Benzoxazine composition and cured benzoxazine product

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 technology]

[0002] Benzoxazines, which are synthesized using phenols, formaldehyde, and amines, undergo ring-opening polymerization simply by heating, and a cured product can be easily obtained. This cured product has excellent properties such as heat resistance, flame retardancy, and electrical insulation, and is therefore widely used in electronic substrates, semiconductor encapsulants, and the like (Patent Documents 1-2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-20011 A [Patent Document 2] Patent Publication No. 2022-13418 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been a demand for faster and larger capacity communications in mobile devices such as smartphones, and radio waves in the high frequency band, which are advantageous in improving communication speeds and transmission efficiency, are being used. However, when conventional benzoxazines are used in electronic substrates or semiconductor encapsulants for electronic devices that use high frequencies, the signal transmission speed becomes slower than expected due to their relatively high dielectric constant and dielectric tangent, and signal loss may easily occur.

[0005] Furthermore, from the standpoint of environmental protection, there has been a shift to lead-free solder, which has a higher melting point, in the manufacturing processes for electronic circuit boards and semiconductor encapsulation materials. However, conventional benzoxazines do not have the heat resistance required for the manufacturing process for electronic circuit boards, which uses lead-free solder.

[0006] The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a benzoxazine composition which gives a benzoxazine cured product having a low dielectric constant and dielectric tangent and excellent heat resistance. [Means for solving the problem]

[0007] As a result of extensive investigations, the present inventors have found that the above object can be achieved by employing the following configuration, and have completed the present invention. That is, the present invention provides the following [1] to [3]. [1] A benzoxazine composition containing a benzoxazine and a polyacenaphthylene. [2] The benzoxazine composition according to the above [1], wherein a mass ratio of the benzoxazine to the polyacenaphthylene is 99 / 1 to 40 / 60. [3] A benzoxazine cured product obtained by heat curing the benzoxazine composition according to [1] or [2] above. Effect of the Invention

[0008] According to the present invention, it is possible to provide a benzoxazine composition which gives a benzoxazine cured product having a low dielectric constant and dielectric tangent and excellent heat resistance. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [Benzoxazine composition] The benzoxazine composition of the present embodiment contains a benzoxazine and a polyacenaphthylene. The details will be explained below.

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

[0011] Phenols Examples of phenols include phenol; 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 into which a substituent has been introduced. These may be used alone 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 The formaldehyde may be in any form, and examples thereof include gaseous formaldehyde, an aqueous formaldehyde solution, and paraformaldehyde obtained by dehydration polymerization of formaldehyde. Of these, an aqueous formaldehyde solution and paraformaldehyde are preferred because they are liquid or solid and can be easily used in the production process.

[0013] Amines The amines are not particularly limited, and examples thereof include aromatic amines such as aniline, 4,4'-methylenebisaniline, 4,4'-oxydianiline, and condensates of aniline and formaldehyde; biscyclohexyldiamines; methylenebiscyclohexyldiamines; alicyclic or linear aliphatic amines such as hexamethylenediamine; and the like. Of these, aniline, 4,4'-methylenebisaniline, 4,4'-oxydianiline, and biscyclohexyldiamines are easily available and are preferred.

[0014] <Method for producing benzoxazines> The method for producing benzoxazines is not particularly limited. For example, preferred methods include a method in which phenol, formaldehyde and 4,4'-oxydianiline are used as raw materials, these raw materials are dissolved in toluene, heated to 80 to 110°C, and reacted for 5 to 20 hours while removing the generated water from the system, and then the toluene is removed by distillation under reduced pressure at 110°C and the obtained solid is recovered; a method in which bisphenol A, formaldehyde and aniline are used instead as raw materials; and the like.

[0015] <Preferred embodiments of benzoxazines> The number of oxazine rings that the benzoxazine has in one molecule is not particularly limited. However, if there are too few oxazine rings in one molecule, the heat resistance and strength of the resulting cured product (benzoxazine cured product) may be insufficient. On the other hand, if there are too many oxazine rings in one molecule, the number of polar groups increases, which may result in high dielectric constant and dielectric properties. For this reason, the number of oxazine rings that a benzoxazine has in one molecule is preferably 2 or 3, and more preferably 2.

[0016] Specific examples of suitable benzoxazines include compounds represented by the following formula:

[0017] [ka] JPEG2025017470000002.jpg2790JPEG2025017470000003.jpg3190

[0018] <Polyacenaphthylenes> Polyacenaphthylenes are polymers of acenaphthylene and / or compounds in which various substituents have been introduced into acenaphthylene.

[0019] The substituent to be introduced into acenaphthylene is not particularly limited, and examples thereof include an alkyl group, a hydroxyl group, a carboxyl group, a halogen group, and an aldehyde group. However, from the viewpoints of availability and the resulting dielectric properties, acenaphthylene having no substituent is preferred.

[0020] Polyacenaphthylenes include homopolymers of acenaphthylenes, or copolymers obtained by mixing acenaphthylenes with other vinyl monomers and polymerizing them.

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

[0022] In the case of radical polymerization, for example, a method in which polymerization is carried out 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 can be mentioned. Examples of the radical initiator include benzoyl peroxide, cumene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-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, 2,2-bis(t- peroxides such as 2,2'-azobis(t-butylperoxy)butane, 2,2-bis(t-butylperoxy)octane, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, di(trimethylsilyl)peroxide, and trimethylsilyltriphenylsilylperoxide; azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis4-methoxy-2,4-dimethoxyvaleronitrile, 2,2'-azobis2,4-dimethylvaleronitrile, 2,2'-azobis2-methylbuturonitrile, and 1,1'-azobiscyclohexane-1-carbonitrile; and the like. Of these, dicumyl peroxide is preferred because it has a half-life temperature of 116° C., which is close to the reaction temperature, and is easy to use.

[0023] In the case of cationic polymerization, for example, a method in which polymerization is carried out in a solvent such as methylene chloride using a cationic polymerization initiator at a temperature of -10 to 100°C (preferably 0 to 80°C) for 5 to 10 hours can be mentioned. The cationic polymerization catalyst is not particularly limited as long as it reacts with a monomer to generate a cationic active species, and typically a protonic acid or a Lewis acid can be used. Examples of the cationic polymerization catalyst include protonic acids such as hydrochloric acid, sulfuric acid, perchloric acid, trifluoroacetic acid, methanesulfonic acid, trifluoromethanesulfonic acid, chlorosulfonic acid, and fluorosulfonic acid; and Lewis acids such as boron trifluoride (BF3), aluminum chloride (AlCl3), titanium tetrachloride (TiCl4), stannic chloride (SnCl4), and ferric chloride (FeCl3). It is preferable that boron trifluoride (BF3) is used in the form of, 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)> The mass ratio of benzoxazines to polyacenaphthylenes (benzoxazines / polyacenaphthylenes) is preferably 99 / 1 to 40 / 60, more preferably 95 / 5 to 45 / 55, further preferably 90 / 10 to 50 / 50, and particularly preferably 85 / 15 to 55 / 45, because the resulting cured product has a lower dielectric constant and a lower dielectric tangent and is more excellent in heat resistance.

[0025] Additives The benzoxazine composition may contain various additives within the scope of the present invention, such as flame retardants, inorganic fillers such as glass fiber, carbon fiber, and silica, etc.

[0026] <Method for producing benzoxazine composition> 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 polyacenaphthylenes while grinding them using a mixer or the like, a method of heating the benzoxazines to a temperature at which they do not harden (e.g., 150°C), adding the polyacenaphthylenes, and melt-mixing them, etc. are included. In terms of ease of operation, the method of grinding and mixing using a mixer or the like is preferred.

[0027] [Benzoxazine cured material] The benzoxazine cured product of the present embodiment can be produced by curing the above-mentioned benzoxazine composition of the present embodiment by heating it at a temperature of, for example, 120 to 250°C (preferably, 150 to 220°C) for 2 to 24 hours (preferably, 3 to 12 hours). This curing is preferably carried out under reduced pressure in order to remove residual moisture, solvent, unreacted monomers, and the like. EXAMPLES

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

[0029] Synthesis Example 1: Synthesis of benzoxazines A 3L separable flask equipped with an oil bath was charged with 432g of 4,4'-oxydianiline, 279g of paraformaldehyde, and 900g of toluene. The mixture was heated to 50°C and stirred for 30 minutes to form a slurry, after which 406g of phenol, which had been previously dissolved by heating, was added to the reaction system from the dropping funnel over 30 minutes. The mixture was then heated to 90-110°C with stirring, and reacted for 5 hours while removing water with a Dean-Stark. The bath temperature was raised to 120°C, and the mixture was concentrated until toluene was no longer distilled, after which the pressure was reduced and the mixture was concentrated at 120°C for another hour. The resulting benzoxazines, which were viscous solids, were transferred to an aluminum tray in a molten state and collected. The amount collected was 805g.

[0030] Synthesis Example 2: Synthesis of polyacenaphthylenes 500g of acenaphthylene and 2000g of toluene were charged into a 3L separable flask equipped with an oil bath and heated to 90°C. 0.54g of azobisisobutyronitrile was dissolved in 100g 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 5L of methanol and the precipitated solid was filtered. The obtained polyacenaphthylenes were vacuum dried at 80°C for 8 hours and collected. The collected amount was 678g.

[0031] Example 1 7 g of the benzoxazine obtained in Synthesis Example 1 and 3 g of the polyacenaphthylene obtained in Synthesis Example 2 were pulverized and mixed using a mixer to obtain a powdery benzoxazine composition.

[0032] <Measurement of glass transition temperature (Tg)> The 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 into a shape of 5 mm in thickness, 5 mm in width, and 10 mm in length using a rotary cutter to obtain a test piece. The obtained test piece was heated from room temperature to 250°C at a rate of 10°C / min in a nitrogen atmosphere using a thermal analyzer TMA-60 manufactured by Shimadzu Corporation in compression mode. The intersection of the tangents near the inflection point in the TMA curve at that time was determined as the glass transition point (unit: °C). The results are shown in Table 1 below.

[0033] <Measurement of relative permittivity and dielectric tangent> The 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 product with a thickness of 3.0 mm. The obtained cured product was cut into 40 mm x 40 mm squares using a rotary cutter, and then the surface was polished with sandpaper to make it smooth and obtain a test piece. The obtained test piece was measured for the dielectric constant and dielectric loss tangent by the coaxial resonance method using a dielectric constant measuring device manufactured by AET Co., Ltd., under the condition of a resonance frequency of 1 GHz. The relative dielectric constant (εr) was obtained by dividing the dielectric constant (ε) by the value of the dielectric constant (ε0) in vacuum. The results are shown in Table 1 below.

[0034] Example 2 9.6 g of the benzoxazine obtained in Synthesis Example 1 and 0.4 g of the polyacenaphthylene obtained in Synthesis Example 2 were pulverized and mixed using a mixer to obtain a powdery benzoxazine composition. Thereafter, the glass transition point, the relative dielectric constant and the 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 (no polynaphthylenes), a cured product was obtained and its glass transition point, dielectric constant and dielectric loss tangent were measured in the same manner as in Example 1. The results are shown in Table 1 below.

[0036] [Table 1]

[0037] <Summary of evaluation results> As shown in Table 1 above, it was found that the cured products of Examples 1 and 2 had lower relative dielectric constants and dielectric tangents, higher glass transition temperatures, and superior heat resistance compared to the cured product of Comparative Example 1.

Claims

1. A benzoxazine composition comprising a benzoxazine and a polyacenaphthylene.

2. 2. The benzoxazine composition according to claim 1, wherein a mass ratio of the benzoxazine to the polyacenaphthylene is from 99 / 1 to 40 / 60.

3. A cured benzoxazine product obtained by heat curing the benzoxazine composition according to claim 1 or 2.

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