JP2009167375A - Thermosetting resin composition, its molded body, cured body, cured molded body, and electronic equipment including them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermosetting resin composition containing a curing agent for dihydrobenzoxazine resins which has a strong effect to promote the ring opening polymerization of dihydrobenzoxazine resins, and is excellent in compatibility, safety and cost-effectiveness. <P>SOLUTION: The thermosetting resin composition contains 0.1-30 pts.wt. of (b) a p-hydroxybenzoate based on 100 pts.wt. of (a) a resin having at least 2 dihydrobenzoxazine ring structures in the molecule. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a thermosetting resin composition capable of curing a dihydrobenzoxazine resin having excellent heat resistance and electrical properties at a lower temperature, a molded body, a cured body, a cured molded body, and an electronic device including the same. .

Conventionally, phenol resin, melamine resin, epoxy resin, unsaturated polyester resin,
Thermosetting resins such as bismaleimide resins are used in a wide range of industrial fields because of their excellent water resistance, chemical resistance, heat resistance, mechanical strength, reliability, and the like based on their thermosetting properties.

However, the phenol resin and the melamine resin generate volatile by-products upon curing, the epoxy resin and the unsaturated polyester resin are inferior in flame retardancy, and the bismaleimide resin is very expensive.

In order to eliminate these drawbacks, a dihydrobenzoxazine ring undergoes a ring-opening polymerization reaction and is thermally cured without generation of a volatile matter causing a problem (hereinafter abbreviated as a benzoxazine compound). Have been studied). Benzoxazine compounds
In addition to the basic characteristics of the thermosetting resin as described above, it has excellent storage stability, has a relatively low viscosity when melted, and has various advantages such as a wide degree of freedom in molecular design. . Such a benzoxazine compound is disclosed in, for example, JP-A-49-47378 (Patent Document 1).

Non-Patent Document 1 discloses that a bisphenol S-type benzoxazine compound has a lower thermosetting temperature than a general oxazine compound. However, this compound has poor dielectric properties.

Non-Patent Document 2 examines various bisphenol-type benzoxazine compounds, and discloses that bisphenols with electron-withdrawing groups, particularly bisphenol S-type benzoxazine compounds, have the lowest curing temperature.

In general, benzoxazine has a high curing temperature, but it is desired to lower the temperature to a process temperature equivalent to that of an epoxy resin that is frequently used for electronic materials. In the bisphenol S-type benzoxazine compound, the characteristics can be adjusted only on the amine side, and it is not possible to meet the demands for lowering the dielectric constant and improving toughness.

In general, curing accelerators are well known as phenols or acids such as carboxylic acids. For example, in Non-Patent Document 3, p-cresol having phenolic OH and sebacic acid having a carboxyl group are compared. Therefore, it is stated that p-cresol is more effective as a catalyst. However, it is not particularly known about superiority or inferiority among phenols.
JP 49-47378 A Konishi Chemical Co., Ltd. website (http://www.konishi-chem.co.jp/technology/oxazin.html) as of May 15, 2007 Journal of the Adhesion Society of Japan, Vol.39, No.11 (2003) Furukawa, Takeshi J. Polym. Sci. Part A. Polym. Chem., 37, 1913 (1999) Ishikawa

An object of the present invention is to provide a thermosetting resin composition containing a curing agent for dihydrobenzoxazine resin, which has a high effect of promoting ring-opening polymerization of dihydrobenzoxazine resin and is excellent in compatibility, safety and cost. Is in providing.

The present invention relates to a thermosetting resin composition comprising b) 0.1 to 30 parts by weight of a p-hydroxybenzoic acid ester with respect to 100 parts by weight of a resin having 2 or more dihydrobenzoxazine structures in the molecule. The object is achieved by providing a product.

The present invention also provides the following.
2. 2. The thermosetting resin composition as described in 1 above, wherein the p-hydroxybenzoic acid ester of b) has two or more p-hydroxybenzoic acid ester moieties in the molecule.

3. The p-hydroxybenzoic acid ester of b) has a molecular weight (number average molecular weight in the case of a polymer) of 152 to 50,000, and a molecular weight (number average molecular weight in the case of a polymer) / 1 p- in one molecule. 3. The thermosetting resin composition as described in 1 or 2 above, wherein the average number of units of the hydroxybenzoic acid ester portion is 151 to 2,000.

4). The resin of a) has a weight average molecular weight of 1,000 to 1 having a dihydrobenzoxazine structure in the main chain obtained by the reaction of a bifunctional phenol, a bifunctional amine and formaldehyde
4. The thermosetting resin composition as described in any one of 1 to 3 above, which is a benzoxazine resin of 00,000.

5. A molded product obtained by partially curing the thermosetting resin composition according to any one of 1 to 4 or without curing.

6). Hardened | cured material obtained from the thermosetting resin composition in any one of said 1-4.

7. 6. A cured molded product obtained by curing the molded product according to 5.

8). An electronic device comprising the molded article according to claim 5, the cured article according to claim 6, or the cured molded article according to claim 7.

According to the present invention, a thermosetting resin composition capable of curing a dihydrobenzoxazine resin excellent in heat resistance and electrical characteristics at a lower temperature, a molded body, a cured body, a cured molded body, and an electron including them Equipment is provided.

Hereinafter, the present invention will be described in detail based on preferred embodiments thereof.
As described above, the thermosetting resin composition of the present invention has a) b) p-hydroxybenzoic acid ester 0 with respect to 100 parts by weight of a resin having two or more dihydrobenzoxazine ring structures in the molecule. 0.1 to 30 parts by weight are included.

The resin a) having two or more dihydrobenzoxazine structures in the molecule used in the present invention is not particularly limited as long as it has two or more dihydrobenzoxazine structures in the resin molecule. Since the thermosetting resin composition of the present invention has such a configuration, a dihydrobenzoxazine resin excellent in heat resistance and electrical characteristics can be cured at a lower temperature.

The resin of component a) can be obtained, for example, by heating and reacting a polyfunctional phenol compound, an amine compound, and an aldehyde compound. In particular, the resin a) is preferably obtained by the reaction of a bifunctional phenol, a bifunctional amine and formaldehyde,
A benzoxazine resin having a dihydrobenzoxazine structure in the main chain having a weight average molecular weight of 1,000 to 100,000 is preferred from the viewpoint of the mechanical strength and heat resistance of the obtained cured product.

Although it does not specifically limit as a bifunctional phenol compound used here,
For example, 4,4′-biphenol, 2,2′-biphenol, 4,4′-dihydroxydiphenyl ether, 2,2′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenylmethane, 2,2′-dihydroxydiphenylmethane, 2, 2-bis (4-hydroxyphenyl) propane, 4,4′-dihydroxybenzophenone, 1,1-bis (
4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) propane,
1,1-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) butane, 1,1-bis (4-hydroxyphenyl) -2-methylpropane, 1,1-
Bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane,
Bis (4-hydroxyphenyl) diphenylmethane, 9,9-bis (4-hydroxyphenyl) fluorene, 2,2-bis (4-hydroxyphenyl) hexafluoropropane,
1,3-bis (4-hydroxyphenoxy) benzene, 1,4-bis (3-hydroxyphenoxy) benzene, 4,4 ′-[1,4-phenylenebis (1-methyl-ethylidene)
] Bisphenol (“Bisphenol P” manufactured by Mitsui Chemicals, “α, α′-bis (
4-hydroxyphenyl) -1,4-diisopropylbenzene "sold under the compound name), 4
, 4 ′-[1,3-phenylenebis (1-methyl-ethylidene)] bisphenol (“Bisphenol M” manufactured by Mitsui Chemicals), etc. are preferred.

The bifunctional amine compound is not particularly limited, and examples thereof include benzidine, o-tolidine, 4,4′-diaminodiphenylmethane, 4,4′-diamino-3,
3′-dimethyldiphenylmethane (“Kayabond C-100” manufactured by Nippon Kayaku), 4, 4′-
Diamino-3,3′-diethyldiphenylmethane (manufactured by Nippon Kayaku “Kayahard AA”),
4,4′-diamino-3,3 ′, 5,5′-tetramethyldiphenylmethane (“Kayabond C-200S” manufactured by Nippon Kayaku), 4,4′-diamino-3,3 ′, 5,5′- Tetraethyldiphenylmethane (“Kayabond C-300S” manufactured by Nippon Kayaku), 4, 4′-diamino-
3,3′-diethyl-5,5′-dimethyldiphenylmethane, 4,4′-diaminodiphenyl ether, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1 , 4-Bis (3-aminophenoxy) benzene, 1,4-
Bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) neopentane, 4,4 ′-[1,3-phenylenebis (1-methyl-ethylidene)] bisaniline (“Bisaniline M manufactured by Mitsui Chemicals, Inc.) )), 4,4 ′-[1,4-phenylenebis (1-methyl-ethylidene)] bisaniline (“Bisaniline P” manufactured by Mitsui Chemicals), 2,2-bis [4
-(4-aminophenoxy) phenyl] propane ("BAPP" manufactured by Wakayama Seika), 2, 2
-Bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, bis (4-
And-aminophenoxy) aromatic diamine compounds such as biphenyl, 3 (4), 8 (9), - bis (aminomethyl) tricyclo [5,2,1,0 ^2,6] decane (Celanese Ltd. "TCD-diamine") , 2,5 (6) -bis (aminomethyl) bicyclo [2,2,1] heptane (“NBDA” manufactured by Mitsui Chemicals) and the like, or 1,4-cyclohexylamine, 3-cyclohexylamine, 1,4-bis (aminomethyl) cyclohexane, 1,3-bis (aminomethyl) cyclohexane, 4,4′-methylenebis (cyclohexylamine), 4,4′-methylenebis (2-methylcyclohexylamine) ), Alicyclic diamine compounds such as isophorone diamine, 1,8-diamino-p-menthane, 1,2-
Diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,8-diaminooctane, 1,10-diaminodecane, 1,12-diamino A linear or branched aliphatic diamine compound such as dodecane, trimethylhexamethylenediamine, 2-methyl-1,5-pentamethylenediamine, and 2,2-dimethyl-1,3-diaminopropane is preferred.

Moreover, the aldehyde compound is not particularly limited, but formaldehyde is preferable, and as the formaldehyde, paraformaldehyde which is a polymer thereof,
It can be used in the form of formalin or the like in the form of an aqueous solution. The reaction proceeds more slowly when paraformaldehyde is used. As other aldehyde compounds, acetaldehyde, propionaldehyde, butyraldehyde and the like can also be used.

In producing the resin as component a), a monofunctional phenol compound can be further used. Moreover, when manufacturing resin of a) component, each said component can be heated and made to react in a suitable solvent. The solvent is not particularly limited, but a material having a high degree of polymerization is more easily obtained when the raw material phenol compound or diamine compound and the product polymer are more soluble. Examples of such a solvent include aromatic solvents such as toluene and xylene, halogen solvents such as chloroform and dichloromethane, ether solvents such as THF and dioxane, and the like.

The thermosetting resin composition of the present invention contains at least the above-described thermosetting resin, that is, a) a resin having two or more dihydrobenzoxazine structures in the molecule as the thermosetting resin. The thermosetting resin composition according to the present invention preferably contains the thermosetting resin as a main component, for example, a resin having two or more dihydrobenzoxazine structures in the molecule as the main component. Preferably, it contains 50 to 100 parts by weight, and the other component preferably contains 0 to 50 parts by weight of another thermosetting resin.

Examples of other thermosetting resins as accessory components include epoxy resins, thermosetting modified polyphenylene ether resins, thermosetting polyimide resins, silicon resins, melamine resins, urea resins, allyl resins, phenol resins, and unsaturated resins. Examples include polyester resins, bismaleimide resins, alkyd resins, furan resins, polyurethane resins, aniline resins, and the like. Among these, an epoxy resin, a phenol resin, and a thermosetting polyimide resin are more preferable from the viewpoint of further improving the heat resistance of a molded body formed from the composition. These other thermosetting resins may be used alone or in combination of two or more.

Next, the p-hydroxybenzoic acid ester of component b) used in the present invention is used as a curing agent for dihydrobenzoxazine resin.

In addition, as a hardening | curing agent used for dihydrobenzoxazine resin, for example, polyfunctional phenols, such as catechol and bisphenol A, sulfonic acids, such as p-toluenesulfonic acid and p-phenolsulfonic acid, benzoic acid, Carboxylic acids such as salicylic acid, oxalic acid, adipic acid, metal complexes such as cobalt (II) acetylacetonate, aluminum (III) acetylacetonate, zirconium (IV) acetylacetonate, calcium oxide,
Metal oxides such as cobalt oxide, magnesium oxide and iron oxide, calcium hydroxide, imidazole and its derivatives, tertiary amines such as diazabicycloundecene and diazabicyclononene and their salts, triphenylphosphine, triphenyl Phosphine / benzoquinone derivatives, triphenylphosphine / triphenylboron salts, tetraphenylphosphonium /
Phosphorus compounds such as tetraphenylborate and derivatives thereof have been known.
As a result of further investigations on these by the present inventors, among compounds having a phenolic OH group, p-hydroxybenzoic acid and its esters are particularly effective in promoting the reaction, and the cured product It has been found that the mechanical and electrical properties are good.

The p-hydroxybenzoic acid ester used in the present invention can be easily obtained by an esterification reaction between p-hydroxybenzoic acid and the corresponding alcohol.

As a catalyst for this esterification reaction, inorganic acids such as hydrochloric acid and sulfuric acid, benzenesulfonic acid, p
-Organic sulfonic acids such as toluenesulfonic acid and methanesulfonic acid, activated clay, acidic clay,
Solid acids such as acidic ion exchange resins can be used. The amount of the catalyst is generally about 0.1 to 30% by weight with respect to the total amount of alcohol corresponding to p-hydroxybenzoic acid.

At this time, dilution may be performed using a solvent inert to the reaction. Examples include aromatic hydrocarbons such as toluene and xylene, halogen-containing compounds such as chloroform and methylene chloride, ethers such as tetrahydrofuran and dioxane, and ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.

Specifically, p-hydroxybenzoic acid and methanol, ethanol, n-propanol,
Esters with monohydric alcohols such as isopropanol, n-butanol, 2-butanol, isobutanol, n-pentanol, n-hexanol, cyclohexanol, 2-ethylhexanol, benzyl alcohol,

p-hydroxybenzoic acid and ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol, 1,12-dodecanediol, neopentyl glycol, 2-methyl-1, Diesters of dihydric alcohols such as 8-nonanediol, polyvalent esters of p-hydroxybenzoic acid and polyhydric alcohols such as trimethylolpropane, pentaerythritol, dipentaerythritol, p-
Hydroxybenzoic acid and the terminal or side chain OH group or OCOR group which is a derivative thereof (
R is an oligomer or polymer having an alkyl group, an aryl group, etc., for example, terminal hydroxypolybutadiene (“Poly bd” manufactured by Idemitsu Kosan Co., Ltd., “NISSO PB-G manufactured by Nippon Soda”).
)), Polyisoprene (“Poly ip” manufactured by Idemitsu Kosan), or hydrogenated products thereof (“Epol” manufactured by Idemitsu Kosan), polyolefin polyol (“Polytail” manufactured by Mitsubishi Chemical)
), Polyester polyol, polycarbonate diol ("PCD" manufactured by Ube Industries), ethylene-vinyl alcohol copolymer, ethylene vinyl acetate copolymer, and polyvalent esters.

Further, as a by-product at the time of this esterification reaction, there may be a compound in a form in which p-hydroxybenzoic acid is further condensed (see the following reaction formula). There is no problem even if it is used.

These may be used alone or in combination of two or more.

p-Hydroxybenzoic acid esters are widely used as preservatives and bactericides, and have higher safety than other phenols. Moreover, the low molecular weight body is excellent in compatibility with the resin. Since it is a widely used material, it can be used at low cost. Moreover, compatibility, a softness | flexibility, water resistance, an electrical property, etc. can be adjusted by selecting an ester part suitably.

The p-hydroxybenzoic acid ester as a curing agent used in the present invention is less likely to adversely affect the electrical properties and mechanical properties of the cured product, and therefore 100 weight of resin having two or more dihydrobenzoxazine ring structures in the molecule. To 30 parts by weight, preferably 0.5 to
Used in a content in the range of 20 parts by weight. If it is less than 0.1 parts by weight, the effect of curing acceleration is low,
If it exceeds 30 parts by weight, the electrical properties and mechanical properties deteriorate.

In addition, p-hydroxybenzoic acid esters used in the present invention have two or more p in the molecule.
-It preferably has a hydroxybenzoic acid ester moiety. Thereby, the curing characteristics, mechanical characteristics, and heat resistance of the cured benzoxazine are further improved.

The p-hydroxybenzoic acid ester of b) used in the present invention has a molecular weight (number average molecular weight in the case of a polymer) of 152 to 50,000, and a molecular weight (number average molecular weight in the case of a polymer) / The average number of units of the p-hydroxybenzoic acid ester part in one molecule is 15
It is preferably 1 to 2,000. When the molecular weight is larger than this range, the handling property at the time of handling deteriorates. The minimum molecular weight 152 is methyl p-hydroxybenzoate, and the minimum value 151 of the average number of units is a compound reacted with 1 mol of ethylene glycol and 2 mol of p-hydroxybenzoic acid (the following formula).

If the average number of units is larger than this value, the effect of promoting curing becomes too low.

In addition, the thermosetting resin composition according to the present invention includes a flame retardant, a nucleating agent, an antioxidant (anti-aging agent), a heat stabilizer, a light stabilizer, an ultraviolet absorber, a lubricant, Flame retardant, antistatic agent,
Various additives such as an antifogging agent, a filler, a softener, a plasticizer, and a colorant may be contained. These may be used alone or in combination of two or more. In preparing the thermosetting resin composition according to the present invention, a reactive or non-reactive solvent can also be used.

[Molded body]
The molded body according to the present invention is obtained by partially curing the thermosetting resin composition described above, if necessary.
Alternatively, it can be obtained without curing. As the molded body of the present invention, since the thermosetting resin described above has moldability before curing, even after being molded before curing and then cured by applying heat (cured molded body), What hardened | cured simultaneously with shaping | molding (hardening body) may be sufficient. Moreover, the dimension and shape in particular are not restrict | limited, For example, a sheet form (plate shape), block shape, etc. are mentioned, Furthermore, other site | parts (for example, adhesion layer) may be provided.

As the curing method, any conventionally known curing method can be used.
Heating may be performed at about 0 to 260 ° C. for several hours. However, if the heating temperature is lower or the heating time is insufficient, curing may be insufficient and mechanical strength may be insufficient. Also, if the heating temperature is too high or the heating time is too long,
Side reactions such as decomposition may occur and the mechanical strength may undesirably decrease. Therefore, it is desirable to select appropriate conditions according to the characteristics of the thermosetting compound to be used.

As described above, the molded article of the present invention comprising the thermosetting resin composition thus obtained is
Since the polymer structure has a benzoxazine structure, excellent dielectric properties can be realized.

Further, the molded article of the present invention is excellent in reliability, flame retardancy, moldability, aesthetics, etc. based on the thermosetting property of the thermosetting resin composition, and has a glass transition temperature (Tg). ) Is high, it can be applied to stressed parts and moving parts, and since no volatile by-products are generated during polymerization, such volatile by-products are not contained in the molded body. This is also preferable for hygiene management.

The molded body of the present invention can be suitably used for applications such as electronic parts / electronic devices and materials thereof, multilayer boards, laminates, sealants, adhesives and the like that are particularly required to have excellent dielectric properties.
Here, specific examples of the electronic device include a mobile phone, a display device, an in-vehicle device, a computer, and a communication device.
In addition, it can be used for applications such as aircraft members, automobile members, and building members.

Although the typical Example in this invention is shown below, this invention is not limited at all by this.

Benzoxazine resin obtained from bisphenol A, aniline and formaldehyde (
A thermosetting resin composition was prepared by mixing 10 parts by weight of methyl p-hydroxybenzoate with 100 parts by weight of Shikoku Kasei “B_a”) in a powder state. This composition was subjected to DSC measurement in an argon atmosphere at a heating rate of 10 ° C./min. As a result, heat generation due to curing was confirmed, and the peak temperature was 209 ° C.

[Comparative Example 1]
Benzoxazine resin obtained from bisphenol A, aniline and formaldehyde (
About Shikoku Kasei "B_a"), DSC measurement was carried out independently under the same conditions as in Example 1. As a result, a peak accompanying curing was confirmed, and the peak temperature was 240 ° C.

[Comparative Example 2]
In Example 1, a thermosetting resin composition was prepared using p-tert-butylphenol instead of methyl p-hydroxybenzoate. About this composition, when DSC measurement was performed on the same conditions as Example 1, the heat_generation | fever accompanying hardening was confirmed and the peak temperature is 225.
° C.

[Synthesis Example 1]
In a glass container equipped with a condenser, a stirrer, and a thermometer, 3500 ml of toluene, 1040.8 g (3 mol) of bisphenol M (manufactured by Mitsui Chemicals), 10 of bisaniline M (manufactured by Mitsui Chemicals)
33.7 g (3 mol), paraformaldehyde (Wako Pure Chemical Industries, 94%) 413.0 g (
12.6 mol) was added and reacted for 12 hours under reflux while removing the generated water.
The solution after the reaction was poured into a large amount of methanol to precipitate the product. Thereafter, the product was separated by filtration and washed with methanol. The washed product was dried under reduced pressure to obtain 2226.9 g of a benzoxazine resin having a dihydrobenzoxazine structure in the main chain. In the molecular weight measurement by GPC of the obtained resin, the weight average molecular weight Mw = 15,800 and the molecular weight distribution Mw / Mn = 3.7. Further, it was confirmed by ¹ H-NMR measurement that it was the target resin.

A thermosetting resin composition was prepared by mixing 10 parts by weight of methyl p-hydroxybenzoate with 100 parts by weight of the benzoxazine resin obtained in Synthesis Example 1 in a powder state. This composition was subjected to DSC measurement in an argon atmosphere at a rate of temperature increase of 10 ° C./min. As a result, heat generation due to curing was confirmed, and the peak temperature was 223 ° C.

[Comparative Example 3]
The benzoxazine resin obtained in Synthesis Example 1 alone was subjected to DSC under the same conditions as in Example 2.
When the measurement was performed, a peak accompanying curing was confirmed, and the peak temperature was 248 ° C.

[Synthesis Example 2]
In a separable flask equipped with stirring, cooling tube and nitrogen introduction tube, 1,9-nonanediol (made by Kuraray) 40.00 g (0.25 mol), p-hydroxybenzoic acid (made by Ueno Pharmaceutical) 68.95 g (0.50 mol), p-toluenesulfonic acid monohydrate (Wako Pure Chemical Industries, Ltd.) 1
. 00 g and 200 ml of methyl isobutyl ketone were mixed. This was put in a 180 ° C. oil bath and reacted for 4 hours while introducing nitrogen gas. Thereafter, the reaction was carried out while removing the solvent little by little under reduced pressure in the system, and almost volatile components were removed over about 4 hours. This was allowed to cool to obtain a light brown viscous product.
This was dissolved in tetrahydrofuran and poured into a large amount of distilled water to remove the catalyst and precipitate the product. By separating the aqueous layer from this, a crude product containing a solvent was isolated. After repeating this operation once again, it was dried in a vacuum oven at 70 ° C. to obtain a light brown viscous product.
As a result of ¹ H-NMR spectrum measured by dissolving the viscous material in heavy acetone, and G
From the results of PC measurement, it was confirmed to be a compound of the following formula.

[Synthesis Example 3]
Bisphenol M in a glass container equipped with a stirrer, condenser, and temperature control jacket
728.5 g (2.1 mol, manufactured by Mitsui Chemicals), Bisaniline M 564.4 g (1.6 m
ol, manufactured by Mitsui Chemicals), 109.6 g of 1,12-dodecanediamine (0.5 mol, manufactured by Ogura Gosei Co., Ltd.), and 16.0 g of phenol (0.2 mol, manufactured by Wako Pure Chemical Industries) were dissolved in 3 L of toluene and 150 ml of isobutanol. I let you. To this, 365 g of paraformaldehyde (Mitsubishi Gas Chemical Co., 91.6%) was added, heated and reacted for 7 hours under reflux. After the obtained solution was filtered, the solvent was removed to obtain a thermosetting resin having a dihydrobenzoxazine structure in the molecule.
When evaluated by GPC measurement, weight average molecular weight Mw = 13,000, molecular weight distribution Mw
/Mn=3.6. It was also confirmed by ¹ H-NMR measurement that the resin had the target structure.

For 100 parts by weight of the benzoxazine resin obtained in Synthesis Example 3, 10 parts by weight of the compound obtained in Synthesis Example 2 was dissolved in a mixed solvent of toluene / tetrahydrofuran and coated on a PET film, and then heated in an oven at 80 ° C. And dried for 1 hour to obtain a film of a thermosetting resin composition.
When this film was subjected to DSC measurement, an exothermic peak accompanying curing was confirmed, but the peak temperature was 232 ° C., and it was confirmed that the reaction started from around 160 ° C. A DSC chart is shown in FIG.

[Comparative Example 4]
A film was produced in the same manner as in Example 3 except that the compound obtained in Synthesis Example 2 was not added. When this film was subjected to DSC measurement, an exothermic peak accompanying curing was confirmed, the peak temperature was 254 ° C., and it was confirmed that the reaction started in a region exceeding 200 ° C. A DSC chart is shown in FIG.

The present invention relates to a thermosetting resin composition capable of curing a dihydrobenzoxazine resin having excellent heat resistance and electrical properties at a lower temperature, a molded body, a cured body, a cured molded body, and an electronic device including them. Have industrial applicability.

6 is a diagram showing a DSC chart of the film of Example 3. FIG. It is a figure which shows the DSC chart of the film of the comparative example 4.

Claims (8)

a) A thermosetting resin composition containing 0.1 to 30 parts by weight of a p-hydroxybenzoic acid ester with respect to 100 parts by weight of a resin having two or more dihydrobenzoxazine structures in the molecule. 2. The thermosetting resin composition according to claim 1, wherein the p-hydroxybenzoic acid ester of b) has two or more p-hydroxybenzoic acid ester moieties in the molecule. The p-hydroxybenzoic acid ester of b) has a molecular weight (number average molecular weight in the case of a polymer) of 152 to 50,000, and a molecular weight (number average molecular weight in the case of a polymer) / 1 p in one molecule.
3. The thermosetting resin composition according to claim 1, wherein the value of the average number of units of the hydroxybenzoic acid ester portion is 151 to 2,000. The resin of a) is a benzoxazine resin having a dihydrobenzoxazine structure in a main chain having a weight average molecular weight of 1,000 to 100,000 obtained by reaction of a bifunctional phenol, a bifunctional amine and formaldehyde. The thermosetting resin composition according to any one of claims 1 to 3. The molded object obtained by making the thermosetting resin composition in any one of Claims 1-4 partially cure, or not making it harden | cure.   A cured product obtained from the thermosetting resin composition according to claim 1.   A cured molded body obtained by curing the molded body according to claim 5. An electronic device comprising the molded body according to claim 5, the cured body according to claim 6, or the cured molded body according to claim 7.