JP2003041001A - Thermosetting resin having dihydrobenzoxazine ring structure, resin composition and cured product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new thermosetting resin of which cured product is excellent in heat resistance, mechanical properties and improving a flame retardant property, and a resin composition containing the same. SOLUTION: This thermosetting resin having a dihydrobenzoxazine ring structure consisting of a compound expressed by following general formula (1) [wherein, R1 , R2 and R3 are each a 1-6C hydrocarbon group (R3 can be H); X is a hydrocarbon ring group expressed by the formula (A); and (n) and (m) are each 0 or 1] or its oligomer, and the resin composition obtained by blending another thermosetting resin having the dihydrobenzoxazine ring structure or an epoxy resin with this resin are provided.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a thermosetting resin having a dihydrobenzoxazine ring structure (hereinafter referred to as DHB resin), which has excellent heat resistance, curing characteristics, flame retardancy, and mechanical and electrical characteristics. (Also called), especially,
The present invention relates to a novel DHB resin which has excellent solubility in an organic solvent before curing and is insoluble after curing.

[0002]

2. Description of the Related Art Various thermosetting resins such as epoxy resin, phenol resin, polyimide resin, melamine resin, and polyimide resin have been developed and applied to fields suitable for respective resin characteristics. Recently, copper-clad laminates for printed wiring boards, adhesives for multilayer wiring boards, sealing materials for semiconductors, adhesives for semiconductor mounting, semiconductor mounting modules, or parts used for automobiles, aircrafts, building members, etc. In the curable resin used for the above, a resin material excellent in stability and reliability under high temperature and high humidity is required. Further, from the viewpoint of environmental load reduction, a halogen-free flame-retardant resin material is strongly desired.

In recent years, it has been reported that a dihydrobenzoxazine resin is a resin having a cured product having better heat resistance and moisture resistance than a conventional phenol resin (H. Ishid).
a, et al., J. Polym. Sci., Vol. 32, p921 (1994),
H. Ishida, et al., J. Appl. Polym. Sci., Vol. 61, 15
95 (1996)). Further, since these resins have ring-opening polymerization reactivity, they exhibit low curing shrinkage, and the cured product after the ring-opening reaction has various characteristics such as low thermal expansion. (H. Ishida, et al., J. Poly
m. Sci., Vol.34, 1019 (1994),). Furthermore, these are
It has also been shown to be reactive with epoxy resins and to be effective as a curing agent (JP-A-4-279922). However, these conventional resins generally have poor toughness in the cured product properties after the completion of the curing reaction, and cannot be said to have sufficient mechanical or electrical properties. Also,
Solubility in various solvents and resins is required in order to form a composite with other resins, but the above-mentioned resins that have been conventionally reported are not soluble in solvents and other organic substances such as liquid epoxy resins. It was inferior.

The DHB resin can be synthesized from a phenol compound, a primary amine and a primary aldehyde as shown in the following reaction formula. The following reaction formula shows the case where aniline is used as the primary amine and formaldehyde is used as the primary aldehyde from phenol as the raw material.

[Chemical 5] The DHB resin thus obtained may be a single compound, but in many cases it is a mixture containing by-products such as oligomers and phenol resins, but the main component is the above reaction product.

[0005] As shown in the following reaction formula, this DHB resin causes a ring-opening polymerization reaction by heating to generate a phenolic hydroxyl group and a tertiary amino group.

[Chemical 6] When using bisphenols as raw materials, difunctional DHB
A resin is obtained, a three-dimensional crosslinking reaction proceeds with the ring-opening polymerization reaction, and a cured product having good mechanical properties is obtained.

DHB resin (including bifunctional DHB resin)
And the composition thereof, JP-B-49-47378, JP-A-2-69
It is known in Japanese Patent Laid-Open No. 567, Japanese Patent Laid-Open No. 4-227922, and the like.
However, the cured products of these have poor toughness, failing to provide sufficient mechanical properties, and have insufficient electrical properties such as dielectric constant. Further, in order to form a composite with other resins, solubility in various solvents and liquid resins is required, but these resins which have been reported hitherto have not been sufficiently soluble.

[0007]

SUMMARY OF THE INVENTION The present invention provides a DHB resin having excellent properties such as heat resistance, flame retardancy and solubility.

[0008]

That is, the present invention is

[Chemical 7] (In the formula, R ₁ and R ₂ are independently a hydrocarbon group having 1 to 6 carbon atoms, R ₃ is hydrogen or a hydrocarbon group having 1 to 6 carbon atoms, and X is represented by the formula (A). Or a group in which 1 to 4 alkyl groups or 1 to 2 fused rings are substituted or condensed, and is a divalent hydrocarbon group having 5 to 20 carbon atoms.

[Chemical 8] (However, Q is a component constituting a carbon 5-membered ring or carbon 6-membered ring), n and m each independently represent 0 or 1), or an oligomer thereof or a partially cured product thereof. And a thermosetting resin having a dihydrobenzoxazine ring structure. Here, it is one of the preferred embodiments of the present invention that X in the general formula (1) is any of divalent hydrocarbon groups represented by the following formulas (2) to (5).

[Chemical 9]

The present invention also provides a bisphenol represented by the following formula (6), an amine represented by the formula (7), and R ₃
Aldehyde represented by CHO (provided that R ₁ , R ₂ ,
R ₃ , X, n and m have the same meaning as in formula (1)), and bisphenol: amine: aldehyde = 1: 1.8
It is a curable resin which has the said dihydrobenzoxazine ring structure obtained by making it react by the molar ratio of -2.2: 3.6-4.4.

[Chemical 10]

Further, the present invention is a curable resin composition mainly comprising the curable resin having the above-mentioned dihydrobenzoxazine ring structure. Furthermore, the present invention provides a curable resin composition in which the above-mentioned curable resin having a dihydrobenzoxazine ring structure is blended with another thermosetting resin having a dihydrobenzoxazine ring structure, an epoxy resin, or both. is there. Further, the present invention is a cured product obtained by curing the curable resin or the curable resin composition.

The thermosetting resin of the present invention is a difunctional DHB resin having in a molecule having a structure in which two structural units having a dihydrobenzoxazine ring are bonded by one ring-constituting carbon atom (( Hereinafter, also referred to as the DHB resin of the present invention). Before curing, this resin has a carbon ring connecting two constitutional units having a dihydrobenzoxazine ring, which lowers the intermolecular force, so that it can be used against organic solvents, liquid epoxy resins, liquid acrylates, etc. Shows high solubility. On the other hand, these resins, after being cured, are cured products having good mechanical properties and electrical properties as well as heat resistance and chemical resistance.

The DHB resin of the present invention has the above general formula (1).
Is a compound represented by or an oligomer or partially cured product thereof. In the general formula (1), R ₁ and R ₂ are independently
It is a hydrocarbon group having 1 to 6 carbon atoms, preferably a methyl group, an ethyl group or a propyl group. R ₃ is hydrogen or a hydrocarbon group having 1 to 6 carbon atoms, preferably hydrogen, methyl group, ethyl group or propyl group. n and m are independently
It represents 0 or 1, but is preferably 0.

X is a group represented by the above formula (A) or a group in which 1 to 4 alkyl groups or 1 to 2 condensed rings are substituted or condensed, and have 2 to 5 carbon atoms. Although it is a valent hydrocarbon group, a methyl group, an ethyl group or a propyl group is preferable as the alkyl group, a carbon 5- to 6-membered ring is preferable as the condensed ring, and an aromatic ring is preferable. Q is a component that forms a 5-membered carbon ring or a 6-membered carbon ring. Formula (A)
The 5- or 6-membered carbon ring contained therein is preferably alicyclic, but may have an unsaturated bond when condensed with an aromatic ring. Preferred X is any divalent hydrocarbon group represented by the above formulas (2) to (5).

The DHB resin of the present invention comprises a bisphenol represented by the formula (6), an amine represented by the formula (7), and R
_The aldehyde represented by ₃ CHO is represented by bisphenol:
It can be obtained by reacting at a molar ratio of amine: aldehyde of about 1: 2: 4. Even if the molar ratio is a theoretical amount, if a side reaction occurs as described above or the molar ratio deviates from the theoretical amount, it is further By-products increase. However, the main component is the DHB resin of the present invention.

The curable resin composition of the present invention is the D of the present invention.
It is a composition containing HB resin as a main component, preferably 50 wt% or more of all resin components. This resin composition is D of the present invention.
As long as the HB resin is the main component of the resin, any resin, filler, additive, etc. may be added. The curable resin composition of the present invention may contain another thermosetting resin having a dihydrobenzoxazine ring structure, an epoxy resin, or both. In this case, the amount of the other thermosetting resin or epoxy resin having a dihydrobenzoxazine ring structure is 1 to 100 parts by weight of the thermosetting resin or epoxy resin, relative to 100 parts by weight of the DHB resin of the present invention. Preferably 10-5
0 parts by weight. The cured product of the present invention is D of the present invention.
It is a cured product obtained by thermally curing the HB resin or the curable resin composition of the present invention.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The DHB resin of the present invention is a resin which is cured by the ring-opening polymerization reaction of dihydrobenzoxazine as described above, and is represented by the general formula (1) from the viewpoint of mechanical properties of the cured product. As described above, it is necessary to have two benzodihydrobenzoxazine ring structures. If only one of these is used, the cured product will be poor in flexibility and will not form a sufficient crosslinked structure, resulting in poor toughness. Also, three or more are also hardened products with poor flexibility. However, these other DHB resins having a dihydrobenzoxazine ring structure can be added for the purpose of improving the physical properties of the DHB resin composition of the present invention.

The DHB resin of the present invention can be synthesized from the bisphenol represented by the formula (6), the primary amine represented by the formula (7) and the aldehyde represented by R ₃ CHO as described above. . Aniline is preferably used as the primary amine, and formaldehyde is preferably used as the aldehyde. The theoretical reaction amount is 1: 2: 4, but the reactivity may vary depending on the reaction conditions and the kind of the raw material compounds, and it is possible that not all the raw material compounds react 100%. Can range around 20%. For example, with respect to 1 mol of bisphenol, a primary amine is 2 to 4 mol, preferably 1.8 to 2.2 mol, and formaldehyde is 3.5 to 5 mol, preferably 3.6 to.
It is preferable to use it in a proportion of 4.4 mol or 2 mol or more, preferably 2 to 4 mol, per 1 mol of primary amine for the reaction. In particular, the aldehyde should be added in a slight excess.
As an advantageous production method, the reaction is carried out by gradually adding a primary amine to a primary aldehyde, then bisphenol is added, and the mixture is kept at 70 to 120 ° C. for 20 minutes to 24 hours to synthesize. At this time, an organic solvent can be used if necessary. After the reaction, the desired DHB resin of the present invention is obtained by isolating and purifying the product by a synthetic chemical method such as extraction and drying and removing volatile components such as condensed water.

As shown in the above reaction formula, the DHB resin of the present invention undergoes a ring-opening polymerization reaction by heating to generate a phenolic hydroxyl group and a tertiary amino group, and at the same time, a three-dimensional crosslinking reaction proceeds, resulting in good mechanical properties. A cured product having specific properties is obtained. This cured product exhibits low hygroscopicity, high glass transition temperature, high strength and high elastic modulus, low shrinkage upon curing, and excellent flame retardancy.

As the bisphenol used as a raw material of the DHB resin of the present invention, compounds represented by the following formulas (a) to (d) are industrially easily available, and the cured product has moisture resistance and electrical characteristics. Since it is also good, it is mentioned as a compound suitable for practical use.

[0020]

[Chemical 11]

[Chemical 12]

As the primary amine, aromatic amines such as aniline, toluidine, anisidine and the like can be mentioned. From the viewpoint of heat resistance, aromatic amines are preferred, and it is advantageous to use aniline as an essential component. is there. Also, aniline or aniline and a plurality of other amines can be used in combination.

As the aldehyde, it is possible to use it as an aqueous solution, such as formaldehyde, acetaldehyde,
Examples thereof include benzaldehyde. With respect to formaldehyde, it can be used in any form as an aqueous formalin solution or paraformaldehyde.

DH of the present invention obtained from the above raw material compounds
As the B resin, for example, compounds represented by the following formulas (A) to (D) or oligomers or partially cured products thereof are preferable. It should be noted that the oligomer may also include an oligomer condensed by the reaction of an aldehyde and an aromatic ring. The oligomer or partially cured product is about 1 to 10 times the molecular weight of the formula (1), and the average molecular weight of the DHB resin of the present invention containing them is 1 to 5 times the molecular weight of the formula (1), preferably 1 ~ 2
It is about double. Any of these can be easily synthesized by the above reaction, and by heating to 150 to 200 ° C., a cured product having excellent mechanical properties, electrical properties, and moisture resistance can be obtained.

[0024]

[Chemical 13]

[Chemical 14]

Before curing, these are ether solvents such as dioxane, tetrahydrofuran and diglyme, ester solvents such as ethyl cellosolve acetate and butyl cellosolve acetate, dimethylformamide, dimethylacetamide and N-methyl-2-pyrrolidinone. Since it has a feature that it is easily dissolved in the amide solvent, the epoxy resin and the acrylate resin, it can be easily mixed with various resins.

The resin having another dihydrobenzoxazine ring structure to be added to the curable resin composition of the present invention is not limited as long as it is different from the DHB resin of the present invention. There is a DHB resin having only one of them, and a DHB resin obtained by using a raw material compound which does not give the DHB resin of the present invention, for example, phenol, naphthol, aliphatic amine and the like. These other DHB resins may be synthesized separately from the DHB resin of the present invention and then mixed, and a raw material compound which does not give the DHB resin of the present invention when synthesizing the DHB resin of the present invention. It is also possible to obtain a mixture by partially using

Specific examples of the other DHB resin include compounds represented by the following formulas (a) to (g) or oligomers thereof.

[0028]

[Chemical 15]

[Chemical 16]

[0029]

[Chemical 17]

The epoxy resin to be added to the curable resin composition of the present invention is not particularly limited, but an epoxy resin derived from a polyfunctional hydroxy compound is advantageous. Preferred epoxy resins include bisphenol A type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin,
Alternatively, from the viewpoint of imparting flexibility, as the low-viscosity epoxy resin, bisphenol F type epoxy resin, propylene glycol-based aliphatic epoxy resin, various alicyclic epoxy resins, glycidyl ester-based epoxy resin, glycidyl amine-type epoxy resin, hydantoin Type epoxy resin, and also has good solubility in hydrogenated bisphenol A type epoxy resin obtained by direct hydrogenation reaction of bisphenol type epoxy resin, and therefore can be used as a mixture.

The present invention will be specifically described below with reference to synthesis examples and examples, but the present invention is not limited to these examples. Example 1 Synthesis example: Synthesis example of resin having spiro ring structure 0.4 mol (37.25 g) of aniline was dissolved in 200 ml of dioxane, 67 g of formaldehyde solution (36-38% aqueous solution) was added dropwise, and reacted at room temperature for 5 hours. Let Then, 0.2 mol (53.6 g) of compound (a) was added, and the mixture was stirred at 100 ° C to 120 ° C.
The reaction was carried out at ℃ for 5 hours. After completion of the reaction, the solvent was removed under vacuum to obtain 97 g of DHB resin (A). Table 1 shows the solubility and softening point of the obtained resin in the organic solvent and the liquid resin. In Table 1, the solubility indicates the solubility of 20 g of DHB resin in 100 g of the solvent, and the mark ◯ indicates that it is completely dissolved. As the organic solvent, N-methyl-2-pyrrolidinone (NMP) and dioxane were used. As the liquid resin, Epicoat 828 (Liquid epoxy resin manufactured by Yuka Shell Epoxy Co., Ltd.) and Celoxide (alicyclic epoxy resin manufactured by Daicel Co., Ltd.) were used.

(Evaluation Method) 10 g of DHB resin was cured on a hot plate maintained at 180 ° C. for 1 hour, and physical properties were measured. The results are shown in Table 2. The glass transition temperature was measured by a dynamic viscoelasticity analyzer (DMA), the thermal expansion coefficient was measured by a thermomechanical analyzer (TMA), and the thermal decomposition initiation temperature (5% weight loss temperature) was measured by a thermogravimetric analyzer (TGA). Used, tensile strength,
The tensile elongation and tensile modulus were measured according to JIS K 6911. Also, after creating a cured product with a water absorption rate of 3 mm,
The cured product was treated under the condition of a PCT (121 ° C, 2 atm) treatment time of 20 hours, and then the weight change before and after the PCT treatment was measured to obtain the water absorption. Furthermore, the dielectric constant (operating frequency 1MHz) is ASTM D 14
The measurement was performed according to the method according to 9.

Examples 2 to 4 DHB resins (B) to (D) of the present invention were synthesized in the same manner as in Example 1 except that the raw material compounds were changed. In addition, the evaluation was performed by the same method as described in Example 1.

Comparative Examples 1 to 3 DHB was carried out in the same manner as in Example 1 except that the raw material compounds were changed.
A resin was synthesized. In addition, the evaluation was performed by the same method as described in Example 1. The solubility and softening point of the resin are shown in Table 1,
The physical properties of the cured product are shown in Table 2. The symbols (A) to (D) and (b), (d), (e) of the DHB resin are DHB.
Corresponds to the symbols attached to the chemical formulas described in the resin description column.

[0035]

[Table 1]

[0036]

[Table 2]

[0037]

EFFECTS OF THE INVENTION The thermosetting resin of the present invention is excellent in solubility in various organic solvents and resins, so that it is easy to form a composite, and the cured product has good electrical and mechanical properties and moisture resistance. The property is also good. Further, the thermosetting resin composition of the present invention has good electrical properties and mechanical properties of the cured product, and also has good moisture resistance. Therefore, the thermosetting resin or the composition thereof of the present invention is used as a laminated board for a printed wiring board, a printed wiring board, a semiconductor encapsulating material, a semiconductor mounting module, other various electronic component peripheral members, or an automobile or an aircraft member. It can be preferably used as a building member, a binder for a carbon fiber, a carbon electrode, various composite materials, or a matrix resin.

Continued front page    F-term (reference) 4J002 CD042 CD052 CD062 CD082                       CD132 CM021 FD142 GL00                       GN00 GQ05                 4J043 PA02 QA07 RA51 SA05 SA42                       SA47 TA02 TA70 TA71 UA031                       UA032 UA041 UA042 UA151                       UA152 UA221 UA222 UA51                       YA13 ZB02 ZB51

Claims (9)

[Claims] 1. The following general formula (1): (In the formula, R ₁ and R ₂ are independently a hydrocarbon group having 1 to 6 carbon atoms, R ₃ is hydrogen or a hydrocarbon group having 1 to 6 carbon atoms, and X is represented by the formula (A). Or a group in which 1 to 4 alkyl groups or 1 to 2 fused rings are substituted or condensed, and is a divalent hydrocarbon group having 5 to 20 carbon atoms. (However, Q is a component constituting a carbon 5-membered ring or carbon 6-membered ring), n and m each independently represent 0 or 1), or an oligomer thereof or a partially cured product thereof. A thermosetting resin having a dihydrobenzoxazine ring structure. 2. The dihydrobenzoxazine ring structure according to claim 1, wherein X in the general formula (1) is any of divalent hydrocarbon groups represented by the following formulas (2) to (5). A thermosetting resin having. [Chemical 3] 3. A bisphenol represented by the formula (6),
An amine represented by the formula (7) and an aldehyde represented by R ₃ CHO (wherein R ₁ , R ₂ , R ₃ , X, n and m have the same meanings as in the formula (1). ) And bisphenol: amine: aldehyde = 1: 1.8-2.2: 3.6-4.4.
The curable resin having a dihydrobenzoxazine ring structure according to claim 1 or 2, which is obtained by reacting at a molar ratio of. [Chemical 4] 4. A curable resin composition containing a curable resin having the dihydrobenzoxazine ring structure according to claim 1, 2 or 3 as a main component. 5. 1 to 100 parts by weight of a thermosetting resin having another dihydrobenzoxazine ring structure is added to 100 parts by weight of the curable resin having a dihydrobenzoxazine ring structure according to claim 1, 2 or 3. Curable resin composition. 6. A curable resin composition comprising 1 to 100 parts by weight of an epoxy resin mixed with 100 parts by weight of the curable resin having a dihydrobenzoxazine ring structure according to claim 1, 2 or 3. 7. A thermosetting resin having 1 to 100 parts by weight of an epoxy resin and 100 parts by weight of a curable resin having a dihydrobenzoxazine ring structure according to claim 1, 2 or 3 and another dihydrobenzoxazine ring structure. A curable resin composition containing 1 to 100 parts by weight of a thermosetting resin. 8. A cured product obtained by curing the curable resin according to claim 1. 9. A cured product obtained by curing the curable resin composition according to claim 4.