoint of being able to employ a solution polymerization method in the production of the liquid crystal polymer, the liquid crystal polymer more preferably has a structural unit derived from one or more polymerizable compounds selected from the group consisting of aromatic hydroxycarboxylic acid halides, aromatic dicarboxylic acid dihalides, aromatic diols, aromatic aminocarboxylic acid halides, aromatic hydroxyamines, aromatic diamines, aliphatic diols, and aliphatic dicarboxylic acid dihalides, and even more preferably has a structural unit derived from an aromatic dicarboxylic acid dihalide and a structural unit derived from an aromatic diol. The polymerizable compounds which form the structural units of the liquid crystal polymer will be described below in order.

[0018] (Aromatic hydroxycarboxylic acids, acylated aromatic hydroxycarboxylic acids, esterified aromatic hydroxycarboxylic acids, aromatic hydroxycarboxylic acid halides) An aromatic hydroxycarboxylic acid is a compound in which a hydroxyl group and a carboxylic acid group are directly bonded to an aromatic hydrocarbon, and to that extent, it is classified as an aromatic hydroxycarboxylic acid even if it contains an aliphatic hydrocarbon group. Specific examples of aromatic hydroxycarboxylic acids include 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 2-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 6-hydroxy-1-naphthoic acid, 7-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 7-hydroxy-1-naphthoic acid, 4'-hydroxyphenyl-4-benzoic acid, 3'-hydroxyphenyl-4-benzoic acid, 4'-hydroxyphenyl-3-benzoic acid, and alkyl group-substituted products thereof, alkoxy group-substituted products thereof, and halogen-substituted products thereof. Examples of alkyl group-substituted products include, but are not limited to, products substituted with an alkyl group having 1 to 6 carbon atoms. Examples of alkoxy group-substituted products include, but are not limited to, products substituted with an alkoxy group having 1 to 6 carbon atoms. Examples of halogen-substituted products include, but are not limited to, products substituted with a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or the like. The aromatic hydroxycarboxylic acids may be used alone or in combination of two or more kinds.

[0019] Examples of the acylated aromatic hydroxycarboxylic acid include the acylated aromatic hydroxycarboxylic acids listed above. In this specification, the term "acylated aromatic hydroxycarboxylic acid" refers to an aromatic hydroxycarboxylic acid in which the hydrogen atom of the hydroxyl group (-OH) is replaced with an acyl group, i.e., -OC(=O)-R. A (R A is an alkyl group or an aryl group.) The acylated aromatic hydroxycarboxylic acid may be used alone or in combination of two or more. Examples of the esterification product of aromatic hydroxycarboxylic acid include esterification products of the specific examples of aromatic hydroxycarboxylic acid. In this specification, the term "esterification product" refers to a product in which a hydroxy group (-OH) of a carboxylic acid group (-C(=O)-OH) is substituted with an alcohol (R B -OR of OH B Replaced with -C(=O)-OR B (R Bis an alkyl group or an aryl group.) The esterification products of aromatic hydroxycarboxylic acids may be used alone or in combination of two or more.

[0020] Examples of aromatic hydroxycarboxylic acid halides include the acid halides of the specific examples of aromatic hydroxycarboxylic acids. In this specification, the acid halide refers to a compound in which a hydroxy group (-OH) of a carboxylic acid group (-C(=O)-OH) is substituted with a halogen atom. Examples of the acid halide include acid fluoride, acid chloride, acid bromide, and acid iodide. Although not particularly limited, the acid halide is preferably an acid chloride from the viewpoint of reactivity and availability of raw materials. The aromatic hydroxycarboxylic acid halide may be used alone or in combination of two or more kinds.

[0021] (Aromatic dicarboxylic acids, esters of aromatic dicarboxylic acids, aromatic dicarboxylic acid dihalides) An aromatic dicarboxylic acid is a compound in which a carboxylic acid group is directly bonded to an aromatic hydrocarbon, and to that extent, it is classified as an aromatic dicarboxylic acid even if it contains an aliphatic hydrocarbon group. Specific examples of aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4'-dicarboxybiphenyl, 3,4'-dicarboxybiphenyl, 4,4'-dicarboxyterphenyl, and their alkyl group-substituted products, alkoxy group-substituted products, and halogen-substituted products. Examples of alkyl group-substituted products include, but are not limited to, products substituted with an alkyl group having 1 to 6 carbon atoms. Examples of alkoxy group-substituted products include, but are not limited to, products substituted with an alkoxy group having 1 to 6 carbon atoms. Examples of halogen-substituted products include, but are not limited to, products substituted with a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or the like. The aromatic dicarboxylic acids may be used alone or in combination of two or more.

[0022] Examples of the esterified aromatic dicarboxylic acid include monoesterified and diesterified products of the specific examples of the aromatic dicarboxylic acid. The esterified aromatic dicarboxylic acid may be used alone or in combination of two or more. Examples of the aromatic dicarboxylic acid dihalide include the acid halides of the specific examples of the aromatic dicarboxylic acid. Examples of the acid halides include acid fluoride, acid chloride, acid bromide, and acid iodide. Although not particularly limited, from the viewpoint of reactivity and availability of raw materials, the acid halide is preferably an acid chloride. Examples of the aromatic dicarboxylic acid dihalide include terephthalic acid dihalide and isophthalic acid dihalide, more preferably terephthalic acid dichloride and isophthalic acid dichloride, and even more preferably isophthalic acid dichloride. The aromatic dicarboxylic acid dihalide may be used alone or in combination of two or more.

[0023] (Aromatic diols, acylated aromatic diols) An aromatic diol is a compound in which a hydroxy group is directly bonded to an aromatic hydrocarbon, and to that extent, it is classified as an aromatic diol even if it contains an aliphatic hydrocarbon group. Specific examples of aromatic diols include benzene-based diols such as hydroquinone and resorcinol; naphthalene-based diols such as 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, and 1,6-dihydroxynaphthalene; binaphthyl-based diols such as 2,2'-dihydroxybinaphthyl; biphenyl-based diols such as 3,3'-dihydroxybiphenyl, 3,4'-dihydroxybiphenyl, and 4,4'-dihydroxybiphenyl; diphenyl ether-based diols such as 4,4'-dihydroxydiphenyl ether; bisphenol-based diols such as bisphenol A and bisphenol F; and alkyl group-substituted products thereof, alkoxy group-substituted products thereof, and halogen-substituted products thereof. Examples of alkyl group-substituted products include, but are not limited to, products substituted with an alkyl group having 1 to 6 carbon atoms. Examples of alkoxy group-substituted products include, but are not limited to, products substituted with an alkoxy group having 1 to 6 carbon atoms. The halogen-substituted compound is not particularly limited, but examples thereof include compounds substituted with a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like. Of the above, the aromatic diol is preferably a biphenyl-based diol or a bisphenol-based diol, more preferably 4,4'-dihydroxybiphenyl, bisphenol A or bisphenol F, and further preferably 4,4'-dihydroxybiphenyl or bisphenol A. The aromatic diol may be used alone or in combination of two or more. In particular, it is preferable to use two or more aromatic diols in combination for the following reasons. When the aromatic diol contains bisphenol A, the solubility in an organic solvent tends to improve. Therefore, the aromatic diol preferably contains a biphenyl-based diol and a bisphenol-based diol, and more preferably contains 4,4'-dihydroxybiphenyl and bisphenol A.

[0024] Examples of the acylated aromatic diol include the acylated aromatic diols specifically mentioned above. The acylated aromatic diols may be used alone or in combination of two or more.

[0025] (Aromatic aminocarboxylic acids, acylated aromatic aminocarboxylic acids, esterified aromatic aminocarboxylic acids, aromatic aminocarboxylic acid halides) An aromatic aminocarboxylic acid is a compound in which an amino group and a carboxylic acid group are directly bonded to an aromatic hydrocarbon, and to that extent, it is classified as an aromatic aminocarboxylic acid even if it contains an aliphatic hydrocarbon group. Specific examples of aromatic aminocarboxylic acids include 4-aminobenzoic acid, 3-aminobenzoic acid, 6-amino-2-naphthoic acid, and their alkyl group-substituted derivatives, alkoxy group-substituted derivatives, and halogen-substituted derivatives. Examples of alkyl group-substituted derivatives include, but are not limited to, those substituted with an alkyl group having 1 to 6 carbon atoms. Examples of alkoxy group-substituted derivatives include, but are not limited to, those substituted with an alkoxy group having 1 to 6 carbon atoms. Examples of halogen-substituted derivatives include, but are not limited to, those substituted with a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or the like. The aromatic aminocarboxylic acid may be used alone or in combination of two or more kinds.

[0026] Examples of the acylated aromatic aminocarboxylic acid include the acylated aromatic aminocarboxylic acids described above. The acylated aromatic aminocarboxylic acid may be used alone or in combination of two or more. Examples of the esterified product of aromatic aminocarboxylic acid include the esterified products of the specific examples of aromatic aminocarboxylic acid. The esterified products of aromatic aminocarboxylic acid may be used alone or in combination of two or more. The aromatic aminocarboxylic acid halide may be the acid halide of the specific example of the aromatic aminocarboxylic acid. The acid halide may be an acid fluoride, an acid chloride, an acid bromide, an acid iodide, etc. Although not particularly limited, from the viewpoint of reactivity and availability of raw materials, the acid halide is preferably an acid chloride. The aromatic aminocarboxylic acid halide may be used alone or in combination of two or more kinds.

[0027] (Aromatic hydroxyamines, acylated aromatic hydroxyamines) An aromatic hydroxyamine is a compound in which a hydroxy group and an amino group are directly bonded to an aromatic hydrocarbon, and to that extent is classified as an aromatic hydroxyamine even if it contains an aliphatic hydrocarbon group. Specific examples of aromatic hydroxyamines include 4-aminophenol, N-methyl-4-aminophenol, 3-aminophenol, 3-methyl-4-aminophenol, 4-amino-1-naphthol, 4-amino-4'-hydroxybiphenyl, 4-amino-4'-hydroxybiphenyl ether, 4-amino-4'-hydroxybiphenyl methane, 4-amino-4'-hydroxybiphenyl sulfide, 2,2'-diaminobinaphthyl, and alkyl group-substituted products thereof, alkoxy group-substituted products thereof, and halogen-substituted products thereof. Examples of alkyl group-substituted products include, but are not limited to, products substituted with an alkyl group having 1 to 6 carbon atoms. Examples of alkoxy group-substituted products include, but are not limited to, products substituted with an alkoxy group having 1 to 6 carbon atoms. Examples of halogen-substituted products include, but are not limited to, products substituted with a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or the like. The aromatic hydroxyamines may be used alone or in combination of two or more kinds.

[0028] Examples of the acylated aromatic hydroxyamine include the acylated aromatic hydroxyamines specifically mentioned above. The acylated aromatic hydroxyamines may be used alone or in combination of two or more.

[0029] (Aromatic diamines, acylated aromatic diamines) An aromatic diamine is a compound in which an amino group is directly bonded to an aromatic hydrocarbon, and to that extent, it is classified as an aromatic diamine even if it has an aliphatic hydrocarbon group. Specific examples of aromatic diamines include 1,4-phenylenediamine, 1,3-phenylenediamine, 1,5-diaminonaphthalene, 1,8-diaminonaphthalene, and their alkyl group-substituted products, alkoxy group-substituted products, and halogen-substituted products. Examples of alkyl group-substituted products include, but are not limited to, products substituted with an alkyl group having 1 to 6 carbon atoms. Examples of alkoxy group-substituted products include, but are not limited to, products substituted with an alkoxy group having 1 to 6 carbon atoms. Examples of halogen-substituted products include, but are not limited to, products substituted with a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or the like. The aromatic diamines may be used alone or in combination of two or more kinds.

[0030] Examples of the acylated aromatic diamine include the acylated aromatic diamines specifically mentioned above. The acylated aromatic diamines may be used alone or in combination of two or more.

[0031] (Aliphatic diols, acylated aliphatic diols) An aliphatic diol is a compound in which a hydroxy group is directly bonded to an aliphatic hydrocarbon, and to that extent, even if it has an aromatic hydrocarbon group, it is classified as an aliphatic diol. It is preferable that the aliphatic diol does not have an aromatic hydrocarbon group. Specific examples of the aliphatic diol include ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 2,2-bis(4-hydroxycyclohexyl)propane, 1,4-cyclohexadiol, 4,4'-bicyclohexanol, tricyclodecane dimethanol, etc. The aliphatic diols may be used alone or in combination of two or more. Examples of the acylated product of an aliphatic diol include the acylated products of the specific examples of the aliphatic diols described above. The acylated products of an aliphatic diol may be used alone or in combination of two or more.

[0032] (Aliphatic dicarboxylic acids, esters of aliphatic dicarboxylic acids, aliphatic dicarboxylic acid dihalides) An aliphatic dicarboxylic acid is a compound in which a carboxylic acid group is directly bonded to an aliphatic hydrocarbon, and to that extent, even if it has an aromatic hydrocarbon group, it is classified as an aliphatic dicarboxylic acid. It is preferable that the aliphatic dicarboxylic acid does not have an aromatic hydrocarbon group. Specific examples of the aliphatic dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, etc. The aliphatic dicarboxylic acid may be used alone or in combination of two or more kinds. Examples of the esterified aliphatic dicarboxylic acid include the esterified products of the specific examples of the aliphatic dicarboxylic acids. The esterified aliphatic dicarboxylic acids may be used alone or in combination of two or more. The aliphatic dicarboxylic acid dihalide may be the acid halide of the specific example of the aliphatic dicarboxylic acid. The acid halide may be an acid fluoride, an acid chloride, an acid bromide, an acid iodide, etc. Although not particularly limited, from the viewpoint of reactivity and availability of raw materials, the acid halide is preferably an acid chloride. The aliphatic dicarboxylic acid dihalide may be used alone or in combination of two or more kinds.

[0033] (Structural Unit (3) Having an Ethylenically Unsaturated Bond-Containing Group) Examples of the ethylenically unsaturated bond-containing group contained in the structural unit (3) include unsaturated aliphatic hydrocarbon groups (3-i) such as vinyl groups, allyl groups, 1-methylallyl groups, isopropenyl groups, 2-butenyl groups, 3-butenyl groups, and styryl groups; and groups (3-ii) containing a heteroatom and an ethylenically unsaturated bond, such as a maleimide group and a group represented by the following general formula (3-1). The ethylenically unsaturated bond-containing group is preferably at least one selected from the group consisting of unsaturated aliphatic hydrocarbon groups (3-i) and groups (3-ii) containing a heteroatom and an ethylenically unsaturated bond. [ka] (In the formula, R b1 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.

[0034] In this specification, groups which contain an unsaturated aliphatic hydrocarbon group in a portion thereof, such as a maleimide group and a group represented by the above general formula (3-1), but which cannot be considered an unsaturated aliphatic hydrocarbon group when viewed as a whole, are not included in the above "unsaturated aliphatic hydrocarbon group".

[0035] R in general formula (3-1) b1 The alkyl group having 1 to 20 carbon atoms represented by may be any of a linear alkyl group, a branched alkyl group, or a cyclic alkyl group, and is preferably a linear alkyl group. The number of carbon atoms in the alkyl group is preferably 1 to 10, more preferably 1 to 5, further preferably 1 to 3, and particularly preferably 1. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and the like, and among these, a methyl group is preferable. From the viewpoint of solubility in an organic solvent, the group represented by the above general formula (3-1) is preferably a group (3-ii) containing a heteroatom and an ethylenically unsaturated bond, and a (meth)acryloyl group (i.e., R b1 is a hydrogen atom or a methyl group), and more preferably a methacryloyl group. In the present embodiment, the term "(meth)acryloyl group" refers to an acryloyl group or a methacryloyl group. The siloxane-modified liquid crystal polymer of this embodiment preferably has the structural unit (3) at the molecular end.

[0036] (Content of each structural unit) The siloxane-modified liquid crystal polymer of the present embodiment has a content of the structural unit (1) derived from a siloxane polymer of preferably 0.1 to 35 mass%, more preferably 0.5 to 30 mass%, and further preferably 1 to 30 mass%, and may be 2 to 20 mass%, 2 to 15 mass%, or 2.5 to 13 mass%. The siloxane-modified liquid crystal polymer of the present embodiment preferably has a content of the structural unit (2) derived from a liquid crystal polymer of 10 to 98 mass%, more preferably 25 to 98 mass%, and further preferably 50 to 98 mass%, and may be 65 to 96 mass%, 65 to 93 mass%, or 75 to 91 mass%. In the siloxane-modified liquid crystal polymer of the present embodiment, the content of the structural unit (3) having an ethylenically unsaturated bond-containing group is preferably 1 to 40 mass%, more preferably 1 to 30 mass%, and further preferably 1 to 20 mass%, and may be 1.5 to 15 mass%, 3 to 15 mass%, or 4 to 13 mass%. The siloxane-modified liquid crystal polymer of the present embodiment may have structural units other than the structural units (1) to (3). However, the total content of the structural units (1) to (3) is preferably 70% by mass or more, more preferably 80% by mass or more, further preferably 90% by mass or more, and particularly preferably 95% by mass or more (all including 100% by mass) based on all structural units. The content of each of the above structural units is 1 The molar ratio of each component was calculated from the H-NMR measurement results and converted to a mass ratio.

[0037] The molecular weight of the siloxane-modified liquid crystal polymer of this embodiment is not particularly limited, but from the viewpoint of solubility in organic solvents, etc., the weight average molecular weight may be 1,000 to 10,000, 1,200 to 9,000, or 1,500 to 7,000. From the same viewpoint, the number average molecular weight of the siloxane-modified liquid crystal polymer of this embodiment may be 500 to 3,000, 800 to 2,500, or 1,000 to 2,300.

[0038] [Method for producing siloxane-modified liquid crystal polymer] The method for producing the siloxane modified liquid crystal polymer of the present embodiment is not particularly limited, but from the viewpoint of suppressing the thermal decomposition of the siloxane polymer used as raw material, it is preferable to adopt a solution polymerization method.Furthermore, in the solution polymerization method, from the viewpoint of suppressing the thermal decomposition of the siloxane polymer and from the viewpoint of suppressing side reaction and sufficiently introducing the structural unit (3), the following production method is preferable. (A preferred embodiment of the method for producing a siloxane-modified liquid crystal polymer) Siloxanediol (1-a), one or more polymerizable compounds (2-a) selected from the group consisting of aromatic diols, aliphatic diols, aromatic hydroxyamines, and aromatic diamines; one or more polymerizable compounds (2-b) selected from the group consisting of aromatic hydroxycarboxylic acid halides, aromatic dicarboxylic acid dihalides, aromatic aminocarboxylic acid halides, and aliphatic dicarboxylic acid dihalides; (Meth)acrylic acid halide (3-a) is mixed in an organic solvent, Furthermore, the present invention provides a method for producing a siloxane-modified liquid crystal polymer by reacting the compound by adding a base having a pKa of 9 or more. A method for producing the siloxane-modified liquid crystal polymer, which is one preferred embodiment (hereinafter, sometimes abbreviated as the production method of this embodiment), will be described below.

[0039] (About ingredients) The siloxane diol (1-a) is the same as the siloxane diol described in the description of the structural unit (1) derived from a siloxane polymer, and the same description is applied. The aromatic diol, aliphatic diol, aromatic hydroxyamine and aromatic diamine which are options for the polymerizable compound (2-a) are the same as the aromatic diol, the aliphatic diol, the aromatic hydroxyamine and the aromatic diamine described in the explanation of the structural unit (2) derived from the liquid crystal polymer, and the same explanation is applied. The aromatic hydroxycarboxylic acid halides, aromatic dicarboxylic acid dihalides, aromatic aminocarboxylic acid halides and aliphatic dicarboxylic acid dihalides, which are options for the polymerizable compound (2-b), are the same as the aromatic hydroxycarboxylic acid halides, aromatic dicarboxylic acid dihalides, aromatic aminocarboxylic acid halides and aliphatic dicarboxylic acid dihalides described in the explanation of the structural unit (2) derived from a liquid crystal polymer, and the same explanation is applied. The (meth)acrylic acid halide (3-a) is a compound that constitutes the structural unit (3) having an ethylenically unsaturated bond-containing group. Examples of the (meth)acrylic acid halide (3-a) include (meth)acrylic acid fluoride, (meth)acrylic acid chloride, (meth)acrylic acid bromide, and (meth)acrylic acid iodide. Although not particularly limited, from the viewpoint of reactivity, the (meth)acrylic acid halide (3-a) is preferably (meth)acrylic acid chloride, and more preferably methacrylic acid chloride.

[0040] (For bases with pKa of 9 or higher) A base with a pKa of 9 or higher has the function of promoting the esterification reaction. If the pKa of the base is less than 9, the side reaction derived from the acid halide (3-a) tends to proceed, and as a result, the (meth)acryloyl group cannot be introduced into the target product. Therefore, the pKa of the base is 9 or more, preferably 9.5 or more, more preferably 10.0 or more, and even more preferably 10.5 or more. There is no particular limit to the upper limit of the pKa of the base, but it is usually 14 or less, and may be 13 or less. Examples of the base having a pKa of 9 or more include 4-dimethylaminopyridine, trimethylamine, triethylamine, N,N-diisopropylethylamine, diazabicyclononene, diazabicycloundecene, etc. Among these, the base having a pKa of 9 or more is preferably at least one selected from the group consisting of trimethylamine and triethylamine.

[0041] (Amount of each raw material and base with a pKa of 9 or higher) The amounts of the siloxane diol (1-a), the polymerizable compound (2-a), the polymerizable compound (2-b), the (meth)acrylic acid halide (3-a) and the base having a pKa of 9 or more used are not particularly limited, but from the viewpoint of the solubility of the resulting siloxane-modified liquid crystal polymer in an organic solvent, it is preferable that the amounts are as shown in Table 1 below. [Table 1]

[0042] In addition, when the amount of the base having a pKa of 9 or more is equal to or more than the lower limit of the range described in Table 1, the esterification reaction tends to be sufficiently promoted, and when the amount is equal to or less than the upper limit, the side reaction tends to be suppressed and the amount of the base mixed into the product tends to be reduced. From the same viewpoint, the amount of the base having a pKa of 9 or more is preferably 0.5 to 5 molar equivalents and more preferably 1 to 3 molar equivalents relative to 1 molar equivalent of the polymerizable compound (2-b). From the same viewpoint, the amount of the base having a pKa of 9 or more is preferably 1 to 8 molar equivalents, more preferably 1.5 to 5 molar equivalents, and even more preferably 1.5 to 3 molar equivalents relative to 1 molar equivalent of the (meth)acrylic acid halide (3-a).

[0043] (Organic solvent) The method for producing the siloxane-modified liquid crystal polymer may be carried out in the presence of an organic solvent, and is preferably carried out in the presence of an organic solvent. Examples of the organic solvent include amide-based solvents such as dimethylformamide (DMF), dimethylacetamide, and N-methylpyrrolidone (NMP); ether-based solvents such as tetrahydrofuran and diethyl ether; and halogen-based solvents such as chloroform and dichloromethane.

[0044] (Operation Procedure) The procedure for the production method of this embodiment is not particularly limited, but from the viewpoint of suppressing side reactions and sufficiently introducing the structural unit (3), it is preferable to carry out the method in the following order. First, mixed solution A is prepared by adding siloxanediol (1-a) and a polymerizable compound (2-a) to an organic solvent, and mixed solution B is prepared by adding a polymerizable compound (2-b) and a (meth)acrylic acid halide (3-a) to an organic solvent. Next, mixed solution B is added (preferably dropwise) to the obtained mixed solution A, and the mixture is thoroughly stirred to prepare mixed solution AB. Thereafter, a base having a pKa of 9 or more is added to the mixed solution AB while stirring, thereby obtaining a siloxane-modified liquid crystal polymer.

[0045] The manufacturing method of this embodiment can be carried out at, for example, 5 to 40°C. Heating is not particularly required, and the method can be carried out at room temperature. However, since the addition of a base having a pKa of 9 or more to the mixed solution AB may cause the mixed solution to heat up, it is preferable to add the base having a pKa of 9 or more slowly, and more preferably to add it dropwise over a period of time, so that the mixed solution AB does not heat up too much. The rate at which the base having a pKa of 9 or more is added to the mixed solution AB may be appropriately adjusted while checking the degree of heat generation. In addition, in order to prevent the mixed solution AB from heating up too much, it is also effective to add (preferably dropwise) the base having a pKa of 9 or more in two or more portions (for example, 2 to 4 portions) in stages.

[0046] (Post-processing) After adding a base having a pKa of 9 or more, the mixture is thoroughly stirred to react, and then mixed with an alcoholic solvent such as methanol, ethanol, or isopropyl alcohol, or a mixed solution of these alcoholic solvents and water, as necessary, to inactivate the polymerizable compound (2-b) and the (meth)acrylic acid halide (3-a) to terminate the polymerization reaction and precipitate the product. After the product is precipitated, the product is obtained by a separation method such as filtration, and washed with an alcoholic solvent such as methanol, ethanol, or isopropyl alcohol, as necessary, to obtain the siloxane-modified liquid crystal polymer of this embodiment. The purity of the obtained siloxane-modified liquid crystal polymer may be increased by a known purification method such as a reprecipitation method or a recrystallization method, as necessary. Specific examples of the reprecipitation method or the recrystallization method include a method in which the obtained siloxane-modified liquid crystal polymer is dissolved again in the organic solvent, and then diluted with an alcoholic solvent or a mixed solution of these alcoholic solvents and water.

[0047] [Thermosetting resin composition] The thermosetting resin composition of the present embodiment is a thermosetting resin composition containing the siloxane-modified liquid crystal polymer of the present embodiment. In the thermosetting resin composition of this embodiment, the content of the siloxane-modified liquid crystal polymer of this embodiment is not particularly limited, but from the viewpoint of reducing transmission loss, it is preferably 1 mass% or more, more preferably 5 mass% or more, even more preferably 10 mass% or more, and particularly preferably 20 mass% or more. There is no particular limit to the upper limit of the content of the siloxane-modified liquid crystal polymer of this embodiment, and it may be 100 mass% or less, 90 mass% or less, 80 mass% or less, or 70 mass% or less. In other words, the content of the siloxane-modified liquid crystal polymer of this embodiment may be 1 to 100 mass%. The thermosetting resin composition of this embodiment may contain components other than the siloxane-modified liquid crystal polymer of this embodiment. The components other than the siloxane-modified liquid crystal polymer of this embodiment are not particularly limited, and include (1) a thermosetting resin other than the siloxane-modified liquid crystal polymer of this embodiment, (2) a curing agent, (3) a curing accelerator, (4) an inorganic filler, (5) an organic filler, (6) a flame retardant, (7) a flame retardant assistant, (8) a thermoplastic resin, (9) a thermoplastic elastomer, (10) an ultraviolet absorber, (11) an antioxidant, (12) a photopolymerization initiator, (13) a fluorescent whitening agent, (14) an adhesion improver, (15) a flow adjuster, (16) a cissing inhibitor, (17) a coupling agent, (18) a heat stabilizer, (19) an antistatic agent, (20) a pigment, (21) a colorant, (22) a lubricant, and (23) an organic solvent. Any of these may be used that is known in the art. The components other than the siloxane-modified liquid crystal polymer of the present embodiment may be used alone or in combination of two or more.

[0048] [Metal foil with resin] The resin-coated metal foil of this embodiment has a layer of the thermosetting resin composition of this embodiment on a metal foil. Hereinafter, the "layer of the thermosetting resin composition" may be referred to as a "resin layer." The resin-attached metal foil can be produced by, for example, applying the thermosetting resin composition of the present embodiment onto a metal foil and then B-staging the thermosetting resin composition in a drying oven, thereby producing a "resin-attached metal foil" having a resin layer on the metal foil. Here, in this specification, B-staging refers to bringing the metal foil into a B-stage state as defined in JIS K6900 (1994), and is also called semi-curing. The drying conditions are not particularly limited, but the drying temperature is preferably 80 to 180°C, more preferably 110 to 160°C. The coating method is not particularly limited, and for example, a known coater such as a die coater, a comma coater, a bar coater, a kiss coater, or a roll coater can be used. Examples of the metal foil of the resin-coated metal foil include copper foil, aluminum foil, tin foil, tin-lead alloy (solder) foil, nickel foil, etc., but other metal foils can also be used. Among these, copper foil is preferred. When using copper foil as the metal foil, the grade and thickness of the copper foil may be appropriately selected according to the circuit design of the semiconductor package to be manufactured, but it is preferable that the copper foil has a copper content of 95 mass% or more. Of the two surfaces of the metal foil, the surface facing the resin layer may be roughened from the viewpoint of adhesion. The roughening treatment can be performed by forming roughening particles on the surface of the metal foil. The roughening particles are preferably electrodeposited particles made of at least one element selected from the group consisting of copper, nickel, phosphorus, tungsten, arsenic, molybdenum, chromium, cobalt, and zinc, or electrodeposited particles made of an alloy containing at least one of these elements. After the roughening treatment, secondary particles, tertiary particles, an anti-rust layer, a heat-resistant layer, or the like may be formed using at least one element selected from the group consisting of nickel, cobalt, copper, and zinc, or an alloy containing at least one of these elements, and the surface may be further subjected to a surface treatment such as a chromate treatment or a silane coupling treatment. In the resin-coated metal foil of this embodiment, the thickness of the resin layer is not particularly limited, but is preferably 5 to 200 μm, more preferably 10 to 100 μm, and further preferably 10 to 50 μm. In the resin-coated metal foil of this embodiment, the thickness of the metal foil is not particularly limited, but is preferably 3 to 20 μm, more preferably 5 to 15 μm, and further preferably 10 to 15 μm.

[0049] [Prepreg] The prepreg of the present embodiment contains the thermosetting resin composition of the present embodiment and a sheet-like fiber reinforcing substrate. The prepreg can be formed by using the thermosetting resin composition of this embodiment and a sheet-like fiber-reinforced substrate. For example, the thermosetting resin composition of this embodiment is impregnated or coated on a sheet-like fiber-reinforced substrate, and then heated and dried in a drying oven at a temperature of 80 to 200°C for 1 to 30 minutes to bring the thermosetting resin composition into a B-stage, thereby producing the prepreg of this embodiment. The solid content of the thermosetting resin composition in the prepreg of the present embodiment is not particularly limited, but is preferably 30 to 90 mass%, more preferably 35 to 80 mass%, further preferably 40 to 70 mass%, and particularly preferably 45 to 60 mass%. When the solid content of the thermosetting resin composition in the prepreg is within the above range, better moldability tends to be obtained when the prepreg is made into a laminate.

[0050] As the sheet-like fiber reinforcement substrate of the prepreg, a known one used in various laminates for electrical insulating materials is used. Examples of the material of the sheet-like fiber reinforcement substrate include inorganic fibers such as E glass, D glass, S glass, and Q glass; organic fibers such as polyimide, polyester, and tetrafluoroethylene; and mixtures thereof. These sheet-like fiber reinforcement substrates have shapes such as woven fabric, nonwoven fabric, roving, chopped strand mat, and surfacing mat. In addition, the thickness of the sheet-like fiber reinforcement substrate is not particularly limited, and for example, a substrate having a thickness of 5 to 200 μm can be used. In addition, from the viewpoints of impregnation of the thermosetting resin composition, heat resistance, moisture absorption resistance, and processability when made into a laminate, a substrate that has been surface-treated with a coupling agent or the like, a substrate that has been mechanically opened, and the like can be used.

[0051] The following hot melt method or solvent method can be used as a method for impregnating or coating the thermosetting resin composition on the sheet-like fiber-reinforced substrate. The hot melt method is a method in which the thermosetting resin composition does not contain an organic solvent, and (1) the thermosetting resin composition is first coated onto a coated paper that has good peelability from the thermosetting resin composition, and then the coated paper is laminated onto a sheet-like fiber-reinforced substrate, or (2) the composition is directly coated onto a sheet-like fiber-reinforced substrate using a die coater. On the other hand, the solvent method is a method in which a thermosetting resin composition is made to contain an organic solvent, a sheet-shaped fiber-reinforced substrate is immersed in the obtained thermosetting resin composition to impregnate the sheet-shaped fiber-reinforced substrate with the thermosetting resin composition, and then the substrate is dried.

[0052] The thickness of the prepreg of the present embodiment is not particularly limited, and may be 10 to 250 μm, 10 to 120 μm, or 10 to 70 μm.

[0053] [Laminate] The laminate of the present embodiment is a laminate containing (i) the resin-coated metal foil of the present embodiment or (ii) the prepreg and metal foil of the present embodiment. A laminate having a metal foil is sometimes called a metal-clad laminate. The laminate of this embodiment can be obtained by hot-pressing one sheet of the resin-coated metal foil of this embodiment, or by arranging two sheets of the resin-coated metal foil so that the metal foil is the outer layer, and then hot-pressing and molding. Alternatively, the laminate can be obtained by arranging metal foil on one or both sides of one prepreg of this embodiment, or by arranging metal foil on one or both sides of two or more stacked prepregs of this embodiment, and then hot-pressing and molding. Another method for producing a laminated board includes a method in which the resin-coated metal foil of the present embodiment is laminated on both sides or one side of the prepreg of the present embodiment or a prepreg other than the prepreg so that the resin side faces the prepreg, and then heated and pressed. In this case, the prepreg may be one prepreg, or two or more prepregs may be laminated. When two or more prepregs are laminated, different prepregs may be combined and laminated. The metal of the metal foil is not particularly limited as long as it is used in electrical insulating material applications. From the viewpoint of electrical conductivity, the metal may be copper, gold, silver, nickel, platinum, molybdenum, ruthenium, aluminum, tungsten, iron, titanium, chromium, or an alloy containing one or more of these metal elements, with copper and aluminum being preferred, and copper being more preferred. From the viewpoint of productivity, the heating temperature during hot and pressure molding is preferably 185° C. or higher, and may be 200 to 300° C., or may be 220 to 250° C. When the heating temperature is within the above range, good productivity tends to be obtained along with excellent dielectric properties and flame retardancy. The pressure and time during hot and pressure molding are not particularly limited, but for example, the pressure can be in the range of 0.2 to 10 MPa and the time can be in the range of 0.1 to 5 hours. In addition, the hot and pressure molding may be performed using a method in which a vacuum state is maintained for 0.5 to 5 hours using a vacuum press or the like. Under the above conditions, a sufficiently cured laminate can be obtained.

[0054] [Multilayer printed wiring board] The multilayer printed wiring board of the present embodiment contains (i) the resin-coated metal foil of the present embodiment, (ii) the prepreg of the present embodiment, or (iii) the laminate of the present embodiment. The multilayer printed wiring board of the present embodiment can be manufactured by carrying out a circuit formation process and a multilayer adhesive process by a known method using the resin-coated metal foil of the present embodiment, the prepreg of the present embodiment, or the laminate of the present embodiment.

[0055] [Semiconductor package] The semiconductor package of this embodiment is formed by mounting a semiconductor element on the multilayer printed wiring board of this embodiment. The semiconductor package of this embodiment can be manufactured, for example, by mounting semiconductor elements such as semiconductor chips and memories at predetermined positions on the multilayer printed wiring board of this embodiment by a known method and sealing the semiconductor elements with sealing resin or the like.

[0056] Although the preferred aspects of the present embodiment have been described above, these are merely examples for the purpose of explaining the present embodiment, and are not intended to limit the scope of the present embodiment to the above-described embodiments. The present embodiment can be embodied in various aspects different from the above-described embodiments without departing from the spirit of the present embodiment. EXAMPLES

[0057] The present embodiment will be specifically described below with reference to examples, although the present embodiment is not limited to the following examples.

[0058] In each example, the weight average molecular weight and the number average molecular weight were measured by the following procedures. (Method of measuring weight average molecular weight and number average molecular weight) The weight average molecular weight and number average molecular weight were calculated by gel permeation chromatography (GPC) from a calibration curve using standard polystyrene. The calibration curve was approximated by a third-order equation using standard polystyrene: TSKstandard POLYSTYRENE (Type; A-2500, A-5000, F-20, F-80) [manufactured by Tosoh Corporation, product name]. The measurement conditions for GPC are shown below. Equipment: High-speed GPC equipment HLC-8320GPC Detector: UV-8320 ultraviolet absorption detector [manufactured by Tosoh Corporation] Column: Guard column; "TSK Guardcolumn SuperHZ-L" + column; "TSKgel SuperHZM-N + TSKgel SuperHZM-M" + "TSKgel SuperH-RC" (all product names manufactured by Tosoh Corporation) Column size: 4.6 x 20 mm (guard column), 4.6 x 150 mm (column), 6.0 x 150 mm (reference column) Eluent: Tetrahydrofuran Sample concentration: 5mg / 5mL Injection volume: 20μL Flow rate: 0.35mL / min Measurement temperature: 40℃

[0059] In each example, the content of each structural unit is as follows: 1 H NMR measurement was carried out, and the integral value (mol) of the peak derived from each structural unit was calculated by mass conversion. ( 1 H NMR measurement conditions) Equipment: Nuclear magnetic resonance equipment "ECX400II" (manufactured by JEOL RESONANCE Co., Ltd.) Solvent: deuterated chloroform (CDCl3 ) Frequency: 400MHz

[0060] [Example 1] In a 0.2L reaction vessel equipped with a stirrer, 93.1 parts by mass of 4,4'-dihydroxybiphenyl, 776.2 parts by mass of bisphenol A, 54.9 parts by mass of siloxane polymer "KF-6001" (functional group equivalent 900, manufactured by Shin-Etsu Chemical Co., Ltd.) having hydroxyl groups at the molecular terminals (more specifically, both terminals), and 3,700 parts by mass of NMP were charged at 25°C. An NMP solution containing 649.7 parts by mass of isophthalic acid dichloride and 125.4 parts by mass of methacrylic acid chloride was added dropwise at 25°C over 26 minutes. The resulting mixture was stirred for 0.5 hours, and then 384.5 parts by mass of triethylamine (pKa = 10.7) was added dropwise to the mixture over 5 minutes, and stirring was continued for 60 minutes. Here, it was confirmed that the mixture was heated by the addition of triethylamine. Further, 384.5 parts by mass of triethylamine was added dropwise again over 5 minutes, stirring was continued for 60 minutes, and 76.9 parts by mass of triethylamine was added dropwise again over 2 minutes, and stirring was continued for 60 minutes. Then, 4,000 parts by mass of NMP was added to dilute the mixture to 1.5 times. The mixture was then gradually added to 48,000 parts by mass of a mixed solvent of methanol and water (water:methanol = 1:3 (volume ratio)) to terminate the reaction and precipitate the product, and the precipitate was collected by filtration to obtain a siloxane-modified liquid crystal polymer. The amounts of each raw material and reagent used are summarized in Table 2. The resulting siloxane-modified liquid crystal polymer was thoroughly washed with methanol, filtered, dried, and then dissolved in CDCl as a solvent. 3 Using 1 H NMR measurements were performed. 1 By assigning the H NMR measurement results, it was confirmed that the siloxane-modified liquid crystal polymer contains all of the structural units derived from 4,4'-dihydroxybiphenyl, bisphenol A, siloxane polymer, isophthalic acid dichloride, and methacrylic acid chloride. The content of each structural unit is shown in Table 2. Also, 1The results of H NMR measurement are shown in Figure 1, and an enlarged view of 7.5 to 6.8 ppm is shown in Figure 2. In Figures 1 and 2, the peaks corresponding to the symbols (a) to (l) assigned to the protons at each site are given the same symbols (a) to (l).

[0061] [Example 2] In a 0.2L reaction vessel equipped with a stirrer, 93.1 parts by mass of 4,4'-dihydroxybiphenyl, 776.2 parts by mass of bisphenol A, 54.9 parts by mass of siloxane polymer "KF-6001" (functional group equivalent 900) having hydroxyl groups at both ends, and 3,700 parts by mass of NMP were charged at 25°C. An NMP solution containing 649.7 parts by mass of isophthalic acid dichloride and 125.4 parts by mass of methacrylic acid chloride was added dropwise at 25°C over 17 minutes. After stirring the resulting mixture for 0.5 hours, 423.0 parts by mass of triethylamine were added dropwise to the mixture over 5 minutes, and stirring was continued for 60 minutes. Here, it was confirmed that the mixture was heated by the addition of triethylamine. Furthermore, 423.0 parts by mass of triethylamine was again added dropwise over 5 minutes, and stirring was continued for 60 minutes. After that, the reaction-terminated liquid was diluted 1.5 times with NMP, and then the reaction-terminated liquid was gradually added to 48,000 parts by mass of a mixture of water and methanol (water:methanol = 1:3 (volume ratio)) to terminate the reaction and precipitate the product, and then the precipitate was collected by filtration to obtain a siloxane-modified liquid crystal polymer. The amounts of each raw material and reagent used are summarized in Table 2. In addition, the siloxane-modified liquid crystal polymer obtained in the same manner as in Example 1 was 1 H NMR measurements were performed. 1 By assigning the H NMR measurement results, it was confirmed that the siloxane-modified liquid crystal polymer contains all of the structural units derived from 4,4'-dihydroxybiphenyl, bisphenol A, siloxane polymer, isophthalic acid dichloride, and methacrylic acid chloride. The content of each structural unit is shown in Table 2.

[0062] [Example 3] In Example 2, the same operation was carried out except that 817.3 parts by mass of hydrogenated bisphenol A was used instead of 776.2 parts by mass of bisphenol A, and siloxane-modified liquid crystal polymer was obtained. The amounts of each raw material and reagent used, and the weight average molecular weight and number average molecular weight of the obtained siloxane-modified liquid crystal polymer are summarized in Table 2. In addition, the siloxane-modified liquid crystal polymer obtained in the same manner as in Example 1 was 1 H NMR measurements were performed. 1 By assigning the results of H NMR measurement, it was confirmed that the siloxane-modified liquid crystal polymer has all of the structural units derived from 4,4'-dihydroxybiphenyl, hydrogenated bisphenol A, siloxane polymer, isophthalic acid dichloride, and methacrylic acid chloride. However, since there were many peaks, it was difficult to determine the content of each structural unit.

[0063] [Examples 4 and 5] A siloxane-modified liquid crystal polymer was obtained by the same procedure as in Example 2, except that the amount of each raw material used was changed as shown in Table 2. The amount of each raw material and reagent used, and the weight average molecular weight and number average molecular weight of the obtained siloxane-modified liquid crystal polymer are summarized in Table 2. In addition, the siloxane-modified liquid crystal polymer obtained in the same manner as in Example 1 was 1 H NMR measurements were performed. 1 By assigning the H NMR measurement results, it was confirmed that the siloxane-modified liquid crystal polymer contains all of the structural units derived from 4,4'-dihydroxybiphenyl, bisphenol A, siloxane polymer, isophthalic acid dichloride, and methacrylic acid chloride. The content of each structural unit is shown in Table 2.

[0064] [Examples 6 to 8] In Example 2, the amounts of each raw material and reagent used were changed as shown in Table 2, and the method of dropping triethylamine was changed as follows, but the same operation was performed to obtain a siloxane-modified liquid crystal polymer. The dropping of triethylamine was performed in the following procedure: 667.8 parts by mass was dropped over 5 minutes, followed by stirring for 60 minutes, and then 667.9 parts by mass was dropped over 5 minutes, followed by stirring for 60 minutes. Table 2 shows the amounts of each raw material and reagent used, and the weight average molecular weight and number average molecular weight of the resulting siloxane-modified liquid crystal polymer. In addition, the siloxane-modified liquid crystal polymer obtained in the same manner as in Example 1 was 1 H NMR measurements were performed. 1 By assigning the H NMR measurement results, it was confirmed that the siloxane-modified liquid crystal polymer contains all of the structural units derived from 4,4'-dihydroxybiphenyl, bisphenol A, siloxane polymer, isophthalic acid dichloride, and methacrylic acid chloride. The content of each structural unit is shown in Table 2.

[0065] [Example 9] The same procedure as in Example 6 was carried out except that the types and amounts of each raw material and the amounts of reagents used were changed as shown in Table 2, to obtain a siloxane-modified liquid crystal polymer. The amounts of each raw material and reagent used are summarized in Table 2. In addition, the siloxane-modified liquid crystal polymer obtained in the same manner as in Example 1 was 1 H NMR measurements were performed. 1 By assigning the H NMR measurement results, it was confirmed that the siloxane-modified liquid crystal polymer contains all of the structural units derived from 4,4'-dihydroxybiphenyl, bisphenol A, siloxane polymer, isophthalic acid dichloride, and methacrylic acid chloride. The content of each structural unit is shown in Table 2.

[0066] [Comparative Example 1] In a 0.2L reaction vessel equipped with a stirrer, 93.1 parts by mass of 4,4'-dihydroxybiphenyl, 776.2 parts by mass of bisphenol A, 54.9 parts by mass of siloxane polymer "KF-6001" (functional group equivalent 900) having hydroxyl groups at both ends, 3.2 parts by mass of pyridine (pKa = 5.3), and 3,700 parts by mass of NMP were charged at 25 ° C. Thereto, an NMP solution containing 649.7 parts by mass of isophthalic acid dichloride and 125.4 parts by mass of methacrylic acid chloride was dropped at 25 ° C. over 61 minutes. After stirring the resulting mixture for 0.5 hours, 299.0 parts by mass of pyridine was dropped into the mixture over 5 minutes, and stirring was continued for 30 minutes. At this time, it was confirmed that the mixture was heated by the dropping of pyridine. Furthermore, 299.0 parts by mass of pyridine was dropped again over 5 minutes, and stirring was continued for 80 minutes. The reaction solution was then gradually poured into 39,000 parts by mass of methanol to terminate the reaction and precipitate the product, which was then filtered to obtain a siloxane-modified liquid crystal polymer. The amounts of each raw material and reagent used are summarized in Table 2. Regarding the obtained siloxane-modified liquid crystal polymer 1 H NMR measurements confirmed that the siloxane-modified liquid crystal polymer had structural units derived from 4,4'-dihydroxybiphenyl, bisphenol A, siloxane polymer, and isophthalic acid dichloride, but no structural units derived from methacryloyl chloride, and that a peak was observed that appeared to be a by-product. When pyridine with a pKa of 5.3 was used, the side reaction of methacryloyl chloride became dominant, making it difficult to incorporate methacryloyl chloride into the siloxane-modified liquid crystal polymer. Also, CDCl 3 There is a lot of insoluble matter in 1 It was difficult to calculate the content of each structural unit by 1 H NMR measurement.

[0067] <Evaluation of solubility> The solubility of the siloxane-modified liquid crystal polymers obtained in the above Examples and Comparative Examples in organic solvents was examined. In a test tube, 0.05 g of the siloxane-modified liquid crystal polymer obtained in each example and 1.0 ml of one of the organic solvents listed in Table 2 were placed, and the resulting mixture was shaken well and stirred, then allowed to stand. The solubility was evaluated according to the following evaluation criteria. The results are shown in Table 2. A: The mixture is transparent and has excellent solubility for the siloxane-modified liquid crystal polymer. B: The mixture is translucent and some of the siloxane-modified liquid crystal polymer is dissolved. C: At least one of aggregation and sedimentation occurs in the mixed liquid, and the solubility of the siloxane-modified liquid crystal polymer is low.

[0068] [Table 2]

[0069] (Explanation of abbreviations in Table 2) KF-6001: Siloxane polymer with hydroxyl groups at both ends (functional group equivalent: 900, manufactured by Shin-Etsu Chemical Co., Ltd.) DHB: 4,4'-dihydroxybiphenyl BPA: Bisphenol A Hydrogenated BPA: 2,2-bis(4-hydroxycyclohexyl)propane BPF: Bisphenol F IPC: Isophthalic acid dichloride MC: Methacrylic acid chloride

[0070] From Table 2, it can be seen that the siloxane-modified liquid crystal polymer of this embodiment has improved solubility in organic solvents. Liquid crystal polymers that are expected to reduce the transmission loss of substrate materials generally have poor solubility in organic solvents, but the siloxane-modified liquid crystal polymer of this embodiment, which has improved solubility in organic solvents, is expected to be a new substrate material. In addition, by using the siloxane-modified liquid crystal polymer of this embodiment, it is expected that the low thermal expansion of the substrate material will be improved. [Industrial Applicability]

[0071] According to the present embodiment, the siloxane-modified liquid crystal polymer can provide a novel substrate material. The resin-coated metal foil, prepreg, laminate, multilayer printed wiring board, semiconductor package, etc., which uses the thermosetting resin composition containing the siloxane-modified liquid crystal polymer, are suitable for electronic component applications that handle high-frequency signals.

Claims

1. A siloxane-modified liquid crystal polymer having a structural unit (1) derived from a siloxane polymer, a structural unit (2) derived from a liquid crystal polymer, and a structural unit (3) having an ethylenically unsaturated bond-containing group.

2. The siloxane-modified liquid crystal polymer according to claim 1, wherein the content of the structural unit (1) is 0.1 to 35 mass %.

3. The siloxane-modified liquid crystal polymer according to claim 1 or 2, wherein the content of the structural unit (2) is 10 to 98 mass %.

4. The liquid crystal polymer constituting the structural unit (2) has a structural unit derived from one or more polymerizable compounds selected from the group consisting of aromatic hydroxycarboxylic acid, acylated aromatic hydroxycarboxylic acid, esterified aromatic hydroxycarboxylic acid, aromatic hydroxycarboxylic acid halide, aromatic dicarboxylic acid, esterified aromatic dicarboxylic acid, aromatic dicarboxylic acid dihalide, aromatic diol, acylated aromatic diol, aromatic aminocarboxylic acid, acylated aromatic aminocarboxylic acid, esterified aromatic aminocarboxylic acid, aromatic aminocarboxylic acid halide, aromatic hydroxyamine, acylated aromatic hydroxyamine, aromatic diamine, acylated aromatic diamine, aliphatic diol, acylated aliphatic diol, aliphatic dicarboxylic acid, esterified aliphatic dicarboxylic acid and aliphatic dicarboxylic acid dihalide.

5. 5. The siloxane-modified liquid crystal polymer according to claim 1, which has a structural unit (3) having an ethylenically unsaturated bond-containing group at a molecular terminal.

6. The siloxane-modified liquid crystal polymer according to any one of claims 1 to 5, wherein the ethylenically unsaturated bond is at least one selected from the group consisting of unsaturated aliphatic hydrocarbon groups (3-i) and groups (3-ii) containing a heteroatom and an ethylenically unsaturated bond.

7. The siloxane-modified liquid crystal polymer according to any one of claims 1 to 6, wherein the ethylenically unsaturated bond-containing group is a (meth)acryloyl group.

8. A thermosetting resin composition comprising the siloxane-modified liquid crystal polymer according to any one of claims 1 to 7.

9. A resin-coated metal foil having a layer of the thermosetting resin composition according to claim 8 on the metal foil.

10. A prepreg comprising the thermosetting resin composition according to claim 8 and a sheet-like fiber-reinforced substrate.

11. A laminate comprising (i) the resin-coated metal foil according to claim 9 or (ii) the prepreg and metal foil according to claim 10.

12. A multilayer printed wiring board comprising: (i) the resin-coated metal foil according to claim 9; (ii) the prepreg according to claim 10; or (iii) the laminate according to claim 11.

13. A semiconductor package comprising the multilayer printed wiring board according to claim 12 and a semiconductor element mounted thereon.

14. Siloxanediol (1-a), one or more polymerizable compounds (2-a) selected from the group consisting of aromatic diols, aliphatic diols, aromatic hydroxyamines, and aromatic diamines; one or more polymerizable compounds (2-b) selected from the group consisting of aromatic hydroxycarboxylic acid halides, aromatic dicarboxylic acid dihalides, aromatic aminocarboxylic acid halides, and aliphatic dicarboxylic acid dihalides; (Meth)acrylic acid halide (3-a) is mixed in an organic solvent, Furthermore, a method for producing a siloxane-modified liquid crystal polymer is provided by adding a base having a pKa of 9 or more to carry out the reaction.

15. The method for producing a siloxane-modified liquid crystal polymer according to claim 14, wherein the base with a pKa of 9 or more is at least one selected from the group consisting of 4-dimethylaminopyridine, trimethylamine, triethylamine, N,N-diisopropylethylamine, diazabicyclononene, and diazabicycloundecene.

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