JP2020032673A - Manufacturing method of fiber-reinforced thermoplastic resin prepreg, prepreg obtained by the manufacturing method, and manufacturing method of fiber-reinforced thermoplastic resin - Google Patents

Abstract

To provide a manufacturing method of a fiber-reinforced thermoplastic resin (FRTP) prepreg capable of improving production speed and avoiding to have low viscosity with an organic solvent for impregnation toward reinforcement fibers (bundle), and a prepreg capable of avoiding adhesion of a matrix resin of an FRTP at a heating contact part of a manufacturing machine stage.SOLUTION: The manufacturing method of a fiber-reinforced thermoplastic resin prepreg includes steps of: (1) preparing a matrix resin composition for impregnation, comprising a polymerizable thermoplastic epoxy resin containing (a) a first bifunctional compound having 2 epoxy groups and (b) a second bifunctional compound having 2 functional groups such as phenolic hydroxyl groups, etc.; (2) controlling an impregnation tank temperature and squeeze molding by introducing a reinforcement fiber bundle by using a squeeze die while impregnating; (3) forming a resin coating layer by coating the squeeze-molded uncured linear object with a molten thermoplastic resin for a surface coating; (4) cooling and solidifying the resin coating layer; and (5) taking up the uncured or semi-cured linear object.SELECTED DRAWING: None

Description

  The present invention is a method for producing a fiber-reinforced thermoplastic resin prepreg obtained by resin-coating an uncured linear material obtained by impregnating a matrix resin composition mainly composed of a thermoplastic resin into a reinforcing fiber bundle, the prepreg, and The present invention relates to a method for producing a fiber-reinforced thermoplastic resin obtained from the prepreg.

An article made of a fiber-reinforced thermosetting resin (hereinafter, sometimes referred to as “FRP”) in which reinforcing fibers are bound with a synthetic resin is an alternative material to a metal article because of its high strength and light weight. It is used in many fields such as automobile parts, electronic parts, agricultural and forestry materials, building materials, furniture and the like. Pipes, rods, linear objects, etc., which use a long fiber bundle such as glass roving, which is one of products using this FRP technology, as a reinforcing fiber and a thermosetting resin as a matrix have been used in various industrial fields for a long time. I have.
In recent years, there has been an increasing demand for using such long materials made of long fiber reinforced resin as individual members in products. In order to be able to be used as such individual components, it is necessary that the long material can be shaped at the time of processing the product to be used so as to conform to the shape of the product. In particular, it is required that a desired shape can be formed and the shape can be stabilized by a temperature stimulus caused by heating.
However, in general, the FRP is completely impregnated with the thermosetting resin as a matrix resin to the inside of the reinforcing fiber, and after curing, due to the properties of the cured thermosetting resin, it is deformed by heating to a desired shape. It is difficult to perform plastic working.

  On the other hand, an article made of a fiber-reinforced thermoplastic resin (hereinafter, sometimes referred to as “FRTP”) in which a reinforcing fiber is impregnated with a thermoplastic resin is capable of plastic deformation to some extent by heating. However, in the case of a FRTP linear material in which a long-fiber reinforcing fiber is impregnated with a thermoplastic resin as a matrix resin, bending by heat shaping is not always easy.

  Patent Document 1 discloses a method for producing a long-fiber reinforced composite material in which a continuous thermoplastic fiber is impregnated with a molten thermoplastic resin while pulling a continuous reinforcing fiber. The method for producing a long fiber reinforced composite material is characterized in that the material is continuously drawn out while being narrowed down, and is then adjusted to a target shape through a shaping nozzle. According to the production method of Patent Document 1, the dispersion of fibers in the obtained composite material and the impregnating property of the resin are good, and an effect that a high-quality composite material can be efficiently and stably obtained can be obtained. ing.

  Further, Patent Document 2 discloses a rope made of a carbon fiber reinforced composite material obtained by twisting a plurality of carbon fiber reinforced composite materials having a diameter of 1 to 5 mm obtained by impregnating a long fiber carbon fiber bundle with a thermoplastic resin and manufacturing the same. A method is disclosed. According to Patent Document 2, it is difficult to uniformly impregnate the resin into the carbon fiber bundle because the melt viscosity of the thermoplastic resin is generally high, but the thermoplastic resin is discharged by an extruder at a constant rate to impregnate the resin. A technique has been disclosed in which a carbon fiber bundle is opened at a portion and impregnated with a resin under pressure, the fiber bundle is shaped into a circle by a die installed separately from an extruder, and wound by a winding device.

  The methods of producing FRTP described in Patent Documents 1 and 2 above all aim to uniformly impregnate a molten thermoplastic resin into a long fiber reinforcing fiber bundle, and the uncured (incomplete) cured No disclosure is made of obtaining a FRTP prepreg of the formula (1) and further curing or heat shaping it.

  On the other hand, Patent Document 3 discloses a pultrusion method for producing a fiber-reinforced thermoplastic resin which can be reused, recycled and subjected to secondary processing, which is difficult with a fiber-reinforced thermosetting resin, even though it is a pultrusion molding using an epoxy resin. A fiber-reinforced thermoplastic resin is formed by polymerizing a bifunctional compound while pulling out a reinforcing fiber impregnated with a bifunctional compound that linearly polymerizes by a polyaddition reaction with a heating mold for the purpose of providing A method for doing so is disclosed. However, in the method of manufacturing the FRTP rod, the pot life of the unreacted matrix resin is improved by mixing the heated monomer and the curing agent immediately before and injecting the mixture into the mold. Polymerization) is rate-determining, and it is difficult to improve the production rate.

  Further, Patent Document 4 aims to provide a high-strength fiber composite material capable of obtaining the original tensile strength of a high-strength fiber yarn even when used in an application in which bending stress is generated, and to provide an applied product thereof. The high-strength fiber bundle is formed by winding a restraining material around the bundle and binding the bundle, and in a state where the high-strength fiber bundle is twisted together with the restraining material by a solidifying agent to form the core wire. Fiber composites have been proposed. As a solidifying agent to be a matrix resin, a polymerizable thermoplastic epoxy resin has been proposed, but in order to enhance the impregnation of the matrix resin into the fibers, a high-viscosity monomer is diluted with an organic solvent to reduce the viscosity. After being impregnated and impregnated, it is transferred to a curing step via a drying step. Therefore, since the organic solvent is vaporized, the environmental property is poor. Further, voids are easily formed in the vaporized portion of the organic solvent in the FRTP, and there is a concern that the physical properties may be deteriorated.

  In addition, the fiber reinforced thermoplastic resin (FRTP) rod can be thermally deformed. However, in the case of a processing method in which the rod is directly brought into contact with a heating body to perform heat shaping, the molten matrix resin adheres to the heating body. As a result, there have been problems such as a decrease in workability and a partial peeling of the FRTP, resulting in insufficient mechanical properties.

JP-A-5-147116 JP-A-5-33278 Japanese Patent No. 5074672 Japanese Patent No. 6129963

  DISCLOSURE OF THE INVENTION The present inventors have made in view of the above-mentioned problems of the prior art, and provided a manufacturing technique of a fiber reinforced thermoplastic resin (FRTP) prepreg capable of improving the production speed, and developed a reinforcing fiber (bundle). To provide a method for producing a fiber-reinforced thermoplastic resin prepreg, which can prevent the viscosity of the impregnating matrix resin composition from being reduced with an organic solvent in order to improve the impregnation property of the impregnating matrix resin composition. In order to provide a prepreg capable of avoiding the adhesion of the matrix resin of FRTP at the heating contact portion in the above, the enthusiastic study was conducted.

As a result, as a method for producing a fiber-reinforced thermoplastic resin prepreg, (1) a matrix resin composition for impregnation with a polymerizable thermoplastic epoxy resin capable of linearly polymerizing the following (a) and (b) by a polyaddition reaction: Preparing the product and supplying it to the impregnation tank,
(A): a first bifunctional compound having two epoxy groups (b): at least one functional group selected from the group consisting of a phenolic hydroxyl group, an amino group, a carboxyl group, a mercapto group, an isocyanate group and a cyanate ester group (2) The temperature inside the impregnation tank is adjusted so that the matrix resin composition for impregnation has a viscosity range of 20 to 1,000 mPa · s, and a squeezer provided on the outlet side of the impregnation tank. Guiding the fiber bundle for reinforcement to the die, while impregnating the matrix resin composition for impregnation into the fiber bundle for reinforcement, impregnation of drawing excess resin composition by the drawing die, a drawing forming step,
(3) forming a resin coating layer by coating the drawn, uncured linear material comprising the reinforcing fiber bundle and the impregnating matrix resin with a molten thermoplastic resin for surface coating;
(4) a step of cooling and solidifying the resin coating layer;
(5) a step of withdrawing an uncured or semi-cured linear material having a cooled and solidified resin coating layer,
It has been confirmed that the above object can be achieved by a manufacturing method having the following in order, and the present invention has been completed.

That is, the present invention provides the following [1] to [7].
[1] A method for producing a fiber bundle for reinforcement and a fiber-reinforced thermoplastic resin prepreg having a matrix resin,
(1) a step of preparing a matrix resin composition for impregnation with a polymerizable thermoplastic epoxy resin capable of linearly polymerizing the following (a) and (b) by a polyaddition reaction and supplying the matrix resin composition to an impregnation tank;
(A): a first bifunctional compound having two epoxy groups (b): at least one functional group selected from the group consisting of a phenolic hydroxyl group, an amino group, a carboxyl group, a mercapto group, an isocyanate group and a cyanate ester group (2) The temperature inside the impregnation tank is adjusted so that the matrix resin composition for impregnation has a viscosity range of 20 to 1,000 mPa · s, and a squeezer provided on the outlet side of the impregnation tank. Guiding the fiber bundle for reinforcement to the die, while impregnating the matrix resin composition for impregnation into the fiber bundle for reinforcement, impregnation of drawing excess resin composition by the drawing die, a drawing forming step,
(3) forming a resin coating layer by coating the drawn, uncured linear material comprising the reinforcing fiber bundle and the impregnating matrix resin with a molten thermoplastic resin for surface coating;
(4) a step of cooling and solidifying the resin coating layer;
(5) a step of withdrawing an uncured or semi-cured linear material having a cooled and solidified resin coating layer,
The method for producing a fiber-reinforced thermoplastic resin prepreg, characterized in that:
[2] The method for producing a fiber-reinforced thermoplastic resin prepreg according to the above [1], wherein in the drawing, the uncured linear material is shaped into a predetermined wire diameter and linear shape.
[3] The fiber-reinforced thermoplastic resin prepreg according to the above [1] or [2], further comprising (6) a pre-curing or thermosetting step following the step (4) of cooling and solidifying the resin coating layer. Production method.
[4] The thermoplastic resin for surface coating forming the resin coating layer has a melting point equal to or higher than the melting point of the matrix resin after thermosetting, and is selected from resins having adhesiveness to the matrix resin. The method for producing a fiber-reinforced thermoplastic resin prepreg according to any one of the above [1] to [3].
[5] The thermoplastic resin for surface coating forming the resin coating layer has a melting point equal to or higher than the melting point of the matrix resin after thermosetting, and is selected from non-adhesive resins with the matrix resin. The method for producing a fiber-reinforced thermoplastic resin prepreg according to any of [1] to [3].
[6] The method according to any one of [1] to [5], wherein the method has a matrix resin having an unreacted epoxy group with a reinforcing fiber bundle and a weight average molecular weight of less than 30,000. Fiber reinforced thermoplastic resin prepreg.
[7] The prepreg obtained by the production method according to any one of [1] to [5] is heated to complete the thermosetting or polymerization reaction of the matrix resin composition, and has a weight average molecular weight of 30,000 or more. A method for producing a fiber-reinforced thermoplastic resin, comprising:

According to the method for producing a fiber-reinforced thermoplastic resin prepreg having a resin coating layer of the present invention, the reinforcing fiber bundle is impregnated with the uncured matrix resin composition for impregnation, and then inserted through a drawing die and drawn. Since the molded uncured linear material is coated with a molten thermoplastic resin to form a resin coating layer, the uncured matrix resin is semi-cured or cured by contact heating in a mold. Pre-curing or curing can be performed without contacting the fixed object with steam, heat medium, etc., without the need to perform the process. Can greatly improve productivity.
In addition, since it has a resin coating layer, an external force is applied to some extent during take-off in a prepreg manufacturing process, a process of manufacturing a directly cured FRTP, an after-cure process, a heating process (shaping) process, and the like. However, it is possible to prevent the shape from being collapsed, and it is possible to avoid the adhesion, transfer, and the like of the matrix resin of FRTP at the heating contact portion of each production machine stand.
Furthermore, in impregnating the reinforcing fiber bundle with the matrix resin composition for impregnation, since the reduction in viscosity due to the organic solvent is avoided, deterioration of the environment due to volatilization of the organic solvent can be prevented.
Since it has a resin coating layer, it is easy to handle as a prepreg.
In addition, by selecting the thermoplastic resin of the resin coating layer having adhesiveness to the matrix resin, the resin coating layer can also be provided with design properties by coloring, texture, weather resistance, light resistance, antistatic property, etc. The application development of the prepreg having the function of (1) can be enabled.
Furthermore, if the thermoplastic resin of the resin coating layer uses a matrix resin and a non-adhesive thermoplastic resin, if the resin coating layer is not required in the final form, it is easily peeled off, and as FRTP itself, Light weight and strength per unit sectional area can be secured.

It is explanatory drawing of the manufacturing process used for the manufacturing method of the fiber reinforced thermoplastic resin prepreg of this invention. It is a perspective view which shows typically the fiber reinforced thermoplastic resin prepreg or the fiber reinforced thermoplastic resin obtained by the manufacturing method of this invention. 1 is a microscope photograph of a cross section of a fiber-reinforced thermoplastic resin obtained by the method for producing a fiber-reinforced thermoplastic resin of the present invention.

  Hereinafter, a method for producing a fiber-reinforced thermoplastic resin prepreg having a resin coating layer of the present invention will be described with reference to the drawings. In the present invention, the drawings are for explaining the technical idea of the present invention, and the dimensional balance between the devices and members in each process and the components are limited to those shown in the drawings. It will not be done.

A method for producing a fiber-reinforced thermoplastic resin prepreg having a resin coating layer according to the present invention will be described with reference to FIG.
<(1) Preparation and supply process of matrix resin composition for impregnation>
First, (1) (a) linearized by a polyaddition reaction including a first bifunctional compound having two epoxy groups and a second bifunctional compound having two functional groups such as a phenolic hydroxyl group. A matrix resin composition for impregnation with a polymerizable thermoplastic epoxy resin is prepared, and the fiber bundle F for reinforcement from the creel 1 is prepared so as to be supplied to the impregnation tank 2.
The matrix resin composition for impregnation is weighed by a predetermined amount from each of the temperature-controlled main agent uM tank 3 and the temperature-controlled curing agent H tank 4, and is stirred and mixed by the static mixer 6 in the mixing unit 5. It is supplied to the temperature-controlled impregnation tank 2 as the impregnation matrix resin composition uMC having a generally appropriate viscosity depending on the temperature.

<(2) Impregnation and drawing process>
A required number of reinforcing fiber bundles F are drawn from the creel 1 and bundled, filled with the prepared liquid impregnating matrix resin composition, and placed in an impregnation tank so as to have a viscosity range of 20 to 1,000 mPa · s. It is introduced into the impregnation tank 2 whose temperature has been adjusted. As the reinforcing fiber bundle F travels in the impregnation tank 2, the matrix resin composition is impregnated between the fibers.
In the method for producing a fiber-reinforced thermoplastic resin prepreg of the present invention, the viscosity of the matrix resin composition for impregnation is more preferably 40 to 300 mPa · s. When the viscosity is less than mPa · s, impregnation is good, but troubles such as dripping from the reinforcing fiber bundle and the resin are unevenly distributed, the reinforcing fiber density becomes non-uniform, and in the case of a linear object. May cause problems such as loss of linearity after complete curing, resulting in bias. When the viscosity exceeds 1,000 mPa · s, the viscosity is high, so that the impregnating property into the reinforcing fiber bundle is deteriorated, voids are generated after curing, leading to a decrease in physical properties, and the passage resistance in the drawing die 7 described later increases. As a result, the fiber bundle may be partially cut or may not be able to be taken off.
In order to adjust the viscosity of the matrix resin composition for impregnation, the temperature of the matrix resin for impregnation may be adjusted to preferably 80 to 150 ° C, more preferably 90 to 130 ° C.
In the present invention, the viscosity of the matrix resin composition for impregnation is measured at an arbitrary temperature with a vibrating viscometer (AS ONE Corporation: VM-10A-M).

The matrix resin composition for impregnation in the impregnation tank 2 is heated in order to lower the viscosity, but the higher the temperature, the more the polyaddition reaction proceeds, the higher the viscosity, and the continuous productivity is hindered. Therefore, it is necessary to adjust the temperature range of the matrix resin composition for impregnation and to shorten the residence time of the matrix resin composition for impregnation in the impregnation tank as much as possible. Therefore, the consumption Ro (mL / min) taken out by impregnating the reinforcing fiber bundle from the impregnation tank, the amount Ri (mL / min) prepared and supplied in the step (1), and the It is necessary to consider the relationship with the amount Rs (mL) of the matrix resin composition for impregnation stored in the equilibrium state.
The amount Ri of the impregnating matrix resin composition to be stored and the amount of the impregnating matrix resin composition are determined by making the supply amount Ri to the impregnation tank equal to the consumption amount Ro and keeping the liquid level constant (equilibrating). When the relationship with the consumption Ro of the substance (mL / min) is defined as the usage rate of the matrix resin for impregnation, it is expressed by the following equation (1).
Usage ratio of matrix resin for impregnation = (Ro / Rs) x 100 (%) / min (1)
It is preferable that the use rate of the preferred matrix resin for impregnation is 5% / min or more, and the more preferred use rate of the matrix resin for impregnation is 50% / min or more from the viewpoint of prevention of curing in the impregnation tank.
In other words, a fresher mixed liquid can be used when the usage rate (consumption ratio) per unit time during production with respect to the amount of the matrix resin composition for impregnation stored in the impregnation tank is as high as possible. Further, by making the consumption amount equal to the supply amount to the impregnation tank, the liquid level in the impregnation tank is also kept uniform (equilibrium state), and stable continuous production can be secured.

<Drawing>
On the outlet side (take-off side) of the impregnation tank 2, a drawing die 7 having a hole corresponding to the shape of the FRTP to be obtained is provided, and the impregnating die 7 impregnated in the reinforcing fiber bundle F is provided. An excess of the matrix resin composition is drawn and continuously taken as an uncured linear product 20 to the take-up side. By arranging a plurality of drawing dies between the inlet and the outlet of the impregnation tank, the impregnating property can be further improved. It is preferable that the hole formed in the drawing die 7 is chamfered on the inlet side or has a gentle taper shape from the inlet side to the outlet side.

<(3) Formation of resin coating layer>
Next, the formed uncured linear material 20 is coated with a molten thermoplastic resin by a coating die 8 attached to a melt extruder, to form an uncured linear material 21 having a resin coating layer. Is immediately introduced into the cooling bath 9 to cool and solidify the resin coating layer. In this state, the fiber reinforced thermoplastic resin prepreg 22 having a resin coating layer and having a substantially uncured interior may be taken out by the takeoff device 11, but the thermosetting tank 10 may be filled with high-pressure steam, and the resin coating may be performed by pre-curing. A fiber-reinforced thermoplastic resin prepreg (23) having a layer and a semi-cured inside can be used.

In the step of forming a resin coating layer by coating the drawn and uncured linear material with a molten thermoplastic resin, for example, the inside of a crosshead of a melt extruder is a guide corresponding to a drawn nozzle hole shape. A fiber-reinforced thermoplastic resin prepreg having a resin coating layer with a more uniform shape can be produced by attaching a guide jacket (not shown) provided with holes so that the tip side of the guide jacket can be as close as possible to the point covered by the molten resin. It is preferable from the viewpoint of doing.
To form a resin coating layer by coating with a molten thermoplastic resin, as a coating die, extrude the molten resin from a discharge port having a diameter larger than the outer diameter (shape) of the uncured linear material, and form a coating die. Either a method using a pull-down type coating die that coats on the take-up machine side from the discharge surface, or a method using a pressure die that makes contact with an uncured linear object in the coating die, but may be a resin coating. In the step of cooling and solidifying the layer, the point of contact between the coating resin and the uncured linear material can be used as the tip of the cooling water tank, and from the viewpoint of suppressing partial curing due to contact with the coating resin, a draw-down type coating die. Is more preferable.

<(4) Step of cooling and solidifying the resin coating layer, (5) Takeover step>
Immediately following the step (4) of cooling and solidifying the resin coating layer, (5) pulling out or (6) the state of the prepreg to be obtained when the method further comprises a thermosetting (pre-curing) step; That is, the temperature and the curing time (residence time) of the thermosetting tank 10 are adjusted according to the degree of polymerization of the curable thermoplastic resin, and the thermosetting resin is taken off. The take-off may be carried out continuously with a belt-type or caterpillar-type take-up machine or a drum winding machine, or may be cut into a fixed length and taken up, or may be appropriately performed according to the intended use.

  Further, in the drawing by the drawing die 7 at the outlet of the impregnation tank, a predetermined wire diameter and a circular shape are obtained by using a drawing die having a hole shape similar to a desired shape when used as a prepreg in a longitudinal section. , An ellipse, a rectangle, a gutter, a flat plate, or the like.

(Reinforcing fiber bundle)
The reinforcing fiber bundle used in the present invention is preferably a substrate having the form of a continuous long fiber bundle or a fiber braid (woven fabric, knit, braid). By using the above-described base material, continuous impregnation and continuous formability of the resin coating layer can be ensured, and the production of a fiber-reinforced thermoplastic resin prepreg having a resin coating layer with excellent productivity becomes possible.

  As the fibers constituting the reinforcing fiber bundle, for example, organic fibers such as aramid fibers and inorganic fibers such as glass fibers and carbon fibers can be used, but glass fibers and carbon fibers are preferably used.

As the glass fiber, a long fiber such as a glass fiber monofilament, a glass fiber strand, a glass fiber roving, and a glass fiber yarn can be used.
Further, a glass fiber braid such as a glass fiber woven fabric, a glass fiber braid, and a glass fiber knit can be applied. In addition, the glass fiber may have been subjected to a surface treatment with a surface treatment agent such as an epoxy silane coupling agent or an acrylic silane coupling agent.

As the glass fiber, a glass fiber roving or a glass fiber fabric is preferable. The glass fiber roving is preferably obtained by further bundling 10 to 200 glass fiber bundles in which 100 to 2,000 glass fiber monofilaments having a diameter of 3 to 100 μm are bundled.
A glass fiber fabric is a glass fiber bundle of 5 to 500 TEX (preferably 22 to 68 TEX) used as a warp and a weft, and the weaving density is 16 to 64 yarns / 25 mm in the warp direction and 15 to 60 yarns / 25 mm in the weft direction. Preferably, it is woven so that The glass fiber bundle constituting the glass fiber fabric is preferably a bundle of 50 to 1,200 glass fiber monofilaments (having a filament diameter of preferably 3 to 23 μm).
The glass fiber fabric is preferably a continuous tape having a width of about 5 to 100 mm cut into a desired width.

  Examples of the glass composition of the above glass fiber include E glass, S glass, C glass and the like, and among them, E glass is preferable. Further, the cross section of the glass fiber monofilament may be circular or flat such as elliptical.

  There are three types of carbon fiber: "pitch-based" made from coal tar pitch or petroleum pitch, "PAN-based" made from polyacrylonitrile, and "rayon-based" made from cellulose fiber. Fibers can also be used in the present invention.

These reinforcing fiber bundles can be woven, braided, or knitted to a desired length by a well-known method, if necessary, or prepared in advance, or a long one is wound around a roll. You may take and use.
The reinforcing fiber bundle may be heated in order to increase the impregnation of the reinforcing fiber with the resin or to remove moisture in the reinforcing fiber.

  The compounding ratio of the reinforcing fibers (bundles) in the fiber-reinforced thermoplastic resin prepreg of the present invention or the cured fiber-reinforced thermoplastic resin is 40 to 80% by volume of the reinforcing fibers (hereinafter referred to as “Vf Is sometimes referred to as "."). If it is less than 40% by volume, the reinforcing property of the reinforcing fiber bundle tends to be low or warpage or undulation tends to be large. If it is more than 80% by volume, the fiber is not impregnated with the resin, and voids are generated, There is a fear that problems such as an increase in the take-up resistance at the dies and a hindrance to smooth continuous production may occur.

(Curable resin having thermoplasticity)
In the present invention, the thermoplastic curable resin constituting the matrix resin includes (a) a first bifunctional compound having two epoxy groups, and (b) a phenolic hydroxyl group, an amino group, a carboxyl group, and a mercapto group. And a second bifunctional compound having at least one functional group selected from the group consisting of an isocyanate group and a cyanate ester group; It is.

(A) As the first bifunctional compound having two epoxy groups, for example, one benzene ring such as catechol diglycidyl ether, resorcin diglycidyl ether, t-butylhydroquinone diglycidyl ether, and phthalic acid diglycidyl ether is used. Alicyclic epoxy compounds such as mononuclear aromatic diepoxy compounds, dimethylolcyclohexanediglycidyl ether, 3,4-epoxycyclohexenylmethyl-3,4-epoxycyclohexenylcarboxylate, limonene dioxide, and bis ( Bisphenol type epoxy compounds such as 4-hydroxyphenyl) methane diglycidyl ether, 1,1-bis (4-hydroxyphenyl) ethane diglycidyl ether, and 2,2-bis (4-hydroxyphenyl) propane diglycidyl ether Oligomer mixture (bisphenol-type epoxy resin), 3,3 ′, 5,5′-tetramethylbis (4-hydroxyphenyl) methane diglycidyl ether, 3,3 ′, 5,5′-tetramer Methyl bis (4-hydroxyphenyl) ether diglycidyl ether and the like can be mentioned.
Hydroquinone diglycidyl ether, methylhydroquinone diglycidyl ether, 2,5-di-t-butylhydroquinone diglycidyl ether, biphenyl type or tetramethyl biphenyl type epoxy resins, bisphenol fluorene type or biscresol fluorene type epoxy resin alone An epoxy resin that exhibits crystallinity and melts at a temperature of 200 ° C. or less even when solid at room temperature and becomes liquid can be used.

Examples of (b) the second bifunctional compound having at least two functional groups selected from the group consisting of a phenolic hydroxyl group, an amino group, a carboxyl group, a mercapto group, an isocyanate group, and a cyanate ester group include, for example, 1 Compounds having two phenolic hydroxyl groups in the molecule are preferred.
Examples of such compounds include mononuclear aromatic dihydroxy compounds having one benzene ring such as catechol, resorcin, hydroquinone, methylhydroquinone, t-butylhydroquinone, and 2,5-di-t-butylhydroquinone; 2,2-bis (4-hydroxyphenyl) propane (bisphenol A), 1,1-bis (4-hydroxyphenyl) ethane (bisphenol AD), bis (hydroxyphenyl) methane (bisphenol F), bisphenolfluorene, biscresol Examples include bisphenols such as fluorene, compounds having a condensed ring such as dihydroxynaphthalene, and bifunctional phenol compounds into which an allyl group is introduced such as diallyl resorcinol, diallyl bisphenol A, and triallyl dihydroxy biphenyl.
Among these, when the above-mentioned bisphenol-type epoxy resins are selected as the first bifunctional compound, bisphenols such as bisphenol A and bisphenol F are used because the softening temperature is low and the handleability is good. Is preferred.
Furthermore, a compound having a fluorene skeleton can be used for at least a part of the first bifunctional compound and / or at least a part of the second bifunctional compound. In this case, the melting temperature of the polymerized resin is used. Can be adjusted to obtain a high-melting resin.

  The compounding amount of the compound (a) and the compound (b) is preferably 0.9 to 1.1 mol, more preferably 0.95 to 1.05 mol, per 1 mol of the compound (a). More preferred.

  The compound (a) and the compound (b) can be linearly polymerized by a polyaddition reaction as exemplified below. The fact that the polymer has been linearly polymerized can be confirmed by the solubility in a solvent, the thermal fusibility and the like. In addition, as long as the object of the present invention is not impaired, it does not exclude that a crosslinked structure is partially present.

(Polymerization catalyst)
A polymerization catalyst can be used for this polymerization reaction. Examples of the polymerization catalyst include a 1,2-alkylenebenzimidazole (TBZ) and a 2-aryl-4,5-diphenylimidazole (NPZ) in addition to a phosphorus-based catalyst. These are used alone or in combination of two or more. Phosphorus-based catalysts are preferred because they improve reflowability.

  Examples of the phosphorus-based catalyst include dicyclohexylphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, cyclohexyldiphenylphosphine, triphenylphosphine, triphenylphosphine-triphenylborane complex, and triphenylphosphine. -M-tolylphosphine-triphenylborane complex and the like. Among them, tri-o-tolylphosphine and tri-m-tolylphosphine-triphenylborane complex are preferable.

  The amount of the polymerization catalyst to be used is generally 0.1 to 10 parts by weight, further 0.4 to 6 parts by weight, particularly 1 to 5 parts by weight, based on 100 parts by weight of the compound (a). However, it is preferable because the balance between short-time polymerizability and pot life is excellent.

When the mixture of the compound (a), the compound (b) and the polymerization catalyst is in a liquid state at room temperature, no heating is required in the step of impregnating the reinforcing fibers, or the viscosity of the mixture is significantly increased with the start of polymerization. Heating to such an extent as not to cause the above is preferable because the viscosity is sufficiently reduced and the impregnation into the reinforcing fibers becomes easy.
Further, even when the compound (a) and the compound (b) are each solid alone, the viscosity when the mixture of the compound (a), the compound (b) and the polymerization catalyst is heated at a temperature of 200 ° C. or less. Is set to 1,000 mPa · s or less, and injected into the impregnation tank 2 using a two-liquid mixing apparatus having a static mixer in the mixing section 5 through the compound (a) and compound (b) pipes. can do.
In the impregnation tank, the compound (a) and the compound (b) may not all be in a molten state, but may be partially unmelted, for example, in a paste state. I do not care.

(Reaction retarder)
In the present invention, a reaction retarder can also be used. In the step of mixing the compound (a), the compound (b) and the curing agent, and the step of impregnating the reinforcing fiber bundle, the resin is frequently heated because it is necessary to uniformly liquefy the resin and reduce the viscosity as much as possible. The polymerization reaction is started before the impregnation of the reinforcing fiber with the resin is completed, and the viscosity increases, which may cause impregnation failure. In order to prevent this, a reaction retarder that delays the reaction at the time of heating for decreasing the viscosity and does not inhibit the reaction at the time of the polymerization reaction after impregnation is preferably used.
As such a reaction retarder, trialkyl borates such as tri-n-butyl borate, tri-n-octyl borate and tri-n-dodecyl borate, and triaryl borates such as triphenyl borate can be used. These are used alone or in combination of two or more. Among these, tri-n-octyl borate is preferred because it is liquid at room temperature and has excellent miscibility and significantly delays the reaction at 80 ° C. or lower.

  The amount of the reaction retarder to be used is preferably such that the boron atom of the borate ester is 0.1 to 2.0 mol per mol of the phosphorus atom of the phosphorus-based catalyst, more preferably 0.5 to 1.2 mol, particularly 0.5 to 1.2 mol. Is 0.7 to 1.0 mol, the polymerization reaction is started before the impregnation of the reinforcing fiber with the resin is completed, the viscosity can be prevented from increasing, and when the polymerization is performed, It is preferable because polymerization is possible.

(Optional components)
In the present invention, as an optional additive, a filler made of an inorganic powder such as an organic powder or aluminum hydroxide, or a known flame retardant may be added.
The above-mentioned polymerization catalyst, reaction retarder, additive and the like can be added to one or both of the reactive compounds before impregnating the reinforcing fiber bundle in advance.

  In the method for producing a prepreg of the present invention, after the impregnation of the reactive compound, the polymerization can proceed in a thermosetting tank, but according to the properties of the prepreg to be obtained, without heating in the thermosetting tank. The semi-cured prepreg can be obtained by taking off or appropriately heating the thermosetting tank. Furthermore, by adjusting the temperature of the thermosetting tank and the staying time (polymerization time), the polymerization reaction can proceed to obtain a completely cured fiber-reinforced thermoplastic resin. When heating the thermosetting bath, the polymerization temperature is around the set temperature. The temperature of the thermosetting bath is generally from about 80 ° C. by hot water heating to about 300 ° C. by steam heating, an electric heater or the like. Depending on the type of the reactive compound, the polymerization catalyst, and the reaction retarder used, the temperature range in which the polymerization reaction occurs is different, but usually, the polymerization temperature is 120 to 200 ° C., and the polymerization time is about 1 to 20 minutes. It is. The polymerization time is preferably about the time of the reactive compound staying inside the thermosetting tank.

  The fiber-reinforced thermoplastic epoxy resin molded product obtained in the process of producing a prepreg that partially cures a polymerization reaction to obtain a semi-cured product by passing through a heated thermosetting tank to obtain a semi-cured product, or in the polymerization reaction process of completely curing, is subjected to polymerization. Since it has a Tg near the temperature, it is desirable to cut or wind it through a cooling step. Cooling may be performed by passing through a cooling water tank. Further, the take-off speed can be about 5 to 100 m / min.

(Thermoplastic resin for forming resin coating layer)
In the method for producing a fiber-reinforced thermoplastic resin prepreg according to the present invention, (3) the step of “drawing an uncured linear material comprising a reinforcing fiber bundle and an impregnating matrix resin into a molten thermoplastic resin for surface coating; The thermoplastic resin used in the step of forming a resin coating layer by coating with a resin (hereinafter, may be simply referred to as “coating resin”) is not affected by the resin composition for impregnation, and is not melt-extruded. A resin that can be extruded from the coating die and coated, wherein the melting point of the coating resin is higher than the melting point of the matrix resin and is preferably 90 to 300 ° C, more preferably 100 to 300 ° C.
The coating resin has a melting point within the above range, and can be selected from resins having adhesiveness to the matrix resin. Examples of the resin having adhesiveness to the matrix resin include polyamide resins such as nylon 12, polyester resins, acrylonitrile-butadiene-styrene copolymer (ABS resin), and acrylic resins.
In addition, the coating resin can be selected from resins having a melting point equal to or higher than the melting point of the matrix resin after thermosetting and being non-adhesive to the matrix resin. Examples of the resin that is non-adhesive to the matrix resin include polyolefin-based resins such as polypropylene and polyethylene, and fluorine-based thermoplastic resins such as fluoroethylene-propylene copolymer (FEP) and perfluoroalkoxyalkane (PFA). it can.

(Fiber reinforced thermoplastic resin prepreg)
The fiber-reinforced thermoplastic resin prepreg of the present invention has an unreacted epoxy group or a matrix resin having a weight average molecular weight of less than 30,000. The prepreg of the present invention is that the thermoplastic epoxy resin of the matrix resin is not fully cured, in a so-called semi-cured state, and is then completely cured by heating such as when the prepreg is used after shaping, and further after-curing. Wherein the weight average molecular weight is less than 30,000. If the weight average molecular weight is more than 30,000, it lacks flexibility when used as a prepreg, and impairs handleability.
In the present invention, the fully cured state and the semi-cured state are determined by FT-IR (Nicolet NEXUS 470 FT-IR, manufactured by Thermo Fisher Scientific Co., Ltd.) and accessories (AVATAR OMNIC-Sampler HATR Accessory, ThermoSergic, ThermoScience, ThermoScience). FT-IR measurement by the single reflection ATR method, and analyzing the obtained spectrum. That is, when the degree of reaction progress is confirmed by a reference peak of a phenyl group (around 1,500 cm ⁻¹ ) and a comparative peak of an epoxy group (around 930 cm ⁻¹ ), the completely cured state is determined at 140 ° C. The case where the ratio was less than 5% even after the reheating for 1 hour was defined as the case where the variation was 5% or more.
In the present invention, the weight average molecular weight is determined by extracting the matrix resin with dimethylformamide (DMF) (about 0.1 wt%) and performing gel permeation chromatography (GPC) [HLC-8220GPC, manufactured by Tosoh Corporation]. It was measured using DMF as a developing solvent and α-M (for a polar solvent, manufactured by Tosoh Corporation) as a filler, and calculated in terms of polystyrene (calibration curve).

(Method for producing fiber-reinforced thermoplastic resin)
The method for producing the fiber-reinforced thermoplastic resin of the present invention comprises heating the prepreg obtained by the method for producing a prepreg according to any of the above, and causing the matrix resin composition to undergo a thermosetting or polymerization reaction to obtain a weight average molecular weight. Is a method of forming a fiber-reinforced thermoplastic resin comprising a matrix resin having a molecular weight of 30,000 or more and reinforcing fibers.
In the method for producing a fiber-reinforced thermoplastic resin according to the present invention, the heating of the prepreg includes, for example, winding the prepreg around an object, braiding the outer periphery of the object, or forming a structural member of the object to reinforce the target object. Is formed by further heating the prepreg to complete the thermosetting or polymerization reaction of the uncured or semi-cured matrix resin composition for impregnation. Incidentally, the completion of thermal curing or polymerization reaction, as described above, the reference peak of the phenyl group (1,500Cm around ^-1), the progress of the reaction between the compared peaks of epoxy groups (930 cm around ^-1) Confirmation is made, and a case where the ratio shows less than 5% fluctuation even by reheating at 140 ° C. for 1 hour is judged as complete curing. The weight average molecular weight of the fiber-reinforced thermoplastic resin after heat curing needs to be 30,000 or more from the viewpoint of developing the strength as a matrix resin.
If the weight average molecular weight is less than 30,000, the strength of the matrix resin is not sufficiently exhibited. The upper limit of the weight average molecular weight of the linearly polymerizable polymerizable thermoplastic epoxy resin as the matrix resin used in the present invention is usually 150,000 or less.

  Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

Fiber reinforced thermoplastic resin prepregs having a resin coating layer according to Examples and Comparative Examples were manufactured, and the following evaluation items were evaluated.
(1) Productivity: The following evaluation was made based on the line (drawing) speed at which stable production was possible continuously.
：: Line speed of 15 m / min or more ：: Line speed of 10 m / min or more and less than 15 m / min Δ: Line speed of 3 m / min or more and less than 10 m / min ×: Line speed of less than 3 m / min (2) Molding Properties: A longitudinal section of a fiber-reinforced thermoplastic resin prepreg having a resin coating layer was observed.
◎: 90% or more of roundness
：: Roundness of 70% or more and less than 90% が あ る: Waviness in the longitudinal direction ×: Less than 70% of roundness (3) Void: existence of voids and voids at the interface with reinforcing fibers per cross section Was observed and the impregnating property was evaluated.
◎: No void of micron (μm) size (hereinafter referred to as “microvoid”) ○: No void, 10 or less microvoids Δ: No void, 10 or more microvoids ×: Voids exist (4) Environmental properties: In preparing the matrix resin composition for impregnation, evaluation was made based on whether or not an organic solvent for dilution was used.
：: No use of diluting solvent ×: Use of diluent (5) Handling property: Handling property when prepreg is after-cured (post-cured) in an oven at 145 ° C. for 1 hour, hot-pressed sample after after-curing at 120 ° C. The handling property when performing was evaluated.
◎: No stickiness at the time of heating ×: Sticky at the time of heating (6) Comprehensive evaluation: Comprehensive evaluation was performed in consideration of the above evaluation items.

Example 1
A glass fiber reinforced thermoplastic resin composition prepreg was produced according to the following steps.
<(1) Preparation of matrix resin composition for impregnation>
Thermoplastic epoxy resin (XNR6850A, Nagase ChemteX) prepared beforehand from (a) a first bifunctional compound having two epoxy groups and (b) a second bifunctional compound having two phenolic hydroxyl groups. (Manufactured by Nagase Chemtex Co., Ltd.) into the hardener tank 4 containing a catalyst and a reaction retarder, and from the tanks 3 and 4, respectively. The mixture was weighed to 100 parts by mass and 2 parts by mass with a gear pump, continuously supplied to the mixing section 5, and stirred and mixed by the static mixer 6 to prepare an impregnation matrix resin composition. The tanks 3, 4 and the mixing section 5 were heated and controlled so that the liquid temperature of the matrix resin composition for impregnation became 110 ° C. The prepared matrix resin composition for impregnation is filled with a fiber-reinforced thermoplastic resin (FRTP) to be finally obtained so that 80% of the volume of the impregnation tank 2 having an inner diameter of 40 mm and a length of 100 mm is filled. Based on the outer diameter of 1.12 mm and the fiber volume content of glass fiber of 56%, the amount of resin used per unit time determined from the matrix resin cross-sectional area and the line (drawing) speed is calculated as 6.50 (mL / min). Then, the supply amount (mL / min) from the mixing section was set to the same amount and supplied to the impregnation tank 2 whose temperature was controlled at 110 ° C.

<(2) Impregnation and drawing process>
Five glass fibers (RS-28, 2,800 dtex, manufactured by Nitto Boshoku Co., Ltd.) were pulled out from the creel 1 as the reinforcing fiber bundle, and the impregnating tank 2 not filled with the matrix resin composition for impregnation was used. And, it passed through a drawing die 7 having an inner diameter of 1.12 mm, and further extended through a coating die 8, a cooling bath 9 and a thermosetting bath 10 to a take-off device 11, and was prepared so as to be ready for take-out.
The glass fiber bundle F is heated at 110 ° C. while taking up the glass fiber bundle F at a rate of 15 m / min, and is impregnated into the glass fiber bundle F in the impregnation tank 2 filled with the matrix resin composition having a viscosity of 60 mPa · s. While being impregnated with the composition, drawing was performed with a drawing die 7 to obtain a circular uncured linear material 20 having an outer diameter of 1.12 mm.

<(3) Step of forming resin coating layer>
A line formed by melting and extruding polypropylene (Prime Polypro J702LJ, melting point: 159 ° C.) from the coating die 8 of the melt extruder and coating the outer periphery of the uncured linear material 20 with a molten resin. A substance 21 was obtained.

<(4) Step of cooling and solidifying the resin coating layer, (6) Pre-curing step, (5) Take-off step>
The linear material 21 was passed through the cooling water tank 9 to cool and solidify the resin coating layer on the surface. Next, it was passed through a thermosetting tank 10 having a length of 30 m, which was steam-heated to 145 ° C., semi-cured, and then taken out by a rubber belt type take-up machine 11 at a speed of 15 m / min. The residence time in the thermosetting tank 10 was 2 minutes.

The obtained semi-cured prepreg (23) has a resin coating layer with a thickness of 0.125 mm on the outer periphery, an outer diameter of the FRTP prepreg portion of 1.12 mm, and a volume content of glass fiber of 56%. The weight average molecular weight of the incompletely cured matrix resin was 12,500. The rate of use of the matrix resin for impregnation in the impregnation tank 2 during running during production is 6.47%, and there is no trouble such as local increase in viscosity in the impregnation tank 2 for 12 hours of continuous production time, and it is stable. Could be manufactured.
Table 1 summarizes the manufacturing conditions and evaluation results.

Example 2 and Example 3
An FRTP prepreg having a resin coating layer was manufactured at a take-up speed of 20 m / min in Example 2, and at a take-up speed of 80 m / min in Example 3, instead of the take-up speed of 15 m / min in Example 1. The residence time in the thermosetting tank 10 was 1.5 minutes and 0.375 minutes.
In addition, the temperature of the resin for impregnation was set to 120 ° C. which was higher by 10 ° C., and the resin viscosity was set to 40 mPa · s. In addition, while balancing the supply amount of the impregnating resin into the impregnation tank and the consumption amount by impregnation into the reinforcing fiber bundle, the use rate of the impregnating matrix resin is 8.62% (Example 2) and 61.33% (Example 2). Example 3).
Table 1 shows these manufacturing conditions and evaluation results.

Examples 4 to 6
In Example 1, the resin temperature of the matrix resin composition for impregnation was 80 ° C., the viscosity was 400 mPa · s, and the take-up speed was 10 m / min. In Example 1, the diameter of the drawing die was 1.80 mm. In Example 5 and Example 1 in which the volume content Vf of the reinforcing fiber was 45% and the take-up speed was 15 m / min, the diameter D of the drawing die was 0.90 mm and the volume content Vf of the reinforcing fiber was 72%. According to Example 6 in which the take-up speed was 10 m / min, a FRTP prepreg having a resin coating layer of PP was produced.
Table 1 shows these manufacturing conditions and evaluation results.

Comparative Examples 1 and 2
In Example 1, the temperature of the matrix resin composition for impregnation was set to 60 ° C., and the viscosity was set to 1,700 mPa · s. In Comparative Example 2, the prepreg was produced while adjusting the line speed by setting the viscosity of the impregnating matrix resin composition to 40 ° C. and the viscosity to 16,000 Pa · s.
Table 2 shows the manufacturing conditions and evaluation results.

Comparative Examples 3 and 4
In Example 1, in order to reduce the viscosity of the matrix resin composition for impregnation, the base material uM of the matrix resin composition for impregnation having the same composition was diluted with methyl ethyl ketone (MEK) to a solid content of 80% by mass, and 100 mPa at 25 ° C. Comparative Example 3 having a viscosity of s, the main component uM of the matrix resin composition for impregnation having the same composition was diluted with methyl ethyl ketone (MEK) to a solid content of 20% by mass to obtain 12 mPa · s at 25 ° C., and a drawing die A prepreg was obtained from Comparative Example 4 in which the diameter was 1.8 mm and Vf was 45%.
Table 2 shows the manufacturing conditions and evaluation results.

Comparative Example 5
In Example 1, when the drawing nozzle 7 was separated from the outlet of the impregnation tank by 400 mm and formed by a drawing nozzle not controlled at 110 ° C., the reinforcing fiber bundle impregnated with the resin was taken out (pulled out). ) It was difficult. Table 2 shows the manufacturing conditions and evaluation results.

Comparative Example 6
In Example 1, in order to confirm the effect of the drawing, the coating with the PP resin was performed in a state where the outer diameter was free without using the drawing nozzle of 1.12 mm. The obtained prepreg was poor in moldability. Table 2 summarizes the manufacturing conditions and evaluation results.

Comparative Examples 7 and 8
In Example 1, the prepreg was produced without coating with the PP resin, and therefore, without cooling and solidifying the resin coating layer, thereby producing a prepreg (Comparative Example 7). The take-up belt had stickiness of the uncured resin, and was extremely lacking in handleability. Table 2 summarizes the manufacturing conditions and evaluation results.
Further, in the same manner as in Example 1, except that the coating resin in Example 1 was changed from PP to linear low-density polyethylene (LLDPE) (manufactured by Prime Polymer Co., Ltd., Evolu 1071C, melting point 100 ° C), A prepreg was produced (Comparative Example 8). Since the coating resin had a low melting point, the obtained prepreg had stickiness during both after-curing at 145 ° C. and hot-pressing at 120 ° C., and was inferior in handleability. Table 2 summarizes the manufacturing conditions and evaluation results.

The method for producing a fiber-reinforced thermoplastic resin prepreg of the present invention comprises impregnating a fiber bundle for reinforcement with an uncured matrix resin composition for impregnation, then inserting the same through a drawing die and drawing and forming the formed uncured resin. The linear material is coated with a molten thermoplastic resin to form a resin coating layer, so that the uncured matrix resin is not heated or cured by contact heating in a mold, Pre-curing treatment and curing treatment can be performed in a non-contact state with a fixed object with a medium or the like, so that the problem of rate-limiting of production speed due to pull-out resistance in the case of mold curing can be solved, greatly improving productivity. It can be used as a prepreg manufacturing method that can be improved.
In addition, since it has a resin coating layer, in the after-cure or heating (shaping) step, even if an external force is applied to some extent at the time of taking, it can be made into a state in which the shape does not collapse, and It can be used as a prepreg that can avoid the adhesion and transfer of the FRTP matrix resin at the heating contact portion of each production machine stand.
Further, in the impregnation of the reinforcing fiber bundle with the matrix resin composition for impregnation, since the viscosity reduction by the organic solvent is avoided, it can be used as a production method and a prepreg capable of preventing the deterioration of the environment due to the volatilization of the organic solvent.
In addition, by selecting the thermoplastic resin of the resin coating layer having adhesiveness to the matrix resin, the resin coating layer can also be provided with design properties by coloring, texture, weather resistance, light resistance, antistatic property, etc. It can be used for various purposes as a prepreg having the function of.
Furthermore, if the thermoplastic resin of the resin coating layer uses a matrix resin and a non-adhesive thermoplastic resin, if the resin coating layer is not required in the final form, it is easily peeled off, and as FRTP itself, It can be used for applications where weight reduction and strength per unit sectional area are ensured.

DESCRIPTION OF SYMBOLS 1 Creel of fiber bundle F for reinforcement 2 Impregnation tank 3 Main tank of matrix resin for impregnation 4 Curing agent tank of matrix resin for impregnation 5 Mixing part 6 Static mixer 7 Drawing die 8 Coating die 9 Cooling tank 10 Thermosetting tank 11 Take-off Apparatus 20 Uncured linear material 21 Uncured linear material having resin coating layer 22 Fiber-reinforced thermoplastic resin prepreg whose inside is almost uncured (23) Fiber-reinforced thermoplastic resin prepreg in semi-cured state by pre-curing F Fiber bundle for reinforcement uM Main agent H Hardener uMC Resin composition for impregnation

Claims (7)

A method for producing a fiber bundle for reinforcement and a fiber reinforced thermoplastic resin prepreg having a matrix resin,
(1) a step of preparing a matrix resin composition for impregnation with a polymerizable thermoplastic epoxy resin capable of linearly polymerizing the following (a) and (b) by a polyaddition reaction and supplying the matrix resin composition to an impregnation tank;
(A): a first bifunctional compound having two epoxy groups (b): at least one functional group selected from the group consisting of a phenolic hydroxyl group, an amino group, a carboxyl group, a mercapto group, an isocyanate group and a cyanate ester group (2) adjusting the temperature in the impregnation tank so that the matrix resin composition for impregnation has a viscosity in the range of 20 to 1,000 mPa · s, and a restrictor provided on the exit side of the impregnation tank. Guiding the fiber bundle for reinforcement to the die, while impregnating the matrix resin composition for impregnation into the fiber bundle for reinforcement, impregnation of drawing excess resin composition by the drawing die, a drawing forming step,
(3) forming a resin coating layer by coating the drawn and uncured linear material comprising the reinforcing fiber bundle and the matrix resin composition for impregnation with a molten thermoplastic resin for surface coating; ,
(4) a step of cooling and solidifying the resin coating layer;
(5) a step of withdrawing an uncured or semi-cured linear material having a cooled and solidified resin coating layer,
The method for producing a fiber-reinforced thermoplastic resin prepreg, characterized in that:   The method for producing a fiber-reinforced thermoplastic resin prepreg according to claim 1, wherein the uncured linear object is shaped into a predetermined wire diameter and linear shape in the drawing.   The method for producing a fiber-reinforced thermoplastic resin prepreg according to claim 1 or 2, further comprising (6) a pre-curing or thermosetting step following the step (4) of cooling and solidifying the resin coating layer.   2. The thermoplastic resin for surface coating forming the resin coating layer, the melting point of which is equal to or higher than the melting point of the matrix resin after thermosetting, and which is selected from resins having adhesive properties with the matrix resin. The method for producing a fiber-reinforced thermoplastic resin prepreg according to any one of claims 1 to 3.   2. The thermoplastic resin for surface coating forming the resin coating layer, the melting point of which is equal to or higher than the melting point of the matrix resin after thermosetting, and selected from non-adhesive resins with the matrix resin. The method for producing a fiber-reinforced thermoplastic resin prepreg according to any one of claims 1 to 3.   The fiber-reinforced heat obtained by the production method according to any one of claims 1 to 5, having a matrix resin having an unreacted epoxy group with a reinforcing fiber bundle and a weight average molecular weight of less than 30,000. Plastic resin prepreg.   A prepreg obtained by the method according to any one of claims 1 to 5, which is heated to cause a thermosetting or polymerization reaction of the matrix resin composition, and a matrix resin having a weight average molecular weight of 30,000 or more. A method for producing a fiber-reinforced thermoplastic resin.