JPH10298404A - Resin composition for molding material and molding obtained by curing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition which has a good curability and emits no odor in curing and gives moldings excellent in mechanical properties, electrical properties and flame retardancy by mixing an essential component being a composition comprising a thermosetting resin having dihydrobenzoxazine rings and a phenolic resin in a specified ratio with glass fibers and an inorganic filler in a specified ratio. SOLUTION: This composition comprises 100 pts.wt. essential component being a composition comprising 60-97 wt.% thermosetting resin having dihydrobenzoxazine rings, for example, obtained from a phenol novolac resin, aniline and HCHO and 3-40 wt.% phenolic resin desirably of a novolac or resol type, 5-150 pts.wt. glass fibers and 0.5-150 pts.wt. inorganic filler (e.g. talc). It is desirable that 1-50 pts.wt. elastomer (e.g. crosslinked acrylonitrile/butadiene copolymer) is added to 100 pts.wt. this resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for a molding material and a molded product obtained by curing the same. The present invention relates to a resin composition for a molding material of a dihydrobenzoxazine-based resin, which is superior in electrical properties and the like and can improve the working environment, and a molded product obtained by curing the same.

[0002]

2. Description of the Related Art Conventionally, molding materials using thermosetting resins include phenolic resins, melamine resins, phenolic resins and melamine resins due to their well-balanced mechanical properties, heat resistance, flame retardancy, electric properties and low cost.
Urea resins and the like have been used. However, these resins emit ammonia (hexamethylenetetramine-curable novolak resin) which causes corrosion of electric parts in addition to inferior flexibility, and emits formaldehyde and water due to a condensation reaction during curing. In addition, they have inherent disadvantages such as formation of voids (resole resin and melamine resin), and furthermore, these volatile components cause problems such as contaminating the surface of the molded article and the mold, or deteriorating the working environment due to odor. In addition, molding materials using no ammonia resol do not generate ammonia, so their electrical properties are relatively good, and demand for electric and electronic applications is expanding, but the problem of mold contamination could not be solved. . Therefore, development of a novel thermosetting resin that does not have these problems has been promoted. One of them is a dihydrobenzoxazine compound (JP-A-49-47387, US Pat. No. 5,152,939). Since the curing of this compound utilizes the ring-opening polymerization reaction of the dihydrobenzoxazine ring, it is thermally cured with almost no generation of volatile components.

In order to solve the above problems, it is necessary to use an unsaturated polyester resin, an epoxy resin, a bismaleimide resin, and the like. In many cases, the phenolic resin or the like is inadequate or very expensive, and cannot be substituted for a phenol resin or the like at a practical level. On the other hand, a cured product of a dihydrobenzoxazine compound utilizing a ring-opening polymerization reaction has better heat resistance and higher strength and flexibility than conventionally known thermosetting resins. However, curing by the ring-opening polymerization reaction has a disadvantage that it requires a longer time than curing by the ordinary phenol resin curing reaction, and it has been attempted to add a curing agent to solve this. , And the generation of volatile components due to the decomposition of the residual hardener, etc., has not led to practical use. In addition, although it has high strength, it has a relatively low bending ratio and relatively low toughness. With the resin composition for molding materials described in JP-A-6-34589, high strength can be achieved, but it is insufficient in terms of fast curing and high toughness.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a molding material for a thermosetting resin having a dihydrobenzoxazine ring, which has improved curability without deteriorating various properties such as mechanical properties and has excellent toughness. An object of the present invention is to provide a resin composition for use and a molded product obtained by curing the same.

[0005]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have formulated a phenol resin as a curing agent into a thermosetting resin having a dihydrobenzoxazine ring, and By blending an organic fiber and an inorganic filler in an amount, and optionally blending an elastomer, the curability and toughness of the thermosetting resin having a dihydrobenzoxazine ring can be improved without reducing various properties such as mechanical properties. They have found that they can be improved, and based on this finding, have completed the present invention. That is, the present invention relates to a thermosetting resin having a dihydrobenzoxazine ring of 60 to 97% by weight and a phenol resin of 3 to 40% by weight.
Containing as an essential component a thermosetting resin composition consisting of
5 to 150 parts by weight of glass fiber and 0.5 to 15 parts by weight of inorganic filler are added to 100 parts by weight of this thermosetting resin composition.
It is intended to provide a resin composition for a molding material, which comprises 0 parts by weight and, if necessary, 1 to 50 parts by weight of an elastomer.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The thermosetting resin having a dihydrobenzoxazine ring used in the present invention is not particularly limited as long as it has a dihydrobenzoxazine ring and is cured by a ring-opening polymerization reaction of the dihydrobenzoxazine ring. For example, the compound is synthesized from a compound having a phenolic hydroxyl group, a primary amine, and formalin according to the following formula.

[0007]

Embedded image (In the formula, R1 is a methyl group, a phenyl group, or a phenyl group substituted with at least one alkyl group or alkoxyl group having 1 to 3 carbon atoms.) Examples of the compound having a phenolic hydroxyl group include polyfunctional phenol, Bisphenol, a bisphenol compound, a trisphenol compound, a tetraphenol compound, a phenol resin, etc. are mentioned. Polyfunctional phenols include catechol, hydroquinone, and resorcinol. Examples of the bisphenol compound include bisphenol A, bisphenol F and its positional isomers, bisphenol S, tetrafluorobisphenol A, and the like. Examples of the phenol resin include a novolak phenol resin, a resol phenol resin, a phenol-modified xylene resin, an alkylphenol resin, a melamine phenol resin, and a phenol-modified polybutadiene.

Specific examples of the primary amine include methylamine, substituted anilines such as aniline, toluidine and anisidine. When the aliphatic amine is used, the resulting thermosetting resin cures quickly but has poor heat resistance. When an aromatic amine such as aniline is used, the cured product obtained by curing the obtained thermosetting resin has good heat resistance, but cures slowly. The thermosetting resin having a dihydrobenzoxazine ring is a compound having at least one hydroxyphenylene group in which at least one of the ortho positions of the hydroxyl group is hydrogen in a molecule (hereinafter referred to as a compound having a reactive hydroxyphenylene group). ) And a primary amine are mixed with 7
70 to 110 ° C., preferably 90 to 110 ° C.
The reaction is performed at 00 ° C. for 20 minutes to 2 hours, and then at 120 ° C.
It is obtained by drying under reduced pressure at the following temperature.

In the above reaction, the primary amine is usually added in an amount of from 0.5 to 1 to 1 mol of all phenolic hydroxyl groups of the compound having a reactive phenyloxyphenylene group.
0 mol, preferably 0.6-1.0 mol, primary amine 1
The reaction is carried out at a ratio of 2 mol or more of formaldehyde to mol. If the amount of the primary amine is less than 0.5 mol, the crosslinking density may be reduced, and the heat resistance may be insufficient. The thermosetting resin having a dihydrobenzoxazine ring is cured by heating to 150 ° C. or higher, preferably 170 to 220 ° C., without using a catalyst or a curing agent and without generating by-products. The thermosetting resin having a dihydrobenzoxazine ring used in the present invention can be used in combination of two or more kinds. Further, these thermosetting resins are previously heated to 80 to 180 ° C., preferably 120 to 180 ° C.
By treating at ~ 160 ° C, a part of it can be pre-polymerized to adjust the curing speed and melt viscosity during molding.

In the present invention, as the phenol resin to be mixed with the thermosetting resin, a novolak type phenol resin or a resol type phenol resin can be used. Examples of the novolak type phenol resin include a phenol novolak resin, a bisphenol novolak resin, a phenol-modified xylene resin, and an alkylphenol resin. As resole phenolic resin, liquid,
Any of solid resols can be used. Also, dimethylene ether type resole, methylol type resole and the like are used. By using a solid dimethylene ether type resol among the resole type phenol resins, the curability can be improved without lowering the mechanical properties. By using a so-called high ortho novolak resin having an ortho ratio of 50% or more among the novolak type phenol resins, the curability can be improved without lowering the mechanical properties.

A thermosetting resin having a dihydrobenzoxazine ring is self-curing but has a slow curing reaction. Therefore, the phenolic resin is added to the total amount of the thermosetting resin having a dihydrobenzoxazine ring and the phenolic resin by 3%.
By blending 〜40% by weight, preferably 5-30% by weight, the curability can be improved without lowering the mechanical properties. If the phenolic resin content exceeds 40% by weight, the curability is improved, but the mechanical properties may be reduced. As described above, since hexamethylenetetramine, which is conventionally used as a curing agent for a novolak resin, is not used, no volatile components such as ammonia are generated during curing, and the working environment can be improved. In addition, a cured product of a resin having a dihydrobenzoxazine structure has a characteristic of having a lower water absorption than a cured product of a conventional thermosetting resin such as an epoxy resin or a phenol resin. This phenomenon is considered to be because the phenolic hydroxyl group is fixed by the interaction with the nitrogen atom. In order to maintain this feature, the thermosetting resin composition of the present invention uses a thermosetting resin having a dihydrobenzoxazine ring as a main component, and
The ratio of the number of phenolic hydroxyl groups to the number of nitrogen atoms in the thermosetting resin having a dihydrobenzoxazine ring in the cured product and the phenolic resin, the number of phenolic hydroxyl groups / the number of nitrogen atoms,
The composition is desirably 1.5 or less, preferably 0.3 to 1.5, particularly preferably 0.5 to 1.10.

In the present invention, the elastomer blended in the thermosetting resin composition as required is not particularly limited, but an elastomer in which a part of the main chain structural unit is crosslinked by the structural unit, Parameter 8 ~
Thirteen elastomers, a thermosetting resin having a dihydrobenzoxazine ring, and a liquid elastomer having a functional group capable of reacting with a phenolic hydroxyl group generated by opening of the dihydrobenzoxazine ring are preferably used. The type of the elastomer is not particularly limited, and examples thereof include polyurethane-based, acrylic-based, polyester-based, polyamide-based, and vinyl acetate-based elastomers. These elastomers include a homopolymer composed of one kind of monomer, a block copolymer composed of two or more kinds of monomers, a graft copolymer, a random copolymer, and a mixture thereof. Particularly preferably, a polyurethane elastomer, an acrylonitrile-butadiene copolymer elastomer, or a polyamide elastomer is used.

In the case of an elastomer in which a part of the main chain structural units are crosslinked with each other, an acrylonitrile-butadiene copolymer elastomer is particularly preferably used. Further, a thermosetting resin having a dihydrobenzoxazine ring in the elastomer and a phenolic hydroxyl group generated by opening the dihydrobenzoxazine ring can react with, for example, a functional group such as an epoxy group, a hydroxyl group or a carboxyl group. Those having a functional group having a high solubility parameter are particularly preferred. The particle size of these elastomers is preferably from 10 nm to 0.2 mm. As a method of cross-linking the structural units of the main chain of the elastomer, radical-polymerization, ionic polymerization, condensation, polyaddition, addition condensation, etc., are performed on elastomers each having a functional group capable of reacting with a part of the main-chain structural units. There are various methods such as crosslinking. Further, there is a method in which an elastomer having an unsaturated bond in the main chain is further crosslinked by further polymerization to obtain a highly crosslinked elastomer. As the acrylonitrile-butadiene copolymer elastomer, one obtained by introducing a functional group such as a carboxyl group into the elastomer main chain and cross-linking by condensation or the like is used. As a highly crosslinked elastomer, a highly crosslinked NB
R is used.

These elastomers having a crosslinked structure are:
When mixed and cured with a thermosetting resin having a dihydrobenzoxazine ring, a sea-island dispersion structure in which the selected particle size is maintained as it is can be easily obtained as long as particle aggregation does not occur, and toughness is improved. In contrast, in a method of depositing and dispersing an elastomer in a thermosetting resin composition such as spinodal decomposition when an elastomer having no crosslinked structure is used, it is difficult to control the particle size of the elastomer, and a uniform sea-island structure cannot be obtained. Sometimes. When the elastomer has a solubility parameter of less than 8,
Since the elastomer is not uniformly dispersed in the thermosetting resin having a dihydrobenzoxazine ring, the toughness does not tend to be improved. When the solubility parameter exceeds 13, the dispersion in the thermosetting resin having a dihydrobenzoxazine ring is poor, the state becomes compatible and the bending rate is improved, but the bending strength tends to decrease. is there. Examples of the functional group of the liquid elastomer having a functional group capable of reacting with a thermosetting resin having a dihydrobenzoxazine ring and a phenolic hydroxyl group generated by opening the dihydrobenzoxazine ring include an amino group, an epoxy group, a carboxyl group, Phenolic hydroxyl groups are mentioned. Before the thermosetting resin having a dihydrobenzoxazine ring is cured, a part of the elastomer may be preliminarily polymerized at 60 to 180 ° C, preferably 80 to 160 ° C. The blending ratio of the elastomer is preferably 100 parts by weight of the resin composition comprising the thermosetting resin having a dihydrobenzoxazine ring and the phenol resin,
It is 1 to 50 parts by weight, more preferably 2 to 40 parts by weight. When the amount is less than 1 part by weight, it is difficult to improve the toughness, and when the amount exceeds 50 parts by weight, the mechanical properties may be deteriorated.

The glass fiber used in the present invention preferably has a fiber diameter of 5 to 20 μm from the viewpoint of the reinforcing effect of the resin and the wear of the mold during molding. If the amount is less than 5 parts by weight, the reinforcing effect is not exhibited, and if it exceeds 150 parts by weight, the abrasion of the mold is increased. Preferably, 50 to 150 parts by weight is used. Also, clay as inorganic filler,
Mica, talc, zeolite and the like can be mentioned. These are used alone or as a mixture of two or more. If the amount is less than 0.5 parts by weight, the electrical properties will decrease, and if it exceeds 150 parts by weight, the strength will decrease. Preferably 2 to 100
Parts by weight are used. The resin composition for a molding material of the present invention may optionally contain additives such as a curing accelerator, a release agent, an adhesion imparting agent, and a coloring agent. As a curing accelerator, catechol, polyfunctional phenol compounds such as bisphenol A, p-toluenesulfonic acid, sulfonic acids such as p-phenolsulfonic acid, benzoic acid, salicylic acid,
Carboxylic acids such as oxalic acid and adipic acid, cobalt (I
I) Metal complexes such as acetylacetonate, aluminum (III) acetylacetonate zirconium (IV) acetylacetonate, metal oxides such as calcium oxide, cobalt oxide, magnesium oxide, iron oxide, calcium hydroxide, imidazole, diaza Bicycloundecene and phenylphosphonic acid and the like. These can be one or two
Used as a mixture of more than one species. For applications in fields requiring even faster curability, a small amount of a curing agent such as hexamethylenetetramine, which has been conventionally used as a curing agent for phenol resins, may be added. Even when such a conventional curing agent is used in combination, by reducing the amount thereof, the generation of volatile components such as ammonia can be suppressed. When such ordinary curing agents are used together, the amount is usually
It is desirable to use 1 to 5 parts by weight based on the total amount of the thermosetting resin having a dihydrobenzoxazine ring and the phenol resin.

As the release agent, stearate, carnauba wax or the like can be used, and as the coloring agent, carbon black or the like can be used. If necessary, a flame retardant improver such as boric acid or aluminum hydroxide can be used. As the adhesion-imparting agent, silane coupling agents such as aminosilane, diaminosilane, triaminosilane, ureido-modified aminosilane, vinylsilane, vinylbenzylaminosilane, benzylaminosilane, cationic silane,
Epoxy silane and the like can be mentioned. These can be one or two
Used as a mixture of more than one species. The resin composition for a molding material of the present invention is kneaded with a heating roll or the like, and then kneaded.
0 to 220 ° C, molding pressure 20 to 70 kgf / cm ² , 3 to
It is cured by compression molding or transfer molding for 10 minutes, and the curability and toughness are improved compared to a thermosetting resin having a dihydrobenzoxazine ring alone, and a cured product having good mechanical properties and flame retardancy can be obtained. . Further, by further post-curing the cured product at 180 to 220 ° C. for 5 to 120 minutes, a molded article having better properties can be obtained.

[0017]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples of the present invention and comparative examples thereof, but the present invention is not limited to these examples.

Examples 1 to 9 and Comparative Examples 1 to 7 [1] Synthesis of thermosetting resin having dihydrobenzoxazine ring (I) (1) Synthesis of phenol novolak resin 1.9 kg of phenol, formalin (37% aqueous solution) )
1.15 kg and 4 g of oxalic acid were charged into a 5-liter flask and reacted at a reflux temperature for 6 hours. Subsequently, the internal pressure was reduced to 6666.1 Pa or less to remove unreacted phenol and water. The obtained resin had a softening point of 89 ° C. (ring and ball method) and a 3 to polynuclear / binuclear ratio of 89/11 (peak area ratio by gel permeation chromatography). (2) Introduction of dihydrobenzoxazine ring 1.7 k of phenol novolak resin synthesized above
g (equivalent to 16 mol of hydroxyl groups) to aniline 0.9
3 kg (corresponding to 10 mol) and stirred at 80 ° C. for 5 hours to prepare a uniform mixed solution. 1.62 kg of formalin was charged into a 5 liter flask, heated to 90 ° C., and a novolak / aniline mixed solution was gradually added thereto over 30 minutes. 30 minutes after the completion of the addition, the mixture was kept at the reflux temperature, and then decompressed to 6666.1 Pa or less at 100 ° C. for 2 hours to remove the condensed water, and heat cured in which 75% of the reactive hydroxyl groups were converted to dihydrobenzoxazine. A functional resin was obtained (m = 1, n = 2.2).

[2] Synthesis of thermosetting resin having dihydrobenzoxazine ring (II) (1) Synthesis of phenol novolak resin 1.9 kg of phenol, formalin (37% aqueous solution)
1.10 kg and 4 g of oxalic acid were charged into a 5-liter flask, and a phenol novolak resin was synthesized in the same manner as in the synthesis (I) of the thermosetting resin having a dihydrobenzoxazine ring. The obtained resin has a softening point of 84 ° C (ring and ball method),
The ratio was 3 to polynuclear / binuclear 82/18 (peak area ratio by gel permeation chromatography). (2) Introduction of a dihydrobenzoxazine ring A dihydrobenzoxazine ring was introduced in the same manner as in the synthesis of a thermosetting resin having a dihydrobenzoxazine ring (I). The obtained thermosetting resin was a phenol novolak resin in which 71% of the reactive hydroxyl groups had dihydrobenzoxazine rings introduced therein (m = 3, n = 5).

[3] Synthesis of thermosetting resin having dihydrobenzoxazine ring (III) 1.70 kg of xylylene-modified phenol resin (Mirex XL-225-3L, trade name, manufactured by Mitsui Toatsu Chemicals, Inc.)
(Corresponding to 10 mol of hydroxyl group), aniline 0.52
kg (5.6 mol), formalin (37% aqueous solution)
A reaction was carried out in the same manner as in the above synthesis method at a compounding ratio of 0.91 kg, and a thermosetting resin having a dihydrobenzoxazine ring introduced into 71% of the reactive hydroxyl groups was synthesized (m = 2.2, n = 2). .8).

[4] Synthesis of novolak type phenol resin (A) 2.4 kg of phenol, formalin (37% aqueous solution)
0.02 kg, paraformaldehyde 0.6 kg, zinc acetate 0.02 kg, benzoic acid 0.06 kg, water 0.0
5 kg is charged into a 5-liter flask, and refluxed at 6 ° C.
Allowed to react for hours. Subsequently, the internal pressure was reduced to 6666.1 Pa or less to remove unreacted phenol and water. The obtained resin had a softening point of 75 to 83 ° C (ring and ball method) and an ortho ratio of 70% (NMR).

[5] Synthesis of novolak type phenol resin (B) 1.9 kg of phenol, formalin (37% aqueous solution)
1.3 kg and 15 kg of oxalic acid were charged into a 5-liter flask and reacted at a reflux temperature for 6 hours. Subsequently, the internal pressure was reduced to 6666.1 Pa or less to remove unreacted phenol and water. The obtained resin had a softening point of 84 ° C. (ring and ball method) and an ortho ratio of 40% (NMR).

[6] Other Compounds As the elastomer, a crosslinked acrylonitrile-butadiene copolymer having a particle diameter of 70 nm (trade name: XER-91, manufactured by Nippon Synthetic Rubber Co., Ltd., acrylonitrile content: 20.0 mol%, carboxyl group-modified copolymer) Coalesced), polyurethane elastomer (trade name: Pandex T5205, manufactured by Dainippon Ink and Chemicals, Incorporated, solubility parameter = 10.
5), polyethylene (Nipolon Hard 1000, trade name, manufactured by Tosoh Corporation, solubility parameter = 7.9), liquid acrylonitrile-polybutadiene copolymer (ATBN1300X16, trade name, manufactured by Ube Industries, Ltd., AN amount: 1.)
65% by weight, amino group content, amine equivalent 900).

[Curing] The raw materials were mixed according to the composition shown in Tables 1 and 2, and kneaded using a biaxial roll, followed by pulverization to prepare a powdery molding material. Next, molding was performed at a mold temperature of 180 ° C. and 1.96 MPa for 15 minutes to produce molded articles. Preheating or post-curing before molding was performed as necessary. Regarding the properties of the resin composition for a molding material, the curability was measured by using a JSR type curast meter, and the time required for the resin composition to be 100% cured at 180 ° C. was measured. The properties of the cured product are
The electrical characteristics were measured according to JIS K6911, and the flame retardancy was measured according to UL-94. For the appearance of the molded product and the stain on the mold, see M-10 manufactured by Meiki Seisakusho.
Using a 0A-TS type injection molding machine, 50 kg of a molding material was molded in the same manner as described above, and evaluated visually. Tables 1 to 4 show the composition and the measurement results in each of Examples and Comparative Examples. In addition, all the composition was shown by the weight part.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

[Table 3]

[0028]

[Table 4]

[0029]

By using the resin composition of the present invention, it is possible to obtain a molding material having a good balance of good mechanical properties, electrical properties, and flame retardancy that cannot be achieved with conventional molding materials such as phenol and melamine. . In addition, since the composition has good curability and does not emit volatile components at the time of curing, it is possible to obtain a molded article having good appearance with little mold stain and odor.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Yoshinori Sato, 1500 Ogawa, Oji, Shimodate, Ibaraki Prefecture Inside the Shimodate Plant of Hitachi Chemical Co., Ltd. (72) Shinichi Kamoshida 1500, Oji Ogawa, Shimodate, Ibaraki Hitachi, Ltd. Inside the Shimodate Plant (72) Inventor Minoru Kakitani 1500 Ogawa, Oji, Shimodate City, Ibaraki Prefecture Inside Shimodate Plant, Hitachi Chemical Co., Ltd. (72) Inventor Shunichi Numata 1500 Oji Ogawa, Shimodate City, Ibaraki Prefecture 72) Inventor K. Tomita 1500, Oji, Shimodate, Ibaraki Pref., Shimodate Plant, Hitachi Chemical Co., Ltd. (72) Inventor Yuki Sato, 1500, Oji, Oji, Shimodate, Ibaraki Pref., Shimodate Plant, Hitachi Chemical Person Hiroto Oda 1500 Ogawa, Oji, Shimodate City, Ibaraki Prefecture Shimodate Plant, Hitachi Chemical Co., Ltd. Inside

Claims (7)

[Claims] 1. A thermosetting resin having a dihydrobenzoxazine ring of 60 to 97% by weight and a phenol resin of 3 to 40%.
% Of a thermosetting resin composition as an essential component, and 100 parts by weight of the thermosetting resin composition, 5 to 150 parts by weight of glass fiber and 0.5% of an inorganic filler.
A resin composition for a molding material, characterized in that the resin composition comprises from 150 to 150 parts by weight. 2. The resin composition for a molding material according to claim 1, wherein the phenol resin is a novolak type phenol resin or a resol type phenol resin. (3) 100 parts by weight of the thermosetting resin composition,
The resin composition for a molding material according to claim 1, further comprising 1 to 50 parts by weight of an elastomer. 4. The resin composition for a molding material according to claim 3, wherein the elastomer is an elastomer in which a part of the main chain structural units are crosslinked with each other. 5. An elastomer having a solubility parameter of 8
The resin composition for a molding material according to claim 3 or 4, which is an elastomer of (1) to (3). 6. The elastomer according to claim 3, wherein the elastomer is a thermosetting resin having a dihydrobenzoxazine ring and a liquid elastomer having a functional group capable of reacting with a phenolic hydroxyl group generated by opening of the dihydrobenzoxazine ring.
Or the resin composition for molding materials according to 5. 7. A molded product obtained by curing the resin composition for a molding material according to claim 1.