Composition and cured product thereof

Abstract

The present invention provides a composition that makes it possible to form a cured product having a low dielectric constant and excellent heat resistance and elongation. The present invention is a composition characterized by containing an amino group-containing polysiloxane (A) and a polymer (B) having a structural unit (U) derived from an unsaturated aliphatic dicarboxylic acid monoester.

Description

Composition and cured product thereof

[0001] The present invention relates to a composition and a cured product thereof. More specifically, the present invention relates to a composition containing an amino group-containing polysiloxane and a specific polymer, and a cured product obtained by curing the composition.

[0002] In recent years, frequencies have become increasingly higher in electrical and electronic devices, such as communication devices like mobile phones, network-related devices like servers, and electronic devices like computers, and the materials used in these electrical and electronic devices are required to be able to handle these higher frequencies.In particular, materials with low dielectric constants are used for the insulating films used in these electrical and electronic devices to reduce transmission loss, but with the recent trend toward higher frequencies, materials with even lower dielectric constants are required.

[0003] Furthermore, insulating films are required to have heat resistance during the manufacturing process and use of electric and electronic devices. Furthermore, for flexible devices such as flexible displays, which are experiencing rapidly increasing demand, insulating films are required to have high strength against deformations such as tension and bending, e.g., high elongation. Polyimide-based materials have been proposed as insulating film materials for such electric and electronic devices (e.g., Patent Documents 1 and 2).

[0004] JP 2015-130281 A JP 2008-195966 A

[0005] However, in Patent Document 1, examples of laminated polyimide films for covering conductors in multilayer insulated wires only show a dielectric constant of about 3.5 at a measurement frequency of 1 MHz, with the lowest example being 3.45. Patent Document 2 lists the physical properties of cured coating films made from thermosetting polyimide resin compositions using specific polyimide resins in Table 3, etc., and indicates the glass transition temperature (Tg), but the heat resistance is far from sufficient. Thus, no material is yet known that can satisfy the heat resistance, dielectric constant in the high-frequency range, and elongation required for insulating films that can accommodate the increasing frequency and flexibility of electric and electronic devices.

[0006] The present invention has been made in view of the above problems, and an object of the present invention is to provide a composition capable of forming a cured product having a low dielectric constant and excellent heat resistance and elongation.

[0007] The present inventors have conducted various studies to achieve the above-mentioned object and have arrived at the present invention. That is, the object of the present disclosure is achieved by the following [1] to [4]. [1] A composition comprising an amino group-containing polysiloxane (A) and a polymer (B) having a structural unit (U) derived from an unsaturated aliphatic dicarboxylic acid monoester. [2] The composition according to [1] above, further comprising inorganic particles. [3] A cured product obtained by curing the composition according to [1] or [2] above. [4] The cured product according to [3] above, which is an insulating film.

[0008] The composition of the present invention contains an amino group-containing polysiloxane (A) and a polymer (B) having a structural unit (U) derived from an unsaturated aliphatic dicarboxylic acid monoester, and therefore can form a cured product having a low dielectric constant and excellent heat resistance and elongation. Therefore, the composition of the present invention can be preferably used as an insulating film material in various technical fields, including electric and electronic devices that use high frequencies.

[0009] The present invention will be described in detail below. A combination of two or more of the individual preferred embodiments of the present invention described below is also a preferred embodiment of the present invention. In this specification, "(meth)acrylate" means "acrylate" or "methacrylate," "(meth)acrylic" means "acrylic" or "methacrylic," and "(meth)acryloyl" means "acryloyl" or "methacryloyl." (Meth)acrylate may also be referred to as a (meth)acrylic acid ester.

[0010] [Composition of the Present Disclosure] The composition of the present disclosure is characterized by comprising an amino group-containing polysiloxane (A) and a polymer (B) having a structural unit (U) derived from an unsaturated aliphatic dicarboxylic acid monoester. The reason why the composition of the present disclosure can form a cured product with a low dielectric constant and excellent heat resistance and elongation is thought to be because it combines a structure with low polarization and flexibility derived from the siloxane.

[0011] <Amino group-containing polysiloxane (A)> In the composition of the present disclosure, the amino group-containing polysiloxane (A) refers to a polymer having a polysiloxane skeleton as its main chain, and an amino group-containing group bonded to at least one of the silicon atoms constituting the polysiloxane skeleton. The polysiloxane skeleton may have a chain structure such as a linear or branched structure, or may have a cyclic structure. Among these, a chain structure is preferred, and a linear structure is more preferred.

[0012] The amino group-containing group is not particularly limited as long as it is an organic group containing an amino group. In the amino group-containing group, the amino group is preferably bonded to a silicon atom constituting the polysiloxane skeleton via a divalent organic group. The amino group-containing group is preferably a hydrocarbon group containing an amino group as a substituent. The hydrocarbon group is preferably an alkyl group, an aryl group, or an aralkyl group, more preferably an alkyl group. The amino group in the amino group-containing group may be any of a primary amino group, a secondary amino group, and a tertiary amino group. The amino group-containing group contains one or more of these. Among the amino groups, a primary amino group or a secondary amino group is preferred, and a primary amino group is more preferred.

[0013] The amino group-containing group is preferably at least one selected from the group consisting of an amino group-containing group represented by the following general formula (1), an amino group-containing group represented by the following general formula (2), and an amino group-containing group represented by the following general formula (3): -R ａ NH ２ (1) (In general formula (1), R ａ is a divalent hydrocarbon group or a group represented by -R-O-R-, and the two Rs may be the same or different and represent a divalent hydrocarbon group. ａ NHR ｂ (2) (In general formula (2), R ａ is a divalent hydrocarbon group or a group represented by -R-O-R-, and the two Rs may be the same or different and represent a divalent hydrocarbon group. ｂ represents a monovalent hydrocarbon group or a group represented by -R-O-R', where R represents a divalent hydrocarbon group and R' represents a monovalent hydrocarbon group.ａ NHR ｃ NH ２ (3) (In general formula (3), R ａ and R ｃ are the same or different and are a divalent hydrocarbon group or a group represented by -R-O-R-, and the two R's are the same or different and are a divalent hydrocarbon group.

[0014] In the above general formulas (1) to (3), R ａ , R ｃ Examples of the divalent hydrocarbon group represented by R include an alkylene group, an arylene group, and an aralkylene group. Among these, an alkylene group is preferred, an alkylene group having 1 to 18 carbon atoms is more preferred, an alkylene group having 1 to 8 carbon atoms is even more preferred, and an alkylene group having 1 to 6 carbon atoms is even more preferred.

[0015] In the above general formula (2), R ｂ Examples of the monovalent hydrocarbon group represented by R' include an alkyl group, an aryl group, and an aralkyl group. Of these, an alkyl group is preferred, an alkyl group having 1 to 18 carbon atoms is more preferred, an alkyl group having 1 to 8 carbon atoms is more preferred, and an alkyl group having 1 to 6 carbon atoms is even more preferred.

[0016] In the above general formulas (1) to (3), R ａ , R ｃ a divalent hydrocarbon group represented by R and R ｂ The monovalent hydrocarbon groups represented by R′ may each have a substituent. The substituent is not particularly limited, but preferred examples thereof include halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms; and hydrophilic groups such as hydroxyl groups and mercapto groups.

[0017] The bonding position of the amino group-containing group in the amino group-containing polysiloxane (A) is not particularly limited. The amino group-containing group may be bonded to a terminal silicon atom of the polysiloxane skeleton, or to a silicon atom other than the terminal, or to both a terminal silicon atom and a silicon atom other than the terminal. A preferred embodiment is (1) in which an amino group-containing group is bonded to at least one terminal silicon atom of the polysiloxane skeleton. When the polysiloxane skeleton has a linear structure, a particularly preferred embodiment is (2) in which an amino group-containing group is bonded to some or all of the silicon atoms other than the terminals of the polysiloxane skeleton, that is, a embodiment in which an amino group-containing group is bonded as a side chain in the polysiloxane skeleton. A more preferred embodiment of the above embodiment (1) or (2) is one in which an amino group-containing group is bonded to at least one terminal silicon atom of the polysiloxane skeleton, and amino group-containing groups are bonded to some or all of the silicon atoms other than those at the terminals of the polysiloxane skeleton.

[0018] The amino group content in the amino group-containing polysiloxane (A) is not particularly limited, but from the viewpoint of the mechanical strength of the cured product obtained from the composition of the present disclosure, the amino group equivalent is preferably 300 to 20,000 g / mol. It is more preferably 500 to 10,000 g / mol, and even more preferably 1,000 to 5,000 g / mol. The amino group equivalent can be a value obtained by a measurement method in accordance with the method described in JIS K 2501:2003 and JIS K 7237. Specifically, the amino group equivalent can be determined by the following method, and it is preferable to use a value obtained by the following method.

[0019] (Method for Measuring Amino Group Equivalent) The above amino group-containing polysiloxane (A) as a sample is dissolved in a mixed solvent of o-nitrotoluene and acetic acid (v / v = 9 / 2) and titrated with a 0.1 mol / L perchloric acid / acetic acid solution using a glass electrode and a reference electrode. The relationship between the reading on the potentiometer or pH meter and the corresponding titration amount of the 0.1 mol / L perchloric acid / acetic acid solution is plotted, and the inflection point obtained on the titration curve is taken as the endpoint. The total amine value is calculated from the amount of 0.1 mol / L perchloric acid / acetic acid solution consumed. The number of moles of amino groups per unit mass is calculated from the total amine value, and the amino group equivalent can be determined by taking the reciprocal of this calculation.

[0020] The weight-average molecular weight of the amino group-containing polysiloxane (A) is not particularly limited, but from the viewpoint of solubility in solvents, it is preferably 100 to 1,000,000, more preferably 500 to 500,000, and even more preferably 1,000 to 100,000. The weight-average molecular weight can be measured by GPC (gel permeation chromatography) using polystyrene as a standard substance, a 1 mM triethylamine-tetrahydrofuran solution as an eluent, a high-speed GPC apparatus HLC-8320GPC (manufactured by Tosoh Corporation), and TSKgel Super HZ4000 and TSKgel Super HZ2000 (manufactured by Tosoh Corporation) as columns.

[0021] In the amino group-containing polysiloxane (A), it is preferable that some or all of the silicon atoms constituting the polysiloxane skeleton are bonded to atoms or functional groups other than the oxygen atoms constituting the siloxane bond and the amino group-containing group. Among the above atoms or functional groups, functional groups are preferred. Examples of the above atoms include hydrogen atoms and halogen atoms, with halogen atoms being preferred. Examples of the above functional groups include hydroxyl groups and organic groups. Examples of the above organic groups include hydrocarbon groups and alkoxy groups, which may have a substituent. Examples of the above hydrocarbon groups are preferably alkyl groups, aryl groups, and aralkyl groups, more preferably alkyl groups and aryl groups, even more preferably methyl groups and phenyl groups, and particularly preferably methyl groups. The number of carbon atoms in the above organic groups is preferably 1 to 12, more preferably 1 to 6, and even more preferably 1 to 4.

[0022] In the amino group-containing polysiloxane (A), it is preferable that the above atoms or functional groups are bonded to all of the silicon atoms constituting the polysiloxane skeleton.It is preferable that a total of two or three atoms or functional groups other than the amino group-containing groups are bonded to each of the silicon atoms constituting the polysiloxane skeleton other than the silicon atoms bonded to the amino group-containing groups.The above atoms or functional groups bonded to the silicon atoms constituting the polysiloxane skeleton may be the same or different.

[0023] In the amino group-containing polysiloxane (A), a particularly preferred form of the polysiloxane skeleton is a dimethylpolysiloxane skeleton, which has a structure in which two methyl groups are bonded to each silicon atom constituting the polysiloxane skeleton (with the proviso that two or three methyl groups are bonded to the terminal silicon atom).

[0024] A particularly preferred embodiment of the amino group-containing polysiloxane (A) is one having the dimethylpolysiloxane skeleton with amino group-containing groups bonded to both terminals of the skeleton.

[0025] The method for producing the amino group-containing polysiloxane (A) is not particularly limited, and can be produced by a conventionally known method. For example, the amino group-containing polysiloxane (A) can be obtained by hydrolyzing and condensing an alkoxysilane compound having an amino group-containing group in an aqueous alcohol in the presence of an acid catalyst. Although only one or more alkoxysilane compounds having an amino group-containing group may be hydrolyzed and condensed, it is preferred to co-hydrolyze and condense one or more alkoxysilane compounds having an amino group-containing group with one or more alkoxysilane compounds other than the alkoxysilane compound having an amino group-containing group (hereinafter also referred to as other alkoxysilane compounds).

[0026] Examples of alkoxysilane compounds having an amino group-containing group include trialkoxysilane compounds such as 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, (N-phenylamino)methyltrimethoxysilane, and diethylaminomethyltriethoxysilane; and dialkoxysilane compounds such as 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, and N-(2-aminoethyl)-3-aminopropylmethyldiethoxysilane. Of these, dialkoxysilane compounds are preferred.

[0027] The other alkoxysilane compounds are not particularly limited, but include tetraalkoxysilane compounds such as tetramethoxysilane and tetraethoxysilane; trialkoxysilane compounds such as methyltrimethoxysilane, ethyltrimethoxysilane, hexyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, benzyltrimethoxysilane, methyltriethoxysilane, and phenyltriethoxysilane; and dialkoxysilane compounds such as dimethyldimethoxysilane, methylphenyldimethoxysilane, cyclohexylmethyldimethoxysilane, vinylmethyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, (3-mercaptopropyl)methyldimethoxysilane, and diphenyldimethoxysilane. Of these, dialkoxysilane compounds are preferred, and dialkoxysilane compounds in which a hydrocarbon group is bonded to a silicon atom are more preferred.

[0028] As the amino group-containing polysiloxane (A) used in the composition of the present disclosure, commercially available products can be used. Among them, commercially available products known as amino-modified silicones are preferred. Preferred commercially available products include, for example, KF-8008, KF-8010, KF-8012, X-22-161A, X-22-161B, X-22-1660B-3, X-22-9409, KF-864, KF-865, KF-868, KF-859, KF-860, KF-880, KF-393, KF-8004, KF-8002, KF-8005, KF-867, KF-8021, KF-869, and KF-861 (all manufactured by Shin-Etsu Chemical Co., Ltd.), DOWSIL BY 16-853U, DOWSIL BY 16-871, DOWSIL BY 16-879B, and DOWSIL BY 16-879B. 16-892 (all manufactured by Dow Toray Industries, Inc.).

[0029] <Polymer (B) Having Structural Unit (U) Derived from Unsaturated Aliphatic Dicarboxylic Acid Monoester> In this specification, the structural unit (U) derived from an unsaturated aliphatic dicarboxylic acid monoester may be simply referred to as the "structural unit (U)," and the polymer (B) having the structural unit (U) derived from an unsaturated aliphatic dicarboxylic acid monoester may be simply referred to as the "polymer (B)."

[0030] The polymer (B) has a structural unit (U) derived from an unsaturated aliphatic dicarboxylic acid monoester as a structural unit. The unsaturated aliphatic dicarboxylic acid is not particularly limited, but preferred examples include unsaturated aliphatic dicarboxylic acids having 4 to 6 carbon atoms, such as maleic acid, fumaric acid, citraconic acid, mesaconic acid, 2-pentenedioic acid, methylenesuccinic acid, 2,4-hexadienedioic acid, and acetylenedicarboxylic acid. Of these, maleic acid is more preferred. One or more of these may be used.

[0031] The unsaturated aliphatic dicarboxylic acid monoester is not particularly limited, and examples thereof include monoalkyl esters and monoaryl esters of the unsaturated aliphatic dicarboxylic acids. These can be obtained, for example, by reacting an unsaturated aliphatic dicarboxylic acid or an unsaturated aliphatic dicarboxylic acid anhydride with a hydroxyl group-containing compound such as an alcohol or phenol. Among these, monoalkyl esters are preferred. Furthermore, the alkyl group in the monoalkyl ester is preferably an alkyl group having 1 to 18 carbon atoms, more preferably an alkyl group having 1 to 12 carbon atoms, even more preferably an alkyl group having 1 to 8 carbon atoms, and particularly preferably an alkyl group having 1 to 6 carbon atoms.

[0032] The polymer (B) is preferably a polymer having a plurality of the structural units (U) as a structural unit, and is also preferably a polymer having the structural unit (U) as a repeating unit. The polymer (B) is more preferably a polymer having a plurality of the structural units (U) as a repeating unit.

[0033] The polymer (B) may be a polymer having only the structural unit (U) as a structural unit, but preferably further has other structural units. The other structural units are not particularly limited, but are preferably structural units derived from polymerizable monomers having ethylenically unsaturated double bonds, and among them, structural units derived from unsaturated aliphatic dicarboxylic acids, structural units derived from unsaturated aliphatic dicarboxylic anhydrides, structural units derived from styrene-based monomers, and structural units derived from (meth)acrylic monomers are more preferred. The polymer (B) preferably has one or more of these structural units as the other structural units.

[0034] The unsaturated aliphatic dicarboxylic acid is as described above, and preferably includes unsaturated aliphatic dicarboxylic acids having 4 to 6 carbon atoms, and among these, maleic acid is more preferred, and it is preferable to include one or more of these. The unsaturated aliphatic dicarboxylic acid anhydride is preferably an anhydride of the preferred unsaturated aliphatic dicarboxylic acid described above, and it is preferable to include one or more of these.

[0035] The styrene-based monomer is not particularly limited, but examples include styrene, α-methylstyrene, p-methylstyrene, tert-methylstyrene, chlorostyrene, vinyltoluene, and 2-styrylethyltrimethoxysilane, and it is preferable to include one or more of these. The styrene-based monomer may have a functional group such as an alkyl group (e.g., methyl group, tert-butyl group), a nitro group, a nitrile group, an alkoxy group, an acyl group, a sulfone group, a hydroxy group, or a halogen atom present on the benzene ring. A polyfunctional styrene-based monomer can also be used as the styrene-based monomer. Divinylbenzene is a preferred example of the polyfunctional styrene-based monomer. Styrene is particularly preferred as the styrene-based monomer.

[0036] The (meth)acrylic monomer is not particularly limited, and examples thereof include conventionally known (meth)acrylic acid, (meth)acrylic acid esters, (meth)acrylamide, (meth)acrylonitrile, etc., and it is preferable to include one or more of these. As the (meth)acrylic acid ester, a polyfunctional (meth)acrylate can also be used. As the (meth)acrylic monomer, (meth)acrylic acid is preferred.

[0037] The polymer (B) preferably has a structural unit derived from a styrene-based monomer as the other structural unit, and more preferably has a structural unit derived from styrene. The presence of a structural unit derived from a styrene-based monomer tends to suppress cure shrinkage during curing.

[0038] As described above, the polymer (B) is preferably a polymer having, as structural units, the structural unit (U) derived from an unsaturated aliphatic dicarboxylic acid monoester and another structural unit, more preferably a polymer having the structural unit (U) and a structural unit derived from a (meth)acrylic monomer and / or a structural unit derived from a styrene monomer, still more preferably a polymer having the structural unit (U) and a structural unit derived from a styrene monomer, and particularly preferably a polymer having the structural unit (U) and a structural unit derived from a styrene.

[0039] The content of the structural unit (U) in the polymer (B) is preferably 20 parts by mass or more and 100 parts by mass or less, relative to 100 parts by mass of all structural units constituting the polymer. From the viewpoint of mechanical strength, the lower limit is more preferably 25 parts by mass or more, and even more preferably 30 parts by mass or more. From the viewpoint of suppressing cure shrinkage, the upper limit is more preferably 80 parts by mass or less, and even more preferably 70 parts by mass or less. That is, the content of the structural unit (U) is preferably 20 to 100 parts by mass, 25 to 80 parts by mass, or 30 to 70 parts by mass, relative to 100 parts by mass of all structural units in the polymer (B).

[0040] The ratio of the structural unit (U) to the other structural units in the polymer (B) is not particularly limited, but the ratio of the structural unit (U) to 100 parts by mass of the other structural units is preferably 20 parts by mass or more and 500 parts by mass or less. From the viewpoint of mechanical strength, the lower limit is more preferably 25 parts by mass or more, and even more preferably 30 parts by mass or more. From the viewpoint of suppressing cure shrinkage, the upper limit is more preferably 400 parts by mass or less, and even more preferably 300 parts by mass or less. That is, the ratio of the structural unit (U) to 100 parts by mass of the other structural units is preferably 20 to 500 parts by mass, more preferably 25 to 400 parts by mass, and even more preferably 30 to 300 parts by mass.

[0041] The content of the structural units derived from the styrene-based monomer in the polymer (B) is preferably 0 to 80 parts by mass, more preferably 20 to 75 parts by mass, and even more preferably 30 to 70 parts by mass, relative to 100 parts by mass of all structural units constituting the polymer.

[0042] The content of the structural units derived from the (meth)acrylic monomer in the polymer (B) is preferably 0 to 80 parts by mass, more preferably 20 to 75 parts by mass, and even more preferably 30 to 70 parts by mass, relative to 100 parts by mass of all structural units constituting the polymer.

[0043] The content of the structural units derived from the unsaturated aliphatic dicarboxylic acid in the polymer (B) is preferably 0 to 80 parts by mass, more preferably 20 to 75 parts by mass, and even more preferably 30 to 70 parts by mass, relative to 100 parts by mass of all structural units constituting the polymer.

[0044] The content of the structural units derived from the unsaturated aliphatic dicarboxylic acid anhydride in the polymer (B) is preferably 0 to 90 parts by mass, more preferably 20 to 85 parts by mass, and even more preferably 30 to 80 parts by mass, relative to 100 parts by mass of all structural units constituting the polymer.

[0045] The polymer (B) may further have another structural unit other than the structural unit (U), the structural unit derived from an unsaturated aliphatic dicarboxylic acid, the structural unit derived from an unsaturated aliphatic dicarboxylic anhydride, the structural unit derived from a styrene-based monomer, and the structural unit derived from a (meth)acrylic monomer. When the polymer (B) further has another structural unit, the content thereof is preferably 10 parts by mass or less, more preferably 7 parts by mass or less, and even more preferably 5 parts by mass or less, relative to 100 parts by mass of all structural units constituting the polymer.

[0046] The structural unit (U) derived from the unsaturated aliphatic dicarboxylic acid monoester has a carboxy group (COOH) and / or a carboxylate (COOM), preferably one having a carboxy group. In other words, in the structural unit (U) contained in the polymer (B), the non-esterified carboxy group of the unsaturated aliphatic dicarboxylic acid is a carboxy group or a salt thereof, preferably a carboxy group. The polymer (B) preferably contains a structural unit (U) having a carboxy group as the structural unit (U). The proportion of the structural unit (U) having a carboxy group in the polymer (B) is not particularly limited, but is preferably 50 mol or more, more preferably 80 mol or more, and particularly preferably 100 mol, relative to 100 mol of the total amount of the structural units (U) contained in the polymer (B).

[0047] The carboxy group equivalent of the polymer (B) is not particularly limited, but is preferably 100 to 500 g / mol. From the viewpoint of mechanical strength, the lower limit is more preferably 125 g / mol or more, and even more preferably 150 g / mol or more. From the viewpoint of suppressing cure shrinkage, the upper limit is more preferably 450 g / mol or less, and even more preferably 400 g / mol or less. That is, the carboxy group equivalent of the polymer (B) is more preferably 125 to 450 g / mol, and even more preferably 150 to 400 g / mol. The carboxy group equivalent can be a value obtained by a measurement method in accordance with the method described in JIS K 2501:2003. Specifically, the carboxy group equivalent can be determined by the following method, and it is preferable to use a value obtained by the following method.

[0048] (Method for measuring carboxyl group equivalent) The amount of sample to be measured for acid value is accurately weighed and dissolved in the titration solvent, and a glass electrode and reference electrode are immersed in the solution. The sample is then titrated with 0.1 mol / L 2-propanolic potassium hydroxide standard solution. A plot is drawn of the relationship between the potentiometer or pH meter reading and the corresponding titration amount of 2-propanolic potassium hydroxide standard solution, and the inflection point on the titration curve is taken as the endpoint. The total acid value is calculated from the amount of 0.1 mol / L 2-propanolic potassium hydroxide standard solution consumed. The carboxyl group equivalent can be determined by calculating the number of moles of carboxyl groups per unit mass from the total acid value and then taking the reciprocal.

[0049] The molecular weight of the polymer (B) is not particularly limited, but from the viewpoints of mechanical strength and solvent solubility, the weight average molecular weight is preferably 3,000 to 120,000. From the viewpoint of mechanical strength, the lower limit of the weight average molecular weight is more preferably 4,000 or more, even more preferably 5,000 or more, and from the viewpoint of solvent solubility, the upper limit is more preferably 100,000 or less, even more preferably 80,000 or less. That is, the weight average molecular weight of the polymer (B) is more preferably 4,000 to 100,000, even more preferably 5,000 to 80,000. The weight average molecular weight can be measured by GPC (gel permeation chromatography) using polystyrene as a standard substance, tetrahydrofuran as an eluent, a high-speed GPC apparatus HLC-8320GPC (manufactured by Tosoh Corporation), and a TSKgel SuperHZ-N (manufactured by Tosoh Corporation) as a column.

[0050] The method for producing the polymer (B) is not particularly limited, and the polymer (B) can be produced by a conventionally known polymerization method such as solution polymerization, emulsion polymerization, or suspension polymerization. Among these, a method using solution polymerization is preferred. For example, a polymer (B) having a structural unit (U) can be obtained by radical polymerization of a monomer composition containing at least an unsaturated aliphatic dicarboxylic acid monoester in a single or mixed solvent such as an ether such as dioxane, a hydrocarbon such as toluene, or a ketone such as acetone, using a radical polymerization initiator.

[0051] The monomer composition may consist of only one or more unsaturated aliphatic dicarboxylic acid monoesters, or may further contain monomers that serve as raw materials for the other structural units, such as unsaturated aliphatic dicarboxylic acid anhydrides, unsaturated aliphatic dicarboxylic acids, (meth)acrylic monomers, and styrene monomers.

[0052] In the above polymerization method, instead of a monomer composition containing at least an unsaturated aliphatic dicarboxylic acid monoester, a monomer composition containing at least an unsaturated aliphatic dicarboxylic acid anhydride is used, and a radical polymerization reaction is carried out in the same manner as above to obtain a polymer (b) having structural units derived from the unsaturated aliphatic dicarboxylic acid anhydride. Then, an esterification reaction is carried out to convert some or all of the structural units into structural units (U), thereby obtaining a polymer (B). In this case, the monomer composition may consist solely of one or more unsaturated aliphatic dicarboxylic acid anhydrides, or may further contain monomers that serve as raw materials for the other structural units, such as (meth)acrylic monomers and styrene-based monomers. Examples of the esterification reaction include a method in which the polymer (b) is reacted with a compound containing a hydroxy group, such as an alcohol or phenol.

[0053] Alternatively, in the above method, instead of the monomer composition containing at least an unsaturated aliphatic dicarboxylic acid anhydride, a monomer composition containing at least an unsaturated aliphatic dicarboxylic acid is used, and a radical polymerization reaction is carried out in the same manner as above to obtain a polymer (b) having structural units derived from an unsaturated aliphatic dicarboxylic acid, and then an esterification reaction is carried out to convert some or all of the structural units into structural units (U), thereby obtaining the polymer (B).

[0054] As the polymer (B) used in the composition of the present disclosure, a commercially available product can be used as it is, or a commercially available product obtained by esterifying an acid anhydride. For example, commercially available products of the polymer (B) include Arastar 700 (manufactured by Arakawa Chemical Industries, Ltd.), XIRAN 1440, XIRAN 2625, XIRAN 17352, XIRAN 3840 (manufactured by Polyscope Co., Ltd.), etc., and one or more of these can be preferably used.

[0055] Commercially available polymers containing structural units derived from acid anhydrides of unsaturated aliphatic dicarboxylic acids include XIRAN1000, XIRAN2000, XIRAN2500, XIRAN3000, XIRAN3500, XIRAN3600, XIRAN4000, XIRAN6000, XIRAN9000, EF10, EF30, EF40, EF41, EF61, and EF80 (all manufactured by POLYSCOPE), and monoesters of one or more of these can be used as polymer (B).

[0056] <Blending Ratio, etc.> In the composition of the present disclosure, the blending ratio of the amino group-containing polysiloxane (A) to the polymer (B) is not particularly limited, but it is preferable that the amino group-containing polysiloxane (A) and the polymer (B) are contained so that the ratio of the structural units (U) in the polymer (B) to the amino groups in the amino group-containing polysiloxane (A) is 1 / 3 to 3 / 1, expressed as a molar ratio. The molar ratio is more preferably 1 / 2 to 2 / 1, and even more preferably 1 / 1. It is also preferable that the ratio of the carboxy groups in the polymer (B) to the amino groups in the amino group-containing polysiloxane (A) is the same as the molar ratio.

[0057] The total content of the amino group-containing polysiloxane (A) and the polymer (B) in the composition of the present disclosure is not particularly limited, but is preferably 5 to 100 parts by mass, more preferably 10 to 80 parts by mass, still more preferably 15 to 70 parts by mass, and particularly preferably 20 to 60 parts by mass, relative to 100 parts by mass of the composition of the present disclosure.

[0058] The content of the amino group-containing polysiloxane (A) in the composition of the present disclosure is not particularly limited, but is preferably 1 to 70 parts by mass, more preferably 5 to 60 parts by mass, and even more preferably 10 to 50 parts by mass, relative to 100 parts by mass of the composition of the present disclosure.

[0059] <Other Components> The composition of the present disclosure may contain a solvent in addition to the amino group-containing polysiloxane (A) and the polymer (B). The solvent is not particularly limited. Examples include polar solvents such as water, alcohols, glycols, glycol derivatives, ethers, esters, ketones, dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, dimethylsulfoxide, sulfolane, and γ-butyrolactone; and hydrocarbon solvents. One or more of these can be used. Among these, it is preferable to contain a polar solvent and a hydrocarbon solvent.

[0060] Among the above polar solvents, alcohols, glycols, glycol derivatives, dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, dimethylsulfoxide, sulfolane, and γ-butyrolactone are preferred, and glycol derivatives are more preferred.

[0061] The alcohols are not particularly limited, but methanol, ethanol, isopropyl alcohol, 1-propanol, 1-butanol, cyclohexanol, etc. are preferred. The glycols are not particularly limited, but ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, glycerin, etc. are preferred. The glycol derivatives are not particularly limited, but examples include glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, and propylene glycol monobutyl ether; glycol monoacetates such as ethylene glycol monoacetate and propylene glycol monoacetate; ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, and the like. Of the glycol derivatives, glycol monoalkyl ethers are preferred.

[0062] The hydrocarbon solvent is not particularly limited, but examples thereof include aliphatic hydrocarbons such as 1-hexane, 1-heptane, and cyclohexane; aromatic hydrocarbons such as toluene and xylene; terpenes such as limonene; etc. Among these, aromatic hydrocarbons and terpenes are preferred, and terpenes are more preferred.

[0063] The content of the solvent in the composition of the present disclosure is not particularly limited, but is preferably 25 to 400 parts by mass, relative to 100 parts by mass of the total content of the amino group-containing polysiloxane (A) and the polymer (B) in the composition of the present disclosure. It is more preferably 50 parts by mass or more, and even more preferably 70 parts by mass or more. The upper limit is more preferably 250 parts by mass or less, and even more preferably 150 parts by mass or less. That is, the content of the solvent is more preferably 50 to 250 parts by mass, and even more preferably 70 to 150 parts by mass, relative to 100 parts by mass of the total content of the amino group-containing polysiloxane (A) and the polymer (B). By containing a solvent in the above range in the composition of the present disclosure, when the composition of the present disclosure is used as a coating composition, a film with excellent film thickness uniformity is more easily obtained.

[0064] The composition of the present disclosure may contain inorganic particles. The inclusion of inorganic particles tends to result in a cured product with improved mechanical strength. The inorganic particles preferably have a low dielectric constant, and the dielectric constant at 10 GHz is preferably 4.0 or less. More preferably, it is 3.5 or less, and even more preferably, it is 3.0 or less. The lower limit is not particularly limited, but is, for example, 0.5 or more. That is, the dielectric constant of the inorganic particles at 10 GHz is preferably 0.5 to 4.0, more preferably 0.5 to 3.5, and even more preferably 0.5 to 3.0. The dielectric constant can be determined as follows.

[0065] (Method for measuring the dielectric constant of inorganic particles) Using a cell filled with inorganic particles as a measurement sample, the dielectric constant is measured at a frequency of 10 GHz using a cavity resonator perturbation method. The measurement is performed in an atmosphere with a temperature of 25°C and a humidity of 50%. The measurement sample is prepared by cutting a polytetrafluoroethylene tube to a length of 10 cm, packing one side with 3 to 5 mm of sealing tape to create a tightly sealed cell, and filling this with inorganic particles. The packing rate of the inorganic particles is calculated from the true density, weight, and volume of the inorganic particles, and the dielectric constant of the inorganic particles is determined using the measurement result using a cell not filled with inorganic particles as a blank.

[0066] The inorganic particles may be crystalline or amorphous in terms of X-ray diffraction, but are preferably amorphous. The structure of the inorganic particles is not particularly limited, and may be a porous structure or a dense structure. They may also be hollow. The shape of the inorganic particles is not particularly limited, and may be any of amorphous, granular, plate-like, columnar, needle-like, etc., but granular is preferred, and among granular shapes, spherical is preferred. The granular shape means a uniform shape with an aspect ratio of 1.5 or less.

[0067] The inorganic particles preferably have an organic group introduced onto their surface. The introduction of the organic group tends to improve the dispersibility of the inorganic particles in the composition of the present disclosure. The organic group is not particularly limited, but examples thereof include hydrocarbon groups such as alkyl groups and aryl groups, (meth)acrylic groups, vinyl groups, and amino groups, and among these, aryl groups and (meth)acrylic groups are preferred.

[0068] The method for introducing organic groups onto the surfaces of the inorganic particles is not particularly limited, but examples thereof include a method in which a silane coupling agent having the organic group, a compound having a phosphate group, or an alcohol is reacted with the surfaces of the inorganic particles, preferably a method in which the hydroxyl groups or alkoxy groups present on the surfaces of the inorganic particles are reacted.

[0069] The average particle size of the inorganic particles is not particularly limited, but is preferably in the range of 1 nm to 1000 nm. When the average particle size of the inorganic particles is in the above range, a thin film having excellent uniformity in physical properties such as dielectric constant tends to be easily obtained. The average particle size of the inorganic particles is more preferably 100 nm or less, even more preferably 50 nm or less, and particularly preferably 20 nm or less. The lower limit is more preferably 5 nm or more. That is, the average particle size of the inorganic particles is more preferably 5 to 100 nm, even more preferably 5 to 50 nm, and particularly preferably 5 to 20 nm.

[0070] The average particle size can be determined by observing the inorganic particles with a SEM (magnification 1,000 to 100,000 times, preferably 10,000 times), analyzing the resulting image to determine the particle sizes (circular area equivalent diameters) of approximately 10 to 1,000 individual particles (primary particles), and evaluating the 50% particle size in the number-based particle size distribution. For the image analysis, known image analysis software (e.g., Mac-View manufactured by Mountech Co., Ltd.) can be used.

[0071] Examples of materials constituting the inorganic particles include inorganic oxides, inorganic nitrides, inorganic carbides, inorganic sulfides, and inorganic hydroxides.The inorganic particles may be composed of one of these materials, or may contain two or more of them.From the viewpoint of easily obtaining a cured product with excellent insulating properties, the materials constituting the inorganic particles are preferably silica, boron nitride, alumina, titania, and zirconia, more preferably silica and alumina, and particularly preferably silica.The silica may be crystalline silica or amorphous silica, but amorphous silica is preferred.

[0072] The content of the inorganic particles is not particularly limited, but from the viewpoint of easily obtaining a cured product with improved mechanical strength, for example, the content of the inorganic particles is preferably 5 to 100 parts by mass relative to 100 parts by mass of the total content of the amino group-containing polysiloxane (A) and the polymer (B) in the composition of the present disclosure. It is more preferably 15 parts by mass or more, and even more preferably 25 parts by mass or more. The upper limit is more preferably 60 parts by mass or less, and even more preferably 50 parts by mass or less. That is, the content of the inorganic particles is more preferably 15 to 60 parts by mass, and even more preferably 25 to 50 parts by mass, relative to 100 parts by mass of the total content of the amino group-containing polysiloxane (A) and the polymer (B).

[0073] The composition of the present disclosure may contain an antioxidant. The antioxidant is not particularly limited, and conventionally known antioxidants can be used, such as phenolic antioxidants, thioether antioxidants, and phosphite antioxidants. In order to more effectively exhibit antioxidant performance, it is preferable to use a phenolic antioxidant in combination with a thioether antioxidant. When the composition of the present disclosure contains an antioxidant, the content of the antioxidant is preferably 0.1 to 5 parts by mass, more preferably 0.5 to 2 parts by mass, per 100 parts by mass of the total content of the amino group-containing polysiloxane (A) and the polymer (B) in the composition of the present disclosure.

[0074] The composition of the present disclosure may contain a thickener to improve processability and stability. Examples of thickeners that can be used include high-viscosity polymers that are soluble or dispersible in organic solvents and clays. Examples include polyester-based thickeners, polyamide-based thickeners, polyimide-based thickeners, polyamic acid (polyamic acid)-based thickeners, and montmorillonite clay-based thickeners. Among these, polyimide-based thickeners and polyamic acid-based thickeners are preferred from the viewpoint of maintaining or reducing the heat resistance and dielectric constant of the cured product after heating. When the composition of the present disclosure contains a thickener, the content of the thickener is preferably 1 to 40 parts by mass, more preferably 2.5 to 35 parts by mass, and even more preferably 5 to 30 parts by mass, per 100 parts by mass of the total content of the amino group-containing polysiloxane (A) and the polymer (B) in the composition of the present disclosure.

[0075] In addition to the components described above, the composition of the present disclosure may contain additives such as a curing accelerator, as long as the effects of the present invention are not impaired.

[0076] [Method for preparing the composition of the present disclosure] The method for preparing the composition of the present disclosure is not particularly limited, and the composition can be prepared by mixing the respective components using a conventionally known method. For example, the composition of the present disclosure can be obtained by mixing the amino group-containing polysiloxane (A) and the polymer (B) in a predetermined ratio. When the amino group-containing polysiloxane is liquid, it may be mixed as is, or may be mixed in the form of a solution dissolved in the above-mentioned preferred solvent. When the amino group-containing polysiloxane is solid, it is preferably mixed in the form of a solution dissolved in the above-mentioned preferred solvent. The same applies to the polymer (B). The mixing method is not particularly limited, and a conventionally known mixing method such as stirring may be used.

[0077] When the composition of the present disclosure contains the inorganic particles, the inorganic particles are preferably dispersed in a solvent and mixed with the mixture of the amino group-containing polysiloxane (A) and the polymer (B). The preferred solvents described above are preferably used as the solvent for dispersing the inorganic particles. The dispersion method for dispersing the inorganic particles is not particularly limited, and examples thereof include conventionally known mixing and dispersion methods such as melt kneading, mixers, ball mills, jet mills, dispersers, sand mills, roll mills, pot mills, and paint shakers. A dispersant or the like may be appropriately added as needed. When the composition of the present disclosure contains additives such as an antioxidant or a curing accelerator, these additives may be added directly or as a solution dissolved in a solvent during or after mixing the amino group-containing polysiloxane (A) and the polymer (B).

[0078] The composition of the present disclosure can be prepared by the method described above. In preparing the composition of the present disclosure, it is preferable to further perform a degassing treatment. By performing a degassing treatment, it is possible to prevent air bubbles from being mixed into the cured product obtained by curing the composition of the present disclosure. Furthermore, it is preferable to perform filtration using, for example, a filter with a pore size of approximately 0.2 to 1 μm, for the purpose of removing foreign matter or the like that has been mixed in during the preparation. Filtration can prevent deterioration in quality due to foreign matter in the composition of the present disclosure and in the cured product obtained using the composition.

[0079] [Cured product and insulating film of the present disclosure] The composition of the present disclosure is preferably used as a curable composition. The cured product of the present disclosure is a cured product obtained by curing the composition of the present disclosure described above. There are no particular limitations on the method for producing the cured product of the present disclosure, as long as it is a method for producing a cured product by curing the composition of the present disclosure, but it preferably includes the following steps 1 and 2 in this order: Step 1: A coating step of coating the composition of the present disclosure onto a substrate; Step 2: A curing step of curing the coated composition

[0080] The method for applying the composition to the substrate in step 1 above is not particularly limited. For example, methods such as spin coating, slit coating, spraying, roll coating, inkjet printing, screen printing, gravure printing, flexographic printing, and dipping can be used. The thickness of the coating film is not particularly limited, but is preferably 10 to 250 μm. It is more preferably 20 μm or more, and even more preferably 30 μm or more. The upper limit is more preferably 200 μm or less, and even more preferably 150 μm or less. In other words, the thickness of the coating film is more preferably 20 to 200 μm, and even more preferably 30 to 150 μm. It is preferable to adjust the thickness of the coating film so that it has a preferred film thickness as a cured product, as described below.

[0081] Examples of the substrate include metal substrates, silicon / inorganic substrates, and composite materials. Examples of the metal substrate include substrates whose surface is primarily composed of a metal such as aluminum, copper, gold, silver, titanium, or molybdenum. Examples of the silicon / inorganic substrate include substrates whose primary components are silicon-related materials such as silicon, silicon nitride, and silicon oxide, and inorganic materials such as glass and quartz. Examples of the composite substrate include substrates made of resin, silicon, silicon nitride, silicon oxide, glass, quartz, or the like, with a thin metal film or the like provided on part or all of the surface. The shape of the substrate is not particularly limited. For example, a plate-like or linear shape is preferred. Among the substrates, silicon / inorganic substrates and metal substrates are preferred, and metal substrates are more preferred, from the viewpoint that a cured product having excellent adhesion to the cured product of the present disclosure is likely to be obtained.

[0082] The curing method in step 2 is preferably a heating method. The heating temperature can be selected appropriately depending on the type of substrate, heating time, etc., but is typically preferably in the range of 100 to 400°C, and more preferably in the range of 150 to 350°C. The heating time can be selected appropriately depending on the type of substrate, heating temperature, etc., but is typically preferably 1 minute to 10 hours, more preferably 10 minutes or more, and even more preferably 30 minutes or more. The upper limit is more preferably 5 hours or less. Heating may be performed by continuously increasing the temperature at a predetermined rate and maintaining the temperature at the predetermined temperature. Alternatively, a method in which the heating temperature is increased stepwise can be used, for example, by performing a first heating step at a temperature of 100°C or higher but less than 200°C for a predetermined time, a second heating step at a temperature of 200°C or higher but less than 300°C for a predetermined time, and a third heating step at a temperature of 300°C or higher but less than 400°C for a predetermined time. The heating atmosphere is not particularly limited, but it is preferably performed in an inert atmosphere such as a nitrogen gas atmosphere or an oxidizing atmosphere such as air.

[0083] The step 2 is usually preferably carried out after the step 1, but a method of carrying out the step 2 and the step 1 simultaneously can also be adopted. This method can be achieved, for example, by carrying out coating while heating the substrate in the step 1.

[0084] When the composition of the present disclosure contains a solvent, it is preferable to carry out the following step 3. Step 3: Solvent Removal Step for Removing Part or All of the Solvent from the Applied Composition In the solvent removal step, a method using heating, a method using reduced pressure (degassing), or a combination of these is preferably used as the method for removing the solvent. Therefore, in the solvent removal step, part or all of the solvent is distilled off from the film of the composition applied to the substrate by heating and / or reduced pressure (degassing), etc. The heating temperature in the solvent removal step is preferably 50 to 150°C, more preferably 120°C or less, and even more preferably less than 100°C. The heating time is preferably 30 seconds to 2 hours, more preferably 10 minutes to 1 hour.

[0085] The above step 3 is preferably carried out after the above step 1, but can also be carried out simultaneously with step 1. Furthermore, the above step 3 is preferably carried out before the above step 2, but can also be carried out simultaneously with step 2. After carrying out the above step 1, a method is preferred in which the substrate and the composition applied to the substrate are heated, and steps 2 and 3 are carried out successively. In this manner, a cured product is formed by curing the composition of the present disclosure on the surface and / or inside of various substrates.

[0086] The film thickness of the cured product is not particularly limited, but is preferably 5 to 500 μm. It is more preferably 10 μm or more, and even more preferably 15 μm or more. The upper limit is more preferably 400 μm or less, and even more preferably 300 μm or less. That is, the film thickness of the cured product is more preferably 10 to 400 μm, and even more preferably 15 to 300 μm. The film thickness can be measured using a micrometer.

[0087] The dielectric constant of the cured product is not particularly limited, but the dielectric constant at 10 GHz is preferably 2.0 or more and 2.9 or less. It is more preferably 2.7 or less, even more preferably 2.6 or less, and particularly preferably 2.5 or less. The lower limit is more preferably 2.1 or more. That is, the dielectric constant of the cured product at 10 GHz is more preferably 2.1 to 2.7, even more preferably 2.1 to 2.6, and particularly preferably 2.1 to 2.5. The dielectric constant can be measured using a network analyzer E8361A (manufactured by Agilent Technologies) by a cavity resonator perturbation method under conditions of a temperature of 25°C, humidity of 50%, and a frequency of 10 GHz, and it is preferable to use the value obtained by this method.

[0088] The cured product has excellent heat resistance. For example, it is preferable that the temperature at which weight loss begins in air is high. Specifically, the temperature at which the weight loss of a cured product reaches 5% by mass when the product is heated from room temperature in an air atmosphere at a heating rate of 10°C / min is referred to as the 5% weight loss temperature. The 5% weight loss temperature of the cured product is preferably 340°C or higher, more preferably 360°C or higher, and even more preferably 380°C or higher. The upper limit is not particularly limited, but is usually 450°C or lower. That is, the 5% weight loss temperature of the cured product is preferably 340 to 450°C, more preferably 360 to 450°C, and even more preferably 380 to 450°C. The 5% weight loss temperature can be measured using a TG-DTA device, and it is preferable to use the value obtained by this method. As the TG-DTA device, TG-DTA2000SR (manufactured by NESZTCH) and MTC1000SA (manufactured by Bruker) are recommended.

[0089] The elongation of the cured product is not particularly limited, but is preferably 5 to 100%. It is more preferably 10% or more, even more preferably 20% or more, even more preferably 30% or more, and particularly preferably 40% or more. The upper limit is more preferably 150% or less. That is, the elongation of the cured product is more preferably 10 to 150%, even more preferably 20 to 150%, even more preferably 30 to 150%, and particularly preferably 40 to 150%. The elongation refers to the elongation at break when a tensile test is conducted, and can be measured by the following method. It is preferable to use the value obtained by this method. (Method for Measuring Elongation) A dumbbell-shaped cutout was punched out from the cured product film so that the area to be tested for the tensile test was 1 cm wide and 3 cm long, and the punched piece was used as a sample. Using an autograph (AG-X Plus, manufactured by Shimadzu Corporation), the sample was stretched at 5 mm / min, the length at break was measured, and the elongation (%) was calculated using the following formula: Elongation (%) = {(length at break (cm) - 3 cm) / 3 cm} x 100

[0090] The cured product is preferably an insulating film. Preferred aspects of the insulating film, such as film thickness, dielectric constant, elongation, and 5% weight loss temperature, are the same as those of the cured product.

[0091] [Uses of the Composition of the Present Disclosure] The uses of the composition of the present disclosure, the cured product thereof, and the insulating film are not particularly limited and can be used for a variety of applications. The composition of the present disclosure is preferably used to form insulating films for electric and electronic devices, such as those found in electronic devices such as computers, communication devices such as mobile phones, and network-related electronic devices such as servers. In particular, it is preferably used to form insulating films that insulate metal wiring, other metal wiring, conductive members, and the like, on substrates such as silicon in electric and electronic devices. Furthermore, insulated electric wires for high-voltage electric devices, such as motors, are required to have a high corona discharge inception voltage, and it is said that reducing the dielectric constant of the insulating layer in the insulated electric wire is effective. Therefore, the composition of the present disclosure can be suitably used to form an insulating layer for the insulated electric wire that constitutes the electric coil of the motor.

[0092] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "parts" means "parts by mass" and "%" means "% by mass."

[0093] <Evaluation of Dielectric Constant> The dielectric constant of each of the cured films obtained in each of the Examples and Comparative Examples was measured as a sample using a network analyzer E8361A (manufactured by Agilent Technologies) by a cavity resonator perturbation method under conditions of a temperature of 25°C, a humidity of 50%, and a frequency of 10 GHz.

[0094] <Evaluation of Heat Resistance: Measurement of 5% Weight Loss Temperature> The cured film obtained in each Example and Comparative Example was used as a sample and heated from room temperature to 500°C at a rate of 10°C per minute in an air stream using a TG-DTA2000SR (manufactured by NESZTCH) or an MTC1000SA (manufactured by Bruker). The temperature at which the weight loss reached 5% was measured and defined as the 5% weight loss temperature.

[0095] <Evaluation of Elongation> The cured film obtained in each Example and Comparative Example was used as a sample. The cured film was punched into a dumbbell shape so that the area to be tested for tensile strength was 1 cm wide and 3 cm long, and the punched piece was used as a sample. Using an autograph (AG-X plus, manufactured by Shimadzu Corporation), the film was stretched at 5 mm / min, and the elongation at break was measured. The elongation (%) was calculated using the following formula: Elongation (%) = {(length at break (cm) - 3 cm) / 3 cm} x 100

[0096] Synthesis Example 1 (Step 1A) 16,500 g of methanol, 3,200 g of water, 1,300 g of 25% aqueous ammonia, and 110 g of acetone were added to a 50 L SUS vessel equipped with a stirrer, a dropping port, and a thermometer, and the mixture was stirred for 30 minutes to obtain a homogeneous mixed solution. The temperature of the mixed solution was adjusted to 49-51°C, and while stirring, 5,700 g of tetramethyl orthosilicate (TMOS) was added dropwise from the dropping port over 90 minutes. After the dropwise addition, stirring was continued for 30 minutes while maintaining the above liquid temperature, to obtain an alcoholic solution suspension of silica particles (Suspension 1A).

[0097] (Step 1B) The temperature of the suspension 1A obtained in step 1A was again raised to 50°C while stirring, and 1,620 g of 3-methacryloxypropyltrimethoxysilane (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.) was added dropwise from the dropping port over 260 minutes while maintaining the liquid temperature. After completion of the dropwise addition, stirring was continued for 15 hours while maintaining the liquid temperature, thereby obtaining an alcoholic solution suspension of silica particles having methacryl groups on the particle surfaces (Suspension 1B).

[0098] (Step 1C) The suspension 1B obtained in the step 1B is subjected to solvent substitution at room temperature using a commercially available ultrafiltration membrane equipped with a ceramic tubular ultrafiltration membrane having a molecular weight cutoff of about 10,000, while adding methanol appropriately, to obtain SiO ２ The suspension was concentrated to a concentration of about 11%, thereby obtaining a methanol suspension of silica particles having methacrylic groups on the particle surface (Suspension 1C).

[0099] (Step 1D) The suspension 1C obtained in step 1C was passed through a column packed with a hydrogen-type strongly acidic cation exchange resin, Amberlite IR-120B (manufactured by Organo Corporation), at room temperature at a flow rate of 3 gases per hour, to obtain a methanol suspension of silica particles having methacrylic groups on the particle surfaces (suspension 1D).

[0100] (Step 1E) 1800 g of the suspension 1D obtained in the step 1D was weighed, and the solvent was concentrated by vacuum distillation using a rotary evaporator at a reduced pressure of 30 to 300 hPa and 40°C while propylene glycol monomethyl ether (PGM) was gradually added to replace the solvent in the suspension with PGM, and SiO ２ By concentrating the dispersion to a concentration of approximately 50%, a PGM dispersion of silica particles having methacrylic groups on the particle surface (Dispersion 1) was obtained. The average particle diameter of the silica particles in the dispersion was 24 nm. The average particle diameter was measured using a scanning electron microscope JSM-7600F manufactured by JEOL Ltd., and the diameters of 50 random particles from the SEM image were measured with a vernier caliper, and the arithmetic mean value of the diameters of the 50 particles was adopted. When photographing with the scanning electron microscope, the measurement magnification was set so that 50 to 100 particles were included in the field of view of one photograph.

[0101] Example 1 A vial was charged with 3.44 g of KF-8012 (manufactured by Shin-Etsu Chemical Co., Ltd., functional group equivalent weight: 2200 g / mol), an amino-modified silicone, as the amino group-containing polysiloxane (A), 1.00 g of a solution prepared by dissolving Arastar 700 (manufactured by Arakawa Chemical Industries, Ltd., carboxy group equivalent weight: 175 to 200 g / mol), a styrene / maleic acid half ester copolymer, in propylene glycol monopropyl ether to a concentration of 50% by mass, as the polymer (B), and 3.20 g of propylene glycol monopropyl ether and 2.95 g of xylene as solvents, and the mixture was stirred to obtain a uniform solution. To the resulting solution, 3.38 g of Dispersion 1 obtained in Synthesis Example 1 above, 0.1 g of a solution in which Adekastab AO-30 (manufactured by ADEKA Corporation) as an antioxidant was dissolved in 1-butanol to a concentration of 20% by mass, and 0.1 g of a solution in which Adekastab AO-503 (manufactured by ADEKA Corporation) was dissolved in 1-butanol to a concentration of 20% by mass were added, and the mixture was kneaded using a foam-removing kneader (manufactured by THINKY Corporation, ARE-300) at 2000 rpm for 3 minutes, and then at 2200 rpm for 2 minutes as a degassing step, to obtain Composition (1).

[0102] The resulting composition (1) was applied to a flat PTFE plate at a constant thickness and thermally cured by heating at 100°C for 30 minutes, 200°C for 30 minutes, 250°C for 30 minutes, and 300°C for 1 hour, forming a cured film (1) with a thickness of 100 to 150 μm on the PTFE plate. The PTFE plate was then peeled off to obtain a free-standing film of the cured film (1). The dielectric constant and other properties of the cured film (1) were evaluated. The results are shown in Table 2.

[0103] [Examples 2 to 7, Comparative Examples 1 and 2] The compositions of Examples 2 to 7 were prepared in the same manner as Example 1, except that the types and amounts of the components, such as the amino group-containing polysiloxane (A) and polymer (B), in Example 1 were changed as shown in Table 1. Using each of the resulting compositions, cured films (2) to (7) were obtained in the same manner as Example 1. On the other hand, the compositions of Comparative Examples 1 and 2 experienced phase separation and gelation, making it impossible to obtain a uniform composition and produce a cured film. The dielectric constant, 5% weight loss temperature, and elongation of each of the cured films obtained in these Examples were evaluated. The results are shown in Table 2.

[0104]

[0105] The commercially available products used in each example and comparative example (listed in Table 1) are as follows: KF-8012: Shin-Etsu Chemical Co., Ltd., amino-modified silicone oil (both terminal type), amino group equivalent 2200 g / mol. KF-8010: Shin-Etsu Chemical Co., Ltd., amino-modified silicone oil (both terminal type), amino group equivalent 430 g / mol. KF-864: Shin-Etsu Chemical Co., Ltd., amino-modified silicone oil (side chain type), amino group equivalent 3800 g / mol. DOWSIL BY 16-879B: Dow-Toray Industries, Inc., amino-modified silicone oil, amino group equivalent 7500 g / mol. Arastar 700: Arakawa Chemical Co., Ltd., styrene-maleic acid resin half ester, acid value 175 to 200. XIRAN3500: manufactured by Polyscope Polymers, styrene-maleic anhydride copolymer (structural units derived from styrene / structural units derived from maleic acid = molar ratio of 3 / 1), weight average molecular weight 80,000. ADK STAB AO-30: manufactured by ADEKA Corporation, phenol-based antioxidant. ADK STAB AO-503: manufactured by ADEKA Corporation, thioether-based antioxidant. The total (parts by mass) value (100) in Table 1 is rounded to one decimal place.

[0106]

[0107] As shown in Table 2, it was confirmed that the cured films obtained in Examples 1 to 7 all had a high 5% weight loss temperature, a low dielectric constant at a frequency of 10 GHz, and high elongation. Therefore, it was revealed that by using the composition of the present disclosure, it is possible to obtain cured products that have excellent heat resistance, a low dielectric constant measured in the high frequency range, and high elongation.

[0108] (Thickener Synthesis Example 1) 2.5 g of XIRAN 3500 (styrene-maleic anhydride copolymer, manufactured by POLYSCOPE) and 2.5 g of butyl acetate were placed in a vial and dissolved with heating and stirring at 60° C. To the resulting solution, a solution prepared by dissolving 0.8 g of 2-ethylhexylamine in 0.8 g of butyl acetate and 2.0 g of propylene glycol monopropyl ether was added dropwise to obtain thickener (1).

[0109] Example 8: To 100 parts by mass of the composition (1) obtained in Example 1, 4 parts by mass of the thickener (1) obtained above was added and stirred to obtain a composition (8). The viscosities of the resulting compositions (8) and (1) were measured at 25°C using an E-type viscometer (TPE-100, manufactured by Toki Sangyo Co., Ltd.) and found to be 1010 mPa·s and 300 mPa·s, respectively. The resulting composition (8) was applied to a flat PTFE plate at a constant thickness and thermally cured by heating at 100°C for 30 minutes, 200°C for 30 minutes, 250°C for 30 minutes, and 300°C for 1 hour to form a cured film (8) with a film thickness of 150 μm on the PTFE plate. The PTFE plate was then peeled off to obtain a freestanding film of the cured film (8). The dielectric constant of the cured film (8) was 2.69, and the 5% weight loss temperature was 380°C.

Claims

1. The present invention relates to a polymer composition comprising an amino group-containing polysiloxane (A), a structural unit (U) derived from an unsaturated aliphatic dicarboxylic acid monoester, and a structural unit (B) derived from a styrene-based monomer, the content of the structural unit (U) derived from the unsaturated aliphatic dicarboxylic acid monoester is 25 parts by mass or more per 100 parts by mass of all structural units constituting the polymer (B).

2. The composition of claim 1 further comprising inorganic particles.

3. The composition described in claim 1, wherein the content of the structural unit (U) derived from the unsaturated aliphatic dicarboxylic acid monoester in the polymer (B) is 25 parts by mass or more and 80 parts by mass or less, relative to 100 parts by mass of all structural units constituting the polymer (B).

4. The composition described in claim 1, wherein the content of the structural unit derived from the styrene-based monomer in the polymer (B) is 20 to 75 parts by mass per 100 parts by mass of all structural units constituting the polymer (B).

5. The composition of claim 1, further comprising a solvent.

6. The composition described in claim 1 for application.

7. A cured product obtained by curing the composition according to any one of claims 1 to 6.

8. The cured product according to claim 7 , which is an insulating film.