JP2011057907A - Thermosetting resin composition and prepreg using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermosetting resin composition suitable for molding a composite material excellent in mechanical properties such as heat resistance and toughness and a prepreg using the thermosetting resin composition. <P>SOLUTION: The thermosetting resin composition includes, as the indispensable components, 5-50 pts.wt. of (component [A]) thermoplastic composite fine particles which have an average particle size of 5-70 μm and are obtained by kneading 1-90 wt.% of silicone fine particles with an average particle size of 1-12 μm and 99-10 wt.% of a thermoplastic resin, 100 pts.wt. of (component [B]) a thermosetting resin, 20-50 pts.wt. of (component [C]) a hardener, and 5-80 pts.wt. of (component [D]) a thermoplastic resin other than component [A]. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a thermosetting resin composition suitable for molding a composite material excellent in mechanical properties such as high heat resistance and toughness, and a prepreg using the resin composition as a matrix resin.

Fiber reinforced plastic (FRP) is a thermosetting resin such as unsaturated polyester resin, epoxy resin, thermosetting polyimide resin, polyethylene, polypropylene, polyamide, polyphenylene sulfide (PPS), polyether ether ketone (PEEK), etc. In recent years, from the aerospace industry to the general industrial field because it is a composite material consisting of a matrix resin of thermoplastic resin and fiber reinforcements such as carbon fiber, glass fiber, and aramid fiber, and it is lightweight and has excellent strength characteristics It is used in a wide range of fields.

Generally, a prepreg which is a molding intermediate base material for FRP is obtained by dissolving a matrix resin in a solvent, mixing a curing agent or an additive, and impregnating a fiber reinforcing material such as cloth, mat, or roving. And, for example, for aircraft structural materials, honeycomb sandwich panels with prepregs as face plates are widely used from the viewpoint of weight reduction. Recently, however, they are applied to aircraft applications other than honeycomb sandwich panels. There are also attempts. However, in aircraft materials that require particularly high heat resistance and toughness (toughness), the conventional FRP has a problem in that mechanical properties such as toughness and impact resistance are significantly lowered at high temperature conditions. there were. Therefore, it is desired to improve mechanical properties such as toughness and impact resistance while maintaining basic performance such as heat resistance.

For example, in the case of a prepreg using a thermosetting resin such as an epoxy resin as a matrix resin, the heat resistance and mechanical properties are good, but on the other hand, the matrix resin has low elongation and is brittle, so the toughness of the composite material There is a problem that it is inferior in impact resistance. Therefore, in order to improve the impact resistance of the composite material, a method of adding a thermoplastic resin to the matrix resin of the prepreg is known (for example, see Patent Documents 1 to 3). However, when the amount of the thermoplastic resin is increased in order to obtain sufficient impact resistance, the adhesiveness of the prepreg is lowered, so that there is a problem that the handleability in the molding process is lowered. Moreover, in such a prepreg, the adhesiveness of the prepreg also decreases over time, and the handleability decreases. It is desired to improve the adhesion and stability of the prepreg while adding the necessary thermoplastic resin. And in order to solve the above problems, a method using a thermosetting resin and a particulate thermoplastic resin as a matrix resin (Patent Documents 4 and 5), an epoxy resin, a thermoplastic resin, and a microcapsule type epoxy resin Methods using a curing agent (Patent Documents 6 and 7) have been proposed. However, the improvement effect of the composite performance such as the handling property such as the laminate property and the impact resistance is not yet sufficient.

Japanese Patent Laid-Open No. 61-250021 JP-A-62-36421 JP 62-57417 A JP-A-6-240024 JP 2006-169541 A JP-A-4-249544 JP-A-5-9262

An object of the present invention is to provide a thermosetting resin composition suitable for molding a composite material excellent in mechanical properties such as heat resistance and toughness, and a prepreg using the thermosetting resin composition. It is in.

The above-mentioned subject is achieved by each mode of the present invention described in the claims 1-11.

The invention described in claim 1 of the present invention includes at least the following component [A], component [B], component [C], and component [D] as essential components in the following proportions: It is a thermosetting resin composition.
Component [A]: Thermoplastic composite fine particles 5 having an average particle size of 5 to 70 μm obtained by kneading 1 to 90 wt% of silicone resin fine particles having an average particle size of 1 to 12 μm and 99 to 10 wt% of a thermoplastic resin ~ 50 parts by weight,
Component [B]: 100 parts by weight of thermosetting resin,
Component [C]: 20 to 50 parts by weight of a curing agent,
Component [D]: 5 to 80 parts by weight of thermoplastic resin other than component [A].

The invention described in claim 2 is characterized in that crater-like holes having a diameter of 1 to 12 μm are present on the surface of the thermoplastic composite fine particles of component [A]. It is a thing.

The invention described in claim 3 is the thermosetting resin composition according to claim 1 or 2, wherein the thermosetting resin of the component [B] contains at least an epoxy resin.

The invention described in claim 4 is the thermosetting resin composition according to claim 3, wherein the epoxy resin contains at least a trifunctional or higher functional epoxy resin.

The invention described in claim 5 is characterized in that the thermosetting resin of component [B] is a thermosetting resin that does not dissolve the thermoplastic resin of component [A]. The curable resin composition according to claim 1. In the present invention, the fact that the thermosetting resin of the component [B] does not dissolve the thermoplastic resin means that the thermoplastic resin is put into the component [B] in the form of pellets, pulverized material or powder and stirred at the curing temperature or lower. However, it means that the particle size hardly changes.

The invention described in claim 6 is characterized in that the curing agent of the component [C] contains at least an aromatic amine-based curing agent. It is an adhesive resin composition.

The invention described in claim 7 has an average particle size of 5 to 70 μm obtained by kneading 1 to 90% by weight of silicone resin fine particles having an average particle size of 1 to 12 μm and 99 to 10% by weight of a thermoplastic resin. Thermoplastic composite fine particles.

The invention described in claim 8 is the thermoplastic composite fine particle according to claim 7, wherein a crater-like hole having a diameter of 1 to 12 μm is present on the surface of the thermoplastic composite fine particle.

The invention described in claim 9 is a prepreg obtained by impregnating a fiber reinforcing material with the thermosetting resin composition according to any one of claims 1 to 6.

The invention described in claim 10 is the prepreg according to claim 9, wherein the fiber reinforcing material is carbon fiber.

The invention described in claim 11 is a composite material obtained by curing the prepreg according to claim 9 or 10.

A composite material obtained by laminating a prepreg using the thermosetting resin composition of the present invention as a matrix resin and curing and molding it has high heat resistance and has improved mechanical properties, particularly toughness.

The thermosetting resin composition of the present invention is obtained by kneading at least component [A], that is, 1 to 90% by weight of silicone resin fine particles having an average particle diameter of 1 to 12 μm and 99 to 10% by weight of a thermoplastic resin. Other than thermoplastic composite fine particles having an average particle size of 5 to 70 μm, component [B], ie, thermosetting resin, component [C], ie, curing agent, and component [D], ie, component [A] A thermoplastic resin is included as an essential component.

The thermosetting resin composition of the present invention uses thermoplastic composite fine particles (component [A]) containing silicone resin fine particles having high heat resistance in the thermoplastic resin as one of the components constituting the composition. It is characterized by.

The proportion of the silicone resin fine particles composing the thermoplastic composite fine particles is appropriately 1 to 90% by weight of the silicone resin fine particles and 99 to 10% by weight of the thermoplastic resin depending on the kind of the resin. The case where the silicone resin fine particles are in the range of 5 to 70% by weight is preferable. 1-12 micrometers is suitable for the average particle diameter of this silicone resin particle, Preferably it is 2-10 micrometers. As a production method, 1 to 90% by weight of silicone resin fine particles having an average particle diameter of 1 to 12 μm and 99 to 10% by weight of a thermoplastic resin are kneaded, compounded, and then pulverized to form particles. And sieved to obtain thermoplastic composite fine particles having an average particle diameter of 5 to 70 μm. The surface of the composite fine particles thus obtained usually has crater-like holes, but in the present invention, those having crater-like holes having a diameter of 1 to 12 μm are preferred. In addition, it is preferable to remove the silicone resin fine particles present in a small amount near the surface of the particles by subjecting the pulverized particulate matter to an air classification process.

The thermoplastic composite fine particles need to be in the form of particles in order to be added to the thermosetting resin composition of the present invention while maintaining homogeneity and moldability. The average particle diameter of the thermoplastic resin fine particles needs to be in the range of 5 to 70 μm. If it is smaller than 5 μm, the bulk density increases, and the viscosity of the thermosetting resin composition may increase significantly, or it may be difficult to add a sufficient amount. On the other hand, if the thickness is larger than 70 μm, it may be difficult to obtain a sheet having a uniform thickness when the obtained thermosetting resin composition is formed into a sheet. More preferably, the average particle size is 5 to 50 μm.

The mixing ratio of the thermoplastic composite fine particles (component [A]) in the thermosetting resin composition of the present invention is the amount of the thermosetting resin (component [B] described later) in the thermosetting resin composition is 100. The amount is 5 to 50 parts by weight, preferably 10 to 40 parts by weight. The method of mixing is not particularly limited, but it is preferable to mix as uniformly as possible. By blending the thermoplastic composite fine particles as described above, the heat resistance of the cured product obtained by curing the thermosetting resin composition of the present invention is hardly lowered, and mechanical properties such as interlaminar fracture toughness are improved. be able to.

The thermosetting resin used as the component [B] of the present invention is not particularly limited, but for example, mainly epoxy resin, bismaleimide resin, oxetane resin, benzoxazine resin, polyester resin, vinyl resin, cyanate ester resin, and the like. The thermosetting resin comprised from these is mentioned. The said thermosetting resin can be selected suitably and can be used 1 type or in mixture of 2 or more types.

An epoxy resin is preferable as the thermosetting resin. A conventionally well-known epoxy resin can be used as an epoxy resin, It does not specifically limit. Specifically, for example, N, N, N ′, N′-tetraglycidyldiaminodiphenylmethane (for example, jER604 manufactured by Japan Epoxy Resin, Sumiepoxy ELM-434 manufactured by Sumitomo Chemical Co., Ltd., ELM-120 manufactured by Asahi Ciba Co., Ltd.) Multifunctionals having a glycidylamino group such as Araldite MY9634, MY-720, Etoto YH434 manufactured by Tohto Kasei), N, N, O-triglycidyl-p-aminophenol (for example, Sumitomo Chemical Co., Ltd. Sumiepoxy ELM-100) Epoxy resin, bisphenol type epoxy resin, alcohol type epoxy resin, hydrophthalic acid type epoxy resin, dimer acid type epoxy resin, alicyclic epoxy resin, etc. bifunctional epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, etc. Novolac type Polyfunctional epoxy resins such as epoxy resins. Furthermore, various modified epoxy resins such as urethane-modified epoxy resin and rubber-modified epoxy resin can also be used. Preferable examples include bisphenol type epoxy resins, alicyclic epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, and urethane-modified bisphenol A epoxy resins in addition to the above-mentioned polyfunctional epoxy resins having a glycidylamino group. Can be mentioned.

Examples of the bisphenol type epoxy resin include bisphenol A type resin, bisphenol F type resin, bisphenol AD type resin, bisphenol S type resin and the like. More specifically, examples of commercially available resins include Japan Epoxy Resin's jER815, jER828, jER834, jER1001, jER807, Mitsui Petrochemical's Epomic R-710, Dainippon Ink and Chemicals' EXA1514, and the like. .

Examples of the alicyclic epoxy resin include Araldite CY-179, CY-178, CY-182 and CY-183 manufactured by Asahi Ciba Co., Ltd. as commercially available resins. Examples of the phenol novolac type epoxy resin include jER152 and jER154 manufactured by Japan Epoxy Resin, DEN431 and DEN485 and DEN438 manufactured by Dow Chemical Co., and Epicron N740 manufactured by Dainippon Ink and Chemicals, Inc. Examples of the cresol novolac epoxy resin include Araldite ECN1235, ECN1273, ECN1280, Nippon Kayaku EOCN102, EOCN103, and EOCN104 manufactured by Asahi Ciba.
Furthermore, examples of the urethane-modified bisphenol A epoxy resin include Adeka Resin EP IV-6 and EP IV-4 manufactured by Asahi Denka.

In the present invention, it is preferable that the epoxy resin contains at least a trifunctional or higher functional epoxy resin. Examples of the epoxy resin having three functional groups include Sumitomo Chemical's ELM-100, ELM-120, YX-4, Hunt05's MY0510, Dainippon Ink's EXD506, and the like.

In the present invention, the thermosetting resin of component [B] preferably does not dissolve the thermoplastic resin used for the thermoplastic composite fine particles of component [A]. In the present invention, the fact that the thermosetting resin does not dissolve the thermoplastic resin means that the thermoplastic resin is put into the thermosetting resin in the form of pellets, pulverized material or powder and stirred when the temperature is lower than the curing temperature. This is the case where the value does not change.

As the thermoplastic resin of component [A] in which the thermosetting resin of component [B] does not dissolve, for example, when a polyfunctional epoxy resin having a glycidylamino group is used as the thermosetting resin, polyether ether ketone (PEEK) ), Polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyamideimide (PAI), nylon 6, nylon 12, amorphous nylon (TR-55), polyamide such as amorphous polyimide (PIXA-M) Etc.

component
The curing agent for [C] is not particularly limited. For example, an epoxy resin is usually used with a known curing agent, but the same applies to the present invention. The curing agent used in the present invention may be anything as long as it is usually used as a curing agent for epoxy resins, but an aromatic amine curing agent is preferred. Specific examples include diaminodiphenylsulfone (DDS), diaminodiphenylmethane (DDM), diaminodiphenyl ether (DPE), and phenylenediamine. These may be used singly or as a mixture of two or more, but DDS is preferable in terms of imparting heat resistance. Moreover, what was microencapsulated with the melanin resin etc. can also be used for an aromatic amine type hardening | curing agent, for example. By including an aromatic amine curing agent in the epoxy resin composition of the present invention, high heat resistance can be expressed in the cured product of the epoxy resin composition.

The same applies to the case where a resin other than an epoxy resin such as an aromatic bismaleimide or alkenylphenol is used as the thermosetting resin. The blending amount of the curing agent can be appropriately used in a desired blending amount in consideration of the presence or absence and addition amount of the curing accelerator, the chemical reaction stoichiometry with the thermosetting resin, and the curing rate of the composition. In the present invention, the mixing ratio of the curing agent (component [C]) in the thermosetting resin composition is the amount of the thermosetting resin (component [B]) in the thermosetting resin composition is 100. When it is given as parts by weight, it is suitably 20 to 50 parts by weight, particularly preferably 10 to 40 parts by weight.

component
[D], that is, the thermoplastic resin other than the component [A] is 5 to 80 when the amount of the thermosetting resin (the component [B]) in the thermosetting resin composition is 100 parts by weight. Part by weight, preferably 5 to 50 parts by weight is used. Such a thermoplastic resin [D] dissolves in the thermosetting resin during the curing process of the thermosetting resin composition, for example, increases the viscosity of the resin composition, and prevents a decrease in the viscosity of the thermosetting resin composition. effective. Moreover, these thermoplastic resins can also be used by disperse | distributing one part or all quantity to a thermosetting resin.

As the thermoplastic resin [D], in addition to thermoplastic resins represented by polyethersulfone (PES) and polyetherimide (PEI), thermoplastic polyimide, polysulfone, polycarbonate, polyetheretherketone, arylate, polyester And carbonate. Among these, thermoplastic polyimide, polyetherimide (PEI), polyethersulfone (PES), and polysulfone can be mentioned as more preferable examples from the viewpoint of heat resistance.

In the present invention, when the amount of the thermoplastic resin [D] other than the component [A] is less than 5 parts by weight with respect to 100 parts by weight of the thermosetting resin, the impact resistance of the resulting prepreg and composite material Becomes insufficient. If it exceeds 80 parts by weight, the viscosity of the resin composition becomes high and the moldability and handleability may be inferior. As mentioned above, Preferably it is 10-80 weight part, More preferably, it is 20-50 weight part.

The thermosetting resin composition of the present invention is within a range that does not impair the effects of the present invention, and as necessary, a curing accelerator other than the above-mentioned components, a reactive diluent, a filler, an anti-aging agent, a difficulty Various additives such as a flame retardant and a pigment may be contained. Examples of the curing accelerator include basic curing agents such as acid anhydrides, Lewis acids, dicyandiamides and imidazoles, urea compounds, and organic metal salts. More specifically, examples of the acid anhydride include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, and the like. Examples of the Lewis acid include boron trifluoride salts, and more specifically, BF ₃ monoethylamine, BF ₃ benzylamine, and the like. Examples of imidazoles include 2-ethyl-4-methylimidazole, 2-ethylimidazole, 2,4-dimethylimidazole, and 2-phenylimidazole. Moreover, 3- [3,4-dichlorophenyl] -1,1-dimethylurea, which is a urea compound, Co [III] acetylacetonate, which is an organometallic salt, and the like can be exemplified. Examples of the reactive diluent include reactive diluents such as polypropylene diglycol / diglycidyl ether and phenyl glycidyl ether.

The method for producing the thermosetting resin composition of the present invention is not particularly limited, and any conventionally known method may be used. For example, the kneading temperature applied during the production of the resin composition can be in the range of 10 to 160 ° C. If it exceeds 160 ° C., the resin component may be thermally deteriorated or a partial curing reaction may be started, and the storage stability of the resulting thermosetting resin composition and the prepreg using the composition may be lowered. If it is lower than 10 ° C., the viscosity of the resin composition is high, and it may be difficult to knead substantially. Preferably it is 20-130 degreeC, More preferably, it is the range of 30-110 degreeC.

A conventionally well-known thing can be used as a kneading machine apparatus. Specific examples include a roll mill, a planetary mixer, a kneader, an extruder, a Banbury mixer, a mixing container provided with a stirring blade, a horizontal mixing tank, and the like. The kneading of each component can be performed in the air or in an inert gas atmosphere. In particular, when kneading is performed in the air, an atmosphere in which temperature and humidity are controlled is preferable. Although not particularly limited, for example, it is preferable to knead in a low humidity atmosphere such as a temperature controlled at a constant temperature of 30 ° C. or lower or a relative humidity of 50% RH or lower.

The kneading of each component may be performed in a single stage, or may be performed in multiple stages by sequential addition. Moreover, when adding sequentially, it can add in arbitrary orders. Moreover, about thermoplastic resin [D] other than component [A], the part or whole quantity can also be provided after making it melt | dissolve in component [B] previously. Moreover, although it does not specifically limit, it is preferable from a viewpoint of the storage stability of the thermosetting resin composition obtained and a prepreg consisting thereof to add a hardening | curing agent last as a kneading | mixing and addition order.

Next, a prepreg which is another embodiment of the present invention will be described. The prepreg of the present invention is a prepreg obtained by impregnating a sheet-like fiber reinforcing material with the thermosetting resin composition of the present invention having excellent wet heat resistance obtained as described above. Examples of the fiber reinforcing material used in the prepreg of the present invention include carbon fiber, glass fiber, aromatic polyamide fiber, polyimide fiber, polybenzoxazole fiber, wholly aromatic polyester fiber, and the like. These can be used alone or in combination of two or more. Although not particularly limited, in order to improve the mechanical properties of the composite material, it is preferable to use carbon fibers having excellent tensile strength. The form of the fiber reinforcing material is preferably a sheet-like material such as a woven fabric, a multiaxial woven fabric, and a unidirectionally aligned product.

The prepreg of the present invention preferably has a constituent thermosetting resin composition content (RC) of 15 to 70% by weight. If it is less than 15% by weight, voids or the like are generated in the obtained composite material, and the mechanical properties may be deteriorated. If it exceeds 70% by weight, the reinforcing effect by the reinforcing fibers becomes insufficient, and the mechanical properties in comparison with weight may be substantially low. Preferably it is the range of 20-60 mass%, More preferably, it is the range of 30-50 weight%. The thermosetting resin composition content (RC) here is a ratio calculated from a change in weight when the resin of the prepreg is decomposed by sulfuric acid decomposition. More specifically, a prepreg is cut out to 100 mm × 100 mm to prepare a test piece, its weight is measured, and the resin remaining in the sulfuric acid is immersed or boiled until the resin component is eluted, and the fiber remaining after filtration is washed with water. It is a value obtained by measuring and calculating the mass after washing with, and drying.

Further, although not particularly limited, as a specific preferred form of the prepreg, for example, a reinforcing fiber layer composed of a reinforcing fiber and a resin composition impregnated between the reinforcing fibers, and a surface of the reinforcing fiber layer It is composed of a coated resin coating layer, and the thickness of the resin coating layer is 2 to 50 μm. When the thickness is less than 2 μm, tackiness becomes insufficient, and the molding processability of the prepreg may be significantly lowered. If it exceeds 50 μm, it will be difficult to wind the prepreg into a roll with a uniform thickness, and the molding accuracy may be significantly reduced. More preferably, it is 5-45 micrometers, More preferably, it is 10-40 micrometers.

One of the characteristics that an aircraft composite material should have is interlaminar fracture toughness. Interlaminar fracture toughness is a technique for evaluating the fracture toughness of a specimen by applying a load to the specimen that has been cracked by a predetermined method and measuring the amount of energy required to generate the crack. Interlaminar fracture toughness is classified into mode I (opening type), mode II (in-plane shear type), and mode III (out-of-plane shear type) depending on the deformation mode. Among them, a particularly important characteristic as an aircraft composite material is mode II interlaminar fracture toughness (GIIc). By using the thermosetting resin composition of the present invention having the above-described configuration, a cured product having a high GIIc, that is, excellent toughness can be obtained. In the present invention, a prepreg in which the composite material obtained by molding and curing has a GIIc of 2500 J / m ² or more is particularly preferable. GIIc here is a value measured according to EN6034.

The manufacturing method of the prepreg of this invention is not specifically limited, It can manufacture using any conventionally well-known method. For example, the above-mentioned thermosetting resin composition of the present invention is applied to a release paper in a thin film shape, and the resin film obtained by peeling is laminated and formed on a sheet-like fiber reinforcing material to be thermosetting. Examples thereof include a so-called hot melt method in which the resin composition is impregnated and a solvent method in which the thermosetting resin composition is made into a varnish using an appropriate solvent and the fiber reinforced material sheet is impregnated with the varnish. Among these, the prepreg of the present invention can be particularly preferably produced by a hot melt method which is a conventionally known production method.

The method for forming the thermosetting resin composition of the present invention into a resin film or sheet is not particularly limited, and any conventionally known method can be used. More specifically, it can be obtained by casting and casting on a support such as release paper or film by die extrusion, applicator, reverse roll coater, comma coater or the like. The resin temperature at the time of forming a film or a sheet can be appropriately set according to the resin composition / viscosity, but the same conditions as the kneading temperature in the method for producing the thermosetting resin composition described above are preferably used. it can.

The impregnation pressurization when the resin sheet is impregnated into the sheet-like fiber reinforcing material may be any pressure in consideration of the viscosity, resin flow, etc. of the resin composition. The impregnation temperature of the resin sheet into the fiber reinforcement sheet is in the range of 50 to 150 ° C. When the temperature is lower than 50 ° C., the viscosity of the resin sheet is high, and the fiber reinforcing material sheet may not be sufficiently impregnated. When the temperature is 150 ° C. or higher, the curing reaction of the resin composition is started, and the storage stability of the prepreg may be reduced, or the drapeability may be reduced. Preferably, it is 60-145 degreeC, More preferably, it is 70-140 degreeC. Further, the impregnation can be performed in multiple stages at an arbitrary pressure and temperature in a plurality of times instead of once.

A composite material produced by molding and curing such as lamination using a prepreg obtained by such means has high moisture and heat resistance properties, and further has excellent impact resistance. This is suitable.

Hereinafter, the present invention will be described in more detail with reference to examples. In the examples and comparative examples, various test methods for resin compositions were performed according to the following methods.

[Measurement of crater diameter on the surface of composite particles]
The diameter of the crater-like hole existing on the surface of the composite fine particle was determined by observation using a scanning electron microscope (SEM).

[Measurement of average particle size of composite fine particles]
The particle size and particle size distribution of the composite fine particles were measured using a particle size / particle size distribution measuring apparatus manufactured by Nikkiso Co., Ltd. The measurement conditions were such that the dispersion medium was water, an amount sample capable of obtaining scattered light sufficient for measurement was added, measurement was performed in absorption mode for 30 seconds, and the volume average particle size was defined as the particle size.

[Measurement of Interlaminar Fracture Toughness (GIIc)]
As an index of toughness, evaluation of GIIc was measured according to EN6034. Two prepregs obtained by cutting a prepreg obtained by a predetermined method and laminating eight layers in the 0 ° direction were produced. A release film for generating an initial crack was sandwiched between the two laminates, and both were combined to obtain a prepreg laminate having a laminate configuration [0] ₁₆ of about 3 mm in thickness. Using a vacuum autoclave molding method, molding was performed at 180 ° C. for 2 hours under a pressure of 0.49 MPa. The obtained molded product has a width of 25.0 mm.
X Cut to a length of 110 mm or more to obtain a GIIc test piece. A GIIc test was performed using this test piece.

A test piece was placed at a position where the crack produced by the release film was 35 ± 1 mm from the fulcrum, and a bending load was applied at a speed of 1 mm / min, and the GIIc test was performed.

[Glass transition temperature (hot / wet condition) measurement]
As an index of heat and humidity resistance, the glass transition temperature was determined by DMA measurement according to EN6032. A prepreg obtained by a predetermined method was cut to obtain a laminate of about 3 mm in which 16 layers were laminated in the 0 ° direction. Using a vacuum autoclave molding method, molding was performed at 180 ° C. for 2 hours under a pressure of 0.49 MPa. The resulting molded product is 5 mm wide.
X A test piece was obtained by cutting to a length of 50 mm. The specimen was immersed in water at 71 ° C. for 2 weeks to absorb moisture. After taking out, the resin composition was measured using a DMA measuring apparatus (Rheogel-E4000 manufactured by UBM Co., Ltd.) by applying a temperature rise rate of 3 ° C./min and a strain of a frequency of 1 Hz by three-point bending. It is the peak temperature of loss viscoelasticity (E ″) obtained.

[Example 1]
27 parts by weight of polyamideimide Torlon 4000T (manufactured by Solvay Advanced Polymers) as the thermoplastic resin for component [A], and Tospearl 130 (average particle diameter of 3 μm) as silicone resin fine particles (manufactured by Momentive Performance Materials) 3 parts by weight was used. This was kneaded at 230 ° C. using a desktop biaxial kneader KRS-S1 manufactured by Kurimoto Shokosho to obtain a composite resin composed of polyamideimide / silicone resin. This composite resin was pulverized using a jet mill. Simultaneously with wind classification, the surface silicone resin fine particles were removed, and composite fine particles having an average particle size of 30 μm were obtained. When the surface state of the fine particles was observed with an electron microscope, a crater having an average diameter of about 2 μm was present on the surface.

As a thermosetting resin of the component [B], 65 parts by weight of a polyfunctional epoxy resin having a glycidylamino group (Japan Epoxy Resin Co., Ltd. jER604), bisphenol type epoxy resin (Japan Epoxy Resin Co., Ltd. jER828) 15 parts by weight, Urethane-modified bisphenol A type epoxy resin (Adeka Resin EPU-6 manufactured by Asahi Denka) was used at a blending ratio of 20 parts by weight. As a curing agent for component [C], 40 parts by weight of 4,4′-diaminodiphenylsulfone (4,4′-DDS) (manufactured by Wakayama Seika Co., Ltd.), which is an aromatic amine curing agent, and component [D] As a thermoplastic resin, 35 parts by weight of polyethersulfone (average particle size: 10 μm) (Sumitomo Chemical Sumika Excel PES5003P) was used.

The various raw materials described above were blended in the following procedure with the compositions shown in Table 1. First, jER604, jER828 and EPU-6 were heated and mixed in a kneader. Subsequently, the obtained resin mixture was transferred to a roll mill, and the curing agent component [C], the thermoplastic resin component [D], and the composite fine particle component [A] were well kneaded to obtain the epoxy resin composition of Example 1. Obtained.

Using the epoxy resin composition obtained above, a prepreg was prepared by the following procedure. The resin composition obtained in Example 1 was cast at 60 ° C. with a film coater to prepare a resin film. By impregnating this resin film with carbon fiber Tenax (trademark of Toho Tenax Co., Ltd.) IMS60, E13, 24K manufactured by Toho Tenax Co., Ltd., the unidirectional fiber reinforcing material (fiber basis weight 190 ± 10 g / m ² ) (RC) A 35% prepreg was obtained.

Sixteen prepregs obtained were laminated and molded into a composite material (molded plate) with an autoclave (curing conditions 180 ° C., 2 hours, 5 kgf / mm ² ). Interlaminar fracture toughness (GIIc) and glass transition temperature (Tg) A test specimen for measurement was obtained. Using this test piece, the GIIc test and Tg measurement were performed, and the results are shown in Table 1.

[Example 2]
The composite resin obtained in the same manner as in Example 1 was pulverized using a jet mill in the same manner as in Example 1. Thereafter, composite fine particles having an average particle diameter of 30 μm were obtained without removing the silicone resin fine particles from the fine particle surface by air classification. When the surface state of the fine particles was observed with an electron microscope, a crater having an average diameter of about 2 μm was present on the surface. Using this composite fine particle [A], a composite material test piece was prepared in the same manner as in Example 1, and the GIIc test and Tg measurement were performed. The results are shown in Table 1. It can be seen that the GIIc value is lower than that of Example 1 due to the presence of the silicone resin fine particles alone.

[Example 3]
The thermoplastic resin and silicone resin fine particles of component [A] are the same as in Example 1, except that the blending ratio is changed to 22.5 parts by weight and 2.5 parts by weight. In this manner, composite fine particles [A] having an average particle diameter of 30 μm were prepared. Using 25 parts by weight of the composite fine particles [A], and using the same amount of the other components as in Example 1, a composite material test piece was prepared in the same manner as in Example 1, and the GIIc test and Tg measurement were performed. The results are shown in Table 1. From Table 1, it can be seen that GIIc is reduced by the reduction of the composite fine particles [A].

[Example 4]
The thermoplastic resin and silicone resin fine particles of component [A] were the same as those in Example 1, except that the blending ratio was changed to 31.5 parts by weight and 3.5 parts by weight. In this manner, composite fine particles [A] having an average particle diameter of 30 μm were prepared. Using 35 parts by weight of the composite fine particles [A], and using the same amount of the other components as in Example 1, a composite specimen was prepared in the same manner as in Example 1, and the GIIc test and Tg measurement were performed. The results are shown in Table 1. From Table 1, it can be seen that the increase in the amount of the composite fine particles [A] has little influence on the value of GIIc (comparison between Examples 1 and 4).

[Example 5]
The thermoplastic resin and silicone resin fine particles of component [A] are the same as those in Example 1, except that the blending ratio is changed to 29.4 parts by weight and 0.6 parts by weight. In this manner, composite fine particles [A] having an average particle diameter of 30 μm were prepared. Using 30 parts by weight of the composite fine particles [A] and using the same amount of the other components as in Example 1, a composite specimen was prepared in the same manner as in Example 1, and the GIIc test and Tg measurement were performed. The results are shown in Table 1. From Table 1, it can be seen that the influence on the toughness of the composite fine particles is reduced as the amount of the silicone particles contained in the composite fine particles [A] is reduced (the toughness is reduced as compared with Example 1).

[Example 6]
The thermoplastic resin and silicone resin fine particles of component [A] were the same as those in Example 1, except that the blending ratio was changed to 9 parts by weight and 21 parts by weight, and the average was obtained in the same manner as in Example 1. Composite fine particles [A] having a particle size of 30 μm were prepared. Using 30 parts by weight of the composite fine particles [A] and using the same amount of the other components as in Example 1, a composite specimen was prepared in the same manner as in Example 1, and the GIIc test and Tg measurement were performed. The results are shown in Table 1. It can be seen that as the amount of the silicone particles increased, the influence on the toughness of the composite fine particles was reduced (comparison of Examples 1 and 6).

[Example 7]
The thermoplastic resin for component [A] used was 27 parts by weight of the same resin as in Example 1, and 3 parts by weight of Tospearl 130 (average particle size 12 μm) was used as the silicone resin fine particles. This was kneaded in the same manner as in Example 1 to obtain a composite resin composed of polyamideimide / silicone resin. This composite resin was pulverized using a jet mill. Simultaneously with wind classification, the surface silicone resin fine particles were removed, and composite fine particles having an average particle size of 30 μm were obtained. When the surface state of the fine particles was observed with an electron microscope, a crater having an average diameter of about 1 μm was present on the surface. Using 30 parts by weight of the composite fine particles [A] and using the same amount of the other components as in Example 1, a composite specimen was prepared in the same manner as in Example 1, and the GIIc test and Tg measurement were performed. The results are shown in Table 1. It can be said that there is no difference in the influence on the toughness as the composite fine particles with the reduction of the diameter of the silicone particles.

[Example 8]
The thermoplastic resin for component [A] used was 27 parts by weight of the same resin as in Example 1, and 3 parts by weight of Tospearl 130 (average particle size 12 μm) was used as the silicone resin fine particles. This was kneaded in the same manner as in Example 1 to obtain a composite resin composed of polyamideimide / silicone resin. This composite resin was pulverized using a jet mill. Simultaneously with wind classification, the surface silicone resin fine particles were removed, and composite fine particles having an average particle size of 30 μm were obtained. When the surface state of the fine particles was observed with an electron microscope, a crater having an average diameter of about 10 μm was present on the surface. Using 30 parts by weight of the composite fine particles [A] and using the same amount of the other components as in Example 1, a composite specimen was prepared in the same manner as in Example 1, and the GIIc test and Tg measurement were performed. The results are shown in Table 1. Although the influence on the toughness of the composite fine particles decreases as the size of the silicone particles increases (toughness decreases), it can be said that the effect is more effective than the non-composited particles (see Comparative Examples below).

[Example 9]
27 parts by weight of the same thermoplastic resin as that of Example 1 was used as the component [A], and 3 parts by weight of Tospearl 130 (average particle diameter 2 μm) was used as the silicone resin fine particles. This was kneaded in the same manner as in Example 1 to obtain a composite resin composed of polyamideimide / silicone resin. This composite resin was pulverized using a jet mill. Simultaneously with wind classification, the surface silicone resin fine particles were removed, and composite fine particles having an average particle size of 5 μm were obtained. When the surface state of the fine particles was observed with an electron microscope, a crater having an average diameter of about 1 μm was present on the surface. Using 30 parts by weight of the composite fine particles [A] and using the same amount of the other components as in Example 1, a composite specimen was prepared in the same manner as in Example 1, and the GIIc test and Tg measurement were performed. The results are shown in Table 1. Although the influence on the toughness of the composite fine particles becomes smaller as the composite fine particles become smaller in diameter, it can be said that the effect is more effective than the non-composited particles (see Comparative Examples below).

[Example 10]
The thermoplastic resin for component [A] used was 27 parts by weight of the same resin as in Example 1, and 3 parts by weight of Tospearl 130 (average particle size 12 μm) was used as the silicone resin fine particles. This was kneaded in the same manner as in Example 1 to obtain a composite resin composed of polyamideimide / silicone resin. This composite resin was pulverized using a jet mill. Simultaneously with wind classification, the surface silicone resin fine particles were removed to obtain composite fine particles having an average particle diameter of 70 μm. When the surface state of the fine particles was observed with an electron microscope, a crater having an average diameter of about 10 μm was present on the surface. Using 30 parts by weight of the composite fine particles [A] and using the same amount of the other components as in Example 1, a composite specimen was prepared in the same manner as in Example 1, and the GIIc test and Tg measurement were performed. The results are shown in Table 1. Although the influence on the toughness of the composite fine particles decreases as the diameter of the composite fine particles increases, it can be said that the effect is more effective than the non-composited particles.

[Comparative Example 1]
A thermosetting resin composition excluding the composite fine particles [A] in Example 1 was prepared, a test piece was prepared in the same manner as in Example 1, and a GIIc test was performed. The results are shown in Table 2. When the composite fine particles [A] were not included, the GIIc of the obtained composite material was significantly reduced.

[Comparative Example 2]
Fine particles of only polyamide-imide Torlon 4000T were prepared according to Example 1. When the fine particles (average particle size was 30 μm) were observed with an electron microscope, the surface was smooth and no crater was present. Using 30 parts by weight of the fine particles instead of the composite particles [A], and using the same amount of the other components as in Example 1, a composite specimen was prepared in the same manner as in Example 1, and GIIc Tests and Tg measurements were performed and the results are shown in Table 2. It is not complexed with silicone resin fine particles, and since there are no crater-like holes on the surface, the surface area is small, the adhesion area with the epoxy resin is small, and there is no anchor effect due to the epoxy resin entering into the holes This is considered to have reduced the GIIc value (comparison with Example 1).

[Comparative Example 3]
Instead of the composite fine particles [A], only 30 parts by weight of the same silicone resin fine particles / Tospearl 130 (average particle diameter 3 μm) as in Example 1 were used, and the same amount of other components as in Example 1 was used. A composite test piece was prepared in the same manner as in Example 1, and the GIIc test and Tg measurement were performed. The results are shown in Table 2. Fracture toughness is significantly reduced with silicone fine particles alone. This is considered to be due to the fact that a silicone resin with a small surface energy has weak adhesion to an epoxy resin, and this is recognized as a defect.

[Comparative Example 4]
Instead of the composite fine particles [A], 27 parts by weight of Torlon 4000T fine particles prepared in Comparative Example 2 and 3 parts by weight of Tospearl 130 fine particles used in Comparative Example 3 were used individually, and the other components were as in Example 1. A test piece of composite material was prepared in the same manner as in Example 1 using the same amount as the test sample, and the GIIc test and Tg measurement were performed. The results are shown in Table 2. When both are added alone without being combined, GIIc shows a very low value. This is considered to be due to the influence of the silicone resin fine particles present alone.

[Comparative Example 5]
The same thermoplastic resin and silicone resin fine particles (average particle diameter 3 μm) as those of Example 1 were used as the component [A]. The blending ratio was 6 parts by weight of thermoplastic resin and 24 parts by weight of silicone resin, and composite fine particles [A] having an average particle size of 120 μm were prepared in the same manner as in Example 1. Using 30 parts by weight of the composite fine particles [A] and using the same amount of the other components as in Example 1, a composite specimen was prepared in the same manner as in Example 1, and the GIIc test and Tg measurement were performed. The results are shown in Table 2. When composite particles containing an excessive proportion of silicone particles and having a large particle size were used, GIIc was remarkably low.

[Comparative Example 6]
In accordance with Example 1, except that PES5003P which is the thermoplastic resin of component [D] was removed, a composite specimen was prepared in the same manner as in Example 1, and the GIIc test and Tg measurement were performed. The results are shown in Table 2. When PES5003P was not added, the value of GIIc was greatly reduced.

[Comparative Example 7]
As a thermosetting resin of component [B], only jER828 which is a bifunctional epoxy resin is used, and other than that, a specimen of a composite material is prepared in the same manner as in Example 1, and a GIIc test and Tg measurement are performed. Are shown in Table 2. Although the value of GIIc was improved, the glass transition temperature under hot wet was remarkably lowered.

From the results of Tables 1 and 2, it can be seen that the examples of the present invention have superior interlaminar fracture toughness (GIIc) and a high glass transition temperature after moisture absorption compared to the comparative examples.

Claims (11)

At least the following component [A]
And a component [B], a component [C], and a component [D] as essential components.
Component [A]: Thermoplastic composite fine particles 5 having an average particle size of 5 to 70 μm obtained by kneading 1 to 90 wt% of silicone resin fine particles having an average particle size of 1 to 12 μm and 99 to 10 wt% of a thermoplastic resin -50 parts by weight Component [B]: Thermosetting resin 100 parts by weight Component [C]: Curing agent 20-50 parts by weight Component [D]: 5-80 parts by weight of thermoplastic resin other than component [A] 2. The thermosetting resin composition according to claim 1, wherein crater-like holes having a diameter of 1 to 12 μm are present on the surface of the thermoplastic composite fine particles of component [A]. The thermosetting resin composition according to claim 1 or 2, wherein the thermosetting resin of the component [B] contains at least an epoxy resin. The thermosetting resin composition according to claim 3, wherein the epoxy resin contains at least a trifunctional or higher functional epoxy resin. The curable resin composition according to any one of claims 1 to 4, wherein the thermosetting resin of the component [B] is a thermosetting resin that does not dissolve the thermoplastic resin of the component [A]. . The thermosetting resin composition according to any one of claims 1 to 5, wherein the curing agent of component [C] contains at least an aromatic amine curing agent. Thermoplastic composite fine particles having an average particle size of 5 to 70 μm obtained by kneading 1 to 90% by weight of silicone resin fine particles having an average particle size of 1 to 12 μm and 99 to 10% by weight of a thermoplastic resin. 8. The thermoplastic composite fine particles according to claim 7, wherein crater-like holes having a diameter of 1 to 12 [mu] m are present on the surface of the thermoplastic composite fine particles. A prepreg obtained by impregnating a fiber reinforcing material with the thermosetting resin composition according to any one of claims 1 to 6. The prepreg according to claim 9, wherein the fiber reinforcing material is carbon fiber. A composite material obtained by curing the prepreg according to claim 9 or 10.