JP6142737B2 - Thermoplastic prepreg and method for producing thermoplastic prepreg - Google Patents

Description

  The present invention relates to a thermoplastic prepreg and a method for producing a thermoplastic prepreg. Specifically, the present invention relates to a thermoplastic resin formed by heat-pressing a sheet for a fiber-reinforced plastic molded article containing a reinforcing fiber component, a matrix resin component containing a thermoplastic super engineering plastic fiber, and a binder component. It relates to prepreg.

  A fiber-reinforced resin molded article obtained by heating and pressurizing a nonwoven fabric containing reinforcing fibers such as carbon fibers and glass fibers has already been used in various fields such as sports, leisure goods and aircraft materials. Thermosetting resins such as epoxy resins, unsaturated polyester resins, or phenolic resins are often used as the matrix resin in these fiber reinforced resin molded products. However, when a thermosetting resin is used, a nonwoven fabric or a prepreg mixed with a thermosetting resin and a reinforcing fiber must be refrigerated and cannot be stored for a long time. In addition, a prepreg refers to the member (precursor) before shaping | molding of the fiber reinforced resin molded object containing a thermosetting resin etc.

  For this reason, in recent years, development of fiber reinforced nonwoven fabrics and prepregs containing reinforcing fibers using a thermoplastic resin as a matrix resin has been promoted. For example, Patent Document 1 discloses a nonwoven fabric containing reinforcing fibers and a thermoplastic resin, and Patent Document 2 discloses a prepreg in which a layer made of a thermoplastic resin is laminated on a reinforcing fiber bundle. Yes. A fiber reinforced nonwoven fabric or prepreg using such a thermoplastic resin as a matrix resin has the advantage of easy storage management and long-term storage. In addition, a nonwoven fabric or prepreg containing a thermoplastic resin is easier to mold than a nonwoven fabric or prepreg containing a thermosetting resin, and a molded product can be molded by performing heat and pressure treatment. Has advantages.

JP-T-2006-524755 International Publication No. 2003/091015 Pamphlet

  A thermoplastic prepreg as described in Patent Document 2 is processed into a plastic molded body by applying heat and pressure processing. However, a plastic molded body molded using a conventional thermoplastic prepreg has a problem that its strength is not sufficient. Moreover, since the plastic molded object shape | molded using the conventional thermoplastic prepreg is not high enough in a flame retardance, the caution was required for the handling.

In order to solve such a problem, it is also conceivable to use a non-woven fabric for FRP molding composed of a non-woven fabric in which a high heat-resistant thermoplastic fiber that is a matrix resin instead of a prepreg and an inorganic fiber that is a reinforcing fiber are mixed (Patent Document 1). ).
However, in recent methods for producing plastic molded bodies, in order to further improve the processing speed, so-called stamping molding is performed in which a high temperature of 300 ° C. to 400 ° C. is rapidly heated by an infrared heater in a free state and quickly pressed by a cold press. Is being adopted. When the nonwoven fabric for FRP molding disclosed in Patent Document 1 is used for such stamping molding, when heated to a high temperature in a free state, the thermoplastic fiber contracts violently, and the sheet shape cannot be maintained. was there. That is, the nonwoven fabric described in Patent Document 1 has a problem that such high-speed processing cannot be performed, and there is a problem that processability to a plastic molded body is low.
This is presumably because thermoplastic fibers are spun while being drawn in the fiber production process, and thus the fibers themselves heat shrink when exposed to a temperature higher than the softening temperature.

  In order to solve the problems of the prior art, the present inventors are thermoplastic prepregs that can form a high-strength and highly flame-retardant plastic molded body, and are suitable for processing into a plastic molded body. The study was advanced for the purpose of providing a high thermoplastic prepreg.

As a result of earnest studies to solve the above problems, the present inventors have found that a sheet for a fiber-reinforced plastic molded article comprising a reinforcing fiber component, a matrix resin component containing a thermoplastic super engineering plastic fiber, and a binder component In the prepreg formed by heat and pressure treatment, the density of the prepreg is specified while relieving the residual stress of the fiber itself by specifying the structure of the fiber reinforced plastic molded sheet and heating the sheet while restraining the sheet. It was found that a thermoplastic prepreg with less shrinkage / deformation of the sheet and excellent processability even when rapidly heated in a free state can be obtained by setting the to a specific range. Furthermore, the present inventors have found that a fiber-reinforced plastic molded body having high strength and high flame retardancy can be obtained by molding such a thermoplastic prepreg, and has completed the present invention.
Specifically, the present invention has the following configuration.

[1] A thermoplastic prepreg formed by subjecting a sheet for fiber-reinforced plastic molded body containing a reinforcing fiber component, a matrix resin component containing a thermoplastic super engineering plastic fiber, and a binder component to heat and pressure treatment, The thermoplastic super engineering plastic fiber has a critical oxygen index of 24 or more, and the thermoplastic prepreg has a density of 0.15 g / cm ³ or more.
[2] The reinforcing fiber component includes inorganic fibers, the fiber diameter of the thermoplastic super engineering plastic fiber is 40 μm or less, and the fiber diameter of the thermoplastic super engineering plastic fiber is 5 times or less of the fiber diameter of the inorganic fiber. The thermoplastic prepreg according to [1], which is characterized in that
[3] JAPAN TAPPI paper pulp test method no. The thermoplastic prepreg according to [1] or [2], wherein the air permeability defined in 5-2 is 250 seconds or less.
[4] In any one of [1] to [3], the binder component is contained in an amount of 0.1 to 10% by mass with respect to the total mass of the thermoplastic prepreg. The thermoplastic prepreg as described.
[5] The thermoplastic prepreg according to any one of [1] to [4], wherein the binder component is compatible with the thermoplastic super engineering plastic fiber in a heated and melted state.
[6] The binder component contains a copolymer containing at least one of a repeating unit derived from a methyl (meth) acrylate-containing monomer and a repeating unit derived from an ethyl (meth) acrylate-containing monomer [1] ] The thermoplastic prepreg according to any one of [5] to [5].
[7] The thermoplastic prepreg according to [6], wherein the binder component contains a binder fiber having a melting point lower than a glass transition temperature of the thermoplastic super engineering plastic fiber.
[8] The thermoplastic prepreg according to [7], wherein the binder fiber includes polyethylene terephthalate or modified polyethylene terephthalate.
[9] The thermoplastic prepreg according to [7] or [8], wherein the thermoplastic super engineering plastic fiber and the binder fiber are chopped strands.
[10] The fiber reinforced plastic molded sheet has a surface layer region and an intermediate region sandwiched between the surface layer regions, and the binder component contained in the surface layer region is a binder component contained in the intermediate region. The thermoplastic prepreg according to any one of [1] to [9], which is more in number.
[11] The copolymer contained in the binder component is localized in the form of a drainage film at the intersection of the fibers constituting the reinforcing fiber component and the matrix resin component [6] to [6] 10]. The thermoplastic prepreg according to any one of [10].
[12] The thermoplastic prepreg according to any one of [1] to [11], wherein the thermoplastic super engineering plastic fiber is at least one selected from polyetherimide fiber or polycarbonate fiber.
[13] The thermoplastic prepreg according to any one of [1] to [12], wherein the thermoplastic super engineering plastic fiber is a polyetherimide fiber.
[14] A fiber-reinforced plastic formed by heat-pressing the thermoplastic prepreg according to any one of [1] to [13] at a temperature equal to or higher than the glass transition temperature of the thermoplastic super engineering plastic fiber. Molded body.
[15] A fiber-reinforced plastic molded body formed by heat-press molding the thermoplastic prepreg according to any one of [1] to [13] at a temperature of 150 to 600 ° C.
[16] A fiber-reinforced plastic molded article, wherein the step of heat and pressure molding according to [14] or [15] is stamping molding.
[17] In the method for producing a thermoplastic prepreg, including a step of heat-pressing a sheet for a fiber-reinforced plastic molded article containing a reinforcing fiber component, a matrix resin component containing a thermoplastic super engineering plastic fiber, and a binder component, A method for producing a thermoplastic prepreg, wherein a limiting oxygen index of the thermoplastic super engineering plastic fiber is 24 or more, and a density of the thermoplastic prepreg is 0.15 g / cm ³ or more.
[18] A step of forming a sheet for a fiber-reinforced plastic molded body is further included before the step of heat and pressure treatment, and the step of forming the sheet for a fiber-reinforced plastic molded body is a dry nonwoven fabric method or a wet nonwoven fabric method. A step of forming a nonwoven fabric sheet by any of the methods, and a step of internally adding, coating or impregnating the nonwoven fabric sheet with a solution containing the binder component or an emulsion containing the binder component, followed by heat drying. The method for producing a thermoplastic prepreg according to [17].
[19] The thermoplastic prepreg according to [17] or [18], wherein the heat and pressure treatment is performed at a temperature equal to or higher than a glass transition temperature of the thermoplastic super engineering plastic fiber. Manufacturing method.
[20] The heat according to any one of [17] to [19], wherein in the heating and pressing step, the sheet for fiber-reinforced plastic molded body is heated and pressed at 150 to 600 ° C. A method for producing a plastic prepreg.
[21] After producing a thermoplastic prepreg using the method for producing a thermoplastic prepreg according to any one of [17] to [20], the thermoplastic prepreg is heated and pressed at 150 to 600 ° C. A method for producing a fiber-reinforced plastic molded product.

  ADVANTAGE OF THE INVENTION According to this invention, the thermoplastic prepreg which can shape | mold the fiber reinforced plastic molding which is high intensity | strength and high flame retardance can be obtained. Furthermore, according to the present invention, a thermoplastic prepreg excellent in processability can be obtained.

  Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be made based on representative embodiments and specific examples, but the present invention is not limited to such embodiments. In the present specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

(Thermoplastic prepreg)
The present invention includes a fiber reinforced plastic molded sheet containing a mixture of a reinforcing fiber component and a matrix resin component containing a thermoplastic super engineering plastic fiber and further containing a binder component at a temperature equal to or higher than the glass transition temperature of the thermoplastic super engineering plastic fiber. The present invention relates to a prepreg formed by heat and pressure treatment. Here, the limiting oxygen index of the thermoplastic super engineering plastic fiber is 24 or more, and the thermoplastic prepreg is heated and pressed at a temperature equal to or higher than the glass transition temperature of the thermoplastic super engineering plastic fiber to set the density to 0.15 g / cm ³ or more. Is. The upper limit of the density is not particularly defined, but the upper limit of the density is a state in which a thermoplastic super engineering plastic resin, a binder, or the like is melt impregnated into the reinforcing fiber and no voids are left. In this case, the density is a weight average value of the density of the thermoplastic super engineering plastic fibers contained in the nonwoven fabric, the density of the reinforcing fiber component, and the density of the binder component. In this invention, the prepreg excellent in processability can be obtained by setting a thermoplastic prepreg as the above structures. Furthermore, since the fiber-reinforced plastic molded body molded using the prepreg of the present invention has high strength and high flame retardancy, it has the advantage of easy storage and handling.

The density of the thermoplastic prepreg of the present invention may be 0.15 g / cm ³ or more after the heating step, preferably 0.2 g / cm ³ or more, and more preferably 0.3 g / cm ³ or more. By setting the density of the thermoplastic prepreg within the above range, a thermoplastic prepreg excellent in processability can be obtained. When the thermoplastic prepreg of the present invention is used, the production efficiency of the plastic molded body can be increased.

  The thermoplastic prepreg of the present invention is a plastic layer formed by heating and pressurizing a sheet for a fiber reinforced plastic molded article containing a reinforcing fiber component, a matrix resin component containing a thermoplastic super engineering plastic fiber, and a binder component. . The sheet for fiber-reinforced plastic molded body may be heated and pressed in a single layer, or may be laminated and heated and pressed to have a desired thickness.

The heating and pressing step is a step of pressing while heating to a temperature equal to or higher than the glass transition temperature of the thermoplastic super engineering plastic fiber. In the heating and pressing step, it is preferable to perform a hot press treatment.
In the heating and pressing step, it is preferable to heat the fiber reinforced plastic molded sheet so that the surface temperature is Tg to Tg + 100 ° C. Here, Tg represents the glass transition temperature of the thermoplastic super engineering plastic fiber. The heating temperature is preferably a temperature range in which the thermoplastic super engineering plastic fibers flow and the reinforcing fibers do not melt.

(Fiber-reinforced plastic molded sheet)
The sheet | seat for fiber reinforced plastic molded objects contains a reinforcement fiber component, the matrix resin component containing a thermoplastic super engineering plastic fiber, and a binder component.

  In the fiber-reinforced plastic molded sheet of the present invention, the mass ratio of the reinforcing fiber component and the thermoplastic super engineering plastic fiber is preferably 1: 0.2 to 1:10, and preferably 1: 0.5 to 1: 5. More preferably, it is more preferably 1: 0.7 to 1: 3. By setting the mass ratio of the reinforcing fiber component and the thermoplastic super engineering plastic fiber within the above range, a thermoplastic prepreg that is lightweight and can form a high-strength fiber-reinforced plastic molded body can be obtained.

  In order to obtain sufficient strength after heating and pressing, the reinforcing fiber component and the matrix resin component are preferably mixed uniformly. For this purpose, it is preferable that the fiber diameters of the reinforcing fiber and the matrix resin fiber are close. From this viewpoint, the fiber diameter of the thermoplastic super engineering plastic fiber is preferably 5 times or less, more preferably 4 times or less, and further preferably 3 times or less, most preferably, the fiber diameter of the reinforcing fiber. Preferably, the fiber diameter of the thermoplastic super engineering plastic fiber is substantially equal to the fiber diameter of the reinforcing fiber.

  In general, since the matrix resin has a high melt viscosity, it is difficult to uniformly disperse the reinforcing fibers when a large amount of the reinforcing fibers are blended by a method such as injection molding, so that the blending ratio of the reinforcing fibers is limited. However, in the fiber-reinforced plastic molded sheet of the present invention, the ratio of reinforcing fibers to matrix resin fibers can be set relatively freely according to the required strength.

  JAPAN TAPPI Paper Pulp and Paper Test Method No. for Fiber Reinforced Plastic Molded Sheet The air permeability defined in 5-2 is preferably 250 seconds or less, more preferably 230 seconds or less, and even more preferably 200 seconds or less. This numerical value indicates that the smaller the number, the easier air can pass through (the better the air permeability). In the present invention, by setting the air permeability of the fiber-reinforced plastic molded sheet within the above range, the molding speed in the heating and pressing step can be increased, and the production efficiency of the thermoplastic prepreg can be increased.

  However, if the sheet before processing is adjusted to be bulky as a material for satisfying the above air permeability, there may be inconveniences when inserting the fiber reinforced plastic molded sheet into a heat press machine or the like in the heating and pressing step. There is. Moreover, there is also a problem that the storage cost is high until the sheet for fiber-reinforced plastic molded body is manufactured and used for the heating and pressing step. Such a problem can be solved by lightly pressing with a hot press or a heat calender before the heat and pressure treatment and appropriately increasing the density. In the case of this method, since air becomes somewhat difficult to pass, it is preferable to increase the density within a range in which the air permeability measured by a method based on the JAPAN TAPPI paper pulp test method can be maintained within a state of 250 seconds or less.

<Reinforcing fiber component>
The reinforcing fiber component includes inorganic fibers. Examples of inorganic fibers include glass fibers and carbon fibers. In addition, these inorganic fibers may use 1 type and may use multiple types. Furthermore, in the present invention, the reinforcing fiber component may contain organic fibers excellent in heat resistance such as aramid fibers and PBO (polyparaphenylene benzoxazole) fibers in addition to such inorganic fibers.
For example, when inorganic fibers such as carbon fibers are used as the reinforcing fiber component, the bending strength, tensile strength, and elastic modulus can be increased by heating and pressing at the melting temperature of the thermoplastic super engineering plastic fibers contained in the sheet for molded articles. A thermoplastic prepreg capable of forming a high fiber-reinforced plastic molded body can be obtained.
When high heat-resistant and high-strength organic fibers such as aramid fibers are used as the reinforcing fiber component, heat that can form a fiber-reinforced plastic molded article suitable for precision polishing equipment that requires high smoothness A plastic prepreg can be obtained. A thermoplastic prepreg formed from a sheet for fiber reinforced plastic molded article containing organic fibers such as aramid as reinforcing fiber is generally heat formed from a sheet for fiber reinforced plastic molded article using inorganic fibers as reinforcing fibers. It is superior in abrasion resistance when they are formed into a fiber-reinforced plastic molded body than plastic prepregs. Even if a part of the fiber reinforced plastic molding is scraped off by rubbing or the like, the shaving is softer than the inorganic fiber, so that there is little risk of damaging the object to be polished.

  The fiber length of the reinforcing fibers is preferably 1 mm or more, more preferably 2 mm or more, and further preferably 3 mm or more. Further, the fiber length of the reinforcing fiber is preferably 40 mm or less, more preferably 35 mm or less, and further preferably 30 mm or less.

  Although it does not specifically limit as a fiber diameter of a reinforced fiber, 3-18 micrometers is preferable. By setting the fiber diameter of the reinforcing fiber within the above range, it can be prevented from being taken into the human body during the manufacturing process or during use, and can be mixed uniformly.

<Matrix resin component>
The matrix resin component includes thermoplastic super engineering plastic fibers. The thermoplastic super engineering plastic fiber is melted by thermoforming to become a matrix resin.

  The thermoplastic super engineering plastic fiber is a fiber of a thermoplastic resin called a super engineering plastic (super engineering plastic), and is obtained by fiberizing a heat-resistant and flame-retardant thermoplastic resin. Examples of thermoplastic super engineering plastic fibers include polyetheretherketone (PEEK), polyamideimide (PAI), polyphenylene sulfide (PPS), polyetherimide (PEI), polyetherketoneketone (PEKK), and the like. Since polyphenylene sulfide (PPS) resin has high chemical resistance and high heat resistance, a fiber reinforced plastic excellent in chemical resistance and strength at high temperature can be obtained. When a polyether ketone ketone (PEKK) resin is used, a fiber reinforced plastic that is particularly superior in chemical resistance and strength at high temperatures than other super engineering plastics can be obtained. Polyetherimide (PEI) resin has excellent adhesion to carbon fiber and glass fiber, and its critical oxygen index is 47, which is very high in the resin block state. Can be obtained.

In the present invention, it is preferable to use at least one selected from polyetherimide (PEI) fiber or polycarbonate (PC) fiber as the thermoplastic super engineering plastic fiber. Among these, it is particularly preferable to use polyetherimide (PEI) fibers obtained by fiberizing a polyetherimide (PEI) resin. Polyetherimide (PEI) resin has a critical oxygen index of 40 or more in a melted and molded state, and a smoke generation amount of about 30 ds when burned for 20 minutes measured by the method described in ASTM E-662. It is preferably used because it emits less smoke.
Although not normally classified as a thermoplastic super engineering plastic fiber, polycarbonate (PC) is also included in the present invention because it is excellent in flame retardancy. Two or more kinds of the thermoplastic super engineering plastic fibers of the present invention can be used. In addition, other than thermoplastic super engineering plastic fibers such as polyamide, polyacetal, polybutylene terephthalate, polyethylene terephthalate, phenol resin, polyurethane, polypropylene, polyethylene, and epoxy resin can be added within the range not impairing the effects of the present invention.

  The thermoplastic super engineering plastic fiber preferably has a critical oxygen index of 24 or more in the fiber state, and more preferably 30 or more. By setting the critical oxygen index of the thermoplastic super engineering plastic fiber within the above range, a molded article sheet having excellent flame retardancy can be obtained. In the present invention, the “limit oxygen index” represents an oxygen concentration necessary to continue combustion, and is a numerical value measured by the method described in JIS K7201. That is, a critical oxygen index of 20 or less is a numerical value indicating that combustion is performed in normal air. The polycarbonate has a limiting oxygen index of 24 to 26.

  The glass transition temperature of the thermoplastic super engineering plastic fiber is preferably 140 ° C. or higher. The thermoplastic super engineering plastic fiber is required to be sufficiently fluid under temperature conditions of 300 ° C. to 400 ° C. when forming the thermoplastic prepreg. In addition, even if it is a super engineering plastic fiber with a glass transition temperature of less than 140 ° C. such as PPS resin fiber, it can be used as long as the super engineering plastic having a resin deflection temperature of 190 ° C. or higher is made into a fiber. Such thermoplastic super engineering plastic fibers are melted by heating and pressurizing to form a resin block having a very high flame retardancy with a limiting oxygen index of 30 or more.

  The fiber diameter of the thermoplastic super engineering plastic fiber is preferably 40 μm or less. Furthermore, the fiber diameter of the thermoplastic super engineering plastic fiber is preferably 5 times or less, more preferably 4 times or less, and further preferably 3 times or less the fiber diameter of the inorganic fiber described above. By setting the fiber diameter of the thermoplastic super engineering plastic fiber within the above range, the density of the thermoplastic prepreg can be set within a desired range. Furthermore, the strength of the fiber-reinforced plastic molded body molded using the thermoplastic prepreg can be further increased.

  The fiber diameter of the thermoplastic super engineering plastic fiber is preferably 40 μm or less, more preferably 35 μm or less, and further preferably 32 μm or less. Especially, it is preferable that the fiber diameter of a thermoplastic super engineering plastic fiber is 1-30 micrometers, and it is more preferable that it is 1-20 micrometers.

  The fiber length of the thermoplastic super engineering plastic fiber is preferably 1 mm or more, more preferably 2 mm or more, and further preferably 3 mm or more. Further, the fiber length of the thermoplastic super engineering plastic fiber is preferably 40 mm or less, more preferably 35 mm or less, and further preferably 30 mm or less. By setting the fiber length of the thermoplastic super engineering plastic fiber within the above range, the dispersibility of the fiber can be improved, and the breakage of the fiber reinforced plastic sheet or the like can be prevented. The fiber diameter and the fiber length may be single, or those having different fiber diameters and fiber lengths may be blended and used.

In the fiber-reinforced plastic molded sheet used in the present invention, there are voids in the sheet because the thermoplastic super engineering plastic fibers are in fiber form.
In the present invention, since the thermoplastic super engineering plastic fiber maintains its fiber form before the heat and pressure treatment, the sheet itself is supple and draped before forming the thermoplastic prepreg. For this reason, it is possible to store and transport the sheet for a fiber-reinforced plastic molded body in the form of winding, and it is characterized by excellent handling properties.

  Further, the sheet for a fiber-reinforced plastic molded body used in the present invention requires only a short time for heating and pressurizing when it is processed into a thermoplastic prepreg, and is excellent in productivity of the thermoplastic prepreg. In order to heat and pressure-treat a sheet for fiber reinforced plastic molding in a short time, it is necessary that the thermoplastic super engineering plastic fiber used be melted quickly at a high temperature. Thinner fiber diameters are preferred. Since the number of contact points between fibers increases as the fiber diameter is thinner, the contact area between fibers increases, heat conduction becomes better, and the heat capacity of the fibers decreases, so the amount of heat required for melting is less It is to become.

<Binder component>
In the present invention, the binder contained in the sheet for fiber-reinforced plastic molded body is generally a heat of phenol resin, urea resin, melamine resin, unsaturated polyester resin, epoxy resin, silicon resin, etc., used for nonwoven fabric production. A curable resin, a thermoplastic resin such as a polypropylene resin, a polyethylene resin, a polyester resin, an acrylic resin, a styrene-acrylic resin, an ethylene-vinyl acetate resin, or a urethane resin, or a PVA resin that melts with hot water can be used.

  The binder component is particularly preferably a resin component that is compatible with the resin when the thermoplastic super engineering plastic fiber that becomes the matrix after the heat and pressure treatment is melted by the heat and pressure treatment. When such a resin component is used as a binder, after the heat and pressure treatment, since there is no interface between the matrix resin and the binder resin, they become high strength. Furthermore, it has the characteristic that there is little fall of the glass transition temperature of matrix resin resulting from a binder component.

  In the present invention, the binder component is preferably contained in an amount of 0.1 to 10% by mass, more preferably 0.4 to 9.5% by mass with respect to the total mass of the thermoplastic prepreg. More preferably, it is 0.5-8 mass%. By making the content rate of a binder component in the said range, the intensity | strength in a manufacturing process can be raised and handling property can be improved. Moreover, by making the content rate of a binder component into the said range, a flame retardance and low smoke generation property are not impaired. Note that as the amount of the binder component increases, both the surface strength and the interlayer strength increase, but conversely, the problem of odor during heat forming tends to occur. However, within the above range, there is hardly any problem of odor, and a fiber reinforced plastic molded sheet that does not cause delamination even after repeated cutting steps can be obtained.

The binder component preferably includes a copolymer obtained by polymerizing a monomer mixture containing at least one monomer of methyl methacrylate, ethyl methacrylate, methyl acrylate and ethyl acrylate. That is, the binder component contains a copolymer containing at least one of a repeating unit derived from a methyl (meth) acrylate-containing monomer and a repeating unit derived from an ethyl (meth) acrylate-containing monomer. Especially, it is preferable that a binder component contains the copolymer containing at least 1 among the repeating unit derived from a methyl methacrylate containing monomer and the repeating unit derived from an ethyl methacrylate containing monomer.
In the present invention, “(meth) acrylate” means containing both “acrylate” and “methacrylate”, and “(meth) acrylic acid” means “acrylic acid” and “methacrylic acid”. Is meant to include both.

  Furthermore, a binder component having a melting point lower than the glass transition temperature of the thermoplastic super engineering plastic fiber is mentioned as a preferable binder component in the present invention. When the binder fiber is mixed with PEI fiber and dispersed in water and made by wet papermaking, it drops from the eyes of the papermaking wire like a granular binder, and the yield decreases or is unevenly distributed on the wire side. It is preferably used because it does not occur. Moreover, interlayer strength can be improved by using such a binder fiber.

As the binder fiber, a polyester resin is preferably used. As the polyester resin, polyethylene terephthalate (PET) is preferable. The modified polyester resin is not particularly limited as long as the melting point is lowered by modifying the polyester resin, but modified polyethylene terephthalate is preferable. As the modified polyethylene terephthalate, copolymerized polyethylene terephthalate (CoPET) is preferable, and examples thereof include urethane-modified copolymerized polyethylene terephthalate. The polyester resin is preferably used because it is compatible with the polyetherimide fiber at the time of heating and melting, so that it is difficult to impair the excellent points such as flame retardancy and low smoke generation property of the polyetherimide resin even after cooling.
The copolymerized polyethylene terephthalate preferably has a melting point of 140 ° C. or lower, more preferably 120 ° C. or lower. Moreover, you may use the modified polyester resin as described in Japanese Patent Publication No. 1-30926. As a specific example of the modified polyester resin, a trade name “Melty 4000” (a fiber in which all fibers are copolymerized polyethylene terephthalate) manufactured by Unitika Ltd. is particularly preferable. As the core-sheath-structured binder fiber, trade name “Melty 4080” manufactured by Unitika Co., Ltd., trade name “N-720” manufactured by Kuraray Co., Ltd. and the like can be suitably used.

Copolymers obtained by polymerizing a monomer mixture containing at least one monomer of methyl methacrylate, ethyl methacrylate, methyl acrylate and ethyl acrylate, and binder fibers such as polyester resin fibers should be used alone. However, it can also be used in combination to further improve the effects of the present invention.
The copolymer is contained in an amount of 0.1 to 4% by mass with respect to the total mass of the thermoplastic prepreg, and the binder fiber is 1.5 to 6% by mass with respect to the total mass of the thermoplastic prepreg. It is preferable to contain. By making the content rate of a copolymer and a binder fiber into the said range, the surface strength and interlayer strength of a thermoplastic prepreg can be raised. In addition, in said range, a preferable result is obtained from the relationship of an odor, when the compounding quantity of the binder which uses a copolymer as a component (liquid binder) is smaller than a polyester resin or a modified polyester resin. Since the polyester binder is compatible with the matrix resin, it is difficult to generate odor even if the addition amount is relatively large, and since the liquid binder tends to be concentrated and concentrated at the intersection of the fibers, such a result is obtained. Estimated.

  A preferable combination as the binder component is a combination of an acrylic emulsion and a chopped PET fiber as a low melting point thermoplastic resin fiber. Specifically, the PET fiber is 1.5 to 6% by mass with respect to 0.3 to 4% by mass of the acrylic binder with respect to the total mass of the thermoplastic prepreg. Preferably, it is 2 to 6% by mass of PET fiber with respect to 1 to 3% by mass of acrylic binder, and more preferably 3 to 5% by mass of PET fiber with respect to 1.5 to 2.5% by mass of acrylic binder.

When the fiber reinforced plastic molded sheet has an intermediate region sandwiched between the surface layer region and the surface layer region, the binder component contained in the surface layer region may be more than the binder component contained in the intermediate region. preferable. In particular, among the binder components, a copolymer containing at least one of a repeating unit derived from a methyl (meth) acrylate-containing monomer and a repeating unit derived from an ethyl (meth) acrylate-containing monomer may be contained in a large amount in the surface layer region. preferable.
Here, the surface layer region of the sheet for fiber-reinforced plastic molded product is two regions located outside when the molded product sheet is divided into approximately three parts in the thickness direction (Z-axis direction). Note that the intermediate region refers to a region between these two regions. The binder component contained in the surface layer region is preferably more than the binder component contained in the intermediate region, and the binder component contained in the surface layer region is 1.1 of the binder component contained in the intermediate region. It is more preferable to be -1.5 times.

  In this way, by concentrating the binder component in the surface layer region, the binder component is effectively heated when heated and pressurized by a high-temperature mold or press plate.・ Volatile. As a result, the binder component remaining in the thermoformed product is suppressed to a very small amount. For this reason, the thermoplastic prepreg of the present invention has high flame retardancy and smoke generation is suppressed.

  The liquid binder comprising as a component a copolymer obtained by polymerizing a monomer mixture containing at least one monomer of methyl methacrylate, ethyl methacrylate, ethyl acrylate, and methyl acrylate is a surface layer region of a sheet for fiber-reinforced plastic molding It is preferable to exist in a concentrated manner. Moreover, it is preferable that these liquid binders are localized in the form of a drainage film at the intersection between the fiber components in both surface layer regions. That is, it is preferable that the copolymer is localized in the form of a water-repellent film at the intersection of the fibers constituting the reinforcing fiber component and the matrix resin component. By being localized in this manner, even if the binder component is small, even in the use process, the fibers falling off in both surface layer regions can be reduced. Moreover, it is suitable for the process which cuts and laminates | stacks on a flat plate immediately after papermaking of the sheet | seat for fiber reinforced plastic moldings, and presses suitably.

  In addition, although it is preferable to concentrate the component containing a copolymer in a surface layer area | region among binder components, binder fiber can also be contained in the intermediate | middle area | region of the sheet | seat for fiber reinforced plastic moldings. Thereby, the interlayer intensity | strength of the sheet | seat for fiber reinforced plastic moldings increases, and the handling property at the time of a thermoforming process is further improved.

  The binder fiber can be contained in the fiber reinforced plastic molded sheet by a method (dry nonwoven fabric method) in which the binder fiber is dispersed in the air together with the reinforcing fiber, the PEI fiber, and the like and captured on the net to form a web. The binder fiber can also be contained in the fiber-reinforced plastic molded sheet by a method such as a method (wet nonwoven fabric method) in which the binder fiber is dispersed in a solvent and then the solvent is removed to form a web.

  Examples of the method for allowing a relatively large amount of the binder to be present in the surface layer of the fiber reinforced plastic molded sheet include the following methods. For example, a production method in which a liquid material in which a binder component is dissolved in a solvent or an emulsion (emulsion) of a binder component is internally added to, applied to, or impregnated into a nonwoven fabric sheet, and is heated and dried. In particular, after a web is formed by a wet nonwoven fabric method or a dry nonwoven fabric method, a liquid material in which a binder component is dissolved in a solvent, or an emulsion (emulsion) of a binder component is applied by dipping or spraying, and dried by heating. The production method is preferably used. According to this method, since the solvent inside the web moves to the surface layers on both sides and evaporates during heating and drying, the binder also concentrates relatively on the surface layer as the solvent moves.

As described above, in order to make the binder component unevenly distributed on the surface layer of the fiber-reinforced plastic molded sheet, a manufacturing method in which a liquid binder component such as a solution or an emulsion of the binder component is used and dried by heating is employed. Can do. In this case, it is preferable that the solvent move more because the uneven distribution of the binder component becomes stronger.
When such a method is employed, it is preferable to form a wet web by a wet nonwoven fabric method, and then apply an aqueous solution or emulsion of the binder to the web by a method such as dipping or spraying, followed by drying. In this case, the web moisture can be adjusted by adjusting the concentration of the binder solution in the aqueous solution or emulsion, or the moisture suction force by wet suction or dry suction in the wet nonwoven fabric manufacturing process.

  In order to make the binder component unevenly distributed, the moisture content in the web is preferably 50% or more, but if there is too much moisture, the drying load increases and the manufacturing cost increases. Is preferably adjusted.

  When the above measures are insufficient, it is also preferable to wet-paper the fiber-reinforced plastic molded sheet to increase the strength aspect ratio as a method of reducing the amount of binder component added. Specifically, the strength ratio (strength aspect ratio) of the machine-making direction (MD direction) and the perpendicular direction (CD direction) can be increased by adjusting the jet wire ratio. In general, when the strength aspect ratio is increased, the fibers tend to line up in one direction, and the density of the nonwoven fabric tends to increase. As a result, the intersections between the fibers increase, so that a sufficient surface strength can be obtained even with a small amount of binder. Such an effect can be clearly obtained usually when the strength aspect ratio is 1.5 or more, more clearly is 3.0 or more, and more clearly is 5.0 or more.

(Fiber shape)
In the present invention, the thermoplastic super engineering plastic fiber and the binder fiber are preferably chopped strands cut to a certain length. In the present invention, the thermoplastic super engineering plastic fibers and the reinforcing fibers contained in the fiber-reinforced plastic molded sheet are also preferably chopped strands cut to a certain length. By setting it as such a form, various fibers can be mixed uniformly in the sheet | seat for fiber reinforced plastic moldings.

  In the above case, the fiber reinforced plastic molded sheet is a method of forming a web by dispersing chopped strands of thermoplastic super engineering plastic fibers, reinforcing fibers and binder fibers in the air and capturing them in a net (dry nonwoven fabric). Method). Further, it may be produced by a method (wet nonwoven fabric method) or the like in which a chopped strand of thermoplastic super engineering plastic fiber, reinforcing fiber, or binder fiber is dispersed in a solvent and then the solvent is removed to form a web.

(Method for producing thermoplastic prepreg)
The manufacturing process of the thermoplastic prepreg of the present invention is performed by heating and pressurizing a fiber reinforced plastic molded sheet containing a reinforcing fiber component, a matrix resin component containing a thermoplastic super engineering plastic fiber, and a binder component to form a thermoplastic prepreg. The process of carrying out is included.
The critical oxygen index of the thermoplastic super engineering plastic fiber is 25 or more, and the density of the thermoplastic prepreg is 0.15 g / cm ³ or more.

  The heating and pressing step in the step of forming the thermoplastic prepreg is a step of pressing while heating the thermoplastic super engineering plastic fiber at a temperature preferably equal to or higher than the glass transition temperature. Specifically, it is preferable to heat and pressurize the fiber-reinforced plastic molded sheet at 150 to 600 ° C., preferably 200 to 500 ° C. The heating temperature is preferably a temperature range in which the thermoplastic resin fibers flow and the reinforcing fibers do not melt.

  In this invention, it is preferable to include the process of forming the sheet | seat for fiber reinforced plastic molding further before the process of heat-press-molding the sheet | seat for fiber reinforced plastic molding. The step of forming a sheet for a fiber-reinforced plastic molded body includes a step of forming a nonwoven fabric sheet by either a dry nonwoven fabric method or a wet nonwoven fabric method, and a solution containing a binder component or an emulsion containing a binder component in the nonwoven fabric sheet. Adding, applying or impregnating. Further, after the internal addition, coating or impregnation, a step of drying by heating is included. By providing such a process, scattering, fluffing, and dropping off of the surface fibers of the fiber-reinforced plastic molded sheet can be suppressed, and a molded sheet having excellent handling properties can be obtained.

  In addition, after the solution containing a binder component or the emulsion containing a binder component is internally added, applied, or impregnated to the nonwoven fabric sheet, it is preferable to rapidly heat the nonwoven fabric sheet. By providing such a heating step, the solution containing the binder component or the emulsion containing the binder component can be transferred to the surface layer region of the sheet for fiber-reinforced plastic molded body. In addition, the binder component can be localized in the form of a water scraping film.

(How to use thermoplastic prepreg)
The thermoplastic prepreg of the present invention can be processed into an arbitrary shape in accordance with the shape of the intended molded product and the molding method. For example, processing using a general stampable sheet heat and pressure molding method, such as heat press molding a thermoplastic prepreg with a hot press, preheating with an infrared heater or the like, and heat press molding with a mold. By doing, it can be set as the plastic molding excellent in intensity | strength and a flame retardance.

  In the present invention, when producing a fiber-reinforced plastic molded body from a thermoplastic prepreg, it is preferable to press-mold the thermoplastic prepreg at a temperature equal to or higher than the glass transition temperature of the thermoplastic super engineering plastic fiber. For example, the conditions for the molding process by hot pressing vary depending on the thermoplastic resin used, but the holding temperature is 150 to 600 ° C, preferably 200 to 500 ° C, more preferably 250 to 450 ° C, and the pressure is 5 to 5. 20 MPa is preferred. In addition, the rate of temperature rise until reaching the desired holding temperature is preferably 3 to 20 ° C./min, the holding time at the desired hot press temperature is 1 to 30 minutes, and then the temperature at which the molded body is taken out ( The cooling rate is preferably 3 to 20 ° C./min while maintaining the pressure up to 200 ° C. or less. Furthermore, although the production efficiency is slightly lowered, it is also preferable from the viewpoint of improving the strength to cool slowly by air cooling from the holding temperature of the hot press to the glass transition temperature of the super engineering plastic fiber at 0.1 to 3 ° C./min. It is also possible to perform hot press molding using rapid heating and rapid cooling (heat and cool) molding, in which case the temperature rise and cooling rate are 30 to 500 ° C./min, respectively. Furthermore, in the case of using an infrared heater, the temperature is 150 to 600 ° C., preferably 200 to 500 ° C., for 1 to 30 minutes, and then molded at a pressure of 30 to 150 MPa.

  Since the plastic molded product obtained by the present invention has excellent mechanical strength and industrially useful productivity, it can be used in various applications.

  The features of the present invention will be described more specifically with reference to examples and comparative examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

(Examples 1-4)
A PAN-based carbon fiber having a fiber diameter of 7 μm and a fiber length of 13 mm and a PPS resin fiber having a fiber diameter shown in Table 1 (manufactured by Fiber Innovation Technology, fiber length of 13 mm, critical oxygen index of 41) and a mass ratio of polyacrylonitrile (PAN) ) It measured so that it might become the polyphenylene sulfide (PPS) resin fiber 60 with respect to the system carbon fiber 40, and it injected | thrown-in to water. The amount of water added was set to be 200 times the total mass of the PAN-based carbon fiber and the PPS resin fiber (that is, the fiber slurry concentration was 0.5%).
To this slurry, the trade name “Emanon 3199” (manufactured by Kao Corporation) is added as a dispersant to 1 part by mass with respect to 100 parts by mass of the fiber (total of PAN-based carbon fiber and PPS fiber), and the fiber is stirred in water A fiber slurry dispersed uniformly was prepared.

Particulate polyvinyl alcohol (PVA) (trade name “OV-N”, manufactured by Unitika Ltd.) was added to water so as to have a concentration of 10%, and stirred to prepare a binder slurry. This granular PVA slurry is put into a fiber slurry, a wet web is formed by wet papermaking, and heated and dried at 180 ° C. to obtain a nonwoven fabric (sheet for fiber reinforced plastic molded body) having a basis weight of 250 g / m ^2. It was.
A thermoplastic prepreg having the density shown in Table 1 was obtained by subjecting this nonwoven fabric (sheet for fiber-reinforced plastic molded body) to heat and pressure treatment at 280 ° C. with a hot press.
In Example 2, the density was adjusted as shown in Table 1 by shortening the heating and pressing time than in Example 1, and in Example 4 by extending the heating and pressing time than in Example 1, The density was adjusted as shown in Table 1.
In Example 3, a thermoplastic prepreg was obtained in the same manner as in Example 1 except that the addition amount of the binder was 12% by mass.
The addition amount of the granular PVA slurry concentration was adjusted as appropriate so that the blending ratio of the granular PVA to the thermoplastic prepreg was as shown in Table 1.

(Example 5)
Except for changing the PPS resin fiber to the PPS fiber having the fiber diameter shown in Table 1 (KB Selen, glass transition temperature 92 ° C., fiber length 13 mm, critical oxygen index 41), the same procedure as in Example 1 was performed. A thermoplastic prepreg was prepared.

(Examples 6 to 9)
The PAN-based carbon fiber having a fiber diameter of 7 μm and a fiber length of 13 mm in Example 1 was changed to a glass fiber having a fiber diameter of 9 μm and a fiber length of 18 mm, and the PPS resin fiber in Example 1 (manufactured by Fiber Innovation Technology) , Glass transition temperature 92 ° C., limiting oxygen index 41) to polyetherimide (PEI) resin fiber (Fibre Innovation Technology, glass transition temperature 220 ° C., fiber length 13 mm, limiting oxygen index 47) shown in Table 2. A non-woven fabric having a basis weight of 250 g / m ² was obtained in the same manner as Example 1 except for the change. The obtained sheets were heated and pressed by a hot press at 280 ° C. to adjust the density appropriately as shown in Table 2, and the thermoplastic prepregs of Examples 6 and 7 were produced.
Moreover, except having changed granular PVA (the product name "OV-N" by Unitika Co., Ltd.) into the PET / coPET modified core-sheath binder fiber (product name "Melty 4080" by Unitika), it is the same as that of Example 6. Thus, a thermoplastic prepreg of Example 8 was produced.

  Further, the glass fiber in Example 6 was changed to a glass fiber having a fiber diameter of 6 μm and a fiber length of 18 mm, and a thermoplastic prepreg of Example 9 was produced in the same manner as in Example 6.

(Examples 10 to 15)
The PPS resin fiber in Example 1 was replaced with a PPS resin fiber having a fiber diameter of 16 μm (manufactured by Fiber Innovation Technology, glass transition temperature 92 ° C., fiber length 13 mm, critical oxygen index 41), and in addition to granular PVA, a wet web was used. Thermoplastic prepregs of Examples 10 to 15 were produced in the same manner as in Example 1 except that the binder liquid shown in Table 3 was added by the spray method in the amount shown in Table 3 after the formation, and dried by heating.

(Examples 16 to 21)
Examples 10 to 15 except that the PPS resin fibers in Examples 10 to 15 were replaced with PEI resin fibers having a fiber diameter of 15 μm (manufactured by Fiber Innovation Technology, glass transition temperature 220 ° C., fiber length 13 mm, critical oxygen index 47). Thermoplastic prepregs of Examples 16 to 21 corresponding to the above were prepared.

(Example 22)
A polycarbonate fiber (fiber length 15 mm, fiber diameter 30 μm, critical oxygen index 25) was used in place of the PEI fiber having a fiber diameter of 15 μm in Example 14 (manufactured by Fiber Innovation Technology, fiber length 13 mm, critical oxygen index 47). A thermoplastic prepreg was produced in the same manner as in Example 16. In addition, the heating temperature at the time of producing a prepreg was 220 degreeC.

(Example 23)
Polycarbonate fiber (fiber length 15 mm, fiber diameter 30 μm, critical oxygen index 25) and PEI fiber (fiber innovation technology, fiber length 13 mm, critical oxygen index 47) having a fiber diameter of 15 μm were mixed at a mass ratio of 50/50. A thermoplastic prepreg was obtained in the same manner as in Example 16 except that it was used. In addition, the heating temperature at the time of producing a prepreg was 280 degreeC.

  In the above binder solution, a PVA aqueous solution in which Kuraray's trade name “PVA117” was dissolved in hot water was used. Moreover, the brand name "GM-1000" by DIC was used for the styrene-acrylic emulsion, and the brand name "AP-X101" by DIC was used for the urethane emulsion.

(Comparative Example 1)
A thermoplastic prepreg was prepared in the same manner as in Example 1 except that the heating and pressing step was omitted after the nonwoven fabric was produced.

(Comparative Example 2)
In Example 1, instead of PPS resin fiber, polyamide 6 resin (manufactured by Toray Industries, trade name “Amilan CM1021”, melting point 210 ° C., limiting oxygen index 20, fiber diameter 20 μm) was used. Thus, a thermoplastic prepreg was produced.

(Stamping molding)
Six thermoplastic prepregs obtained by the methods of the above Examples and Comparative Examples were laminated, heated at 400 ° C. for 60 seconds with an IR heater, then pressed at 20 MPa for 60 seconds with a cold press, and fiber reinforced plastic. A molded body was obtained. In Example 22, the temperature of the IR heater was 300 ° C., and in Example 23, the temperature of the IR heater was 350 ° C.

(Evaluation)
(Appearance of plastic molding)
The appearance of the obtained fiber reinforced plastic was evaluated according to the following criteria. In addition, the thing with this favorable external appearance evaluation represents that the handling property (processing appropriateness) of a thermoplastic prepreg is favorable.
◎: Good with no voids, etc. ○: Slightly voids can be confirmed Δ: Voids are generated but there is no practical problem ×: Appearance is poor due to voids and cannot be used as a product

(Bending strength of plastic molding)
The bending strength of the plastic molded body was measured by a method based on JIS K7074.

(Flame retardance evaluation)
Evaluation of the flame retardancy of the plastic molding was carried out based on the limiting oxygen index test (ASTM D2863).

  As shown in Tables 1 to 4, the fiber reinforced plastic molded body obtained by heating and pressing the thermoplastic prepregs of Examples 1 to 23 is a heat called a super engineering plastic having a specific critical oxygen index. It has high strength and good appearance because it is made by heat-press molding a thermoplastic prepreg having plastic resin fibers and reinforcing fibers made of carbon fiber or glass fiber and having a density of a certain level or more. It is a fiber-reinforced plastic body.

  In Examples 22 and 23 in which polycarbonate is used as the super engineering plastic fiber, the flame retardancy tends to decrease, but it is at a level that is not a problem in practice.

  On the other hand, in the comparative example 1 in which heating and pressurization were not performed after the nonwoven fabric was manufactured and the density was low, the sheet contracted violently in the infrared heater heating step in stamping molding, and the molding process was impossible. Further, Comparative Example 2 has a low critical oxygen index and lacks flame retardancy.

  By using the thermoplastic prepreg of the present invention, a fiber-reinforced plastic molded article having high strength and high flame retardancy can be obtained. Furthermore, according to the present invention, a thermoplastic prepreg excellent in processability can be obtained, and industrial applicability is high in the field of plastic molding and the like.

Claims (22)

A thermoplastic prepreg formed by heat-pressing a sheet for a fiber-reinforced plastic molded article containing a reinforcing fiber component, a matrix resin component containing a thermoplastic super engineering plastic fiber, and a binder component,
The thermoplastic super engineering plastic fiber has a critical oxygen index of 24 or more,
JAPAN TAPPI paper pulp test method no. The air permeability specified in 5-2 is 250 seconds or less,
The thermoplastic prepreg has a density of 0.15 g / cm ³ or more. The reinforcing fiber component includes inorganic fibers,
2. The heat according to claim 1, wherein a fiber diameter of the thermoplastic super engineering plastic fiber is 40 μm or less, and a fiber diameter of the thermoplastic super engineering plastic fiber is 5 times or less of a fiber diameter of the inorganic fiber. Plastic prepreg. The thermoplastic prepreg according to claim 1 or 2 , wherein the binder component is contained in an amount of 0.1 to 10% by mass with respect to the total mass of the thermoplastic prepreg. The thermoplastic prepreg according to any one of claims 1 to 3 , wherein the binder component is compatible with the thermoplastic super engineering plastic fiber in a heated and melted state. The binder component, according to claim 1-4, characterized by containing a copolymer including at least one of repeating units derived from methyl (meth) acrylate-containing monomer derived repeat units and ethyl (meth) acrylate-containing monomer The thermoplastic prepreg according to any one of the above. The thermoplastic prepreg according to claim 5 , wherein the binder component contains a binder fiber having a melting point lower than a glass transition temperature of the thermoplastic super engineering plastic fiber. The thermoplastic prepreg according to claim 6 , wherein the binder fiber includes polyethylene terephthalate or modified polyethylene terephthalate. The thermoplastic prepreg according to claim 6 or 7 , wherein the thermoplastic super engineering plastic fiber and the binder fiber are chopped strands. The sheet for fiber-reinforced plastic molded body has a surface layer region and an intermediate region sandwiched between the surface layer region,
The thermoplastic prepreg according to any one of claims 1 to 8 , wherein the binder component contained in the surface layer region is greater than the binder component contained in the intermediate region. Copolymer contained in the binder component, any one of claims 5-9, characterized in that localized to paddle membrane at the intersections of fibers constituting the matrix resin component and the reinforcing fiber component 2. The thermoplastic prepreg according to item 1. The thermoplastic prepreg according to any one of claims 1 to 10 , wherein the thermoplastic super engineering plastic fiber is at least one selected from polyetherimide fiber or polycarbonate fiber. The thermoplastic prepreg according to any one of claims 1 to 11 , wherein the thermoplastic super engineering plastic fiber is a polyetherimide fiber. A thermoplastic prepreg formed by heat-pressing a sheet for a fiber-reinforced plastic molded article containing a reinforcing fiber component, a matrix resin component containing a thermoplastic super engineering plastic fiber, and a binder component,
  The thermoplastic super engineering plastic fiber has a critical oxygen index of 24 or more,
  The binder component contains a copolymer containing at least one of a repeating unit derived from a methyl (meth) acrylate-containing monomer and a repeating unit derived from an ethyl (meth) acrylate-containing monomer,
  In the fiber reinforced plastic molded sheet, the copolymer contained in the binder component is localized in the form of a drainage membrane at the intersection of the fibers constituting the reinforcing fiber component and the matrix resin component,
  The density of the thermoplastic prepreg is 0.15 g / cm. ^Three A thermoplastic prepreg characterized by the above. A thermoplastic prepreg formed by heat-pressing a sheet for a fiber-reinforced plastic molded article containing a reinforcing fiber component, a matrix resin component containing a thermoplastic super engineering plastic fiber, and a binder component,
  The thermoplastic super engineering plastic fiber has a critical oxygen index of 24 or more,
  The sheet for fiber-reinforced plastic molded body has a surface layer region and an intermediate region sandwiched between the surface layer region,
  The binder component contained in the surface region is more than the binder component contained in the intermediate region,
  The density of the thermoplastic prepreg is 0.15 g / cm. ^Three A thermoplastic prepreg characterized by the above. A fiber-reinforced plastic molded body formed by heat-press molding the thermoplastic prepreg according to any one of claims 1 to 14 at a temperature equal to or higher than the glass transition temperature of the thermoplastic super engineering plastic fiber. In a method for producing a thermoplastic prepreg comprising a step of subjecting a fiber reinforced plastic molded article sheet comprising a reinforcing fiber component, a matrix resin component containing a thermoplastic super engineering plastic fiber, and a binder component to heat and pressure treatment,
The thermoplastic super engineering plastic fiber has a critical oxygen index of 24 or more,
JAPAN TAPPI paper pulp test method no. The air permeability specified in 5-2 is 250 seconds or less,
The method for producing a thermoplastic prepreg, wherein the density of the thermoplastic prepreg is 0.15 g / cm ³ or more. Before the step of heating and pressurizing, further comprising the step of forming a sheet for fiber-reinforced plastic molded body,
The step of forming the fiber-reinforced plastic molded sheet includes a step of forming a nonwoven sheet by a dry nonwoven fabric method or a wet nonwoven fabric method,
The method for producing a thermoplastic prepreg according to claim 16 , further comprising a step of internally adding, applying or impregnating the nonwoven fabric sheet with a solution containing the binder component or an emulsion containing the binder component, followed by heating and drying. The method for producing a thermoplastic prepreg according to claim 16 or 17 , wherein, in the heating and pressing step, the heating and pressing treatment is performed at a temperature equal to or higher than a glass transition temperature of the thermoplastic super engineering plastic fiber. The method for producing a thermoplastic prepreg according to any one of claims 16 to 18 , wherein in the heating and pressurizing step, the fiber-reinforced plastic molded sheet is heated and pressurized at 150 to 600 ° C. . A thermoplastic prepreg is produced by using the method for producing a thermoplastic prepreg according to any one of claims 16 to 19, and then the thermoplastic prepreg is heated and pressed at 150 to 600 ° C. A method for producing a fiber-reinforced plastic molding. After manufacturing a thermoplastic prepreg using the method for manufacturing a thermoplastic prepreg according to any one of claims 16 to 19, the thermoplastic prepreg is heated to a temperature equal to or higher than a glass transition temperature of the thermoplastic super engineering plastic fiber. A method for producing a fiber-reinforced plastic molded article, characterized by heat-press molding. The method for producing a fiber-reinforced plastic molded body, wherein the step of heat and pressure molding according to claim 20 or 21 is stamping molding.