Benzoxazine compositions and cured benzoxazine products

Abstract

To provide a benzoxazine composition that yields a cured benzoxazine product with low dielectric constant and dielectric loss tangent as well as superior heat resistance.SOLUTION: A benzoxazine composition contains a benzoxazine and a polyacenaphthylene. Preferably, the mass ratio of the benzoxazine to the polyacenaphthylene is 99 / 1-40 / 60.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a benzoxazine composition and a cured benzoxazine product. [Background Art]

[0002] Benzoxazines synthesized from phenols, formaldehyde and amines undergo ring-opening polymerization merely upon heating, allowing a cured product to be easily obtained. Since the cured product has excellent properties such as heat resistance, flame retardancy, and electrical insulation, it is widely used in electronic substrates, semiconductor encapsulating materials, and the like (Patent Documents 1 to 2). [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 2017-20011 [Patent Document 2] Japanese Unexamined Patent Publication No. 2022-13418 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] In recent years, mobile devices such as smartphones have been required to achieve higher-speed communication and larger capacity, and radio waves in high frequency bands, which are advantageous for improving communication speed and transmission efficiency, are used. However, when conventional benzoxazines are used for electronic substrates and semiconductor encapsulating materials of electronic devices that use high frequency bands, the dielectric constant and dielectric loss tangent are relatively high, so the signal transmission speed becomes slower than the originally expected value, and signal loss may also easily occur.

[0005] Furthermore, from the perspective of environmental protection, replacement with lead-free solder having a high melting point has been progressing in the manufacturing process of electronic substrates and semiconductor encapsulating materials. However, conventional benzoxazines do not have sufficient heat resistance that is required in the manufacturing process of electronic substrates using lead-free solder.

[0006] The present invention has been made in view of the above points, and aims to provide a benzoxazine composition that yields a benzoxazine cured product having a low dielectric constant and dielectric loss tangent, and excellent heat resistance. [Means for solving the problem]

[0007] As a result of diligent research, the inventors of this invention discovered that the above objective can be achieved by adopting the following configuration, and thus completed the present invention. In other words, the present invention provides the following [1] to [3]. [1] A benzoxazine composition containing benzoxazines and polyacenaphthylenes. [2] The benzoxazine composition according to [1], wherein the mass ratio of the benzoxazine to the polyacenaphthylene is 99 / 1 to 40 / 60. [3] A cured benzoxazine product obtained by heat curing the benzoxazine composition described in [1] or [2] above. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a benzoxazine composition that yields a benzoxazine cured product having a low dielectric constant and dielectric loss tangent, and excellent heat resistance. [Modes for carrying out the invention]

[0009] [Benzoxazine composition] The benzoxazine composition of this embodiment contains benzoxazines and polyacenaphthylenes. The details are explained below.

[0010] <Benzoxazines> Benzoxazines are compounds containing an oxazine ring, synthesized using phenols, formaldehyde, and amines.

[0011] Phenols Examples of phenols include phenols; cresols; xylenols; various substituted phenols; biphenols such as bisphenol A, bisphenol F, bisphenol S, and 4,4′-biphenol; bishydroxyphenyl ethers such as 4,4′-bishydroxyphenyl ether; various phenol resins; and those to which substituents have been introduced. These may be used individually or in combination of two or more. Of these, phenol, bisphenol A, bisphenol F, and bisphenol S are preferred because they are readily available and inexpensive.

[0012] Formaldehyde Formaldehyde may be in any form, such as gaseous formaldehyde; an aqueous solution of formaldehyde; or paraformaldehyde, which is obtained by dehydration polymerization of formaldehyde. Of these, aqueous formaldehyde solution and paraformaldehyde are preferred because they are liquid or solid and easy to use in the manufacturing process.

[0013] Amines The amines are not particularly limited and include, for example, aromatic amines such as aniline, 4,4′-methylenebisaniline, 4,4′-oxydianiline, and condensates of aniline and formaldehyde; biscyclohexyldiamines; methylenebiscyclohexyldiamines; and alicyclic or linear aliphatic amines such as hexamethylenediamine. Of these, aniline, 4,4′-methylenebisaniline, 4,4′-oxydianiline, and biscyclohexyldiamines are readily available and therefore preferred.

[0014] Method for producing benzoxazines The method for producing benzoxazines is not particularly limited. For example, a method comprising using phenol, formaldehyde and 4,4'-oxydianiline as raw materials, dissolving these raw materials in toluene, heating the mixture to 80 to 110°C, allowing reaction for 5 to 20 hours while removing generated water out of the system, then removing toluene by vacuum distillation at 110°C, and recovering the obtained solid; a method comprising using bisphenol A, formaldehyde and aniline instead as raw materials; and the like are suitably mentioned.

[0015] Preferred Embodiments of Benzoxazines The number of oxazine rings contained in one molecule of the benzoxazine is not particularly limited. However, if the number of oxazine rings per molecule is too small, the heat resistance and strength of the obtained cured product (cured benzoxazine product) may be insufficient. On the other hand, if the number of oxazine rings per molecule is too large, the increase in polar groups may lead to increased dielectric constant and deteriorated dielectric properties. For this reason, the number of oxazine rings contained in one molecule of the benzoxazine is preferably 2 or 3, and more preferably 2.

[0016] Specific examples of suitable benzoxazines include, for example, compounds represented by the following formula.

[0017]

Chemical Formula

[0018] Polyacenaphthylenes Polyacenaphthylenes are polymers of acenaphthylene and / or compounds obtained by introducing various substituents into acenaphthylene.

[0019] Substituents introduced into acenaphthylene are not particularly limited, and examples thereof include alkyl groups, hydroxyl groups, carboxyl groups, halogen groups, and aldehyde groups. However, from the viewpoint of availability and the resulting dielectric properties, unsubstituted acenaphthylene is preferred.

[0020] Polyacenaphthylenes are homopolymers of acenaphthylenes, or copolymers obtained by polymerizing acenaphthylenes with other vinyl monomers.

[0021] The polymerization method is not particularly limited, and any of radical polymerization, cationic polymerization, or anionic polymerization can be used.

[0022] In the case of radical polymerization, for example, one method involves polymerization in a solvent such as toluene using a radical initiator at a temperature of 80 to 150°C (preferably 90 to 120°C) for 5 to 10 hours. Examples of radical initiators include benzoyl peroxide, cumene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexine-3, di-t-butyl peroxide, t-butylcumyl peroxide, α,α-bis(t-butylperoxy-m-isopropyl)benzene, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, dicumyl peroxide, di-t-butylperoxyisophthalate, t-butylperoxybenzoate, and 2,2-bis(t- Examples include peroxides such as butylperoxy)butane, 2,2-bis(t-butylperoxy)octane, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, di(trimethylsilyl)peroxide, and trimethylsilyltriphenylsilylperoxide; and azo compounds such as 2,2′-azobisisobutyronitrile, 2,2′-azobis-4-methoxy-2,4-dimethoxyvaleronitrile, 2,2′-azobis-2,4-dimethylvaleronitrile, 2,2′-azobis-2-methylbuturonitrile, and 1,1′-azobiscyclohexane-1-carbonitride. Of these, dicumyl peroxide is preferred because its half-life temperature is 116°C, which is close to the reaction temperature and makes it easy to use.

[0023] In the case of cationic polymerization, for example, one method involves using a cationic polymerization initiator in a solvent such as methylene chloride and polymerizing at a temperature of -10 to 100°C (preferably 0 to 80°C) for 5 to 10 hours. The cationic polymerization catalyst is not particularly limited as long as it reacts with the monomer to produce a cationic active species, and usually a protonic acid or Lewis acid can be used. Examples of protonic acids include hydrochloric acid, sulfuric acid, perchloric acid, trifluoroacetic acid, methanesulfonic acid, trifluoromethanesulfonic acid, chlorosulfonic acid, and fluorosulfonic acid; Lewis acids include boron trifluoride (BF3), aluminum chloride (AlCl3), titanium tetrachloride (TiCl4), stannous chloride (SnCl4), and ferric chloride (FeCl3); and so on. Furthermore, boron trifluoride (BF3) is preferably used as, for example, a boron trifluoride-4-methyltetrahydropyran complex, a boron trifluoride-diethyl ether complex, or a boron trifluoride-phenol complex.

[0024] <Mass ratio (benzoxazines / polyacenaphthylenes)> For the reason that the dielectric constant and dielectric loss tangent of the resulting cured product are lower and the heat resistance is better, the mass ratio of benzoxazines to polyacenaphthenes (benzoxazines / polyacenaphthenes) is preferably 99 / 1 to 40 / 60, more preferably 95 / 5 to 45 / 55, even more preferably 90 / 10 to 50 / 50, and particularly preferably 85 / 15 to 55 / 45.

[0025] <Additives> The benzoxazine composition may contain various additives, as long as they do not impair the objectives of the present invention. Examples of additives include flame retardants; inorganic fillers such as glass fibers, carbon fibers, and silica; and the like.

[0026] <Method for producing benzoxazine compositions> The method for producing the benzoxazine composition is not particularly limited. For example, a method of mixing a predetermined amount of benzoxazines and a predetermined amount of polyacenaphthenes while grinding them using a mixer or the like; a method of heating the benzoxazines to a temperature that does not harden (e.g., 150°C), adding the polyacenaphthenes, and melt-mixing them; etc. The method of grinding and mixing using a mixer or the like is preferred because it is easy to operate.

[0027] [Benzoxazine-based cured products] The cured benzoxazines of this embodiment can be produced by curing the benzoxazine composition of this embodiment described above by heating it at a temperature of 120 to 250°C (preferably 150 to 220°C) for 2 to 24 hours (preferably 3 to 12 hours). This curing process is preferably carried out under reduced pressure in order to remove any remaining moisture, solvent, unreacted monomers, etc. [Examples]

[0028] The present invention will be specifically described below with reference to examples. However, the present invention is not limited to the examples described below.

[0029] <Synthesis Example 1: Synthesis of Benzoxazines> 432 g of 4,4′-oxydianiline, 279 g of paraformaldehyde, and 900 g of toluene were charged into a 3 L separable flask equipped with an oil bath. The temperature was raised to 50°C and stirred for 30 minutes to form a slurry. Then, 406 g of phenol, which had been preheated and dissolved, was added to the reaction system via a dropping funnel over 30 minutes. Subsequently, the mixture was heated to 90-110°C with stirring and reacted for 5 hours while removing water with a Dean-Stark filter. The bath temperature was raised to 120°C and the mixture was concentrated until no more toluene distilled off. Then, under reduced pressure, the mixture was further concentrated at 120°C for 1 hour. The resulting viscous solid, benzoxazines, was collected in its molten state by transferring it to an aluminum tray. The amount recovered was 805 g.

[0030] <Synthesis Example 2: Synthesis of Polyacenaphthylenes> 500 g of acenaphthylene and 2000 g of toluene were placed in a 3 L separable flask equipped with an oil bath, and the temperature was raised to 90°C. 0.54 g of azobisisobutyronitrile was dissolved in 100 g of toluene and added dropwise to the reaction system over 1 hour using a dropping funnel. After reacting at 90°C for 48 hours, the mixture was gradually added to 5 L of methanol, and the precipitated solid was filtered. The resulting polyacenaphthylenes were vacuum-dried at 80°C for 8 hours and recovered. The recovered amount was 678 g.

[0031] <Example 1> Seven g of benzoxazines obtained in Synthesis Example 1 and three g of polyacenaphthylenes obtained in Synthesis Example 2 were ground and mixed using a mixer to obtain a powdered benzoxazine composition.

[0032] Measurement of glass transition temperature (Tg) A powdered benzoxazine composition was placed in an aluminum cup and cured in a vacuum oven at 150°C for 2 hours, 170°C for 2 hours, 190°C for 2 hours, and 210°C for 2 hours to obtain a cured product. The obtained cured product was cut using a rotary cutter to obtain test specimens with a thickness of 5 mm, a width of 5 mm, and a length of 10 mm. The obtained test specimens were heated from room temperature to 250°C at a rate of 10°C / min in a nitrogen atmosphere using a Shimadzu TMA-60 thermal analyzer in compression mode. The intersection of the tangents near the inflection point in the TMA curve was determined as the glass transition point (unit: °C). The results are shown in Table 1 below.

[0033] Measurement of relative permittivity and dielectric loss tangent A powdered benzoxazine composition was placed in an aluminum cup and cured at 150°C for 2 hours, 170°C for 2 hours, 190°C for 2 hours, and 210°C for 2 hours to obtain a cured material with a thickness of 3.0 mm. The obtained cured material was cut into 40 mm x 40 mm squares using a rotary cutter, and then the surface was polished with sandpaper to obtain test specimens. The dielectric constant and dielectric loss tangent of the obtained test specimens were determined using a dielectric constant measuring device manufactured by AET Corporation by the coaxial resonance method under the condition of a resonance frequency of 1 GHz. The relative permittivity (εr) was determined by dividing the dielectric constant (ε) by the value of the permittivity of vacuum (ε0). The results are shown in Table 1 below.

[0034] <Example 2> 9.6 g of benzoxazines obtained in Synthesis Example 1 and 0.4 g of polyacenaphthylenes obtained in Synthesis Example 2 were ground and mixed using a mixer to obtain a powdered benzoxazine composition. Subsequently, the glass transition temperature, relative permittivity, and dielectric loss tangent were measured in the same manner as in Example 1. The results are shown in Table 1 below.

[0035] <Comparative Example 1> Except for using 10 g of benzoxazines (polynaphthylenes were not used), a cured product was obtained in the same manner as in Example 1, and the glass transition temperature, relative permittivity, and dielectric loss tangent were measured. The results are shown in Table 1 below.

[0036] [Table 1]

[0037] <Summary of Evaluation Results> As shown in Table 1 above, the cured products of Examples 1 and 2 were found to have lower relative permittivity and dielectric loss tangent, as well as a higher glass transition temperature and superior heat resistance compared to the cured product of Comparative Example 1.

Claims

1. It contains benzoxazines and polyacenaphthylenes, The mass ratio of the benzoxazines to the polyacenaphthylenes is 99 / 1 to 70 / 30. The benzooxazine compounds are at least one of the compounds represented by the following formula, A benzoxazine composition in which the polyacenaphthylenes are homopolymers of acenaphthylenes. 【Chemistry 1】 【change】 【change】

2. A cured benzoxazine product obtained by heat curing the benzoxazine composition described in claim 1.

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