JP2015093984A - Reinforcing fiber substrate for fiber-reinforced resin composite and molding thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fiber-reinforced resin composite which combines excellent mechanical properties, heat resistance, fire retardancy and dimensional stability and is efficiently producible at low costs.SOLUTION: A reinforcing fiber substrate consists of a fabric of a reinforcing fiber superimposed with a fabric composed of a fiber of a thermoplastic resin. A thermoplastic resin composite material is obtained by laminating the reinforcing fiber substrate and thermoforming, and the thermoplastic resin has a glass transition temperature of 100°C or higher and a specified resin viscosity, or melt flow rate.

Description

  The present invention relates to a fiber reinforced resin composite having excellent mechanical properties, heat resistance, flame retardancy, and dimensional stability.

  Fiber reinforced resin composites made of carbon fiber, glass fiber, and other reinforced fibers and resin materials are lightweight and have excellent specific strength and specific rigidity, so they are used in electrical / electronic applications, civil engineering / architecture applications, automotive applications, aircraft, etc. Widely used for applications. As resin materials, thermosetting resins represented by epoxy resins are widely known, and since they are excellent in strength, rigidity, chemical resistance, and performance reproducibility (quality), they are already used in aircraft structural members. Adoption is progressing in the sports field. On the other hand, thermosetting resins have been mentioned as problems such as long molding cycle, poor production yield, huge amount of molding equipment, large initial investment, difficult recycling. In order to increase the versatility and aim for adoption in a wide range of fields such as automobiles, railways, and electricity / electronics, technical innovation is required.

  In recent years, attention has been focused on thermoplastic resin materials from the viewpoint of productivity improvement and recyclability, which are problems of thermosetting resin materials. While thermoplastic resin materials are expected to improve the above-mentioned productivity (short-time molding) and recyclability, the viscosity of the resin itself is higher than that of the thermosetting resin before curing. It is relatively difficult to impregnate, and finding an efficient method therefor has been an issue.

  For the production of fiber reinforced thermoplastic resin composites, there is a wide range of methods in which a base material in which a reinforcing fiber is impregnated with a resin is used, these reinforcing fiber base materials are laminated in a number corresponding to the material design, and heated and pressed again. Are known. As a method for producing such a reinforced fiber base material, (1) powdering a thermoplastic resin, applying it to a fabric made of reinforced fibers, and applying heat and pressure to impregnate the resin into the reinforced fibers in advance. (2) Method of manufacturing by sandwiching a film material made of thermoplastic resin between layers of a fabric made of reinforcing fibers, and heating and pressing the laminated material, (3) Reinforcement A method in which a fabric made of fibers is impregnated with a solvent in which a thermoplastic resin is dissolved, and the solvent is volatilized and removed so that the thermoplastic resin is supported on reinforcing fibers, and (4) the above (2) And a method using a nonwoven fabric made of a thermoplastic resin instead of the film between layers of a fabric made of reinforcing fibers is known.

  In the method (1) described above, since it is difficult to uniformly apply the thermoplastic resin powder onto the fabric made of reinforcing fibers and it is difficult to make the particle size of the powder uniform, the thermoplastic resin onto the fabric made of reinforcing fibers is difficult. Is difficult to arrange uniformly, and the quality of the resulting reinforcing fiber substrate remains low. Furthermore, since the reinforcing fiber substrate obtained by this method is heated and pressurized, the impregnation of the thermoplastic resin into the reinforcing fiber has progressed relatively firmly, but as a result, it becomes a plate and cannot be bent. , Drapability is poor and it is difficult to form a complex shape.

  In the method (2), since the film-like material is disposed between the layers of the reinforcing fibers, air does not escape during heating and press molding, and easily causes voids in the molded body, resulting in high-quality fibers. There is a problem that it is difficult to obtain a reinforced composite. Further, like (1), since the drapeability of the film is poor, it is not suitable for forming into a complicated shape (for example, Patent Document 1).

  Furthermore, in the method (3), from the viewpoint of impregnating the resin into the reinforcing fiber in advance, it is an excellent method compared to other methods, but the resin is in a high ratio with respect to the reinforcing fiber. In addition to being difficult to impregnate, in order to perform sufficient impregnation, it is necessary to repeat the impregnation step and the step of drying the solvent, and there is a problem that the handleability is poor. Furthermore, since an organic solvent is used, it is necessary to dry and remove the solvent sufficiently before molding. If solvent removal is insufficient, the solvent volatilizes during heat molding, resulting in foaming inside the molded body. Also, there is a concern about the influence on the human body, such as physical property deterioration accompanying it, or suction of the solvent into the body.

  Several methods using a non-woven fabric as a thermoplastic resin material, such as the method (4) described above, are also disclosed. For example, Patent Literature 2 discloses a fiber base material in which a nonwoven fabric layer is formed by air blowing a thermoplastic resin in a molten state onto a fabric made of reinforcing fibers and bonded to the reinforcing fibers at the interface. . In this method, since the thermoplastic resin is disposed on the reinforcing fiber base material in the form of a nonwoven fabric, the resin impregnation property at the time of molding is good, and the draping property of the fiber base material is not impaired. There is no problem with sex. However, not all thermoplastic resins can be applied to air blow molding. Especially, thermoplastic resins with excellent heat resistance and dimensional stability generally have high viscosity, and air blow molding is difficult. There is. Moreover, in order to enable air blow molding, it is necessary to lower the viscosity, that is, the molecular weight of the thermoplastic resin as a raw material, but such low molecular weight thermoplastic resin has the strength of the fiber-reinforced resin composite obtained. There is a concern that the physical properties such as impact properties will deteriorate.

  Moreover, in patent document 3, the fabric which consists of a thermoplastic resin is overlap | superposed on the unidirectionally aligned reinforcement fiber sheet formed by spreading each of a plurality of reinforcing fiber bundles widely and thinly, and is heated and pressed, thereby strengthening. A reinforcing fiber base material obtained by impregnating a fiber sheet with a thermoplastic resin is disclosed. However, in the above technique, the prescription for sufficiently impregnating the thermoplastic resin into the reinforcing fiber largely depends on the technique of opening the reinforcing fiber bundle, and there is a problem that the usable reinforcing fiber is limited.

  Furthermore, there is no description regarding the polyetherimide fiber or the semi-aromatic polyamide fiber as the fiber made of the thermoplastic resin constituting the fabric made of the thermoplastic resin used here, and it is described in detail regarding the thermoplastic resin. However, it cannot be said that the fiber and the fabric made of the thermoplastic resin optimal for the fiberization and the fabrication of the thermoplastic resin and the resin impregnation of the reinforcing fiber are sufficiently explained.

Japanese Patent Laid-Open No. 5-96638 Japanese Patent No. 4292994 Japanese Patent No. 4324649

  As described above, the application of the fiber reinforced resin composite has been diversified. Especially for thermoplastic resin materials that are attracting attention from the viewpoint of productivity and recyclability, in order to increase their versatility and expand their applications to the automotive, marine, and electrical / electronic fields, we will maintain high mechanical properties. On the other hand, there is a need for a technique that has both the formability that can be formed into various shapes and that can be manufactured efficiently and at low cost. In addition, with increasing market needs such as safety and security, heat resistance, flame retardancy, dimensional stability, and the like have been demanded, and fiber reinforced resin composites that can satisfy them are desired.

  As a result of intensive studies in order to solve the above-mentioned problems, the present inventors made a reinforced fiber base material by superposing a fabric made of reinforcing fibers and a nonwoven fabric made of a thermoplastic resin having a specific configuration, and the fibers It has been found that a thermoplastic resin composite having high mechanical properties, heat resistance, flame retardancy, and dimensional stability can be produced efficiently and at low cost by laminating the substrates and thermoforming.

That is, the present invention relates to a nonwoven fabric composed of fibers made of a thermoplastic resin with respect to a fabric having at least one form selected from the group consisting of woven fabrics made of reinforcing fibers, knitted fabrics, and aligned yarn sheet materials. The present invention relates to a reinforcing fiber base material that is superposed and satisfies all of the following conditions.
(1) The glass transition temperature of the thermoplastic resin is 100 ° C. or higher.
(2) The melt flow rate (MFR) of the thermoplastic resin is 20 to 80 g / 10 min at a temperature 30 ° C. higher than the crystal melting temperature in the case of a crystalline resin, and the glass transition in the case of an amorphous resin. It is 20 to 80 g / 10 min at a temperature 120 ° C. higher than the temperature.

In the present invention, preferably, the reinforcing fiber base material is composed of a thermoplastic resin, the average fineness of a single fiber is 0.1 to 12 dtex, and the non-woven fabric is made of the thermoplastic resin. The basis weight is 5 to 500 g / m ² , the thickness is 0.1 to 10 mm, and the bulk density is 0.01 to 1.0 g / cm ^3. .

  In the present invention, it is preferable that the fiber made of a thermoplastic resin constituting the reinforcing fiber base is a polyetherimide fiber, a polyether ketone ketone fiber, a thermoplastic polyimide fiber, and a semi-aromatic polyamide fiber. It is comprised regarding said reinforced fiber base material comprised by at least 1 sort (s) selected from the group which consists of.

  The above-mentioned reinforcement is characterized in that the polyetherimide fiber is composed of an amorphous polyetherimide resin having the following general formula, a glass transition temperature of 200 ° C. or more, and having no melting point. A fiber substrate is preferred.

（式中、Ｒ１は、６〜３０個の炭素原子を有する２価の芳香族残基であり、Ｒ２は、６〜３０個の炭素原子を有する２価の芳香族残基、２〜２０個の炭素原子を有するアルキレン基、２〜２０個の炭素原子を有するシクロアルキレン基、及び２〜２０個の炭素原子を有するアルキレン基で連鎖停止されたポリジオルガノシロキサン基からなる群より選択された２価の有機基を表す。）

Wherein R1 is a divalent aromatic residue having 6 to 30 carbon atoms, and R2 is a divalent aromatic residue having 6 to 30 carbon atoms, 2 to 20 2 selected from the group consisting of an alkylene group having 2 carbon atoms, a cycloalkylene group having 2 to 20 carbon atoms, and a polydiorganosiloxane group chain-terminated with an alkylene group having 2 to 20 carbon atoms Represents a valent organic group.)

  The above-mentioned reinforced fiber base material, wherein the polyether ketone ketone fiber is represented by the following general formula and has a glass transition temperature of 130 ° C. or higher and is made of a crystalline polyether ketone ketone resin. It is preferable that

  The thermoplastic polyimide fiber is made of a polyimide resin composed of 99.9 to 50% by weight of a thermoplastic polyimide having a repeating unit represented by the following formula and 0.1 to 50% by weight of an aromatic polyetherimide. It is preferable that it is said reinforced fiber base material characterized by these.

（式中、Ｘは直結、炭素数１ないし１０の２価の炭化水素基、六フッ素化されたイソプロピリデン基、カルボニル基、チオ基、またはスルホニル基からなる群より選択された基を表し、またＲは炭素数２以上の脂肪族基、環式脂肪族基、単環式芳香族基、縮合多環式芳香族基、芳香族基が直接または架橋員により相互に連結された非縮合多環式芳香族基からなる群より選択された４価の基を表す。）

(Wherein X represents a direct bond, a group selected from the group consisting of a divalent hydrocarbon group having 1 to 10 carbon atoms, a hexafluorinated isopropylidene group, a carbonyl group, a thio group, or a sulfonyl group; R represents an aliphatic group having 2 or more carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, or a non-condensed polycyclic group in which aromatic groups are connected to each other directly or by a cross-linking member. Represents a tetravalent group selected from the group consisting of cyclic aromatic groups.)

  The semi-aromatic polyamide-based fiber is the above-mentioned reinforcing fiber substrate, characterized in that it is made of a polyamide-based resin composed of an aromatic dicarboxylic acid unit and an aliphatic alkylenediamine unit having 6 to 18 carbon atoms. preferable.

  The semi-aromatic polyamide fiber contains 60 to 100 mol of a dicarboxylic acid unit containing 50 to 100 mol% of a terephthalic acid unit and 1,9-nonanediamine unit and / or 2-methyl-1,8-octanediamine unit. Preferably, the reinforcing fiber substrate is made of a polyamide-based resin composed of% diamine units.

  Preferably, the reinforcing fiber constituting the reinforcing fiber base is composed of at least one selected from the group consisting of carbon fiber, glass fiber, wholly aromatic polyester fiber, aramid fiber, ceramic fiber, and metal fiber. The present invention relates to the above-mentioned reinforcing fiber base material.

  The present invention is preferably obtained by heat-pressing the reinforcing fiber base at a temperature higher than the flow start temperature of the fiber made of a thermoplastic resin constituting the fiber base. The present invention relates to a fiber reinforced resin composite obtained from the above reinforced fiber base material.

  More preferably, when the fiber reinforced resin composite is obtained by heat-press molding the reinforcing fiber base at a temperature higher than the flow start temperature of the fiber comprising the thermoplastic resin constituting the fiber base, The present invention relates to a fiber-reinforced resin composite obtained from the above-mentioned reinforcing fiber base material, which is preliminarily molded at a temperature lower than the flow start temperature to be in a semi-impregnated state.

  According to the present invention, it has excellent mechanical properties, heat resistance, flame retardancy, dimensional stability, and formability, and low-cost formability, and is particularly suitable for applications that are exposed to high temperature environments. It is possible to provide an adapted fiber reinforced resin composite. Further, the fiber reinforced resin composite of the present invention does not require a special thermoforming process, and can be manufactured at a low cost by a normal thermoforming process such as compression molding or GMT molding, and further, depending on the purpose. The shape can also be designed freely, and there are many such as general industrial materials field, electrical / electronic field, civil engineering / architecture field, aircraft / automobile / railway / ship field, agricultural material field, optical material field, medical material field, etc. It can be used very effectively for the purpose of.

The schematic diagram of the metal mold | die used in order to shape | mold the reinforced fiber base material of this invention, and to obtain a fiber reinforced resin composite.

  The present invention will be specifically described below.

(Fiber made of thermoplastic resin)
The fiber made of a thermoplastic resin used in the present invention (hereinafter sometimes referred to as a thermoplastic fiber) is a resin glass that forms the fiber from the viewpoints of mechanical properties, heat resistance, flame retardancy, and dimensional stability. It is important that the transition temperature is 100 ° C. or higher. In general, it is well known that the mechanical properties of macromolecules greatly drop at the glass transition temperature at which the amorphous part molecules move. For example, even a thermoplastic fiber having a melting point of 200 ° C. or higher, such as PET or nylon 6, has excellent heat resistance because its mechanical properties greatly drop at a glass transition temperature around 60 to 80 ° C. It ’s hard to say. Therefore, when a thermoplastic fiber having a glass transition temperature of less than 100 ° C. is used, it cannot be said that the resulting fiber-reinforced resin composite has high heat resistance, and practical use is restricted. The glass transition temperature of the thermoplastic resin used in the present invention is preferably 105 ° C. or higher, more preferably 110 ° C. or higher. In addition, the said glass transition temperature is computed by the measuring method as described in the Example mentioned later.

  The viscosity of the resin forming the thermoplastic fiber used in the present invention is such that when the resin is a crystalline resin, the melt flow rate (MFR) at a temperature 30 ° C. higher than the crystal melting temperature is 20 to 80 g / 10 min. It is important that, in the case of an amorphous resin, it is important that the MFR at a temperature 120 ° C. higher than the glass transition temperature is 20 to 80/10 min. Thus, the thermoplastic fiber is used to form a nonwoven fabric, which is superposed on a fabric made of reinforcing fibers to form a reinforcing fiber substrate, the fiber substrate is laminated, and heated and pressed to reinforce the thermoplastic resin. Sufficient impregnation can be achieved when impregnating the substrate, and a fiber-reinforced resin composite having excellent mechanical properties can be obtained. Preferably, the crystalline resin is 40 to 60 g / 10 min, and the amorphous resin is 40 to 60 g / 10 min. The melt flow rate is calculated by the measurement method described in Examples described later.

  Further, the molecular weight distribution of the resin forming the thermoplastic fiber is not particularly limited, but from the viewpoint of obtaining the moldability and uniformity of mechanical properties of the obtained fiber-reinforced resin composite, the weight average molecular weight (Mw ) And the number average molecular weight (Mn), the molecular weight distribution (Mw / Mn) is preferably 2.3 or less. When the molecular weight distribution exceeds 2.3, when the fiber base material is heated and pressed, the flowability of the resin is uneven, and molding unevenness occurs. There may be variations in mechanical properties. The weight average molecular weight (Mw), number average molecular weight (Mn), and molecular weight distribution are calculated in terms of polystyrene, for example, by gel permeation chromatography (GPC), which is a type of size exclusion chromatography (SEC). Can do.

  The type of thermoplastic fiber used in the present invention is not particularly limited as long as it satisfies the above-mentioned glass transition temperature and viscosity (MFR) conditions. For example, polyetherimide fiber, polyether ketone ketone fiber , Thermoplastic polyimide fibers, semi-aromatic polyamide fibers, polyether ether ketone fibers, polyphenylene sulfide fibers, polysulfone fibers, polycarbonate fibers and the like. In particular, in the field of transportation equipment such as aerospace, automobiles, and ships that require high heat resistance, flame retardancy, and dimensional stability, polyetherimide fibers, polyether ketone ketone fibers, and thermoplastics that excel in the above performance. Polyimide fibers and semi-aromatic polyamide fibers can be preferably used. These may be used alone or in combination of two or more kinds of fibers.

  The polyetherimide fiber used in the present invention is an aliphatic, alicyclic or aromatic ether in which the resin constituting the fiber is represented by the following general formula from the viewpoint of flame retardancy and heat resistance. A polyetherimide resin containing a unit and a cyclic imide as a repeating unit, having an amorphous property and melt moldability, and having a glass transition temperature of 200 ° C. or higher is preferable.

（式中、Ｒ１は、６〜３０個の炭素原子を有する２価の芳香族残基であり、Ｒ２は、６〜３０個の炭素原子を有する２価の芳香族残基、２〜２０個の炭素原子を有するアルキレン基、２〜２０個の炭素原子を有するシクロアルキレン基、及び２〜２０個の炭素原子を有するアルキレン基で連鎖停止されたポリジオルガノシロキサン基からなる群より選択された２価の有機基を表す。）

Wherein R1 is a divalent aromatic residue having 6 to 30 carbon atoms, and R2 is a divalent aromatic residue having 6 to 30 carbon atoms, 2 to 20 2 selected from the group consisting of an alkylene group having 2 carbon atoms, a cycloalkylene group having 2 to 20 carbon atoms, and a polydiorganosiloxane group chain-terminated with an alkylene group having 2 to 20 carbon atoms Represents a valent organic group.)

  In the present invention, as a resin constituting the polyetherimide fiber, 2, 2-bis [4- (2) mainly having a structural unit represented by the following formula from the viewpoints of amorphousness, melt moldability, and cost. , 3-dicarboxyphenoxy) phenyl] propane dianhydride and m-phenylenediamine are more preferably used. Such a polyetherimide resin is commercially available from Servic Innovative Plastics under the trademark “Ultem”.

  The polyether ketone ketone fiber used in the present invention is represented by the following general formula from the viewpoint of flame retardancy and heat resistance, has a glass transition temperature of 130 ° C. or higher, and is a crystalline polyether ketone ketone. It is preferable to consist of a resin.

  The thermoplastic polyimide fiber used in the present invention is composed of 99.9 to 50% by weight of a thermoplastic polyimide having a repeating unit represented by the following formula and an aromatic polyether imide from the viewpoint of flame retardancy and heat resistance. It is preferable that it consists of a polyimide-type resin which consists of 1 to 50 weight%. As such a polyimide resin, for example, those disclosed in JP-A-3-199234 can be used.

（式中、Ｘは直結、炭素数１ないし１０の２価の炭化水素基、六フッ素化されたイソプロピリデン基、カルボニル基、チオ基、またはスルホニル基からなる群より選択された基を表し、またＲは炭素数２以上の脂肪族基、環式脂肪族基、単環式芳香族基、縮合多環式芳香族基、芳香族基が直接または架橋員により相互に連結された非縮合多環式芳香族基からなる群より選択された４価の基を表す。）

(Wherein X represents a direct bond, a group selected from the group consisting of a divalent hydrocarbon group having 1 to 10 carbon atoms, a hexafluorinated isopropylidene group, a carbonyl group, a thio group, or a sulfonyl group; R represents an aliphatic group having 2 or more carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, or a non-condensed polycyclic group in which aromatic groups are connected to each other directly or by a cross-linking member. Represents a tetravalent group selected from the group consisting of cyclic aromatic groups.)

  In addition, the semi-aromatic polyamide fiber used in the present invention is, from the viewpoint of heat resistance, the semi-aromatic polyamide resin constituting the fiber is an aromatic dicarboxylic acid unit and an aliphatic alkylenediamine unit having 6 to 18 carbon atoms. And a dicarboxylic acid unit containing 50 to 100 mol% of a terephthalic acid unit, a 1,9-nonanediamine unit and / or 2-methyl-1,8-octanediamine. It is preferable that it consists of a polyamide-type resin which consists of a diamine unit which contains a unit 60-60 mol%. Such a semi-aromatic polyamide-based resin is commercially available from Kuraray, for example, under the trademark “Genesta”.

  The thermoplastic fiber used in the present invention may contain an antioxidant, an antistatic agent, a radical inhibitor, a matting agent, an ultraviolet absorber, a flame retardant, an inorganic substance and the like as long as the effects of the present invention are not impaired. . Specific examples of such inorganic substances include carbon nanotubes, fullerenes, talc, wollastonite, zeolite, sericite, mica, kaolin, clay, pyrophyllite, silica, bentonite, alumina silicate and other silicates, silicon oxide, magnesium oxide, Metal oxides such as alumina, zirconium oxide, titanium oxide, iron oxide, carbonates such as calcium carbonate, magnesium carbonate, dolomite, sulfates such as calcium sulfate and barium sulfate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, etc. Hydroxides, glass beads, glass flakes, glass powders, ceramic beads, boron nitride, silicon carbide, carbon black and silica, graphite and the like are used.

  Production of the thermoplastic fiber used in the present invention is not particularly limited, and a known melt spinning apparatus can be used. That is, it can be obtained by melting and kneading thermoplastic polymer pellets and powders with a melt extruder, introducing the molten polymer into a spinning cylinder, measuring it with a gear pump, and winding the yarn discharged from the spinning nozzle. The take-up speed at that time is not particularly limited, but it is not preferred if molecular orientation occurs on the spinning line, and it is preferably taken in the range of 500 to 4000 m / min. If it is less than 500 m / min, it is not preferable from the viewpoint of productivity. On the other hand, if it exceeds 4000 m / min, not only the molecular orientation is sufficient to cause shrinkage at high temperatures, but also fiber breakage tends to occur. Therefore, it is not preferable.

  In the production of the thermoplastic fiber of the present invention, it is preferable not to perform a stretching step in order to ensure process passability in the production process of the fiber reinforced resin composite and dimensional stability of the resulting composite. When stretching is performed as in the conventional fiber manufacturing process, entropy shrinkage occurs due to the increase in molecular motion during thermoforming, and the thermoplastic fiber undergoes large shrinkage, heating the reinforcing fiber substrate. There is a concern that the process passability at the time of molding is deteriorated and the appearance of the obtained composite is poor.

  The average fineness of the single fiber of the thermoplastic fiber used in the present invention is preferably 0.1 to 12 dtex. In order to obtain a fiber reinforced resin composite having excellent mechanical properties and uniform quality, the nonwoven fabric made of thermoplastic fibers in the reinforcing fiber base material as a precursor should have a uniform basis weight and thickness. Is desirable. As the average fineness is smaller, the number of thermoplastic fibers constituting the nonwoven fabric increases, and a uniform nonwoven fabric can be obtained. Furthermore, since the surface area of the thermoplastic fiber constituting the nonwoven fabric is increased, the thermoplastic fiber is easily melted in the subsequent hot press molding, which is desirable because the resin impregnation property to the reinforcing fiber is improved. However, if the average fineness is less than 0.1 dtex, the nonwoven fabric may be entangled in the nonwoven fabric manufacturing process, and a nonwoven fabric with uniform quality may not be obtained. On the other hand, when the average fineness is larger than 12 dtex, the number of thermoplastic fibers constituting the nonwoven fabric is too small, and a uniform nonwoven fabric may not be obtained. The average fineness of the thermoplastic fiber is more preferably 0.2 to 9 dtex, still more preferably 0.3 to 8 dtex.

  The average fiber length of the single fiber of the thermoplastic fiber used in the present invention is preferably 0.5 to 60 mm. If the average fiber length is less than 0.5 mm, the fibers may fall off during the process of manufacturing the nonwoven fabric, and particularly when the nonwoven fabric is manufactured by wet papermaking, the drainage during the process may be deteriorated. Is not preferable because it may greatly deteriorate the value. When the average fiber length is larger than 60 mm, it is not preferable because the processability may deteriorate due to entanglement of thermoplastic fibers in the nonwoven fabric manufacturing process. More preferably, it is 1-55 mm, More preferably, it is 3-50 mm. In addition, there is no restriction | limiting in particular regarding the cross-sectional shape of the thermoplastic fiber used by this invention, Circular, hollow, flat, or atypical cross sections, such as a star shape, may be sufficient. The fiber used here may be used in the form of, for example, a shortcut fiber, a staple fiber, etc., and an appropriate fiber form can be freely selected in the production of the nonwoven fabric.

(Nonwoven fabric made of thermoplastic fibers)
The method for producing the nonwoven fabric comprising the thermoplastic fiber of the present invention is not particularly limited, and examples thereof include spunlace nonwoven fabric, needle punched nonwoven fabric, steam jet nonwoven fabric, dry papermaking method, and wet papermaking method. The nonwoven fabric of the present invention includes water-soluble polymer fibers such as polyvinyl alcohol fibers, heat-sealing fibers such as polyethylene terephthalate fibers, and pulp-like products of para-aramid fibers and wholly aromatic polyester fibers). Also good. Moreover, in order to improve the uniformity and press-fit property of paper, you may apply | coat the binder by spray drying or add a hot press process.

It is preferable that the fabric weight of the nonwoven fabric which consists of a thermoplastic fiber of this invention is 5-500 g / m < ² >. When the basis weight is less than 5 g / m ² , the formation of spots becomes large and the process passability deteriorates, which is not preferable. A case where the basis weight is larger than 500 g / m ² is not preferable for the same reason. More preferably, it is 6-300 g / m < ² >, More preferably, it is 7-200 g / m < ² >.

  Moreover, it is preferable that the thickness of the nonwoven fabric which consists of a thermoplastic fiber of this invention is 0.1-10 mm. If the thickness is less than 0.1 mm, undesired spots increase, and the nonwoven fabric breaks or cracks. In addition, when the thickness is larger than 10 mm, in addition to the problem of formation unevenness, there arises a problem that the operability when the base material is placed on the mold at the time of molding is extremely deteriorated. More preferably, it is 1-7 mm, More preferably, it is 1-5 mm.

Furthermore, it is preferable that the bulk density of the nonwoven fabric which consists of the thermoplastic fiber of this invention is 0.01-1.0 g / cm < ³ >. When the bulk density is less than 0.01 g / cm ³ , the nonwoven fabric becomes bulky, so that the operability at the time of molding is deteriorated, or there is a concern that problems such as opening or tearing of the nonwoven fabric may occur. Moreover, when the bulk density exceeds 1.0 g / cm ³ , the nonwoven fabric is close to a plate shape, which causes a problem that it cannot be shaped depending on the mold shape.

(Reinforced fiber)
The reinforcing fiber used in the present invention is not particularly limited as long as the effects of the present invention are not impaired, and may be an organic fiber or an inorganic fiber, and may be used alone or in combination of two or more. Also good. For example, examples of inorganic fibers include carbon fibers, glass fibers, silicon carbide fibers, alumina fibers, ceramic fibers, basalt fibers, and various metal fibers (for example, gold, silver, copper, iron, nickel, titanium, stainless steel, etc.). Examples of organic fibers include wholly aromatic polyester fibers, polyphenylene sulfide fibers, aramid fibers, polysulfonamide fibers, phenol resin fibers, polyimide fibers, and fluorine fibers.

  Of these reinforcing fibers, carbon fibers, glass fibers, wholly aromatic polyester fibers, aramid fibers, ceramic fibers, and metal fibers are preferred from the viewpoint of mechanical properties, flame retardancy, heat resistance, and availability. Used.

(Reinforced fiber base material and fiber reinforced resin composite)
The fiber-reinforced resin composite of the present invention is composed of the thermoplastic fiber with respect to a fabric having at least one form selected from the group consisting of a woven fabric, a knitted fabric, and an aligned yarn sheet-like material composed of the reinforcing fibers. It is important to use a reinforcing fiber base material formed by laminating the formed nonwoven fabrics. Preferably, the fiber reinforced resin composite can be obtained by laminating one or a plurality of the reinforcing fiber bases and performing heat and pressure molding at a temperature equal to or higher than the flow start temperature of the thermoplastic fiber.

  There is no particular limitation on the heat and pressure molding method, and general compression molding such as stampable molding, pressure molding, vacuum pressure molding, and GMT molding is preferably used. What is necessary is just to set the shaping | molding temperature at that time according to the flow start temperature and decomposition temperature of the thermoplastic fiber to be used. For example, when the thermoplastic fiber is made of a crystalline resin, the molding temperature is preferably in the range from the melting point of the thermoplastic fiber to (melting point + 100 ° C.). Moreover, when a thermoplastic fiber consists of an amorphous resin, it is preferable that a shaping | molding temperature is the range of the glass transition temperature of a thermoplastic fiber or more and (glass transition temperature +200 degreeC) or less.

The pressure at the time of heat and pressure molding is not particularly limited, but is usually 0.05 N / mm ² or more. The time for the heat and pressure molding is not particularly limited, but the polymer may be deteriorated when exposed to a high temperature for a long time. Therefore, it is usually preferably within 30 minutes. Further, the thickness and density of the obtained fiber reinforced resin composite can be appropriately set depending on the type of reinforcing fiber and the applied pressure. Furthermore, there is no restriction | limiting in particular also in the shape of the fiber reinforced resin composite obtained, and it can set suitably. Depending on the purpose, multiple layers of non-woven fabrics made of thermoplastic fibers with different specifications or reinforced fiber base materials are laminated, or placed separately in a mold of a certain size, and heated and pressed. It is also possible. In some cases, it can be molded together with other reinforcing fiber fabrics or fiber reinforced resin composites. And according to the objective, it is also possible to heat-press-mold again the fiber reinforced resin composite obtained by heat-press-molding once.

  Moreover, when the fiber-reinforced resin composite of the present invention is formed by heating and pressing the reinforcing fiber base at a temperature higher than the flow start temperature of the fiber made of a thermoplastic resin constituting the fiber base, It is preferable from the viewpoint of the formability that the composite is obtained by press-molding in advance at a temperature lower than the flow start temperature and making it a semi-impregnated state.

  The fiber reinforced resin composite preferably has a bending strength and a flexural modulus at 24 ° C. of 150 MPa or more and 5 GPa or more, respectively. When the bending strength and the flexural modulus are smaller than 150 MPa and 5 GPa, respectively, use is limited, which is not preferable. Preferably, the bending strength and the elastic modulus are 160 MPa or more and 5.5 GPa or more, respectively, more preferably 170 MPa or more and 6 GPa or more.

In addition, the density of the fiber reinforced resin composite of the present invention is preferably 2.00 g / cm ³ or less. If the density is greater than 2.00 g / m ³ , it cannot be said to be a fiber-reinforced resin composite that contributes to weight reduction, and its use may be limited. More preferably, it is 1.95 g / cm < ³ > or less, More preferably, it is 1.90 g / cm < ³ > or less.

  Furthermore, the fiber reinforced resin composite of the present invention preferably has a thickness of 0.5 mm or more. When the thickness is less than 0.5 mm, the strength of the resulting fiber-reinforced resin composite is lowered and the production cost is increased, which is not preferable. Preferably, it is 0.7 mm or more, more preferably 1 mm or more.

  The fiber-reinforced resin composite of the present invention not only has excellent mechanical properties and heat resistance, flame retardancy, dimensional stability, and moldability, but can be manufactured at low cost without requiring a special process. , PCs, displays, OA equipment, mobile phones, personal digital assistants, digital video cameras, optical equipment, audio, air conditioners, lighting equipment, toy products, housings for other home appliances, trays, chassis, interior members, or cases thereof Electrical and electronic equipment parts such as, civil works such as columns, panels, reinforcing materials, building material parts, various members, various frames, various hinges, various arms, various axles, various wheel bearings, various beams, various pillars, various members , Various frames, various beams, various supports, various rails, various hinges, outer panels or body parts, bumpers, moldings, undercovers , Engine covers, rectifier plates, spoilers, cowl louvers, aero parts and other exterior parts, instrument panels, seat frames, door trims, pillar trims, handles, various parts such as modules, or motor parts, CNG tanks, gasoline tanks, fuel pumps , Air intake, intake manifold, carburetor main body, carburetor spacer, various pipes, various fuel systems such as valves, exhaust systems or intake system parts, motorcycle structural parts, landing gear pods, winglets, spoilers, edges It is suitably used for aircraft parts such as ladders, elevators, failings, and ribs.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited at all by this Example. In the following examples, each item including the glass transition temperature of the thermoplastic resin is measured by the following method.

[Glass transition temperature ° C]
The glass transition temperature of the thermoplastic resin has a temperature dependence of loss tangent (tan δ) at a frequency of 10 Hz and a heating rate of 10 ° C./min using a solid dynamic viscoelastic device “Rheospectra DVE-V4” manufactured by Rheology. Measured and determined from the peak temperature. Here, the peak temperature of tan δ is a temperature at which the first derivative of the amount of change with respect to the temperature of the value of tan δ becomes zero.

[MFR g / 10min]
The MFR of the thermoplastic resin is “Melt Indexer L244-2531” manufactured by Techno Seven, which is 30 ° C. higher than the crystal melting temperature in the case of a crystalline resin, and the glass transition in the case of an amorphous resin. It was calculated by measuring the discharge amount at a nozzle diameter of 2.095 mmφ and a load of 6.66 kg for 10 minutes at a temperature 120 ° C. higher than the temperature.

[Molecular weight distribution (Mw / Mn)]
The molecular weight distribution of the thermoplastic resin was measured using water permeation gel permeation chromatography (GPC) and 1500 ALC / GPC (polystyrene conversion). Using chloroform as a solvent, the sample was dissolved so as to be 0.2% by weight, and then filtered and used for measurement. The molecular weight distribution (Mw / Mn) was determined from the ratio of the obtained weight average molecular weight (Mw) and number average molecular weight (Mn).

[Average fineness dtex]
One hundred fibers were randomly extracted from the multifilament of thermoplastic fibers, the fineness of each was measured, and the average fineness of single fibers was determined.

[Average fiber length mm]
100 pieces were randomly extracted from the cut yarn of the thermoplastic fiber, the length of each fiber was measured, and the average fiber length was determined.

[Weight per unit g / m ² , thickness mm, bulk density g / m ³ ]
The nonwoven fabric made of thermoplastic fibers was measured according to the JIS L1913 test method, and an average value of n = 3 was adopted.

[Bending strength MPa, flexural modulus GPa]
With respect to the fiber reinforced resin composite, the bending strength and the flexural modulus at 24 ° C. and 100 ° C. were measured according to ASTM 790.

[Flame retardance]
The flame retardancy of the fiber reinforced resin composite was measured according to the method of UL94 V standard.

[Impregnation]
The evaluation regarding the impregnation property of the reinforcing fiber base was evaluated in three stages as follows according to the area ratio occupied by voids in the cross section by observing the cross section of the fiber reinforced resin composite with a scanning electron microscope (SEM).
○: Area occupied by voids is less than 10% Δ: Area occupied by voids is 10% or more and less than 30% ×: Area occupied by voids is 30% or more

[Shaping formability]
With respect to the formability of the reinforcing fiber base material, it was evaluated in three stages from the following viewpoints by observing the appearance of the resulting fiber reinforced resin composite when molded using a mold as shown in FIG. .
○: No appearance of wrinkles and the like is good.
Δ: Wrinkles and the like are seen in part of the appearance.
X: A hole etc. are seen in some external appearances, and it is inferior.

[Example 1]
(1) A polyetherimide (hereinafter sometimes abbreviated as PEI) polymer (“ULTEM 9001” manufactured by Servic Innovative Plastics), which is an amorphous resin, was vacuum-dried at 150 ° C. for 12 hours. The glass transition temperature of the resin used here was 217 ° C., and the MFR was 42 g / 10 min at 337 ° C. (120 ° C. higher than the glass transition temperature).
(2) The polymer of (1) was discharged from a round hole nozzle under the conditions of a spinning head temperature of 390 ° C., a spinning speed of 1500 m / min, and a discharge rate of 50 g / min, to obtain a PEI fiber multifilament of 2640 dtex / 1200 f. . Next, after crimping the obtained fiber, the length was cut to 51 mm to obtain a staple fiber.
(3) The appearance of the obtained fiber was good without fluff and the like, the average fineness of the single fiber was 2.2 dtex, and the average fiber length was 51.1 mm.
(4) The obtained staple fiber is made into a fabric by a spunlace method, and roll-pressed at 190 ° C., thereby comprising a PEI fiber having a basis weight of 100 g / m ² , a thickness of 0.5 mm, and a bulk density of 0.2 g / cm ^3. A nonwoven fabric was obtained.
(5) A carbon fiber woven fabric as a fabric made of reinforcing fibers (made of Toei Tenax “W-3101: 3K woven fabric, 200 g / m ² basis weight”) on the upper and lower surfaces of the PEI fiber obtained in (4) above. Reinforced fiber base material was obtained as a set of laminated non-woven fabrics, and after the six fiber base materials were laminated (total basis weight = 2400 g / m ² ), the temperature at which all PEI fibers melted was 360 ° C. A flat plate was formed by compression molding for 3 minutes to obtain a fiber reinforced resin composite, wherein the weight ratio of the reinforced fiber and the thermoplastic resin in the composite was 1: 1.
(6) The appearance of the obtained composite was good, and voids in the cross section of the composite were hardly observed, resulting in excellent impregnation properties. The bending strength and flexural modulus at room temperature are 710 MPa, 41.7 GPa and the flexural modulus and flexural modulus at 100 ° C. are 570 MPa and 33.8 GPa, respectively, and the retention rates are 80% and 81%, respectively. It was excellent in heat resistance. Moreover, the flame retardance passed UL94 V-0 standard.
(7) Using the same fiber base material as in (5), the shaping was carried out with the mold shown in FIG. The obtained fiber reinforced resin composite had no noticeable wrinkles or misalignment of the base material, and had a good appearance and excellent formability.

[Example 2]
With respect to the nonwoven fabric of (4) of Example 1, the basis weight is 40 g / m ² , the thickness is 0.2 mm, the bulk density is 0.2 g / cm ³ , and the composite of (5) is weight ratio (reinforced fiber: thermoplastic resin) ) Was obtained by the same method as in Example 1 except that the reinforcing fiber base material was laminated so as to be 1: 2.5. Appearance of the obtained composite is good, bending strength at room temperature and bending elastic modulus are 990 MPa, 58.4 GPa, bending strength at 100 ° C., bending elastic modulus are 832 MPa and 50.2 GPa, respectively. The retention rates were 84% and 86%, respectively, and the heat resistance was excellent. Moreover, the flame retardance passed UL94 V-0 standard, and it was excellent also in the impregnation property and the shaping property.

[Example 3]
With respect to the fabric comprising the reinforcing fiber of (5) of Example 1, a fiber reinforced resin composite was prepared in the same manner as in Example 1 except that it was a glass fiber fabric ("M205K 104H: 200 g / m ² " manufactured by Unitika). The appearance of the obtained composite was good, the bending strength at room temperature and the bending elastic modulus were 550 MPa, 19.1 GPa, bending strength at 100 ° C., and the bending elastic modulus were 440 MPa and 15.5, respectively. At 5 GPa, the retention rates were 80% and 81%, respectively, and the heat resistance was excellent, and the flame retardancy passed the UL94 V-0 standard, impregnation and formability. It was excellent.

[Example 4]
(1) A semi-aromatic polyamide polymer (“Genesta PA9MT” manufactured by Kuraray Co., Ltd.), which is a crystalline resin, was vacuum-dried at 80 ° C. for 12 hours. The resin used here had a glass transition temperature of 125 ° C., a crystal melting temperature of 262 ° C., and an MFR of 292 ° C. (30 ° C. higher than the crystal melting temperature) and 30 g / 10 min.
(2) The polymer of (1) was discharged from a round hole nozzle under the conditions of a spinning head temperature of 310 ° C., a spinning speed of 1500 m / min, and a discharge rate of 50 g / min, to obtain a multifilament of semi-aromatic polyamide fiber. Subsequently, the obtained fiber was crimped and cut into a length of 51 mm to obtain a staple fiber.
(3) The appearance of the obtained fiber was good without fluff and the like, the average fineness of the single fiber was 0.7 dtex, and the average fiber length was 51.2 mm.
(4) The obtained staple fiber is made into a fabric by the spunlace method, and roll pressed at 150 ° C. to give a semi-aromatic polyamide system having a basis weight of 100 g / m ² , a thickness of 0.5 mm, and a bulk density of 0.2 g / cm ^3. A nonwoven fabric made of fibers was obtained.
(5) Carbon fiber fabric as a fabric composed of reinforcing fibers (on the upper and lower surfaces of “W-3101: 3K fabric, 200 g / m ² basis weight” manufactured by Toho Tenax Co., Ltd.) The semi-aromatic polyamide system obtained in (4) above Reinforced fiber base material was obtained as a set of non-woven fabrics made of fibers, and after lamination of 6 fiber base materials (total basis weight = 2400 g / m ² ), all semi-aromatic polyamide fibers were A flat plate was formed by compression molding at 320 ° C. for 3 minutes to obtain a fiber reinforced resin composite.
(6) Appearance of the obtained composite is good, bending strength and bending elastic modulus at room temperature are 600 MPa, 48.3 GPa, bending strength at 100 ° C., bending elastic modulus are 498 MPa and 40. respectively. At 6 GPa, the retention rates were 83% and 84%, respectively, and the heat resistance was excellent. On the other hand, since the semi-aromatic polyamide-based resin does not have flame retardancy, it did not pass the UL94 V-0 standard, but was excellent in impregnation and formability.

[Example 5]
(1) Polyetherketoneketone (hereinafter, sometimes abbreviated as PEKK) polymer (Arkema “8000 series”), which is a crystalline resin, was vacuum-dried at 80 ° C. for 12 hours. The glass transition temperature of the resin used here was 160 ° C., the crystal melting temperature was 305 ° C., and the MFR was 335 ° C. (30 ° C. higher than the crystal melting temperature) and 50 g / 10 min.
(2) The polymer of (1) was discharged from a round hole nozzle under the conditions of a spinning head temperature of 370 ° C., a spinning speed of 1500 m / min, and a discharge rate of 50 g / min, to obtain a PEKK-based fiber multifilament. Subsequently, the obtained fiber was crimped and cut into a length of 51 mm to obtain a staple fiber.
(3) The appearance of the obtained fiber was good without fluff and the like, the average fineness of the single fiber was 5.0 dtex, and the average fiber length was 51.1 mm.
(4) Fabricating the staple fiber by the spunlace method and roll pressing at 190 ° C. to obtain a nonwoven fabric made of PEKK fiber having a basis weight of 100 g / m ² , a thickness of 0.5 m, and a bulk density of 0.2 g / cm ³ It was.
(5) Carbon fiber fabric as a fabric made of reinforcing fibers (made of PEKK-based fiber obtained in (4) above and below both sides of “W-3101: 3K fabric, 200 g / m ² basis weight” manufactured by Toho Tenax Co., Ltd.) Reinforced fiber base material was obtained as a set of laminated non-woven fabrics, and after laminating six of the fiber base materials (total weight = 2400 g / m ² ), 390 ° C., the temperature at which all PEKK fibers melt The plate was molded by compression molding for 3 minutes to obtain a fiber-reinforced resin composite.
(6) Appearance of the obtained composite is good, bending strength at room temperature and bending elastic modulus are 730 MPa, 42.5 GPa, bending strength at 100 ° C., bending elastic modulus are 621 MPa, 36. At 1 GPa, the retention rates were 85% and 85%, respectively, and the heat resistance was excellent. Moreover, the flame retardance passed UL94 V-0 standard, and it was excellent also in the impregnation property and the shaping property.

[Example 6]
(1) A thermoplastic polyimide polymer (“PL450C” manufactured by Mitsui Chemicals), which is a crystalline resin, was vacuum-dried at 80 ° C. for 12 hours. The resin used here had a glass transition temperature of 250 ° C., a crystal melting temperature of 387 ° C., and an MFR of 417 ° C. (30 ° C. higher than the crystal melting temperature) and 55 g / 10 min.
(2) The polymer of (1) was discharged from a round hole nozzle under the conditions of a spinning head temperature of 420 ° C., a spinning speed of 1500 m / min, and a discharge rate of 50 g / min, to obtain multifilaments of thermoplastic polyimide fibers. Subsequently, the obtained fiber was crimped and cut into a length of 51 mm to obtain a staple fiber.
(3) The appearance of the obtained fiber was good without fluff and the like, the average fineness of the single fiber was 5.6 dtex, and the average fiber length was 51.1 mm.
(4) The fiber staple fiber obtained in the above (3) is made into a fabric by a spunlace method and roll-pressed at 190 ° C., whereby the basis weight is 100 g / m ² , the thickness is 0.5 mm, and the bulk density is 0.2 g / cm ^3. A nonwoven fabric made of thermoplastic polyimide fiber was obtained.
(5) Carbon fiber woven fabric as a reinforcing fiber base material (from Toho Tenax Co., Ltd. “W-3101: 3K woven fabric, 200 g / m ² basis weight”) on the upper and lower surfaces of the thermoplastic polyimide fiber obtained in (4) above Reinforced fiber base material was obtained as a set of laminated non-woven fabrics, and after laminating 6 pieces of the fiber base material (total weight = 2400 g / m ² ), at a temperature at which all thermoplastic polyimide fibers melt. A flat plate was formed by compression molding at 400 ° C. for 3 minutes to obtain a fiber-reinforced resin composite.
(6) The appearance of the obtained composite was good and the operability during molding was also excellent. Flexural strength and flexural modulus at room temperature are 650 MPa, 41.5 GPa, and flexural strength and flexural modulus at 100 ° C. are 585 MPa and 36.9 GPa, respectively, and their retention rates are 90% and 89%, respectively. It was excellent in heat resistance. Moreover, the flame retardance passed UL94 V-0 standard, and it was excellent also in the impregnation property and the shaping property.

[Comparative Example 1]
(1) The basis weight is 100 g / m ^{2 in} the same manner as in Example 1 except that the polyetherimide polymer of Example 1 is a resin having a lower viscosity (“ULTEM 1040” manufactured by Servic Innovative Plastics). A nonwoven fabric made of PEI fibers having a thickness of 0.5 mm and a bulk density of 0.2 g / cm ³ was obtained. The resin used here had a glass transition temperature of 217 ° C. and an MFR of 337 ° C. (120 ° C. higher than the glass transition temperature) and 105 g / 10 min.
(2) Carbon fiber fabric as a reinforcing fiber substrate (nonwoven fabric made of PEI fibers obtained in (1) above and below both surfaces of “W-3101: 3K fabric, 200 g / m ² basis weight” manufactured by Toho Tenax Co., Ltd. A reinforced fiber base material was obtained as a set of superposed fibers, and after laminating six of the fiber base materials (total basis weight = 2400 g / m ² ), at a temperature of 360 ° C., the temperature at which all PEI fibers melt. A flat plate was formed by compression molding for 3 minutes to obtain a fiber-reinforced resin composite.
(3) The appearance of the obtained composite was good, and almost no voids in the cross section of the composite were observed. However, the bending strength and flexural modulus at room temperature are 560 MPa, 39.1 GPa, and the flexural modulus and flexural modulus at 100 ° C. are 420 MPa and 30.1 GPa, respectively, and the retention rates are 75% and 77%, respectively. The mechanical properties were inferior. On the other hand, flame retardancy passed UL94 V-0 standard.
(4) Using the same fiber base material as in (2), the forming was carried out with the mold shown in FIG. The obtained fiber reinforced resin composite has no noticeable wrinkles or misalignment of the base material, and there is no problem in the formability. However, as described above, the viscosity of the resin used is low. The mechanical properties were inferior.

[Comparative Example 2]
(1) Carbon fiber woven fabric as a reinforcing fiber base (“W-3101: 3K woven fabric, 200 g / m ² basis weight” manufactured by Toho Tenax Co., Ltd.) films made of PEI resin (“Sumilite FS manufactured by Sumitomo Bakelite Co., Ltd.”) -1450: 75 μm thickness ”) was obtained as a set to obtain a reinforced fiber base material. After the six fiber base materials were laminated (total basis weight = 2340 g / m ² ), all the PEI film was A flat plate was formed by compression molding at a melting temperature of 360 ° C. for 3 minutes to obtain a fiber reinforced resin composite, where the glass transition temperature of the resin used here was 217 ° C., and the MFR was 337 ° C. It was 42 g / 10 min at 120 ° C. higher than the transition temperature.
(2) Although the appearance of the obtained composite was good, voids that could be confirmed in the cross section of the composite were observed, resulting in poor impregnation properties. The bending strength and bending elastic modulus at room temperature are 610 MPa, 38.1 GPa, and the bending strength and bending elastic modulus at 100 ° C. are 476 MPa and 30.1 GPa, respectively, and the holding ratios are 78% and 79%, respectively. The mechanical properties were inferior. On the other hand, flame retardancy passed UL94 V-0 standard.
(3) Using the same fiber base material as in (1), the forming was carried out with the mold shown in FIG. The obtained fiber reinforced resin composite was slightly wrinkled or misaligned with the fiber base, resulting in poor appearance and poor formability.

[Comparative Example 3]
(1) Carbon fiber woven fabric as a reinforcing fiber base ("W-3101: 3K woven fabric, 200 g / m ² basis weight" manufactured by Toho Tenax Co., Ltd.), pre-ground and coated with PEI powder having an average particle size of 80 μm Then, it was press-molded at 300 ° C. for 3 minutes by a hot press molding machine to prepare a reinforced fiber base material.The resin used here had a glass transition temperature of 217 ° C. and an MFR of 337 ° C. (120 from the glass transition temperature). It was 42 g / 10 min at 6 ° C. After laminating 6 sheets of this reinforcing fiber base material (total weight = 3050 g / m ² ), compression molding was performed at 360 ° C., which is the temperature at which all PEI powder melts, for 3 minutes. The flat plate was molded to obtain a fiber reinforced resin composite, and the operability such as installation of the base material during molding was good.
(2) Although the appearance of the obtained composite was good, voids that could be confirmed in the cross section of the molded product were observed, resulting in poor impregnation properties. The bending strength and bending elastic modulus at room temperature are 600 MPa and 37.5 GPa, respectively, the bending strength and bending elastic modulus at 100 ° C. are 462 MPa and 28.9 GPa, respectively, and the holding ratios are 77% and 77%, respectively. The physical properties were inferior. On the other hand, flame retardancy passed UL94 V-0 standard.
(3) When forming was carried out with the mold shown in FIG. 1, wrinkles were confirmed in the appearance of the molded product, and the forming shape was inferior.

[Comparative Example 4]
(1) A polyamide-based polymer (“UBE nylon 6” manufactured by Ube Industries), which is a crystalline resin, was vacuum-dried at 90 ° C. for 12 hours. The glass transition temperature of the resin used here was 48 ° C., the crystal melting temperature was 225 ° C., and the MFR was 40 g / 10 min at 255 ° C. (30 ° C. higher than the crystal melting temperature).
(2) The polymer of (1) was discharged from a round hole nozzle under the conditions of a spinning head temperature of 230 ° C., a spinning speed of 3000 m / min, and a discharge rate of 25 g / min to obtain a polyamide fiber multifilament. Subsequently, the obtained fiber was crimped and cut into a length of 51 mm to obtain a staple fiber.
(3) The appearance of the obtained fiber was good without fluff and the like, the average fineness of the single fiber was 3.0 dtex, and the average fiber length was 51.0 mm.
(4) The fiber staple fiber obtained in the above (3) is made into a fabric by a spunlace method and roll-pressed at 150 ° C., whereby the basis weight is 100 g / m ² , the thickness is 0.5 mm, and the bulk density is 0.2 g / cm ^3. A nonwoven fabric made of a polyamide fiber was obtained.
(5) Carbon fiber woven fabric as a reinforcing fiber substrate (nonwoven fabric made of polyamide fiber obtained in (4) above and below both surfaces of “W-3101: 3K woven fabric, 200 g / m ² basis weight” manufactured by Toho Tenax Co., Ltd. A reinforced fiber base material was obtained as a set of superposed fibers obtained by laminating 6 sheets of the fiber base material (total basis weight = 2400 g / m ² ), and at a temperature of 250 ° C. at which all polyamide fibers melt. A flat plate was formed by compression molding for 3 minutes to obtain a fiber-reinforced resin composite.
(6) The appearance of the obtained composite was good, and it was excellent in impregnation and formability. However, the bending strength and bending elastic modulus at room temperature are 620 MPa, 45.0 GPa, and the bending strength and bending elastic modulus at 100 ° C. are 267 MPa and 18.0 GPa, respectively, and the holding ratios are 43% and 40%, respectively. The heat resistance was greatly inferior. Furthermore, the flame retardancy did not pass the UL94 V-0 standard.

  According to the present invention, there is provided a fiber reinforced resin composite that has excellent mechanical properties and heat resistance, flame retardancy, dimensional stability, and moldability, and is applied to applications that are often exposed to a high temperature environment. It is possible to provide. Further, the fiber reinforced resin composite of the present invention can be manufactured at a low cost by a normal thermoforming process such as compression molding or GMT molding without requiring a special thermoforming process. Can be designed freely, and has many applications including general industrial materials field, electrical / electronic field, civil engineering / architecture field, aircraft / automobile / railway / ship field, agricultural material field, optical material field, medical material field, etc. Can be used very effectively.

1: Mold form 2: Mold upper lid

Claims (11)

Reinforcement in which a non-woven fabric composed of fibers made of thermoplastic resin is superimposed on a fabric having at least one form selected from the group consisting of woven fabrics made of reinforcing fibers, knitted fabrics, and aligned yarn sheets. A reinforcing fiber base material, which is a fiber base material and satisfies all of the following conditions.
(1) The glass transition temperature of the thermoplastic resin is 100 ° C. or higher.
(2) The melt flow rate (MFR) of the thermoplastic resin is 20 to 80 g / 10 min at a temperature 30 ° C. higher than the crystal melting temperature in the case of a crystalline resin, and the glass transition in the case of an amorphous resin. It is 20 to 80 g / 10 min at a temperature 120 ° C. higher than the temperature. The average fineness of the single fiber of the thermoplastic resin constituting the reinforcing fiber base is 0.1 to 12 dtex, and the basis weight of the nonwoven fabric made of the thermoplastic resin is 5 to 500 g / The reinforcing fiber substrate according to claim 1, wherein m ^{2 has} a thickness of 0.1 to 10 mm, and a bulk density of 0.01 to 1.0 g / cm ³ .   The fiber comprising the thermoplastic resin constituting the reinforcing fiber base is at least selected from the group consisting of polyetherimide fiber, polyether ketone ketone fiber, thermoplastic polyimide fiber, and semi-aromatic polyamide fiber. The reinforcing fiber substrate according to claim 1 or 2, wherein the reinforcing fiber substrate is composed of one kind. The said polyetherimide type fiber consists of an amorphous polyetherimide type resin which is shown by the following general formula, and whose glass transition temperature is 200 degreeC or more and does not have melting | fusing point, It is characterized by the above-mentioned. Reinforcing fiber substrate as described in 1.

Wherein R1 is a divalent aromatic residue having 6 to 30 carbon atoms, and R2 is a divalent aromatic residue having 6 to 30 carbon atoms, 2 to 20 2 selected from the group consisting of an alkylene group having 2 carbon atoms, a cycloalkylene group having 2 to 20 carbon atoms, and a polydiorganosiloxane group chain-terminated with an alkylene group having 2 to 20 carbon atoms Represents a valent organic group.) The said polyether ketone ketone type | system | group fiber is shown by the following general formula, Glass transition temperature is 130 degreeC or more, and consists of crystalline polyether ketone ketone type | system | group resin of Claim 3 characterized by the above-mentioned. Reinforced fiber substrate.

The thermoplastic polyimide fiber is made of a polyimide resin composed of 99.9 to 50% by weight of a thermoplastic polyimide having a repeating unit represented by the following formula and 0.1 to 50% by weight of an aromatic polyetherimide. The reinforcing fiber substrate according to claim 3, wherein

(Wherein X represents a direct bond, a group selected from the group consisting of a divalent hydrocarbon group having 1 to 10 carbon atoms, a hexafluorinated isopropylidene group, a carbonyl group, a thio group, or a sulfonyl group; R represents an aliphatic group having 2 or more carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, or a non-condensed polycyclic group in which aromatic groups are connected to each other directly or by a cross-linking member. Represents a tetravalent group selected from the group consisting of cyclic aromatic groups.)   The reinforcing fiber substrate according to claim 3, wherein the semi-aromatic polyamide fiber is made of a polyamide resin comprising an aromatic dicarboxylic acid unit and an aliphatic alkylenediamine unit having 6 to 18 carbon atoms. .   The semi-aromatic polyamide fiber contains 60 to 100 mol of a dicarboxylic acid unit containing 50 to 100 mol% of a terephthalic acid unit and 1,9-nonanediamine unit and / or 2-methyl-1,8-octanediamine unit. It consists of a polyamide-type resin which consists of a diamine unit which contains%, The reinforcing fiber base material of Claim 3 characterized by the above-mentioned.   The reinforcing fiber constituting the reinforcing fiber substrate is composed of at least one selected from the group consisting of carbon fiber, glass fiber, wholly aromatic polyester fiber, aramid fiber, ceramic fiber, and metal fiber. The reinforcing fiber substrate according to any one of claims 1 to 8.   The reinforcing fiber base material is obtained by heat-press molding at a temperature higher than a flow start temperature of a fiber made of a thermoplastic resin constituting the fiber base material. A fiber-reinforced resin composite obtained from the reinforcing fiber base material according to any one of the above items.   When the reinforcing fiber base material is heated and pressure-molded at a temperature higher than the flow starting temperature of the fiber made of the thermoplastic resin constituting the fiber base material, the flow start is performed in advance. The fiber-reinforced resin composite obtained from the reinforcing fiber base material according to any one of claims 1 to 10, wherein the fiber-reinforced resin base material is pressure-molded at a temperature lower than the temperature to be in a semi-impregnated state.

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