Modified hydrogenated aromatic vinyl polymer

Abstract

To provide a modified hydrogenated aromatic vinyl polymer that exhibits superior solvent solubility and low dielectric properties while maintaining adhesion to a substrate such as a metal.SOLUTION: A modified hydrogenated aromatic vinyl polymer is a modified product of a hydrogenated aromatic vinyl polymer with an unsaturated carboxylic acid or an anhydride thereof, the modified product having a modification rate of 0.1 to 2 mass%. The hydrogenated aromatic vinyl polymer may be hydrogenated polystyrene, and the hydrogenated aromatic vinyl polymer may have a hydrogenation level of 90% or more.SELECTED DRAWING: None

Description

Technical Field

[0001] An object of the present invention is to provide a modified hydrogenated aromatic vinyl polymer having excellent solvent solubility, heat resistance, low dielectric properties, and adhesiveness to substrates such as metals.

Background Art

[0002] Generally, as an electric and electronic circuit board, an insulating board obtained by laminating and subjecting to a pressure and heat treatment sheets (prepregs) impregnated with a resin dissolved in an organic solvent on a substrate such as paper or glass, called a copper-clad laminate (CCL), and then applying a copper foil to the surface thereof, or a flexible printed circuit board (FPC), which is obtained by bonding a conductor foil such as copper via an insulating adhesive layer on a flexible base film, is mainly used.

[0003] Here, as the resin for the prepreg and the insulating adhesive layer, thermosetting resins such as epoxy resins, acrylic resins, phenolic resins, polyphenylene ether resins, polyimide resins, and bismaleimide resins are used. A varnish in which these thermosetting resins are dissolved in an organic solvent is applied, and after lamination, it is thermoset by heating and pressurization to obtain a circuit board excellent in heat resistance, adhesiveness, water resistance, mechanical strength, and electrical properties. In recent years, multilayer circuit boards used in electric and electronic devices have been progressing in miniaturization, weight reduction, and high functionality of the devices, and further requirements such as further multilayerization, high density, thinning, weight reduction, and improvement of reliability and moldability have been demanded.

[0004] An important performance required for materials including resin materials constituting electric and electronic components such as laminates for electric and electronic circuits is low dielectric properties. In recent years, for the improvement of the information transmission amount and speed, the communication frequency has been increasing, and among them, the increase in transmission loss (α) has become a major problem. The lower the value of this transmission loss (α), the less the attenuation of the information signal, which means that high reliability of communication can be ensured. Since α is proportional to the frequency (f), α increases in communication in the high-frequency region, leading to a decrease in reliability. Further, α is the dielectric tangent (tanδ) and the dielectric constant (ε r) is also proportional to the square root of α. Therefore, as a method for suppressing α, methods such as reducing tanδ and ε can be mentioned. r For high-speed transmission of communication signals, materials with low tanδ and ε, that is, materials with low dielectric properties, are required. r

[0005] For example, epoxy resin is widely used as a resin for circuit boards because of its excellent adhesiveness and heat resistance. However, various improvements and inventions have been made because tanδ and ε r are large. Specifically, Patent Documents 1 and 2 disclose inventions of a modified hydrogenated block copolymer and its composition that improve solvent solubility and adhesiveness to a substrate such as metal in order to improve the low dielectric properties of materials for electrical and electronic components such as laminates for electrical and electronic circuits. In addition, Patent Document 3 discloses an invention using a modified hydrogenated aromatic vinyl polymer for the purpose of improving the compatibilization of a hydrogenated aromatic vinyl polymer and an inorganic filler.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, the modified hydrogenated block copolymers of Patent Documents 1 and 2 have insufficient solvent solubility, making it difficult to produce sheets and adhesive layers. The modified hydrogenated aromatic vinyl polymer of Patent Document 3 has insufficient low dielectric properties.

[0008] The present invention has been made in view of such problems. That is, an object of the present invention is to provide a modified hydrogenated aromatic vinyl polymer that has adhesiveness to a substrate such as metal and is excellent in solvent solubility and low dielectric properties. **Means for Solving the Problems**

[0009] As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by using a modified product of a hydrogenated aromatic vinyl polymer with an unsaturated carboxylic acid or its anhydride. That is, the present invention has the following features.

[0010] [1] A modified hydrogenated aromatic vinyl polymer which is a modified product of a hydrogenated aromatic vinyl polymer with an unsaturated carboxylic acid or its anhydride, and the modification rate of the modified product is 0.1 to 2% by mass. [2] The modified hydrogenated aromatic vinyl polymer according to [1], wherein the hydrogenated aromatic vinyl polymer is hydrogenated polystyrene. [3] The modified hydrogenated aromatic vinyl polymer according to [1] or [2], wherein the hydrogenated aromatic vinyl polymer has a hydrogenation level of 90% or more.

[0011] [4] A laminate in which a layer containing the modified hydrogenated aromatic vinyl polymer according to [1] or [2] is laminated on a substrate. [5] The laminate according to [4], wherein the layer containing the modified hydrogenated aromatic vinyl polymer is at least one selected from a filling layer, an adhesive layer, an insulating layer, and a substrate core layer. [6] The modified hydrogenated aromatic vinyl polymer according to [1] or [2], which is for electric and electronic parts. [7] An electric and electronic part containing the modified hydrogenated aromatic vinyl polymer according to [1] or [2].

[0012] [8] A polymer-containing varnish obtained by mixing 1 to 60% by mass of the modified hydrogenated aromatic vinyl polymer according to [1] or [2] and 40 to 99% by mass of an organic solvent. A thermosetting resin-containing varnish obtained by adding at least one thermosetting resin selected from epoxy resins, acrylic resins, phenolic resins, polyphenylene ether resins, polyimide resins, and bismaleimide resins and a curing agent to the polymer-containing varnish described in [9][8].

[10] A method for manufacturing an electric / electronic component by applying the polymer-containing varnish described in [8] to a substrate.

[11] A method for manufacturing an electric / electronic component by applying the thermosetting resin-containing varnish described in [9] to a substrate.

[0013]

[12] An adhesive for electric / electronic components containing the modified hydrogenated aromatic vinyl polymer described in [1] or [2].

[13] The adhesive for electric / electronic components described in

[12] in film form or liquid form.

[14] A material for semiconductor encapsulation containing the modified hydrogenated aromatic vinyl polymer described in [1] or [2].

[15] A copper-clad laminate having a layer containing the modified hydrogenated aromatic vinyl polymer described in [1] or [2].

[0014]

[16] A flexible printed wiring board having a layer containing the modified hydrogenated aromatic vinyl polymer described in [1] or [2].

[17] A multilayer printed wiring board having a layer containing the modified hydrogenated aromatic vinyl polymer described in [1] or [2].

[18] An insulating sheet containing the modified hydrogenated aromatic vinyl polymer described in [1] or [2].

[19] A prepreg containing the modified hydrogenated aromatic vinyl polymer described in [1] or [2].

[20] A capacitor containing the modified hydrogenated aromatic vinyl polymer described in [1] or [2]. [Effect of the Invention]

[0015] According to the present invention, it is possible to provide a modified hydrogenated aromatic vinyl polymer that has excellent adhesion to substrates such as metals, and also has excellent solvent solubility and low dielectric properties. [Embodiments for Carrying Out the Invention]

[0016] The present invention will be described in detail below. However, the following description is only an example of the embodiments of the present invention, and the present invention is not limited to the following description as long as it does not exceed the gist of the invention. When the expression "~" is used below, it shall be used as an expression including the numerical values or physical property values before and after it.

[0017] The modified hydrogenated aromatic vinyl polymer of the present invention is a modified product of a hydrogenated aromatic vinyl polymer with an unsaturated carboxylic acid and / or an unsaturated carboxylic anhydride.

[0018] <Hydrogenated aromatic vinyl polymer> The hydrogenated aromatic vinyl polymer used as a raw material for the modified hydrogenated aromatic vinyl polymer of the present invention is obtained by homopolymerizing or copolymerizing an aromatic vinyl monomer to obtain an aromatic vinyl polymer, and then hydrogenating it. The aromatic vinyl monomer is a monomer represented by the general formula (1).

[0019] [Chemical formula]

[0020] In this general formula (1), R is hydrogen or an alkyl group. This alkyl group may be mono-substituted or multi-substituted with a functional group such as a halo group, a nitro group, an amino group, a hydroxy group, a cyano group, a carbonyl group, and a carboxyl group. The number of carbon atoms of the alkyl group is preferably 1 to 6. Among these, R is preferably hydrogen.

[0021] Also, in this general formula (1), Ar is a phenyl group, a biphenyl group, a halophenyl group, an alkylphenyl group, an alkylhalophenyl group, a naphthyl group, a pyridinyl group, or an anthracenyl group. Among these, the above Ar is preferably a phenyl group or an alkylphenyl group, and more preferably a phenyl group.

[0022] Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, vinyltoluene (including all isomers, particularly p-vinyltoluene), ethylstyrene, propylstyrene, butylstyrene, vinylbiphenyl, vinylnaphthalene, vinylanthracene (all isomers), and mixtures thereof.

[0023] The hydrogenation of the aromatic vinyl polymer can be carried out by hydrogenation of the aromatic vinyl polymer by a general method, specifically, nuclear hydrogenation.

[0024] Examples of the hydrogenated aromatic vinyl polymer include hydrogenated products of aromatic vinyl polymers such as polystyrene, styrene / α-methylstyrene copolymer, and styrene / vinylnaphthalene copolymer. Among these, hydrogenated polystyrene, which is a hydrogenated product of polystyrene, is preferred.

[0025] The lower limit of the weight average molecular weight (Mw) of the hydrogenated aromatic vinyl polymer is preferably 100,000 or more. The upper limit of Mw is preferably 400,000 or less, more preferably 300,000 or less, and still more preferably 200,000 or less. If Mw is at least the lower limit value, the mechanical strength does not decrease, and if it is at most the upper limit value, the moldability does not deteriorate.

[0026] Here, the Mw of the hydrogenated aromatic vinyl polymer is a value in terms of polystyrene measured under the following conditions using gel permeation chromatography (GPC). · Equipment: "GPC HLC-8220" manufactured by Tosoh Corporation · Column: Three "PLgel 5μm Mixed-B (7.5 mm I.D. × 30 cm l × 2)" manufactured by Agilent Technologies, Inc. (The calibration of the column was performed by measuring monodisperse polystyrene (0.5 mg / mL solutions of A500, A2500, F1, F2, F4, F10, F20, F40, F288) manufactured by Tosoh Corporation, and the elution volume and the logarithm of the molecular weight were approximated by a cubic equation.) · Detector: RI (internal organ) · Solvent: Chloroform · Temperature: 40 °C · Flow rate: 1.0 mL / min · Injection volume: 100 μL · Concentration: 0.1 mass%

[0027] Further, the hydrogenation level of the hydrogenated aromatic vinyl polymer is preferably 90% or more, more preferably 95% or more, and still more preferably 97% or more. Note that the hydrogenation level of the hydrogenated aromatic vinyl polymer indicates the ratio at which the aromatic vinyl polymer is saturated by hydrogenation. Such a high level of hydrogenation is preferable for heat resistance and low dielectric properties. The hydrogenation level of the hydrogenated aromatic vinyl polymer is determined using proton NMR.

[0028] <Hydrogenation level of hydrogenated aromatic vinyl polymer> [Measurement by proton NMR] · Apparatus: "AVANCE400 spectrometer" manufactured by Bruker · Solvent: Tetrachloroethane · Concentration: 0.045 g / 1.0 mL · Measurement: Proton NMR · Resonance frequency: 400 MHz · Flip angle: 45 degrees · Data acquisition time: 4 seconds · Pulse repetition time: 10 seconds · Number of integrations: 64 · Measurement temperature: 80 °C · Hydrogenation level of aromatic vinyl polymer block unit: Reduction rate of integral value at 6.8 - 7.5 ppm

[0029] The melt flow rate (MFR) of the hydrogenated aromatic vinyl polymer is preferably 0.1 g / 10 min or more, more preferably 0.2 g / 10 min or more, from the viewpoints of the molding method and the appearance of the molded article. Also, from the viewpoint of material strength, it is preferably 200 g / 10 min or less, more preferably 100 g / 10 min or less, and still more preferably 50 g / 10 min or less. Note that the MFR was measured according to ISO R1133 under the conditions of a measurement temperature of 230 °C and a measurement load of 2.16 kg.

[0030] The hydrogenated aromatic vinyl polymer may be used alone, or two or more thereof having different monomer unit compositions, physical properties, etc. may be used in combination.

[0031] <Modification operation of the hydrogenated aromatic vinyl polymer> Next, the modification operation of the hydrogenated aromatic vinyl polymer will be described. This modification operation is carried out by adding an unsaturated carboxylic acid and / or its anhydride as a modifier to the hydrogenated aromatic vinyl polymer and reacting them.

[0032] Examples of the unsaturated carboxylic acid and / or its anhydride as the modifier include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, nadic acids, and anhydrides thereof. Specific examples of the acid anhydride include maleic anhydride, citraconic anhydride, and nadic anhydrides.

[0033] Examples of the nadic acids or their anhydrides include endo-cis-bicyclo[2.2.1]hept-2,3-dicarboxylic acid (nadic acid (trademark)), methyl-endo-cis-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid (methyl nadic acid (trademark)), and their anhydrides. Among these unsaturated carboxylic acids and / or their anhydrides, acrylic acid, maleic acid, nadic acid, maleic anhydride, and nadic anhydride are preferred. The unsaturated carboxylic acid and / or its anhydride may be used alone or in combination of two or more.

[0034] By modifying the hydrogenated aromatic vinyl polymer with the above-mentioned unsaturated carboxylic acid and / or its anhydride, a modified hydrogenated aromatic vinyl polymer can be obtained. As the modification method, solution modification, melt modification, solid-phase modification by irradiation with electron beams or ionizing radiation, modification in supercritical fluids, etc. are preferably used. Among these, melt modification excellent in equipment and cost competitiveness is preferable, and melt kneading modification using an extruder excellent in continuous productivity is more preferable. Examples of the apparatus used at this time include a single-screw extruder, a twin-screw extruder, a Banbury mixer, and a roll mixer. Among these, a single-screw extruder and a twin-screw extruder excellent in continuous productivity are preferable.

[0035] Generally, the modification of a hydrogenated aromatic vinyl polymer with an unsaturated carboxylic acid and / or its anhydride is carried out by a graft reaction in which the carbon-hydrogen bond of the secondary carbon of the main chain constituting the hydrogenated aromatic vinyl polymer is cleaved to generate a carbon radical, and an unsaturated functional group is added thereto. As a source of carbon radicals, in addition to the electron beam and ionizing radiation described above, a method of raising the temperature or a radical generator such as an azo compound, an inorganic peroxide, or an organic peroxide can also be used.

[0036] Examples of the azo compound include azobisisobutyronitrile, azobisdimethylvaleronitrile, azobis(2-methylbutyronitrile), and dizonitrophenol. Examples of the inorganic peroxide include hydrogen peroxide, potassium peroxide, sodium peroxide, calcium peroxide, magnesium peroxide, and barium peroxide.

[0037] Examples of the organic peroxide include those included in the group of hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxy esters, and ketone peroxides. Specifically, hydroperoxides such as cumene hydroperoxide and t-butyl hydroperoxide; dialkyl peroxides such as dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, and 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3; diacyl peroxides such as lauryl peroxide and benzoyl peroxide; peroxy esters such as t-butyl peroxyacetate, t-butyl peroxybenzoate, and t-butyl peroxyisopropyl carbonate; and ketone peroxides such as cyclohexanone peroxide can be mentioned. These radical generators may be used alone or in combination of two or more. Among these radical generators, from the viewpoints of cost and operability, it is preferable to use an organic peroxide as the radical generator.

[0038] [Melt-kneading modification] The generally used melt-kneading modification operation is to blend a radical generator such as a hydrogenated aromatic vinyl polymer, an unsaturated carboxylic acid and / or its anhydride, and an organic peroxide, put it into a kneader or an extruder, and perform extrusion while heating and melt-kneading, and cool the molten resin coming out from the tip die in a water tank or the like to obtain a modified hydrogenated aromatic vinyl polymer.

[0039] The blending ratio of the hydrogenated aromatic vinyl polymer and the unsaturated carboxylic acid and / or its anhydride is preferably 0.2 to 5 parts by mass of the unsaturated carboxylic acid and / or its anhydride with respect to 100 parts by mass of the hydrogenated aromatic vinyl polymer. If the blending ratio of the unsaturated carboxylic acid and / or its anhydride with respect to the hydrogenated aromatic vinyl polymer is at least the above lower limit, a predetermined modification rate necessary for achieving the effects of the present invention can be obtained. Also, if it is at most the above upper limit, unreacted unsaturated carboxylic acid and / or its anhydride will not remain, and it will not have an adverse effect on the adhesive strength and low dielectric characteristics.

[0040] When an organic peroxide is used as the radical generator, the mixing ratio of the unsaturated carboxylic acid and / or its anhydride and the organic peroxide is preferably 1 to 100 parts by mass of the organic peroxide with respect to 100 parts by mass of the unsaturated carboxylic acid and / or its anhydride. If the mixing ratio of the organic peroxide with respect to the unsaturated carboxylic acid and / or its anhydride is at least the lower limit, a predetermined modification rate necessary for achieving the effects of the present invention can be obtained. Further, if it is at most the upper limit, deterioration of the hydrogenated aromatic vinyl polymer does not occur and the hue does not deteriorate. As the melt-kneading modification conditions, for example, in a single-screw extruder or a twin-screw extruder, it is preferable to extrude at a temperature of 200 to 300°C.

[0041] [Molecular weight reduction of the modified hydrogenated aromatic vinyl polymer] By treating the hydrogenated aromatic vinyl polymer or the modified hydrogenated aromatic vinyl polymer with an organic peroxide, the secondary carbon-hydrogen bond of the main chain constituting the hydrogenated aromatic vinyl polymer or the modified hydrogenated aromatic vinyl polymer is once cleaved, and from the generated carbon radical structure, carbon-carbon bond cleavage accompanied by β-hydrogen elimination occurs, causing molecular weight reduction, and a modified hydrogenated aromatic vinyl polymer having a low molecular weight can be obtained from a hydrogenated aromatic vinyl polymer or a modified hydrogenated aromatic vinyl polymer having a high molecular weight. This operation may be performed after the modification or simultaneously with the modification. That is, by blending a large amount of the organic peroxide, molecular weight reduction can be caused simultaneously with the modification.

[0042] When performing molecular weight reduction on the modified hydrogenated aromatic vinyl polymer, the mixing ratio of the modified hydrogenated aromatic vinyl polymer and the organic peroxide is 0.01 to 2 parts by mass of the organic peroxide with respect to 100 parts by mass of the modified hydrogenated aromatic vinyl polymer. As the melt-kneading modification conditions, for example, in a single-screw extruder or a twin-screw extruder, it is preferable to extrude at a temperature of 200 to 300°C.

[0043] [Modification rate] The modification rate of the modified hydrogenated aromatic vinyl polymer with the unsaturated carboxylic acid and / or its anhydride is 0.1% by mass or more from the viewpoint of adhesion strength, preferably 0.3% by mass or more, and more preferably 0.5% by mass or more. On the other hand, from the viewpoint of low dielectric properties, it is 2% by mass or less. If the modification rate is at least the above lower limit, sufficient adhesion strength can be obtained. Further, if it is at most the above upper limit, there is no generation of odor or deterioration of color, the solubility in an organic solvent is also good, and the low dielectric properties are excellent. The low dielectric properties mean that the dielectric tangent and the dielectric constant are low, and it becomes possible to suppress the dielectric tangent and the dielectric constant of the entire resin composition by adding the modified hydrogenated aromatic vinyl polymer and the modified hydrogenated aromatic vinyl polymer to a thermosetting resin, and an improvement in signal transmission efficiency can be expected when used as a laminate for electric and electronic circuits.

[0044] The dielectric tangent of the modified hydrogenated aromatic vinyl polymer at a measurement frequency of 10 GHz is preferably less than 0.005, more preferably less than 0.0025, and even more preferably less than 0.001. The lower the dielectric tangent, the more likely it is to suppress the transmission loss at high frequencies. Also, the dielectric constant of the modified hydrogenated aromatic vinyl polymer according to the present invention is preferably low. Specifically, at a measurement frequency of 10 GHz, it is preferably 2.4 or less, more preferably 2.3 or less, and even more preferably 2.2 or less. The lower the dielectric constant, the more likely it is to suppress the transmission loss at high frequencies. The in-plane dielectric properties of the modified hydrogenated aromatic vinyl polymer flat plate can be measured by using an electric press machine to produce a flat plate under the conditions of a molding temperature of 230 to 250 ° C and a press pressure of 5 to 10 MPa, and using this flat plate and the cavity resonator method.

[0045] The dielectric tangent of the modified hydrogenated aromatic vinyl polymer tends to slightly deteriorate due to modification with an unsaturated carboxylic acid and / or its anhydride. Therefore, in order to keep the dielectric tangent low, it is necessary to control the modification rate as described later. The modification rate of the modified hydrogenated aromatic vinyl polymer can be measured by proton NMR after subjecting the modified hydrogenated aromatic vinyl polymer to methyl esterification treatment.

[0046] <Modification rate of modified hydrogenated aromatic vinyl polymer> [Measurement by proton NMR] · Apparatus: "AVANCE400 spectrometer" manufactured by BRUKER · Solvent: Heavy orthodichlorobenzene · Concentration: 20 mg / 0.62 mL · Measurement: Proton NMR · Resonance frequency: 400 MHz · Flip angle: 45 degrees · Data acquisition time: 4 seconds · Pulse repetition time: 10 seconds · Number of integrations: 64 · Measurement temperature: 120 °C · Modification rate of the modified hydrogenated aromatic vinyl polymer by unsaturated carboxylic acid and / or its anhydride: Reduction rate of integral value at 3.42 - 3.94 ppm

[0047] The modification rate of the modified hydrogenated aromatic vinyl polymer means the content rate of the unsaturated carboxylic acid and / or its derivative component calculated from the absorption specific to the carboxylic acid and / or its derivative when measured with an infrared spectroscopic measuring device (JASCO FT / IR610, manufactured by JASCO Corporation) using a calibration curve created from the quantitative value obtained by quantifying the unsaturated carboxylic acid and / or its derivative component in the modified hydrogenated aromatic vinyl polymer by proton NMR. For example, the absorption specific to the carboxylic acid and / or its derivative in a sample press-molded into a sheet shape with a thickness of about 100 μm, specifically 1900 - 1600 cm -1It can be determined by measuring the carbonyl characteristic absorption of (C=O stretching vibration band). Incidentally, in the modification with an unsaturated carboxylic acid and / or its anhydride, although 100% is not used for the reaction and the unsaturated carboxylic acid and / or its anhydride that has not reacted with the raw material propylene-based polymer may remain in the modified hydrogenated aromatic vinyl polymer, the modification rate (graft rate) in the present invention shall mean the value measured by the above method.

[0048] <Heat resistance> The heat resistance of the modified hydrogenated aromatic vinyl polymer according to this invention can be evaluated by the Vicat softening temperature, and the higher this is, the higher the heat resistance, which is preferable. The Vicat softening temperature of a general modified hydrogenated aromatic vinyl polymer is in the range of 130°C to 350°C. This Vicat softening temperature can be measured by first using an injection molding machine to injection mold a flat plate with a thickness of 2 mm and dimensions of 4 cm × 8 cm at a molding temperature of 270°C and a mold temperature of 70°C. Then, three of the obtained flat plates are stacked and measured by the method described in JIS K7206 (1999).

[0049] <Varnish of modified hydrogenated aromatic vinyl polymer> The modified hydrogenated aromatic vinyl polymer of the present invention can be dissolved in an organic solvent to form a varnish (hereinafter, may be referred to as a "polymer-containing varnish"). Here, the varnish represents a state in which the modified hydrogenated aromatic vinyl polymer is dissolved in an organic solvent. That is, it represents a state in which the modified hydrogenated aromatic vinyl polymer is molecularly dispersed in the organic solvent.

[0050] The modified hydrogenated block polymer known as a low dielectric material has insufficient solubility in organic solvents and, even if it dissolves, gels and is not suitable for coating. However, the modified hydrogenated aromatic vinyl polymer of the present invention exhibits specific properties in this regard. That is, the modified hydrogenated aromatic vinyl polymer of the present invention has good compatibility with organic solvents and can obtain a polymer-containing varnish without gelation. Since the modified hydrogenated aromatic vinyl polymer of the present invention has good compatibility with an organic solvent, when a polymer-containing varnish is applied as described below, it has excellent thickness accuracy, and it is difficult to generate defects such as foreign matter, peeling, and surface abnormalities (for example, orange peel) during application, and it is possible to produce high-quality sheets, laminates, adhesive layers, etc.

[0051] The reason why the modified hydrogenated aromatic vinyl polymer and the organic solvent have good compatibility is that the modified hydrogenated aromatic vinyl polymer has a modified site, and by using an organic peroxide as a radical generator, during the modification operation, the modification and molecular weight reduction treatment, or the molecular weight reduction treatment performed after the modification, is affected by the fact that the weight average molecular weight (Mw) of the obtained modified hydrogenated aromatic vinyl polymer decreases. The upper limit of the weight average molecular weight (Mw) of this modified hydrogenated aromatic vinyl polymer is preferably 300,000 or less, more preferably 200,000 or less, and still more preferably 100,000 or less. Also, the lower limit of Mw is preferably 10,000 or more, more preferably 20,000 or more, and still more preferably 30,000 or more. If Mw is below the above upper limit value, compatibility with the organic solvent can be ensured, and if it is above the above lower limit value, a decrease in mechanical strength can be suppressed.

[0052] Examples of the organic solvent in which the modified hydrogenated aromatic vinyl polymer of the present invention can be dissolved include aromatic solvents, aliphatic solvents, alicyclic solvents, and cyclic ether solvents. Examples of the aromatic solvent include benzene, toluene, xylene, ethylbenzene, chlorobenzene, bromonaphthalene, etc., examples of the aliphatic solvent include hexane, heptane, octane, nonane, decane, etc., examples of the alicyclic solvent include cyclopentane, cyclohexane, cycloheptane, cyclodecane, etc., and examples of the cyclic ether solvent include tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, 4-methyltetrahydropyran, etc. These may be used alone or in combination of two or more. Among these, from the viewpoints of handleability and ease of distillation, toluene, cyclohexane, and tetrahydrofuran are preferred, and toluene is particularly preferred.

[0053] Also, organic solvents other than those described above can be added as long as the effects of the present invention are not inhibited. Examples of other organic solvents that can be used include ketones such as acetone, methyl ethyl ketone, cyclohexanone, acetophenone, and benzophenone; alcohols such as methanol, ethanol, isopropyl alcohol, and butanol; phenols such as phenol, cresol, and naphthol; ethers such as ethylene glycol monomethyl ether; and amides such as N,N-dimethylformamide and N,N-dimethylacetamide.

[0054] The concentration of the modified hydrogenated aromatic vinyl polymer or the entire polymer such as the modified hydrogenated aromatic vinyl polymer and the thermosetting resin in the polymer-containing varnish is preferably 1 to 60% by mass. Within the above concentration range, the solution viscosity becomes appropriate, and gelation does not occur, so it can be suitably used for coating work. The concentration of the modified hydrogenated aromatic vinyl polymer or the entire polymer such as the modified hydrogenated aromatic vinyl polymer and the thermosetting resin in the varnish is more preferably 2 to 40% by mass.

[0055] [Solvent Solubility] The solvent solubility of the modified hydrogenated aromatic vinyl polymer according to this invention can be evaluated by the following method. First, using the above organic solvent as the solvent, mix the modified hydrogenated aromatic vinyl polymer so as to have the concentration to be measured in the organic solvent, and stir in an oil bath heated to 60°C for 20 minutes. Then, let it return to room temperature. At this time, if it is visually judged that the modified hydrogenated aromatic vinyl polymer is completely dissolved and has fluidity, it can be evaluated that it has solubility. On the other hand, if undissolved portions of the modified hydrogenated aromatic vinyl polymer can be visually confirmed, it is cloudy, or it has no fluidity and is gelled, it can be evaluated that the solubility is not sufficient.

[0056] [Content of Other Components] The polymer-containing varnish can be applied as it is or after containing other components to a substrate or the like to obtain a laminate. As will be described later, this laminate can be used as an electric and electronic component. As the other components, components that dissolve in the polymer-containing varnish when contained and have specific performances are preferable. Examples of the components having such characteristic performances include thermosetting resins, photocurable resins, curing agents, ultraviolet absorbers, antioxidants, coupling agents, plasticizers, fluxes, flame retardants, colorants, dispersants, emulsifiers, low elasticizing agents, diluents, defoaming agents, ion trap agents, inorganic fillers, organic fillers, and the like.

[0057] [Thermosetting resin] Examples of the thermosetting resin include at least one resin selected from epoxy resins, acrylic resins (thermosetting acrylic resins), phenol resins, polyphenylene ether resins, polyimide resins, and bismaleimide resins. Note that this thermosetting resin is a thermosetting resin before curing. By heating in the presence of the curing agent, the thermosetting resin undergoes a crosslinking reaction or a chain extension reaction to increase its molecular weight and cure.

[0058] [Curing agent] The curing agent indicates, for example, a substance that contributes to the crosslinking reaction and / or the chain length extension reaction between the epoxy groups of the epoxy resin. In the present invention, even a substance that is usually called a "curing accelerator" is regarded as a curing agent as long as it contributes to the crosslinking reaction and / or the chain length extension reaction between the epoxy groups of the epoxy resin.

[0059] In addition, the curing agents for acrylic resins, phenol resins, polyphenylene ether resins, polyimide resins, and bismaleimide resins refer to substances for causing a crosslinking reaction and / or a chain length extension reaction with respect to these resins. There is no particular limitation on the curing agent used for the epoxy resin, and all those generally known as epoxy resin curing agents can be used. As the curing agents used for the above acrylic resin, phenolic resin, and bismaleimide resin, phenolic curing agents, amide curing agents, imidazoles, active ester curing agents, etc. are preferable from the viewpoint of enhancing heat resistance. These curing agents may be used alone or in combination of two or more.

[0060] As the curing agent used for the above polyphenylene ether resin, a curing agent capable of three-dimensionally crosslinking polyphenylene ether can be used. Specifically, as the crosslinking type curing agent, polyfunctional vinyl compounds, vinylbenzyl ether compounds, allyl ether compounds, or trialkenyl isocyanurate can be used.

[0061] The polyfunctional vinyl compounds include divinylbenzene, divinylnaphthalene, and divinylbiphenyl. The vinylbenzyl ether compounds are synthesized by the reaction of phenol and vinylbenzyl chloride. The allyl ether compounds are synthesized by the reaction of styrene monomer, phenol, and allyl chloride. Trialkenyl isocyanurate has good compatibility, and triallyl isocyanurate or triallyl cyanurate can be used.

[0062] As the curing agent used for the above polyimide resin, imidazole compounds such as 1,2-dimethylimidazole, heterocyclic compounds containing a nitrogen atom such as isoquinoline, basic compounds such as triethylamine and triethanolamine, etc. can be mentioned.

[0063] [Content of thermosetting resin and curing agent] In the varnish containing the polymer and the varnish (thermosetting resin-containing varnish) containing the above thermosetting resin and curing agent, the contents of the thermosetting resin and the curing agent can be arbitrarily set according to their types and the intended uses.

[0064] [Laminate of modified hydrogenated aromatic vinyl polymer] The modified hydrogenated aromatic vinyl polymer of the present invention has good adhesive strength to substrates such as metals, glass, and plastics, and can provide a non-sticky adhesive surface, and a laminate with a metal, glass, or plastic can be obtained. The lamination method is not particularly limited, and known lamination methods such as hot pressing, lamination, melt extrusion molding, insert injection molding, plating, etc. can be used.

[0065] In addition, a laminate can also be obtained by applying the polymer-containing varnish to a metal or the like and then removing the solvent. As the coating method, in addition to a bar coater, a blade coater, a die coater, a gravure roll coater, a spray coat, etc., it is also possible to coat with a brush. The coating thickness can be adjusted as needed, but usually 1 to 1000 μm is preferable. It is also possible to distill off the solvent from the coated surface after coating. Usually, it is preferable to use hot air blowing, but it is also possible to combine a reduced pressure treatment and heating, or to perform a pressure press simultaneously.

[0066] Examples of the substrate, which is the material to be coated for obtaining the laminate, include metals and alloys such as copper, aluminum, iron, stainless steel, nickel, zinc, titanium, and tungsten; glasses such as glass plates, glass fiber mats, glass fiber cloths, and glass wool; plastics such as polyethylene, polypropylene, polybutene, ethylene-α-olefin copolymers, propylene-α-olefin copolymers, ethylene-acrylic ester copolymers, ethylene-vinyl monomer copolymers, polyamides, and ethylene-vinyl acetate copolymers (EVOH). These may be in the form of plates or films, or may have other shapes, and may be a single material or a composite, and may be single-layered or laminated.

[0067] Among these substrates, copper is preferable from the viewpoints of electrical conductivity and economy for electronic members such as circuit boards, and aluminum is preferable from the viewpoints of light weight and workability for applications such as battery packaging.

[0068] Examples of the layer containing the modified hydrogenated aromatic vinyl polymer of the present invention in the laminate include a filling layer, an adhesive layer, an insulating layer, a substrate core layer, and the like.

[0069] In addition, the sheet laminated on the base material and peeled off from the base material can be used as a single sheet. In particular, a sheet obtained by laminating a thermosetting resin-containing varnish on the base material and peeling it off from the base material is thermosetting, and thus has particularly excellent strength and heat resistance, and is effective for electrical and electronic components such as circuit boards.

[0070] [Adhesion to Copper-Clad Laminate] As an example of a method for evaluating the adhesion to a laminate, particularly a laminate having a metal laminated on its surface, a method for evaluating the adhesion of the modified hydrogenated aromatic vinyl polymer according to the present invention to a copper-clad laminate can be mentioned. First, the modified hydrogenated aromatic vinyl polymer according to the present invention is laminated on a copper-clad laminate, and then air is blown from a distance of 5 cm with an air gun adjusted to an air pressure of 0.5 MPa, and the adhesion state of the modified hydrogenated aromatic vinyl polymer at that time is visually observed. At this time, if no peeling portion can be confirmed and the entire surface is in an adhered state, it can be determined that the adhesion is good. When this adhesion is good, the life of electrical and electronic components such as circuit boards laminated with the modified hydrogenated aromatic vinyl polymer according to the present invention can be made longer. As the copper-clad laminate, for example, a laminate obtained by impregnating glass fibers with an epoxy resin and thermosetting it (referred to as "glass epoxy") and laminating a copper foil can be used.

[0071] Examples of the method for laminating the modified hydrogenated aromatic vinyl polymer according to the present invention on a copper-clad laminate include, for example, the following methods. First, to obtain a clean copper surface, the copper-clad laminate is immersed in a degreasing agent for 3 minutes and then taken out, and a pretreatment of washing with pure water is performed. Next, pellets of the modified hydrogenated aromatic vinyl polymer according to the present invention are placed on the copper-clad laminate, and after preheating at 230 °C for 10 minutes using an electric press, it is pressed at a pressure of 5 MPa for 3 minutes. Thereby, a modified hydrogenated aromatic vinyl polymer-copper-clad laminate can be produced.

[0072] <Use> The modified hydrogenated aromatic vinyl polymer of the present invention has heat resistance, low dielectric properties, excellent solubility in organic solvents, excellent adhesiveness to metals, glass, and plastics, and an effect that a varnish containing this also gives excellent adhesiveness to metals, glass, and plastics. Therefore, it can be applied to various fields such as adhesives, paints, electrical and electronic components, and insulating materials for electrical and electronic components. In particular, it is useful as materials for electrical and electronic components such as insulation casting, laminated materials, and encapsulation materials in the electrical and electronic fields.

[0073] Also, as an example of the use of the modified hydrogenated aromatic vinyl polymer of the present invention or a varnish using this, laminated plates for electrical and electronic circuits such as copper foil laminated plates, flexible printed wiring boards, and multilayer printed wiring boards; adhesives including adhesives for electrical and electronic components such as film adhesives and liquid adhesives; semiconductor encapsulation materials such as semiconductor encapsulants, underfill agents, and interchip fillers such as interchip fillers for 3D-LSI; insulating sheets, prepregs, heat dissipation substrates, capacitors, and low dielectric property modifiers for thermosetting resins used for them can be mentioned.

[0074] <Modified hydrogenated aromatic vinyl polymer laminate containing a conductive metal layer> The modified hydrogenated aromatic vinyl polymer of the present invention can also be suitably used as a laminate containing a conductive metal layer such as the above-mentioned laminated plate for electrical and electronic circuits (modified hydrogenated aromatic vinyl polymer laminate containing a conductive metal layer). In the conductive metal layer-containing modified hydrogenated aromatic vinyl polymer laminate, a layer composed of two or more modified hydrogenated aromatic vinyl polymers may be formed, and the modified hydrogenated aromatic vinyl polymer of the present invention may be used in at least one layer. Further, two or more conductive metal layers may be formed.

Examples

[0075] Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In the following examples and comparative examples, various physical properties were measured by the following methods.

[0076] <Modification rate> Using the above-described measurement method, the modification rate of the modified hydrogenated aromatic vinyl polymer was determined. The higher the modification rate, the higher the adhesive strength obtained, but the low dielectric properties tend to deteriorate.

[0077] <Heat resistance> Using a Sumitomo Heavy Industries, Ltd. SE-18D injection molding machine, a flat plate with a thickness of 2 mm and a size of 4 cm × 8 cm was injection molded at a molding temperature of 270 ° C and a mold temperature of 70 ° C. Three obtained plates were stacked, and the Vicat softening temperature was measured by the method described in JIS K7206 (1999). The measured value of the Vicat softening temperature was used as an evaluation of heat resistance.

[0078] <Adhesiveness> As the copper-clad laminate, a printed circuit board glass epoxy (FR-4) manufactured by Sun Hayato Co., Ltd., single-sided, 1.6t × 100 × 100 mm, and a copper foil thickness of 35 μm was used (note that "t" in "1.6t" means "thickness"). The copper-clad laminate to be used was immersed in a degreasing agent (Sun Hayato Co., Ltd.: Hayabright EX) for 3 minutes, taken out, and pre-treated by washing with pure water. Modified hydrogenated aromatic vinyl polymer pellets were placed on the copper-clad laminate, preheated at 230 ° C for 10 minutes using an electric press, and then pressed at a pressure of 5 MPa for 3 minutes to produce a modified hydrogenated aromatic vinyl polymer-copper-clad laminate. The adhesion strength of the modified hydrogenated aromatic vinyl polymer to the copper-clad laminate was confirmed by blowing air from a distance of 5 cm with an air gun adjusted to an air pressure of 0.5 MPa and visually observing the adhesion state of the modified hydrogenated aromatic vinyl polymer at that time. Those that did not peel off were marked as ○, and those that peeled off were marked as ×.

[0079] <Low dielectric characteristics> Using an electric press, a flat plate of the modified hydrogenated aromatic vinyl polymer with a size of 4 cm × 4 cm and a thickness of 250 μm was produced under the conditions of a molding temperature of 230 to 250°C and a press pressure of 5 to 10 MPa. Using this flat plate, the dielectric tangent and dielectric constant in the in-plane direction of the flat plate were measured using the cavity resonator method. The measurement frequency was set to 10 GHz.

[0080] <Solvent solubility> 2.5 g (10% by mass) and 5.0 g (20% by mass) of the modified hydrogenated aromatic vinyl polymer pellets were respectively placed in screw bottles, and 22.5 g (10% by mass) and 20.0 g (20% by mass) of toluene as an organic solvent were added. Using a stirrer in an oil bath heated to 60°C, after stirring for 20 minutes, the screw bottles were taken out of the oil bath and returned to room temperature. At that time, if the pellets were completely dissolved and had fluidity, the solubility was marked as ○, and if there were unmolten pellets remaining or if it was gelled and had no fluidity, the solubility was marked as ×.

[0081] <Raw materials> [Hydrogenated aromatic vinyl polymer (a-1)] Hydrogenated polystyrene: · Density (ASTM D792): 0.94 g / cm 3 · MFR (230°C, 2.16 kg): 0.5 g / 10 min · Hydrogenation level of the hydrogenated aromatic vinyl polymer: 99.9% or more · Mw: 10,0000 Note that the hydrogenated polystyrene was produced by hydrogenating polystyrene by a general method.

[0082] [Hydrogenated block polymer (b-1)] Manufactured by Mitsubishi Chemical Corporation: Zelas (Trademark Registered) MC930: · Density (ASTM D792): 0.94 g / cm 3 · MFR (230 °C, 2.16 kg): 1 g / 10 min · Hydrogenated aromatic vinyl polymer block unit: Hydrogenated polystyrene with a content of 65 mol% and a hydrogenation level of 99.5% or more · Hydrogenated conjugated diene polymer block unit: Hydrogenated polybutadiene with a content of 35 mol% and a hydrogenation level of 99.5% or more · Block structure: Pentablock structure, total hydrogenation level: 99.5% or more · Mw: 72,000

[0083] [Modified hydrogenated aromatic vinyl polymer (A-1)] Maleic anhydride 1.3 parts by mass and organic peroxide (manufactured by NOF Corporation: Perhexa 25B (2,5-dimethyl-2,5-di(t-butylperoxy)hexane)) 0.065 parts by mass were well stirred at a compounding ratio of 100 parts by mass of the hydrogenated aromatic vinyl polymer (a-1). After that, using a twin-screw extruder (manufactured by Japan Steel Works, Ltd., TEX25αIII), melt-kneading was carried out at a cylinder temperature of 240 °C, a screw rotation speed of 400 rpm, and a discharge rate of 10 kg / h to obtain a modified hydrogenated aromatic vinyl polymer (A-1).

[0084] [Modified hydrogenated block polymer (B-1)] Maleic anhydride 1.3 parts by mass and organic peroxide (manufactured by NOF Corporation: Perhexa 25B (2,5-dimethyl-2,5-di(t-butylperoxy)hexane)) 0.065 parts by mass were well stirred at a compounding ratio of 100 parts by mass of the hydrogenated block polymer (b-1). After that, using a twin-screw extruder (manufactured by Japan Steel Works, Ltd., TEX25αIII), melt-kneading was carried out at a cylinder temperature of 240 °C, a screw rotation speed of 400 rpm, and a discharge rate of 10 kg / h to obtain a modified hydrogenated block polymer (B-1).

[0085] <Example 1> Using the modified hydrogenated aromatic vinyl polymer (A-1), evaluations were carried out on the weight average molecular weight, modification rate, heat resistance, solvent solubility, low dielectric property, and adhesiveness. The results are shown in Table 1.

[0086] <Comparative Example 1> Using the hydrogenated aromatic vinyl polymer (a-1) instead of the modified hydrogenated aromatic vinyl polymer (A-1), evaluations were carried out on the weight average molecular weight, modification rate, heat resistance, solvent solubility, low dielectric property, and adhesiveness in the same manner as in Example 1. The results are shown in Table 1.

[0087] <Comparative Example 2> Using the modified hydrogenated block polymer (B-1) instead of the modified hydrogenated aromatic vinyl polymer (A-1), evaluations were carried out on the weight average molecular weight, modification rate, heat resistance, solvent solubility, low dielectric property, and adhesiveness in the same manner as in Example 1. The results are shown in Table 1.

[0088]

Table 1

[0089] <Results> From Table 1, it was found that Example 1 corresponding to the present invention is excellent in heat resistance, solvent solubility, low dielectric property, and adhesiveness. On the other hand, it was found that the adhesiveness was poor in unmodified Comparative Example 1, and the heat resistance and solvent solubility were poor in Comparative Example 2 containing a hydrogenated conjugated diene polymer block unit.

Industrial Applicability

[0090] The adhesive-modified hydrogenated aromatic vinyl polymer of the present invention is excellent in solvent solubility, heat resistance, low dielectric property, and adhesiveness to substrates such as metals, and is very useful as materials and modifiers for electrical and electronic circuit laminates such as copper foil laminates, flexible printed wiring boards, multilayer printed wiring boards, and capacitors, adhesives such as film adhesives and liquid adhesives, semiconductor encapsulation materials, underfill materials, interchip fills for 3D-LSI, insulating sheets, prepregs, and heat dissipation substrates.

Claims

1. A modified product of a hydrogenated aromatic vinyl polymer with an unsaturated carboxylic acid or its anhydride, The modified hydrogenated aromatic vinyl polymer having a modification rate of the modified product of 0.1 to 2% by mass.

2. The modified hydrogenated aromatic vinyl polymer according to Claim 1, wherein the hydrogenated aromatic vinyl polymer is hydrogenated polystyrene.

3. The modified hydrogenated aromatic vinyl polymer according to Claim 1 or 2, wherein the hydrogenated aromatic vinyl polymer has a hydrogenation level of 90% or more.

4. A laminate in which a layer containing the modified hydrogenated aromatic vinyl polymer according to Claim 1 or 2 is laminated on a substrate.

5. The laminate according to Claim 4, wherein the layer containing the modified hydrogenated aromatic vinyl polymer is at least one selected from a filling layer, an adhesive layer, an insulating layer, and a substrate core layer.

6. The modified hydrogenated aromatic vinyl polymer according to Claim 1 or 2, which is for electrical and electronic parts.

7. An electrical and electronic part containing the modified hydrogenated aromatic vinyl polymer according to Claim 1 or 2.

8. A polymer-containing varnish obtained by mixing 1 to 60% by mass of the modified hydrogenated aromatic vinyl polymer according to Claim 1 or 2 and 40 to 99% by mass of an organic solvent.

9. A thermosetting resin-containing varnish obtained by adding at least one thermosetting resin selected from an epoxy resin, an acrylic resin, a phenolic resin, a polyphenylene ether resin, a polyimide resin, and a bismaleimide resin and a curing agent to the polymer-containing varnish according to Claim 8.

10. A method for manufacturing an electrical and electronic part by coating a substrate with the polymer-containing varnish according to Claim 8.

11. A method for manufacturing an electrical and electronic part by coating a substrate with the thermosetting resin-containing varnish according to Claim 9.

12. An adhesive for electrical and electronic components containing the modified hydrogenated aromatic vinyl polymer according to Claim 1 or 2.

13. The adhesive for electrical and electronic components according to Claim 12, which is in film form or liquid form.

14. A material for semiconductor encapsulation containing the modified hydrogenated aromatic vinyl polymer according to Claim 1 or 2.

15. A copper-clad laminate having a layer containing the modified hydrogenated aromatic vinyl polymer according to Claim 1 or 2.

16. A flexible printed wiring board having a layer containing the modified hydrogenated aromatic vinyl polymer according to Claim 1 or 2.

17. A multilayer printed wiring board having a layer containing the modified hydrogenated aromatic vinyl polymer according to Claim 1 or 2.

18. An insulating sheet containing the modified hydrogenated aromatic vinyl polymer according to Claim 1 or 2.

19. A prepreg containing the modified hydrogenated aromatic vinyl polymer according to Claim 1 or 2.

20. A capacitor containing the modified hydrogenated aromatic vinyl polymer according to Claim 1 or 2.

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