JP7505668B2 - Modified hydrogenated polyolefin, resin composition, insulating film, semiconductor device, and method for producing modified hydrogenated polyolefin - Google Patents

Description

The present invention relates to modified hydrogenated polyolefins, resin compositions, insulating films, semiconductor devices, and methods for producing modified hydrogenated polyolefins. In particular, the present invention relates to resin compositions, insulating films, semiconductor devices, and methods for producing modified hydrogenated polyolefins that are compatible with high frequencies.

In response to recent demands for faster transmission signals on printed wiring boards, the frequency of transmission signals is becoming significantly higher. Accordingly, materials used in printed wiring boards are required to be able to reduce transmission loss in the high frequency range, specifically in the frequency range of 1 GHz or higher.

As an adhesive used for insulating layers of printed wiring boards, for example, a thermosetting resin composition is known that uses modified polyphenylene ether (hereinafter referred to as modified PPE) as a thermosetting resin and further adds a styrene-based thermoplastic elastomer, making it possible to form the composition into a film (Patent Document 1).

Insulating layers of printed wiring boards and the like may be required to have solder heat resistance. From the standpoint of solder heat resistance, it is considered preferable for the thermosetting resin composition to contain a larger number of crosslinking components.

However, if the amount of thermosetting resin is simply increased and the amount of styrene-based thermoplastic elastomer is decreased in order to improve solder heat resistance, there is a problem in that the elastic modulus of the insulating layer, etc. will become high.

In recent years, materials, including insulating layers, are sometimes required to have a low modulus of elasticity at low temperatures, such as 0°C or lower, in addition to a high modulus of elasticity at room temperature. In such cases, previously known resin compositions may not be able to sufficiently reduce the modulus of elasticity.

JP 2016-147945 A

The objective of the present invention is to provide a modified hydrogenated polyolefin that has a low elastic modulus when cured and has excellent solder heat resistance and high-frequency characteristics.

The present invention relates to a modified hydrogenated polyolefin, a resin composition, an insulating film, a semiconductor device, and a method for producing a modified hydrogenated polyolefin, which have the following features and thereby solve the above problems.
[1] A modified hydrogenated polyolefin represented by the formula: (IMA)-(hydroxyl-terminated hydrogenated PO)-(IMA),
Here, IMA is a (meth)acrylate having an isocyanate group represented by the general formula (1): CH ₂ ═CR-COO-R′-NCO (wherein R represents hydrogen or a methyl group, and R′ represents an alkylene group having 1 to 3 carbon atoms);
The hydroxyl-terminated hydrogenated PO is a hydroxyl-terminated hydrogenated polyolefin,
The OH group of the hydroxyl-terminated hydrogenated PO and the NCO group of the IMA form a urethane bond.
[2] A resin composition comprising the modified hydrogenated polyolefin according to [1] above and a styrene-based thermoplastic elastomer.
[3] The resin composition according to [2] above, further comprising a thermosetting resin having a radically polymerizable double bond at a molecular end.
[4] An insulating film comprising the resin composition according to [2] or [3] above.
[5] A cured product of the resin composition described in [2] or [3] above, or a cured product of the insulating film described in [4] above.
[6] A semiconductor device comprising a cured product of the resin composition described in [2] or [3] above, or a cured product of the insulating film described in [4] above.
[7] A method for producing a modified hydrogenated polyolefin represented by the formula: (IMA)-(hydroxyl-terminated hydrogenated PO)-(IMA), which comprises reacting IMA with hydroxyl-terminated hydrogenated PO.
Here, IMA is a (meth)acrylate having an isocyanate group represented by chemical formula (1): CH ₂ ═CR-COO-R′-NCO (wherein R represents a hydrogen atom or a methyl group, and R′ represents an alkylene group having 1 to 3 carbon atoms);
The hydroxyl-terminated hydrogenated PO is a hydroxyl-terminated hydrogenated polyolefin,
The OH group of the hydroxyl-terminated hydrogenated PO and the NCO group of the IMA are bonded to each other through a urethane bond.

According to the present invention [1], it is possible to provide a modified hydrogenated polyolefin whose cured product has a low elastic modulus and excellent solder heat resistance and high frequency characteristics.

According to the present invention [2], it is possible to provide a resin composition that can be formed into a film and has a low dielectric tangent.

According to the present invention [4], it is possible to provide an insulating film in which the cured product has a low elastic modulus, excellent solder heat resistance, and a low dielectric tangent.

According to the present invention [5], it is possible to provide a cured product of the above resin composition or the above insulating film, which has excellent solder heat resistance and a low dielectric loss tangent. According to the present invention [6], it is possible to provide a semiconductor device having excellent solder heat resistance by using a cured product of the above resin composition or the above insulating film, which has excellent solder heat resistance and a low dielectric loss tangent.

According to the present invention [7], it is possible to easily produce a modified hydrogenated polyolefin whose cured product has a low elastic modulus and excellent solder heat resistance and high frequency characteristics.

This is an FT-IR chart. This is an FT-IR chart.

[Modified hydrogenated polyolefin]
The modified hydrogenated polyolefin of the present invention (hereinafter referred to as modified hydrogenated polyolefin) is represented by the formula: (IMA)-(hydroxyl-terminated hydrogenated PO)-(IMA),
Here, IMA is a (meth)acrylate having an isocyanate group represented by the general formula (1): CH ₂ ═CR-COO-R′-NCO (wherein R represents hydrogen or a methyl group, and R′ represents an alkylene group having 1 to 3 carbon atoms);
The hydroxyl-terminated hydrogenated PO is a hydroxyl-terminated hydrogenated polyolefin,
The OH group of the hydroxyl-terminated hydrogenated PO and the NCO group of the IMA form a urethane bond.

This modified hydrogenated polyolefin is compatible with styrene-based thermoplastic elastomers. Therefore, a resin composition containing modified hydrogenated polyolefin and styrene-based thermoplastic elastomer can be made into a film. Furthermore, when modified PPE is used in combination with the resin composition, it is possible to reduce elasticity at low temperatures while taking advantage of the properties of the modified PPE (humidity resistance and heat resistance).

(IMA) is a (meth)acrylate having an isocyanate group represented by the general formula (1): CH ₂ ═CR-COO-R′-NCO (wherein R represents hydrogen or a methyl group, and R′ represents an alkylene group having 1 to 3 carbon atoms), and from the viewpoint of thermal reactivity (thermal radical curing), R represents a methyl group, and from the viewpoint of the reactivity of the isocyanate group, R′ represents an alkylene group having 2 carbon atoms, represented by the chemical formula (2):

2-isocyanatoethyl methacrylate represented by the formula:

Examples of (hydroxyl-terminated hydrogenated PO) include hydroxyl-terminated hydrogenated polyolefins in which the repeating units of 1,4-bonds (corresponding to p, q, r, s, t, and u in the following general formulae (3) and (4)) exceed 50% by mass, and hydroxyl-terminated hydrogenated polyolefins in which the repeating units of 1,2-bonds (corresponding to q and t in the following general formulae (3) and (4)) exceed 50% by mass. From the viewpoint of being able to make the elastic modulus of the cured product of the resin composition 5 GPa or less at a low temperature such as -40°C, for example, hydroxyl-terminated hydrogenated polyolefins in which the repeating units of 1,4-bonds exceed 50% by mass are preferred, hydroxyl-terminated hydrogenated polyolefins in which the repeating units of 1,4-bonds exceed 60% by mass are more preferred, and hydroxyl-terminated hydrogenated polyolefins in which the repeating units of 70% by mass are even more preferred.

Hydroxyl-terminated hydrogenated polyolefins containing more than 50% by mass of repeating units of 1,4-bonds (hereinafter referred to as hydroxyl-terminated hydrogenated 1,4PO) include those represented by the general formula (3):

(where n is 40-60, p is 0.1-0.3, q is 0.1-0.3, and r is 0.4-0.8) Hydrogenated 1,4-polybutadiene with hydroxyl groups at the ends, or general formula (4):

(where m is 25-45, s is 0.1-0.3, t is 0.1-0.3, and u is 0.4-0.8) is a hydrogenated hydroxyl-terminated 1,4-polyisoprene. Here, the number average molecular weight of the hydroxyl-terminated hydrogenated 1,4PO of general formula (3) is preferably 2200-3200, and the number average molecular weight of the hydroxyl-terminated hydrogenated 1,4PO of general formula (4) is preferably 1800-3000. The number average molecular weight is determined by gel permeation chromatography (GPC) using a calibration curve based on standard polystyrene.

[Method for producing modified hydrogenated polyolefin]
The method of the present invention for producing a modified hydrogenated polyolefin represented by the formula (IMA)-(hydroxyl-terminated hydrogenated PO)-(IMA) comprises reacting IMA with hydroxyl-terminated hydrogenated PO, where IMA is a (meth)acrylate having an isocyanate group represented by the general formula (1): CH ₂ ═CR-COO-R'-NCO (wherein R is a hydrogen atom or a methyl group, and R' is an alkylene group having 1 to 3 carbon atoms);
The hydroxyl-terminated hydrogenated PO is a hydroxyl-terminated hydrogenated polyolefin,
The OH group of the hydroxyl-terminated hydrogenated PO and the NCO group of the IMA are bonded to form a urethane bond.

This manufacturing method makes it possible to easily produce modified hydrogenated polyolefins that, when used in film-formable resin compositions, can maintain a low elastic modulus without increasing the amount of other thermosetting resins.

[Resin composition]
The resin composition of the present invention (hereinafter referred to as the resin composition) contains (A) the modified hydrogenated polyolefin described above and (B) a styrene-based thermoplastic elastomer. The modified hydrogenated polyolefin (A) may be used alone or in combination of two or more kinds. The resin composition can be formed into a film and has a low elastic modulus after curing. In addition, the cured product of the resin composition has excellent solder heat resistance and a low dielectric loss tangent.

(B) The styrene-based thermoplastic elastomer imparts flexibility and good dielectric properties (i.e., low dielectric constant and low dielectric tangent) to the resin composition.

The styrene-based thermoplastic elastomer is not particularly limited. Non-hydrogenated or partially hydrogenated styrene-based thermoplastic elastomers are preferred because they have particularly excellent heat resistance. Examples of such styrene-based thermoplastic elastomers include styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene propylene-styrene block copolymer (SEPS), and styrene-butadiene butylene-styrene block copolymer (SBBS). Examples of hydrogenated styrene-based thermoplastic elastomers include styrene-ethylene/butylene-styrene block copolymer (SEBS), styrene-(ethylene-ethylene/propylene)-styrene block copolymer (SEEPS), and styrene-ethylene/propylene-styrene block copolymer (SEPS). SEBS and SEEPS are preferred from the viewpoint of excellent dielectric properties. In addition, styrene-based thermoplastic elastomers are compatible with component (A) and also with polyphenylene ether (PPE), modified PPE, and other options for component (C). This allows the production of resin compositions containing components (A) to (C). Furthermore, component (B) contributes to lowering the elasticity of the cured resin composition, making it suitable for applications that impart flexibility to insulating films and require low elasticity of 5 GPa or less for the cured resin composition.

The weight average molecular weight of the styrene-based thermoplastic elastomer is preferably 30,000 to 200,000, and more preferably 50,000 to 150,000. The weight average molecular weight is determined by gel permeation chromatography (GPC) using a calibration curve of standard polystyrene. The styrene-based thermoplastic elastomer may be used alone or in combination of two or more types.

It is preferable that the resin composition further contains (C) a thermosetting resin having a radically polymerizable double bond at the molecular end.

An example of a thermosetting resin having a radically polymerizable double bond at the molecular end is polyphenylene ether having an unsaturated double bond at the molecular end and a number average molecular weight of 800 to 4500. Component (C) imparts adhesion, high frequency characteristics, and heat resistance to the resin composition. Here, high frequency characteristics refers to the property of reducing transmission loss in the high frequency range. A preferred example of a thermosetting resin having a radically polymerizable double bond at the molecular end is polyphenylene ether having a styrene group at the end (hereinafter also referred to as modified PPE).

As a polyphenylene ether (modified PPE) having a styrene group at the end, a compound represented by general formula (5) is preferred because it has excellent high-frequency characteristics.

(In formula (5), -(O-X-O)- is represented by general formula (6) or (7).)

(In formula (6), R ¹ , R ² , R ³ , R ⁷ , and R ⁸ may be the same or different and each is an alkyl group having 6 or less carbon atoms or a phenyl group. R ⁴ , R ⁵ , and R ⁶ may be the same or different and each is a hydrogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group.)

(In formula (7), R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ may be the same or different and are a hydrogen atom, an alkyl group having 6 or less carbon atoms or a phenyl group. -A- is a linear, branched or cyclic divalent hydrocarbon group having 20 or less carbon atoms.)

(In formula (5), -(Y-O)- is represented by general formula (8), and one type of structure or two or more types of structures are randomly arranged.)

(In formula (8), R ¹⁷ and R ¹⁸ may be the same or different and each is an alkyl group having 6 or less carbon atoms or a phenyl group. R ¹⁹ and R ²⁰ may be the same or different and each is a hydrogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group.)

(In formula (5), a and b are integers between 0 and 100, with at least one of them not being 0.)

(-A- in formula (7) includes, but is not limited to, divalent organic groups such as methylene, ethylidene, 1-methylethylidene, 1,1-propylidene, 1,4-phenylenebis(1-methylethylidene), 1,3-phenylenebis(1-methylethylidene), cyclohexylidene, phenylmethylene, naphthylmethylene, and 1-phenylethylidene.)

(As the compound represented by formula (5), R ¹ , R ² , R ³ , R ⁷ , R ⁸ , R ¹⁷ , and R ¹⁸ are preferably alkyl groups having 3 or less carbon atoms, and R ⁴ , R ⁵ , R ⁶ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁹ , and R ²⁰ are preferably hydrogen atoms or alkyl groups having 3 or less carbon atoms, and more preferably -(O-X-O)- represented by general formula (6) or general formula (7) is general formula (9), general formula (10), or general formula (11), and -(Y-O)- represented by general formula (4) is general formula (12) or formula (13), or a structure in which formulas (12) and (13) are randomly arranged.)

The method for producing the compound represented by formula (5) is not particularly limited, and for example, the compound can be produced by subjecting a bifunctional phenylene ether oligomer obtained by oxidative coupling of a bifunctional phenolic compound with a monofunctional phenolic compound to vinylbenzyl etherification of the terminal phenolic hydroxyl group of the resulting bifunctional phenylene ether oligomer. (C) The thermosetting resin having a radically polymerizable double bond at the molecular end may be used alone or in combination of two or more kinds.

From the viewpoint of low elastic modulus and solder heat resistance, it is preferable that the amount of the modified hydrogenated polyolefin (A) is 5 to 60 parts by mass per 100 parts by mass of the total of the modified hydrogenated polyolefin (A), the styrene-based thermoplastic elastomer (B), and the PPE (C).

The amount of (B) styrene-based thermoplastic elastomer is preferably 5 to 80 parts by mass per 100 parts by mass of the total of (A) modified hydrogenated polyolefin, (B) styrene-based thermoplastic elastomer, and (C) PPE. If there is too little (B) styrene-based thermoplastic elastomer, the cured product tends to become hard and brittle, and if there is too much, the solder heat resistance tends to deteriorate.

The amount of (C) PPE is preferably 0 to 45 parts by mass per 100 parts by mass of the total of (A) modified hydrogenated polyolefin, (B) styrene-based thermoplastic elastomer, and (C) PPE. If there is too much (C) PPE, the cured product tends to become hard and brittle.

Other resins than those mentioned above, such as epoxy resin, maleimide resin, cyanate resin, polyimide resin, etc., may also be used in combination.

The resin composition may further contain a filler (D). (D) may be an inorganic filler or an organic filler. It is preferable to contain an inorganic filler as the (D) component from the viewpoint of lowering the coefficient of thermal expansion (CTE) of the cured product of the thermosetting resin. It is preferable that the (D) component is a silica filler or a fluorine-based resin filler from the viewpoint of high frequency characteristics.

Examples of silica fillers include, but are not limited to, fused silica, spherical silica, crushed silica, crystalline silica, and amorphous silica. From the viewpoints of dispersibility of the silica filler, fluidity of the resin composition, surface smoothness of the cured product, dielectric properties, low thermal expansion coefficient, adhesiveness, and the like, spherical fused silica is preferable. In addition, the average particle size of the silica filler (if not spherical, its average maximum diameter) is not particularly limited, but from the viewpoint of improving moisture resistance after curing due to the small specific surface area, it is preferably 0.05 to 20 μm, more preferably 0.1 to 10 μm, and even more preferably 1 to 10 μm. Here, the average particle size of the silica filler refers to the volume-based median diameter measured by a laser scattering diffraction type particle size distribution measuring device. (D) Fillers may be used alone or in combination of two or more types.

When an inorganic filler is used as component (D), from the viewpoint of lowering the CTE, it is preferably present in the resin composition (excluding the solvent) at 45 to 75% by volume, and more preferably at 50 to 70% by volume. If there is too little inorganic filler, the desired CTE of the resin composition after curing cannot be achieved, and if there is too much inorganic filler, the peel strength of the resin composition after curing is likely to decrease. The inorganic filler (D) may be surface-treated with a silane coupling agent.

The resin composition may contain additives such as organic peroxides as curing accelerators for components (A) and (C), coupling agents such as silane coupling agents (integral blends), defoamers, leveling agents, thixotropic agents, dispersants, antioxidants, and flame retardants, within the scope of the invention.

Examples of organic peroxides include t-butyl peroxybenzoate (Perbutyl Z, manufactured by Nippon Oil & Fats Co., Ltd.) and dicumyl peroxide (Percumyl D, manufactured by Nippon Oil & Fats Co., Ltd.).

Examples of silane coupling agents include p-styryltrimethoxysilane (Shin-Etsu Chemical Co., Ltd., KBM-1403), bis(triethoxysilylpropyl)tetrasulfide (Shin-Etsu Chemical Co., Ltd., KBE-846), 7-octenyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd., KBM-1083), methacryloxyoctyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd., KBM-5803), Examples of the flame retardant include 3-methacryloxypropyltrimethoxysilane (KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.), 3-methacryloxypropyltriethoxysilane (KBE-503, manufactured by Shin-Etsu Chemical Co., Ltd.), 3-glycidoxypropyltrimethoxysilane (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.), and 3-glycidoxypropyltriethoxysilane (KBE-403, manufactured by Shin-Etsu Chemical Co., Ltd.). Examples of the flame retardant include metal phosphinate (OP-935, manufactured by Clariant Japan).

The resin composition can be prepared by dissolving or dispersing the raw materials constituting the resin composition, such as components (A), (B), and, if necessary, (C), in an organic solvent. The device for dissolving or dispersing these raw materials is not particularly limited, but examples that can be used include a mixer equipped with a heating device, a dissolver, a mortar and pestle machine, a three-roll mill, a ball mill, a planetary mixer, and a bead mill. These devices may also be used in appropriate combination.

Examples of organic solvents include aromatic solvents such as toluene and xylene, and ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone. The organic solvents may be used alone or in combination of two or more. From the viewpoint of workability, the resin composition preferably has a viscosity in the range of 200 to 3000 mPa·s. The viscosity is measured using an E-type viscometer at a rotation speed of 50 rpm and 25°C.

The resulting resin composition can be formed into a film, and after curing, it has a low elastic modulus, excellent high-frequency characteristics, and excellent solder heat resistance. This resin composition is particularly excellent in that it has a low elastic modulus at low temperatures after curing.

[Insulating film]
The insulating film of the present invention includes the above-mentioned resin composition. This insulating film can provide an insulating film having a low elastic modulus after curing, excellent solder heat resistance, and low dielectric tangent. The insulating film of the present invention is formed into a desired shape from the resin composition. Specifically, the insulating film can be obtained by applying the above-mentioned resin composition onto a support and then drying it. The support is not particularly limited, and examples thereof include metal foils such as copper and aluminum, and organic films such as polyester resins, polyethylene resins, and polyethylene terephthalate resins (PET). The support may be subjected to a release treatment with a silicone-based compound or the like. The resin composition can be used in various shapes, and the shape is not particularly limited.

The method for applying the resin composition to the support is not particularly limited, but from the viewpoint of thinning and controlling the film thickness, the gravure method, slot die method, and doctor blade method are preferred. By using the slot die method, it is possible to obtain an uncured film of the resin composition, i.e., an insulating film, having a thickness of 5 to 300 μm.

Drying conditions can be set appropriately depending on the type and amount of organic solvent used in the resin composition, the thickness of the coating, etc., and can be, for example, 50 to 120°C and about 1 to 60 minutes. The insulating film obtained in this manner has good storage stability. The insulating film can be peeled off from the support at the desired time.

The insulating film can be cured, for example, at 150 to 230°C for 30 to 180 minutes. The insulating film can be cured after sandwiching it between substrates on which wiring made of copper foil or the like is formed, or after appropriately laminating insulating films on which wiring made of copper foil or the like is formed. The insulating film can also be used as a coverlay film to protect the wiring on the substrate, and the curing conditions in this case are also the same. The resin composition can also be cured in the same manner. During curing, the film can be press-cured at a pressure of, for example, 1 to 5 MPa.

The insulating film of the present invention can be used to form a printed wiring board. This printed wiring board is produced by using the above-mentioned resin composition or the above-mentioned insulating film and curing it. This printed wiring board has excellent high-frequency characteristics and solder heat resistance. Examples of multilayer wiring boards include printed wiring boards for high-frequency applications such as substrates for microwave and millimeter-wave communication, particularly automotive millimeter-wave radar substrates. The method for producing a multilayer wiring board is not particularly limited, and the same method as that for producing a printed wiring board using a general prepreg can be used.

[Cured product of resin composition or cured product of insulating film]
The cured product of the above-mentioned resin composition of the present invention or the cured product of the above-mentioned insulating film has excellent solder heat resistance and a low dielectric tangent.

[Semiconductor Device]
The semiconductor device of the present invention includes a cured product of the above-mentioned resin composition or a cured product of the above-mentioned insulating film. The cured product of the above-mentioned resin composition or the cured product of the above-mentioned insulating film has excellent solder heat resistance and low dielectric tangent, and is therefore highly reliable. Here, the term "semiconductor device" refers to any device that can function by utilizing semiconductor properties, and includes electronic components, semiconductor circuits, modules incorporating these, electronic devices, and the like.

The present invention will be described with reference to examples, but the present invention is not limited to these. In the following examples, parts and percentages indicate parts by mass and percentages by mass, unless otherwise specified.

[Synthesis Example 1: Synthesis of modified hydrogenated polyisoprene]
Into a round-bottom flask in which 150 parts by mass of toluene had been added in advance as a solvent, 100 parts by mass of hydroxyl-terminated hydrogenated 1,4-polyisoprene (manufactured by Idemitsu Kosan Co., Ltd., trade name: Epole, hydroxyl content: 0.94 mol/kg) was added, and then, while stirring with a stirrer to prevent the liquid from splashing, 16.3 parts by mass of 2-isocyanatoethyl methacrylate (manufactured by Showa Denko K.K., trade name: Karenz MOI, molecular weight: 155.15) was added in an amount such that the isocyanate equivalent was 1:1 relative to the hydroxyl equivalent of the hydroxyl-terminated hydrogenated 1,4-polyisoprene, and the mixture was allowed to react at room temperature while continuing to stir. Sampling was performed after 24 hours, 48 hours, and 7 days, and the reduction in isocyanate groups due to the reaction between the hydroxyl groups and the isocyanate groups, and the formation and increase of urethane bonds were observed by FT-IR. An FT-IR chart is shown in FIG. 1. The vertical axis of Fig. 1 indicates absorbance (Abs), and the horizontal axis indicates wave number (unit: cm ^-1 ). The same is true for Fig. 2 below. In Fig. 1, "(1)" is a chart of hydroxyl-terminated hydrogenated 1,4-polyisoprene alone, "(2)" is a chart of 2-isocyanatoethyl methacrylate alone, "24h" is a chart of the reaction system 24 hours after the start of mixing, and "48h" is a chart of the reaction system 48 hours after the start of mixing.

For the FT-IR measurements, the above product (liquid) was thinly applied to a base with a spatula, and then dry nitrogen was sprayed onto the base at room temperature to remove the toluene, and the resulting dried sample was used as the measurement sample. The device used was a PerkinElmer fully automated FTIR microscope system Spectrum Spotlight 400, and ZnSe was used as the crystal to perform the FT-IR measurements using the ATR method.

As peaks of groups that do not change after the reaction, the "CH" peak in (1) and the "CO" peak in (2) are used as the standard, and their magnitudes are listed together with the "24h" and "48h" charts so that the changes in the magnitudes of other peaks can be seen. In the charts (1) and (2) in Figure 1, it was found that peaks belonging to "NH" appeared after 24 and 48 hours, and were larger after 48 hours than after 24 hours. On the other hand, in the chart (2), the peaks belonging to "NCO" significantly decreased after 24 and 48 hours, and were smaller after 48 hours than after 24 hours. This shows that the NCO group of 2-isocyanatoethyl methacrylate reacted with the OH group of the hydroxyl-terminated hydrogenated 1,4-polyisoprene to form a urethane bond.

Next, the FT-IR chart is shown in Figure 2. "48h" in Figure 2 shows the chart of the reaction system 48 hours after the start of mixing, and "7 days" shows the chart of the reaction system 7 days after the start of mixing. In Figure 2, as in Figure 1, the size of the "CH" peak is made uniform, and the chart is written so that the changes in the size of the other peaks can be seen. As shown in Figure 2, there was almost no change in the NCO peak and the N-H peak after 48 hours and 7 days, so it was determined that the reaction had completed in 48 hours.

From the above, it was confirmed that in this formulation, hydroxyl-terminated hydrogenated 1,4-polyisoprene and 2-isocyanatoethyl methacrylate react easily at room temperature, and the terminal hydroxyl groups of hydroxyl-terminated hydrogenated 1,4-polyisoprene react with the isocyanate groups of 2-isocyanatoethyl methacrylate, resulting in the formation of methacryloyl-terminated hydrogenated polyisoprene to which methacryloyl groups have been added via urethane bonds. With this formulation and conditions, the reaction was still insufficient after 24 hours, and the reaction was completed after 48 hours. The non-volatile content (nV) was measured after 7 days and was found to be 55.0%. The liquid temperature was also measured during the reaction, but there was no change in temperature. This sample with a non-volatile content of 55.0% was used to prepare the resin composition and film below.

[Synthesis Example 2: Synthesis of modified hydrogenated polybutadiene]
Synthesis Example 2 was performed under the same conditions as Synthesis Example 1, except that hydroxyl-terminated hydrogenated 1,2-polybutadiene (manufactured by Nippon Tankatsu Co., Ltd., product name: GI-2000, number average molecular weight: 2000, hydroxyl value: 40 to 55 (KOH mg/g)) was used instead of hydroxyl-terminated hydrogenated 1,4-polyisoprene. This sample with a nonvolatile content of 43.6% was used to prepare the following resin compositions and films.

[Preparation of resin composition and film]
Each component was weighed out according to the formulation (solid content equivalent) shown in Table 1, mixed by stirring, and then dispersed using a wet-type micronizer (Nanomizer MN2-2000AR, manufactured by Yoshida Kikai Kogyo Co., Ltd.) to obtain a liquid resin composition. This liquid resin composition was applied to one side of a support (a PET film subjected to a release treatment) and dried at 100°C for 10 minutes to obtain a film with a support (thickness: 100 μm).

Here, in Synthesis Examples 1 and 2 shown in Table 1, the modified hydrogenated polyolefins obtained in the above Synthesis Examples 1 and 2 were
G1652MU is made of Kraton Polymers' SEBS (styrene ratio 30%).
Septon 4044 is a mixture of SEEPS (styrene ratio 32%) manufactured by Kuraray Co., Ltd.
OPE-2St 2200 is a styrene-terminated PPE (molecular weight (Mn): 2200) manufactured by Mitsubishi Gas Chemical Co., Inc.
Perbutyl Z is t-butyl peroxybenzoate manufactured by Nippon Oil & Fats Co., Ltd.
KBM-1403 is p-styryltrimethoxysilane manufactured by Shin-Etsu Chemical Co., Ltd.
For FB-3SDX, spherical silica (average particle size: 3.4 μm) manufactured by Denka was used.
〔Evaluation methods〕

<Compatibility>
First, the resin and the solvent alone were mixed and stirred to prepare a clear solution, which was then left for a day and then observed for appearance. If there was no turbidity or layer separation and the compatibility was good, it was marked as "○", and if there was turbidity or layer separation and the compatibility was judged to be poor, it was marked as "×". Table 1 shows the results of the compatibility test.

<Dielectric constant (ε), dielectric tangent (tan δ)>
The film with the support was heat cured at 200°C for 60 minutes, peeled off from the support, and then cut into a size of 50 mm x 70 mm. The thickness was measured, and the dielectric constant (ε) and dielectric loss tangent (tan δ) were measured by a dielectric resonator method (SPDR method) (10 GHz). Table 1 shows the results of the dielectric properties. The dielectric constant (ε) is preferably 3.5 or less. The dielectric loss tangent (tan δ) is preferably 0.003 or less.

<Evaluation of Elastic Modulus>
The sample cured by heating at 200°C for 60 minutes was cut into a size of 40 mm x 10 mm, and the elastic modulus was measured at room temperature (25°C) and low temperature (-40°C) using a DMA. The results of the elastic modulus are shown in Table 1. The elastic modulus at 25°C is preferably 3 GPa or less. The elastic modulus at -40°C is preferably 5 GPa or less.

<Evaluation of solder heat resistance>
The support was peeled off from the film with the support. Copper foil (CF-T9FZSV, manufactured by Fukuda Metal Foil and Powder Co., Ltd., thickness: 18 μm) was attached to both sides of this film with the roughened surface facing inward, and press cured with a press machine under the conditions of 200 ° C × 60 minutes, pressure: 3 MPa. This was cut into a size of 30 mm × 30 mm to prepare a test piece, and placed on the surface of a solder bath heated to each temperature of 260, 270, 280, 290, and 300 ° C for 60 seconds to observe whether or not a blister occurred. The test was performed with n = 3, and those that did not blister were evaluated as "○", and those that blistered were evaluated as "×". Table 2 shows the results of the solder heat resistance of Example 5 and Comparative Example 1.

As can be seen from Table 1, Examples 1 to 7 showed good results in compatibility, relative dielectric constant (ε), dielectric tangent (tan δ), and elastic modulus. As can be seen from Table 2, in terms of solder heat resistance, Example 5, in which half the amount of the styrene-based thermoplastic elastomer in Comparative Example 1 was replaced with modified hydrogenated polyolefin, showed good resistance up to 290°C. In contrast, Comparative Example 1, which did not contain modified hydrogenated polyolefin, showed good resistance up to 270°C, but blistering occurred at 280°C. Reference Example 1, which contained modified hydrogenated polyolefin but did not contain styrene-based thermoplastic elastomer, showed poor compatibility. For this reason, evaluation of other items was not possible.

The modified hydrogenated polyolefin of the present invention is extremely useful because, when used in combination with a styrene-based thermoplastic elastomer, it can improve solder heat resistance by crosslinking while keeping the low-temperature elastic modulus low without compromising dielectric properties.

Claims (5)

It is a modified hydrogenated polyolefin represented by the formula: (IMA)-(hydroxyl-terminated hydrogenated PO)-(IMA),
Here, IMA is a (meth)acrylate having an isocyanate group represented by the general formula (1): CH ₂ ═CR-COO-R′-NCO (wherein R represents hydrogen or a methyl group, and R′ represents an alkylene group having 1 to 3 carbon atoms);
The hydroxyl-terminated hydrogenated PO is a hydroxyl-terminated hydrogenated polyolefin,
A resin composition comprising a modified hydrogenated polyolefin in which the OH group of the hydroxyl-terminated hydrogenated PO and the NCO group of the IMA are urethane-bonded , and a styrene-based thermoplastic elastomer. The resin composition according to claim 1 , further comprising a thermosetting resin having a radically polymerizable double bond at a molecular end. An insulating film comprising the resin composition according to claim 1 or 2 . A cured product of the resin composition according to claim 1 or 2 , or a cured product of the insulating film according to claim 3 . A semiconductor device comprising a cured product of the resin composition according to claim 1 or 2 , or a cured product of the insulating film according to claim 3 .