JP2022098042A - Fiber-reinforced thermoplastic resin filament for 3d printer and molded article of the same - Google Patents

Abstract

To provide a fiber-reinforced thermoplastic resin filament for a 3D printer which has good flowability in filament molding and molding followability of a complicated shape, and expresses excellent dynamics properties applicable to a structural material, low variation, and excellent dimensional stability, and a molded article of the same.SOLUTION: A fiber-reinforced thermoplastic resin filament for a 3D printer, which is obtained by aligning a plurality of continuous reinforcement fibers in one direction to form a reinforced fiber bundle, and impregnating the reinforcement fibers with a thermoplastic resin, has a plurality of notches crossing the continuous reinforcement fibers.SELECTED DRAWING: Figure 1

Description

The present invention relates to a fiber-reinforced thermoplastic resin filament for a 3D printer and a molded product thereof.

The fiber-reinforced thermoplastic resin base material, which is made by impregnating a plurality of continuous reinforcing fibers with a thermoplastic resin, has excellent specific strength and rigidity, a high weight reduction effect, and high heat resistance and chemical resistance. It is preferably used for transportation equipment such as aircraft and automobiles, industrial use, sports, and various uses such as electric / electronic parts (for example, Patent Document 1 and Patent Document 2). In recent years, due to the increasing demand for weight reduction, the replacement of metal parts with resin parts and the miniaturization and modularization of parts are progressing mainly for aircraft and automobile applications, so that they have excellent moldability and are excellent in formability. There is a need to develop materials with excellent mechanical properties.

In recent years, a molding method in which a thermoplastic resin is melt-laminated, such as a 3D printing method, has attracted attention as a molding method for a fiber-reinforced thermoplastic resin base material. A method of producing a shape while melt-laminating a thermoplastic resin is being developed in various fields because it is advantageous in terms of cost (for example, Patent Document 3). As the fiber-reinforced thermoplastic resin base material applied to such a molding method, a method of extruding a reinforced fiber cut into short fibers together with a thermoplastic resin to produce a fiber-reinforced thermoplastic resin strand has been the mainstream. However, it is difficult to improve the fiber content of the short fiber reinforced thermoplastic resin base material, and the reinforcing effect is limited due to the short fiber length.

As a method of exhibiting a high reinforcing effect, a method of applying a continuous fiber reinforced thermoplastic resin base material as shown in Patent Document 4 has been studied.

Japanese Unexamined Patent Publication No. 2013-26171 Japanese Unexamined Patent Publication No. 5-50434 Special Table 2009-500194 Japanese Unexamined Patent Publication No. 2017-128072

In the method of molding a thermoplastic resin filament containing continuous fibers as shown in Patent Document 4 by the FDM (Fused Deposition Modeling) method (Fused Deposition Modeling Method), it is continuous when producing a modeled product having a complicated shape or a large curvature. It is necessary to fold the fibers many times, and if the continuous fibers are twisted or twisted at the folded portion, there is a problem that the strength of the portion is lowered.

In addition, a method of cutting continuous fibers at the folded portion to form a model is also conceivable, but for the purpose of increasing the strength of the modeled product by using the folded angle continuous fibers, a modeled product in which the fibers are cut at multiple points is used. There was a problem that the contradiction of making it occurred.

In view of the background of the prior art, the subject of the present invention is excellent mechanical properties applicable to structural materials, having good fluidity at the time of filament molding, molding followability of complicated shapes, and low variation thereof. It is an object of the present invention to provide a fiber-reinforced thermoplastic resin filament for a 3D printer, which exhibits properties and excellent dimensional stability, and a molded product thereof.

In order to solve the above problems, the present invention mainly has the following configurations.
[1] A fiber-reinforced thermoplastic resin filament for a 3D printer in which a plurality of continuous reinforcing fibers are aligned in one direction to form a reinforcing fiber bundle and the reinforcing fibers are impregnated with a thermoplastic resin, and the continuous reinforcing fibers. A fiber-reinforced thermoplastic resin filament for a 3D printer, characterized by having a plurality of cuts across the fiber.
[2] The fiber-reinforced thermoplastic resin filament for a 3D printer according to [1], wherein the fiber length of the reinforcing fiber cut by the notch is 3 mm or more and 100 mm or less.
[3] The fiber-reinforced thermoplastic resin filament for a 3D printer according to [1] or [2], wherein the depth of cut is 0.05 mm or more and less than 1 mm.
[4] The 3D printer according to any one of [1] to [3], wherein the absolute value θ of the angle between the notch and the reinforcing fiber in the longitudinal direction is 2 ° or more and 25 ° or less. Fiber reinforced thermoplastic resin filament.
[5] The fiber-reinforced thermoplastic resin filament for a 3D printer according to any one of [1] to [4], wherein the cut length is 0.05 mm or more and 25 mm or less.
[6] The 3D according to any one of [1] to [5], wherein the reinforcing fiber has a volume ratio of 15 to 85%, and the thermoplastic resin has a volume ratio of 85 to 15%. Fiber reinforced thermoplastic resin filament for printers.
[7] The fiber-reinforced thermoplastic resin filament for a 3D printer according to any one of [1] to [6], wherein the reinforcing fiber is at least one selected from carbon fiber, glass fiber, and aramid fiber.
[8] The thermoplastic resin is made of polyphenylene sulfide (PPS) resin, polyetherimide (PEI) resin, polyphenylene ether ether ketone (PEEK) resin, polyphenylene ether ketone (PEK) resin, and polyetherketone ketone (PEKK) resin. The fiber-reinforced thermoplastic resin filament for a 3D printer according to any one of [1] to [7], which is at least one selected.
[9] A molded product obtained by using the fiber-reinforced thermoplastic resin filament for a 3D printer according to any one of [1] to [8].

According to the present invention, a fiber-reinforced thermoplastic resin filament for a 3D printer, which is obtained by impregnating a plurality of continuous reinforcing fibers with a thermoplastic resin and having a plurality of cuts across the continuous reinforcing fibers, is stable in molding by a 3D printer due to the effect of the cuts. A molded product obtained by using this because it has excellent properties, has a filament length of a certain length or more, has a high fiber content, and is excellent in quality such as void ratio, uniformity of reinforcing fibers, and straightness of reinforcing fibers. Can be expected to have a high reinforcing effect.

It is an enlarged plan view which shows an example of the cut pattern of the cut fiber reinforced thermoplastic resin filament of this invention. It is an enlarged plan view which shows another example of the cut pattern of the cut fiber reinforced thermoplastic resin filament of this invention. It is a top view which shows the further example of the cut pattern of the cut fiber reinforced thermoplastic resin filament of this invention. It is a top view which shows an example of the molding which incorporated the cut fiber reinforced thermoplastic resin filament of this invention into a 3D printer.

Hereinafter, the present invention will be described in detail together with embodiments.

The fiber-reinforced thermoplastic resin filament for a 3D printer according to the present invention is formed by aligning a plurality of continuous reinforcing fibers in one direction to form a reinforcing fiber bundle, and impregnating the reinforcing fibers with a thermoplastic resin. It is characterized by having multiple cuts across a series of reinforcing fibers.

In the present invention, the continuous reinforcing fiber means a fiber in which the reinforcing fiber is substantially uninterrupted in the fiber-reinforced thermoplastic resin. Ideally, all the single yarns in the filament are not interrupted, but if 80% or more of the single yarns are not interrupted, it can be said that the state is "uninterrupted". Examples of the form and arrangement of the reinforcing fibers in the present invention include those aligned in one direction, braids, tows and the like. Above all, it is preferable that the reinforcing fibers are arranged in one direction because the mechanical properties in a specific direction can be efficiently enhanced.

The type of the reinforcing fiber is not particularly limited, and examples thereof include inorganic fibers such as carbon fibers, metal fibers, and organic fibers. Two or more of these may be used.

Examples of the carbon fiber include PAN-based carbon fiber made from polyacrylonitrile (PAN) fiber, pitch-based carbon fiber made from petroleum tar or petroleum pitch, and cellulose-based carbon made from viscose rayon or cellulose acetate. Examples thereof include vapor-phase growth-based carbon fibers made from fibers and hydrocarbons, and these graphitized fibers. Among these carbon fibers, PAN-based carbon fibers are preferably used because they have an excellent balance between strength and elastic modulus.

Examples of the metal fiber include fibers made of a metal such as iron, gold, silver, copper, aluminum, brass, and stainless steel.

Examples of the organic fiber include fibers made of an organic material such as aramid, polybenzoxazole (PBO), polyphenylene sulfide, polyester, polyamide, and polyethylene. Examples of the aramid fiber include a para-based aramid fiber having excellent strength and elastic modulus, and a meta-based aramid fiber having excellent flame retardancy and long-term heat resistance. Examples of the para-aramid fiber include polyparaphenylene terephthalamide fiber and copolyparaphenylene-3,4'-oxydiphenylene terephthalamide fiber, and examples of the meta-type aramid fiber include polymethaphenylene isophthalamide fiber. Can be mentioned. As the aramid fiber, a para-type aramid fiber having a higher elastic modulus than the meta-type aramid fiber is preferably used.

Examples of other inorganic fibers include fibers made of an inorganic material such as glass, basalt, silicon carbide, and silicon nitride. Examples of the glass fiber include E glass fiber (for electricity), C glass fiber (for corrosion resistance), S glass fiber, and T glass fiber (high strength and high elasticity). Basalt fiber is a fiber made from basalt, which is a mineral, and has extremely high heat resistance. Basalt generally contains 9-25% by weight of the iron compound FeO or FeO ₂ and 1-6% by weight of the titanium compound TiO or TiO ₂ , but the amount of these components is increased in the molten state. It is also possible to make it into fibers.

Since the fiber-reinforced thermoplastic resin filament in the embodiment of the present invention is often expected to serve as a reinforcing material, it is desirable to exhibit high mechanical properties, and in order to exhibit high mechanical properties, the reinforcing fiber is desired. It is preferably at least one selected from carbon fiber, glass fiber and aramid fiber. Above all, it is more preferable to contain carbon fiber.

The fiber-reinforced thermoplastic resin filament of the present invention has good fluidity, molding followability of a complicated shape, and is continuously reinforced in order to exhibit excellent mechanical properties, its low variation, and excellent dimensional stability. It is characterized by having a plurality of cuts in the fiber. By inserting a specific cut pattern into a specific base material called a fiber-reinforced thermoplastic resin filament composed of unidirectionally aligned reinforcing fibers and a matrix resin, and forming the filament base material in 3D, such a problem can be solved. It was found that the solution would be solved at once. The filament base material used in the present invention includes reinforcing fibers aligned in one direction and a reinforcing fiber base material completely impregnated with resin, and the fibers are not completely impregnated with resin. It is assumed that the resin semi-impregnated base material (semi-preg: hereinafter, also referred to as semi-impregnated prepreg) integrated with the above is included.

In the fiber-reinforced thermoplastic resin filament of the present invention, it is preferable that the fiber length L of the reinforced fiber cut by the cut is 3 mm or more and 100 mm or less. In the present invention, the fiber length L refers to the length of the reinforcing fiber divided by an arbitrary cut and an equivalent cut paired with the arbitrary cut, as shown by an example in reference numeral 6 in FIG. .. By inserting a notch in the entire surface of the fiber-reinforced thermoplastic resin filament and setting the fiber length L of all the fiber length L of the fiber-reinforced thermoplastic resin filament to 100 mm or less, the fiber can flow during modeling, especially in the fiber longitudinal direction. Because it can flow, it is also excellent in molding followability for complicated shapes. If there is no notch, that is, if only continuous fibers are used, the fibers do not flow in the longitudinal direction of the fibers, so that a complicated shape cannot be formed at the time of modeling. When the fiber length L is less than 3 mm, the fluidity is further improved, but the high mechanical properties required for the structural material cannot be obtained even if other requirements are satisfied. Considering the relationship between fluidity and mechanical properties, L is more preferably in the range of 20 to 60 mm.

The fiber-reinforced thermoplastic resin filament of the present invention preferably has a depth of cut H of 0.05 mm or more and less than 1 mm from the viewpoint of mechanical properties. Since the strength tends to decrease as the depth of cut becomes deeper, it is possible to greatly improve the strength and secure the fluidity by reducing H. H is more preferably 0.1 mm or more and 0.5 mm or less, and further preferably 0.2 mm or more and 0.4 mm or less.

In the present invention, it is preferable that the absolute value θ of the angle formed by the notch and the longitudinal direction of the reinforcing fiber is 2 ° or more and 25 ° or less. Even if θ is larger than 25 °, fluidity and high mechanical properties can be obtained, but when θ is 25 ° or less, the mechanical properties are significantly improved. On the other hand, if θ is smaller than 2 °, sufficient fluidity and mechanical properties can be obtained, but it becomes difficult to make a stable cut. That is, when the notch falls on the fiber, the fiber easily escapes from the blade when making the notch. Considering the relationship between the ease of control of the cut and the mechanical properties, it is more preferably in the range of 5 to 15 °.

Hereinafter, an example of a preferable cutting pattern will be described with reference to FIGS. 1 to 3.

FIG. 1 shows a fiber-reinforced thermoplastic resin filament in which a plurality of controlled cuts 4 are formed at equal intervals on a fiber-reinforced thermoplastic resin filament made of continuously reinforced fibers. The fiber is divided between the paired notches 4 in the fiber longitudinal direction, and the interval (fiber length L) 6 is set to 3 to 100 mm so that substantially all of the reinforcing fibers on the fiber-reinforced thermoplastic resin filament can be formed. The fiber length L can be set to 3 to 100 mm. In addition, "substantially all of the reinforcing fibers are divided by the notch" means that 95% or more of the number of reinforcing fibers contained in the fiber-reinforced thermoplastic resin filament is divided into 10 to 100 mm. To tell. It is preferable that the fiber length L is constant over the entire surface because the fluidity can be easily controlled and the strength variation can be further suppressed.

Further, as shown in FIGS. 1 to 3, when the angle 5 formed by the notch and the reinforcing fiber is θ, the absolute value of θ is preferably in the range of 2 to 25 ° over the entire surface.

FIG. 2 shows fiber reinforced thermoplastic resin filaments with different notch patterns. The fiber-reinforced thermoplastic resin filament 7 of FIG. 2 has notches arranged at two types of spacing. It is preferable to change the cutting interval as shown in FIG. 2 because it becomes easier to partially control the fluidity at the time of modeling.

FIG. 3 shows a fiber-reinforced thermoplastic resin filament having a notch pattern different from that of FIGS. 1 and 2. The fiber-reinforced thermoplastic resin filament 7 of FIG. 3 has notches arranged at two different angles. It is preferable to change the angle of cut as shown in FIG. 3 because it becomes easier to partially control the fluidity at the time of modeling.

The cuts shown in FIGS. 2 and 3 show an example, and the cut intervals and angles and the cut length T may be different from each other. By combining them well, the mechanical properties and the time of modeling can be obtained. It is possible to arbitrarily control the liquidity of.

In the present invention, the cut length T can be arbitrarily set, but the cut length is preferably 0.05 mm or more and 25 mm or less, and more preferably 0.1 mm or more and 5 mm or less.

In order to obtain the notched fiber-reinforced thermoplastic resin filament of the present invention, as a method of making a notch in the fiber-reinforced thermoplastic resin filament, first, a fiber-reinforced thermoplastic resin filament is prepared, and then manual work or cutting using a cutter is performed. There is a method of making a notch by a machine, or a method of continuously pressing a rotating roller having a blade arranged at a predetermined position in a process of manufacturing a fiber-reinforced thermoplastic resin filament. The former is suitable for simply making a cut in the fiber-reinforced thermoplastic resin filament, and the latter is suitable for mass production in consideration of production efficiency. In the present invention, since the cutting angle is small, the amount of fibers to be cut per unit length of the blade is reduced, and the fibers can be cut with a small force, so that the durability of the blade can be improved. When using a rotating roller, the roller may be directly machined to provide a predetermined blade, but a flat plate may be machined from a magnet roller or the like and a sheet-shaped mold with the blade arranged at a predetermined position may be wound around it. This is preferable because the blade can be easily replaced. By using such a rotating roller, it is possible to satisfactorily insert a notch even with a notch fiber reinforced thermoplastic resin filament having a small notch depth (specifically, even if it is 1 mm or less).

In the fiber-reinforced thermoplastic resin filament used in the present invention, the reinforcing fiber is usually composed of one or a plurality of reinforcing fiber bundles in which a large number of single fibers are bundled. The number of single fibers of the reinforcing fibers when one or a plurality of reinforcing fiber bundles are arranged is preferably 500 to 50,000. From the viewpoint of handleability, the number of single fibers of the reinforcing fiber is more preferably 1,000 to 50,000, further preferably 1,000 to 40,000, and particularly preferably 1,000 to 30,000. .. The upper limit of the number of single fibers of the reinforcing fiber may be such that the dispersibility and handleability can be kept good in consideration of the balance with the quality and handleability such as voids and dispersibility.

In the present invention, the outermost layer of the fiber-reinforced thermoplastic resin filament can be coated with the thermoplastic resin. By covering the outer peripheral portion with a thermoplastic resin, the adhesiveness at the time of molding can be improved. The resin to be coated may be the same as the fiber-reinforced thermoplastic resin filament, or may be a different resin.

The fiber-reinforced thermoplastic resin filament in the present invention has a thermoplastic resin layer on at least a part of the outer peripheral portion of the filament, and the volume ratio of the thermoplastic resin layer present on at least a part of the outer peripheral part of the filament is the fiber-reinforced heat. It is preferably 50% or less with respect to the total volume of the plastic resin filament. The presence of the resin layer on the outer peripheral portion of the filament can improve the adhesiveness between the filaments (horizontal direction or vertical direction) during 3D printing molding.

The thermoplastic resin layer may be in a state of completely covering the outer peripheral portion of the filament, or may be partially present on the outer peripheral portion. Further, the thermoplastic resin layer to be coated may be the same thermoplastic resin as the fiber-reinforced thermoplastic resin filament, or may be a different thermoplastic resin.

If the volume ratio of the thermoplastic resin layer present in at least a part of the outer peripheral portion of the filament becomes too large with respect to the volume of the entire fiber-reinforced thermoplastic resin filament, the resin layer in which the reinforcing fiber does not exist at the time of molding is used. Material destruction will occur, and if the amount is too small, the effect of improving the adhesiveness between the filaments will be small. Therefore, the volume ratio of the thermoplastic resin layer may be 50% or less of the total volume of the fiber-reinforced thermoplastic resin filament. It is preferable, more preferably 20% or less, still more preferably 10% or less. The lower limit is not particularly limited, but is preferably 1% or more.

The proportion of the thermoplastic resin layer was evaluated by observing the cross section of the fiber-reinforced thermoplastic resin filament in the thickness direction as follows.

(Evaluation method of the ratio of the thermoplastic resin layer)
A sample in which the fiber-reinforced thermoplastic resin filament as a sample is embedded in epoxy resin is prepared, and the sample is polished until a cross section perpendicular to the axial direction of the fiber-reinforced thermoplastic resin filament can be observed well. did. The polished sample was photographed at a magnification of 300 times using an ultra-depth color 3D shape measuring microscope VHX-9500 (controller unit) / VHZ-100R (measurement unit) (manufactured by KEYENCE CORPORATION).

The cross-sectional area of the fiber-reinforced thermoplastic resin filament and the area of the thermoplastic resin layer are obtained from the photographed cross-sectional image, and the volume ratio of the thermoplastic resin layer is calculated by the following formula (1). This was carried out in three cross sections, and the arithmetic mean value was taken as the volume ratio of the thermoplastic resin layer.
Volume ratio of the thermoplastic resin layer (%) = 100 × (total area of the thermoplastic resin layer) / (total area of the fiber-reinforced thermoplastic resin filament) ... (1)

If the interface of the thermoplastic resin layer is difficult to see from the cross-sectional photograph, an circumscribing circle is drawn with reference to the outermost reinforcing fiber of the fiber-reinforced thermoplastic resin filament, and the inside thereof is used as the fiber-reinforced thermoplastic resin filament portion. By forming the outside thereof as a thermoplastic resin layer, the volume ratio of the thermoplastic resin layer is determined.

One reinforcing fiber bundle is preferably composed of 500 to 50,000 single fibers of reinforcing fibers having an average diameter of 5 to 10 μm.

In the fiber-reinforced thermoplastic resin filament according to the present invention, it is preferable that the thermoplastic resin is a polymer alloy. By using a thermoplastic polymer alloy resin, impregnation property, mechanical properties, and adhesiveness can be improved. For example, by using a thermoplastic resin as a polymer alloy composed of a high-viscosity thermoplastic resin and a low-viscosity thermoplastic resin, both high mechanical properties and impregnation properties can be achieved. Further, by using a polymer alloy in which the thermoplastic resin is combined with a resin having high toughness, the interlayer strength when the fiber-reinforced thermoplastic resin filament is formed is improved.

Examples of the thermoplastic resin used in the present invention include polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, polytrimethylene terephthalate (PTT) resin, polyethylene naphthalate (PEN) resin, and liquid crystal polyester resin. Polyethylene, polyethylene (PE) resin, polypropylene (PP) resin, polybutylene resin and other polyolefins, styrene resin, polyoxymethylene (POM) resin, polyamide (PA) resin, polycarbonate (PC) resin, polymethylene Methacrylate (PMMA) resin, polyvinyl chloride (PVC) resin, polyphenylene sulfide (PPS) resin, polyphenylene ether (PPE) resin, modified PPE resin, polyimide (PI) resin, polyamideimide (PAI) resin, polyetherimide (PEI) ) Resin, polysulfone (PSU) resin, modified PSU resin, polyether sulfone resin, polyketone (PK) resin, polyether ketone (PEK) resin, polyether ether ketone (PEEK) resin, polyether ketone ketone (PEKK) resin, Fluorine resins such as polyarylate (PAR) resin, polyether nitrile resin, phenol resin, phenoxy resin, polytetrafluoroethylene resin, and polystyrene resin, polyolefin resin, polyurethane resin, polyester resin, polyamide resin , Polybutadiene-based resin, polyisoprene-based resin, fluororesin and other thermoplastic elastomers, copolymers and modified products thereof, and resins blended with two or more kinds thereof may be used. In particular, from the viewpoint of heat resistance and long-term durability, polyphenylene sulfide resin, polyarylene ether ketone resin, polyetherimide resin, polyether sulfone resin, and liquid crystal polymer resin are more preferable.

Examples of the polyetherketone (PAEK) resin include polyetherketone (PEK) resin, polyetheretherketone (PEEK) resin, polyetheretherketoneketone (PEEKK) resin, and polyetherketoneketone (PEKK) resin. Polyetherketone etherketoneketone (PEKEKK) resin, polyetheretherketone etherketone (PEEKEK) resin, polyetheretheretherketone (PEEEK) resin, polyetherdiphenyletherketone (PEDEK) resin and the like, copolymers thereof, modifications thereof. It may be a body, a resin blended with two or more kinds, and the like.

The polymer alloy constituting the thermoplastic resin in the present invention is a fiber-reinforced thermoplastic resin filament in which the polymer alloy has a biphasic continuous structure having a structural period of 0.001 to 10 μm, or the polymer alloy has a particle diameter of 0.001. It is preferable to form a sea-island structure composed of an island phase of about 10 μm and a sea phase. High mechanical properties and heat resistance can be exhibited by controlling the structure to be a biphasic continuous structure in the range of 0.001 μm to 10 μm or a sea island structure consisting of an island phase and a sea phase in the particle size range of 0.001 to 1 μm. It is more preferable to form a biphasic continuous structure in the range of 0.01 μm to 5 μm, or a sea island structure consisting of an island phase and a sea phase in the particle size range of 0.01 to 5 μm, both in the range of 0.1 μm to 1 μm. A phase continuous structure or a particle size in the range of 0.05 to 1 μm is more preferable.

Further, in order to confirm these two-phase continuous structures or dispersed structures, it is preferable to confirm a regular periodic structure. This is because, for example, in addition to confirming that a biphasic continuous structure is formed by observation with an optical microscope or observation with a transmission electron microscope, the scattering maximum is achieved in the scattering measurement performed using a small angle X-ray scattering device or a light scattering device. It is necessary to confirm that it will appear. The existence of the scattering maximum in this scattering measurement is a proof of having a regular phase-separated structure with a certain period, and the period Λm (nm) corresponds to the structural period in the case of a two-phase continuous structure and in the case of a dispersed structure. Corresponds to the interparticle distance. Further, the value can be calculated by the equation (2) using the wavelength λ (nm) in the scattering body of the scattered light and the scattering angle θm (deg °) that gives the scattering maximum.
Λm = (λ / 2) / sin (θm / 2) ... (2)

Further, even if the size of the structural period in the two-phase continuous structure or the distance between particles in the dispersed structure is within the above range, if there is a partially structurally coarse portion, for example, when an impact is received, that is the starting point. The original polymer alloy characteristics may not be obtained, such as the progress of destruction. Therefore, the uniformity of the interparticle distance in the structural period or dispersed structure in the biphasic continuous structure of the polymer alloy is important. This uniformity can be evaluated by the small-angle X-ray scattering measurement or the light scattering measurement of the polymer alloy described above. Since the phase-separated structure size that can be analyzed differs between the small-angle X-ray scattering measurement and the light scattering measurement, it is necessary to use them appropriately according to the phase-separated structure size of the polymer alloy to be analyzed. Small-angle X-ray scattering and light scattering measurements provide information about the size of the structural period in a biphasic continuous structure or the interparticle distance in a dispersed structure, as well as its distribution. Specifically, the peak position of the scattering maximum in the spectra obtained by these measurements, that is, the scattering angle θm (deg °) corresponds to the size of the structural period in the biphasic continuous structure or the interparticle distance in the dispersed structure, and the peak of the peak position. The way it spreads corresponds to the uniformity of the structure. In order to obtain physical properties such as excellent mechanical properties, it is preferable that the structure uniformity is high, and the polymer alloy in the present invention has a maximum scattering spectrum obtained by small-angle X-ray scattering measurement or light scattering measurement. It is characterized by.

The fiber-reinforced thermoplastic resin filament of the present invention is obtained by impregnating a plurality of continuous reinforcing fibers with the above-mentioned thermoplastic resin, and if necessary, further, a filler, other kinds of polymers, various additives, etc. May be contained.

As the filler, any material generally used as a filler for resin can be used, and the strength, rigidity, heat resistance, and dimensional stability of the fiber-reinforced thermoplastic resin base material and the molded product using the same can be further improved. be able to. Examples of the filler include glass fiber, carbon fiber, potassium titanate whisker, zinc oxide whisker, aluminum borate whisker, aramid fiber, alumina fiber, silicon carbide fiber, ceramic fiber, asbestos fiber, stone fiber, metal fiber and the like. Fibrous inorganic filler, warastenite, zeolite, sericite, kaolin, mica, talc, clay, pyrophyllite, bentonite, montmorillonite, asbestos, aluminosilicate, alumina, silicon oxide, magnesium oxide, zirconium oxide, titanium oxide, oxidation Non-fibrous inorganic fillers such as iron, calcium carbonate, magnesium carbonate, dolomite, calcium sulfate, barium sulfate, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, glass beads, ceramic beads, boron nitride, silicon carbide, silica, etc. Can be mentioned. Two or more of these may be contained. These fillers may be hollow. Further, it may be treated with a coupling agent such as an isocyanate-based compound, an organic silane-based compound, an organic titanate-based compound, an organic borane-based compound, and an epoxy compound. Further, as the montmorillonite, organic montmorillonite in which the interlayer ion is cation-exchanged with an organic ammonium salt may be used. If the fibrous filler is made of discontinuous fibers, it can be provided with a function without impairing the reinforcing effect of the reinforcing fibers made of continuous fibers.

Examples of various additives include antioxidants, heat-stabilizing agents (hindered phenol-based, hydroquinone-based, phosphite-based and their substitutes, copper halides, iodine compounds, etc.), and weather-resistant agents (resorcinol-based, salicylate-based). , Benzotriazole, benzophenone, hinderedamine, etc.), antistatic agents and lubricants (aliphatic alcohol, aliphatic amide, aliphatic bisamide, bisurea, polyethylene wax, etc.), pigments (cadmium sulfide, phthalocyanine, carbon black, etc.) , Dyes (niglocin, aniline black, etc.), plasticizers (octyl p-oxybenzoate, N-butylbenzene sulfonamide, etc.), antistatic agents (alkylsulfate-type anionic antistatic agents, quaternary ammonium salt-type cationic antistatic agents) Antistatic agents, non-ionic antistatic agents such as polyoxyethylene sorbitan monostearate, betaine-based antistatic agents, etc.), flame retardant agents (melamine cyanurate, hydroxides such as magnesium hydroxide, aluminum hydroxide, polyphosphoric acid) Ammonium, brominated polystyrene, brominated polyphenylene oxide, brominated polycarbonate, brominated epoxy resin, or a combination of these brominated flame retardants and trioxide antimon, etc.) and the like. Two or more of these may be blended.

The fiber-reinforced thermoplastic resin filament of the present invention can be obtained by impregnating a plurality of continuous reinforcing fibers with a thermoplastic resin, and as an impregnation method, for example, a film-shaped thermoplastic resin is melted and pressed. This is a film method in which the reinforcing fiber bundle is impregnated with the thermoplastic resin. After blending the fibrous thermoplastic resin and the reinforcing fiber bundle, the fibrous thermoplastic resin is melted and pressed to heat the reinforcing fiber bundle. Comingle method impregnated with plastic resin, powdered thermoplastic resin is dispersed in the gaps between fibers in the reinforced fiber bundle, and then the powdered thermoplastic resin is melted and pressed to apply the thermoplastic resin to the reinforced fiber bundle. Examples thereof include a powder method of impregnating the reinforcing fiber bundle and a drawing method of impregnating the reinforcing fiber bundle with the thermoplastic resin by immersing the reinforcing fiber bundle in the molten thermoplastic resin and applying pressure. The extraction method is preferable because it is possible to produce a wide variety of fiber-reinforced thermoplastic resin filaments having various thicknesses and fiber volume contents.

In the fiber-reinforced thermoplastic resin filament of the present invention, the average value S of the roundness parameters s of the cross section evaluated by the following method is 60% or more, and a plurality of perfect circles used for calculating the average value S. It is preferable that the coefficient of variation of the diameter length of the circumscribing circle, which is the basis of the degree parameter s, is 0% to 10%. The average value S is 60% or more, and the coefficient of variation of the diameter length of the circumscribed circle, which is the source of the plurality of roundness parameters s used to calculate the average value S, is 0% to 10%. As a result, process passability and modeling stability are improved. The average value S of the roundness parameter s is more preferably 70% or more, and further preferably 80% or more. Further, the coefficient of variation of the diameter length of the circumscribed circle, which is the source of the plurality of roundness parameters s used to calculate the mean value S, is more preferably 5% or less, and further preferably 3% or less. preferable.

(Calculation of the average value S of the roundness parameter s)
(I) Take a photograph of the cross section perpendicular to the axial direction of the fiber-reinforced thermoplastic resin filament.
(Ii) Draw an inscribed circle and a circumscribed circle of the filament in the cross-sectional image, and obtain the diameter and length of each.
(Iii) The roundness parameter s defined by the following equation (3) is calculated.
(Iv) The procedure of (i) to (iii) is repeated at a plurality of locations of the fiber-reinforced thermoplastic resin filament for the 3D printer, and the average value S of the roundness parameter s is calculated.
Roundness parameter s = diameter of inscribed circle / diameter of circumscribed circle x 100 ... (3)

(Evaluation method of coefficient of variation)
The fiber-reinforced thermoplastic resin filament as a sample is embedded in an epoxy resin "Epoquick" (registered trademark: manufactured by Buehler) and cured at room temperature for 24 hours, and then in the orientation direction of the reinforcing fiber in the fiber-reinforced thermoplastic resin filament. The vertical cross section is polished, and then the polished surface is magnified 300 times using an ultra-deep color 3D shape measuring microscope VHX-6000 (controller part) / VH-ZST (measuring part) (manufactured by Keyence Co., Ltd.). Taken at. The imaging range was the range in which the entire cross section of the fiber-reinforced thermoplastic resin filament was captured. About the cross-sectional photograph of the fiber thermoplastic resin filament taken, draw a circle inscribed in the filament shape (including the outermost resin layer) and a circle inscribed, and calculate the diameter and length of each, and use the equation (1) to determine the roundness parameter. s was calculated. The polished surface was photographed over 20 or more sheets while changing the cross-sectional observation position of the fiber-reinforced thermoplastic resin filament, and the roundness parameter s of the fiber-reinforced thermoplastic resin filament obtained from each cross-sectional photograph was taken. The average value S may be obtained, and the roundness of the fiber-reinforced thermoplastic resin filament can be quantitatively evaluated from the value.

Further, the coefficient of variation of the plurality of roundness parameters s used for calculating the average value S is obtained from the equation (4), and the coefficient of variation is preferably 10% or less. Fiber-reinforced thermoplastic resin filaments with a coefficient of variation of more than 10% have poor process passability and cause clogging and the like. The coefficient of variation is more preferably 5% or less, further preferably 3% or less.
Coefficient of variation (%) = standard deviation of roundness parameter s / mean value of roundness parameter s × 100 ... (4)

Further, the coefficient of variation of the circumscribed circle, which is the source of the plurality of roundness parameters s used for calculating the mean value S, is obtained from the equation (5), and the coefficient of variation is preferably 10% or less. Fiber-reinforced thermoplastic resin filaments with a coefficient of variation of more than 10% do not have stable filament thickness, and the discharge rate during 3D printing becomes unstable, which causes deterioration in the quality of molded products. The coefficient of variation is more preferably 5% or less, further preferably 3% or less.
Coefficient of variation (%) = standard deviation of circumscribed circle diameter length / mean value of circumscribed circle diameter length x 100 ... (5)

Further, in the fiber-reinforced thermoplastic resin filament of the present invention, it is preferable that the ratio of the absolute value of the orientation angle of the reinforcing fibers with respect to the filament axial direction defined by the following method being 0 to 4 degrees is 90% or more of the whole. .. When the ratio of the absolute value of the orientation angle of the reinforcing fibers to 0 to 4 degrees is 90% or more of the whole, the strength utilization rate of the reinforcing fibers is high and an excellent reinforcing effect can be expected. It is more preferably 0 to 2 degrees, and even more preferably 0 to 1 degree. Further, the ratio is more preferably 93% or more, further preferably 95% or more.

(Evaluation method of the ratio of the orientation angle of the reinforcing fibers)
A fiber-reinforced thermoplastic resin filament as a sample was sampled to a length of 20 mm, embedded in an epoxy resin "Epoquick" (registered trademark: manufactured by Buehler), and cured at room temperature for 24 hours. Then, the vertical cross section of the fiber-reinforced thermoplastic resin filament, which was substantially parallel to the orientation direction of the reinforcing fibers, was polished to half the filament thickness. Next, the polished surface is imaged using an ultra-deep color 3D shape measurement microscope VHX-6000 (controller unit) / VH-ZST (measurement unit) (manufactured by KEYENCE CORPORATION) so that the entire vertical cross section with a length of 20 mm can be captured. The image was taken at a magnification of 200 times using the connection function.

The image angle was adjusted so that the filament axial direction was horizontal (0 degree) using the image processing software GIMP for the photograph of the longitudinal cross section of the photographed fiber thermoplastic resin filament. Then, using the image processing software Image j, binarization processing was performed at a value at which the contour of the reinforcing fiber could be clearly discriminated. Image j was used to approximate an ellipse to the image subjected to the binarization treatment, and the orientation angle (Angle) of the ellipse was obtained. Regarding the result of ellipse approximation, in order to exclude polishing debris and noise at the time of binarization, the result of the major axis (Major) value smaller than 50 was deleted, and only the result of ellipse approximation of the reinforcing fiber was extracted. After converting the orientation angle of the reinforcing fibers into the display of −90 degrees to 90 degrees for the extracted results, the absolute value was obtained, and a histogram was created to obtain the ratio of the orientation angles. The value of the main axis (Major) is an example and is easily affected by the brightness and noise of the captured image. Therefore, a value that can clearly distinguish between the reinforcing fiber and noise is manually obtained by comparing with the binarized image. You may.

Further, the length of the fiber-reinforced thermoplastic resin filament of the present invention is preferably 1 m or more. When the length is 1 m or more, the thermoplastic resin can be continuously molded, and when the reinforcing fibers are continuous, a high reinforcing effect can be expected.

The thickness of the fiber-reinforced thermoplastic resin filament of the present invention is preferably 0.01 to 3 mm. When the thickness is 0.01 mm or more, the strength of the molded product obtained by using the fiber-reinforced thermoplastic resin filament can be improved. 0.1 mm or more is more preferable. On the other hand, when the thickness is 3 mm or less, the flexibility of the fiber-reinforced thermoplastic resin filament can be ensured and the handleability at the time of molding is improved. 2 mm or less is more preferable, and 1 mm or less is further preferable. The thickness was measured by measuring 20 points at arbitrary positions of the fiber-reinforced thermoplastic resin filament with a caliper and obtaining the average value.

The bending rigidity of the fiber-reinforced thermoplastic resin filament of the present invention is preferably 1 N · m ² or less. If the bending rigidity is 1 N · m ² or less, the flexibility of the filament can be ensured and the handleability at the time of molding is improved. 0.1 N · m ² or less is more preferable, 0.01 N · m ² or less is further preferable, and 0.005 N · m ² or less is particularly preferable.

The fiber volume content (Vf) of the fiber-reinforced thermoplastic resin filament of the present invention is 15% by volume or more and 85% by volume or less of the reinforcing fiber when the entire fiber-reinforced thermoplastic resin filament is 100% by volume. Is preferable. By containing 15% by volume or more of the reinforcing fiber, the strength of the molded product obtained by using the fiber-reinforced thermoplastic resin filament can be further improved. Vf is more preferably 30% by volume or more, further preferably 40% by volume or more. On the other hand, by containing 85% by volume or less of the reinforcing fiber, it is easier to impregnate the reinforcing fiber with thermoplasticity. The reinforcing fibers in the fiber-reinforced thermoplastic resin filament are more preferably 75% by volume or less, further preferably 70% by volume or less.

(Vf evaluation method)
For the volume content Vf of the fiber-reinforced thermoplastic resin filament, after measuring the mass W0 (g) of the fiber-reinforced thermoplastic resin filament, the continuous fiber-reinforced thermoplastic resin filament is heated in air at 550 ° C. for 3 hours to heat it. The plastic resin component was burned off, and the mass W1 (g) of the remaining reinforcing fiber was measured and calculated by the formula (6).
Vf (volume%) = (W1 / ρf) / {W1 / ρf + (W0-W1) / ρr} × 100 ... (6)
ρf: Density of reinforcing fibers (g / cm ³ )
ρr: Thermoplastic resin density (g / cm ³ )

The fiber-reinforced thermoplastic resin filament of the present invention preferably has a void ratio of 10% or less in the fiber-reinforced thermoplastic resin filament. When the void ratio is 10% or less, the mechanical properties of the fiber-reinforced thermoplastic resin filament can be exhibited without impairing the mechanical properties of the reinforcing fibers. 5% or less is more preferable, and 2% or less is further preferable.

(Evaluation method of void rate)
The void ratio of the fiber-reinforced thermoplastic resin filament was determined by observing the cross section of the fiber-reinforced thermoplastic resin filament in the thickness direction as follows. After embedding the fiber-reinforced thermoplastic resin filament in the epoxy resin "Epoquick" (registered trademark: manufactured by Buehler) and curing it at room temperature for 24 hours, the thickness direction cross section of the fiber-reinforced thermoplastic resin filament can be observed well. The sample was polished until it became. The polished sample was photographed at a magnification of 300 times using an ultra-depth color 3D shape measurement microscope VHX-6000 (controller unit) / VH-ZST (measurement unit) (manufactured by KEYENCE CORPORATION). The imaging range was the range in which the entire cross section of the fiber-reinforced thermoplastic resin filament was captured. In the photographed image, the total cross-sectional area of the fiber-reinforced thermoplastic resin filament and the area of the portion having a void (void) were obtained, and the impregnation rate was calculated by the formula (7).
Void ratio (%) = 100 × (total area occupied by voids) / (total area of fiber-reinforced thermoplastic resin filament) ... (7)

The fiber-reinforced thermoplastic resin filament for a 3D printer of the present invention preferably has an average value D of the dispersion parameter d (%) defined by the following method of 90% or more. When the average value D is 90% or more, it is possible to reduce the variation in the mechanical properties of the fiber-reinforced thermoplastic resin filament.

(Calculation of the average value D of the variance parameter d (%))
(I) Take a photograph of the cross section perpendicular to the axial direction of the filament so that the entire cross section of the fiber-reinforced thermoplastic resin filament for the 3D printer can be seen.
(Ii) The entire cross-sectional image is divided into square units having a side length defined by the formula (8).
(Iii) The variance parameter d (%) defined by the equation (9) is calculated.
(Iv) The procedure of (i) to (iii) is repeated at a plurality of locations of the fiber-reinforced thermoplastic resin filament for the 3D printer, and the average value D of the dispersion parameter d is calculated.
1.5a ≤ t ≤ 2.5a (a: fiber diameter, t: length of one side of the unit) ... (8)
Dispersion parameter d (%) = number of units containing reinforcing fibers in the evaluation section / number of all units including even a part of filament in the evaluation section × 100 ... (9)

(Evaluation method of variance parameter d and mean value D)
The fiber-reinforced thermoplastic resin filament as a sample is embedded in an epoxy resin "Epoquick" (registered trademark: manufactured by Buehler) and cured at room temperature for 24 hours, and then in the orientation direction of the reinforcing fiber in the fiber-reinforced thermoplastic resin filament. The vertical cross section is polished, and then the polished surface is magnified 300 times using an ultra-deep color 3D shape measuring microscope VHX-6000 (controller part) / VH-ZST (measuring part) (manufactured by Keyence Co., Ltd.). Taken at. The imaging range was the range in which the entire cross section of the fiber-reinforced thermoplastic resin filament was captured. Image analysis was performed on the photographed cross-sectional view of the fiber thermoplastic resin filament using Imagej, and the photograph was divided into substantially square units having the length of one side and not overlapping with each other. The substantially square units were image-analyzed in order, the units containing the reinforcing fibers in the substantially square units were counted, and the dispersion parameter d was calculated from the equation (9). The above image processing is obtained by calculating the number of units containing reinforcing fibers in the unit with respect to the number of units containing even a part of the filament in the partitioned substantially square unit. In principle, the discriminant analysis method is used for binarization, but in some cases it is possible to perform it manually while comparing it with the photograph taken. Further, the reinforcing fibers contained in the unit are counted if even a part of the reinforcing fibers is contained, and even if two or more reinforcing fibers are contained, the unit is counted as one. While changing the cross-sectional observation position of the fiber-reinforced thermoplastic resin filament, the polished surface was photographed over 20 or more sheets, and the average of the dispersion parameter d of the fiber-reinforced thermoplastic resin filament obtained from each cross-sectional photograph was taken. The value D may be obtained, and from that value, the distribution state of the reinforcing fibers in the fiber-reinforced thermoplastic resin filament can be quantitatively evaluated.

The size of the unit determined by the formula (8) is defined by the relation with the diameter of the observed reinforcing fiber. If the size of the unit is smaller than the range of the equation (8), the dispersion parameter is converged on the volume content and the dispersibility cannot be accurately expressed. On the other hand, if it is larger than the range of the equation (8), the value is constant regardless of whether the dispersibility is good or bad, and is not accurate. Therefore, the size of the unit is preferably in the range of the formula (8).

Further, the coefficient of variation of the plurality of variance parameters d used to calculate the average value D can be obtained from the equation (10). The density of the reinforcing fibers increases at each location in the fiber-reinforced thermoplastic resin filament having a coefficient of variation of more than 4%. Therefore, the coefficient of variation is preferably 4% or less, more preferably 3% or less.
Coefficient of variation (%) = standard deviation of variance parameter d / mean value of variance parameter d × 100 ... (10)

As described above, in the fiber-reinforced thermoplastic resin filament according to the embodiment of the present invention, the ratio of the absolute value of the orientation angle of the reinforcing fibers with respect to the filament axial direction defined by the method described above is 90 degrees. % Or more, and the ratio of the absolute value of the orientation angle of the reinforcing fibers being 0 to 4 degrees is 90% or more of the whole, so that the strength utilization rate of the reinforcing fibers is high and an excellent reinforcing effect can be expected. It is more preferably 0 to 2 degrees, and even more preferably 0 to 1 degree. Further, the ratio is more preferably 93% or more, further preferably 95% or more.

A molded product can be obtained by laminating one or more fiber-reinforced thermoplastic resin filaments of the present invention in an arbitrary configuration and then molding while applying heat and / or pressure as necessary.

As a method of applying heat and / or pressure, for example, a press molding method in which a molding material laminated with an arbitrary configuration is placed in a mold or on a press plate, and then the mold or the press plate is closed and pressed, an arbitrary configuration is used. An autoclave molding method in which the molded material laminated in step 1 is put into an autoclave and pressurized and heated. The molded material laminated with an arbitrary configuration is wrapped in a film, etc. The bagging molding method, the wrapping tape method in which the tape is wound while applying pressure to the continuous fiber reinforced thermoplastic resin laminated with an arbitrary configuration and heated in the oven, the continuous fiber reinforced thermoplastic resin laminated with an arbitrary configuration is placed in the mold. Internal pressure molding method that injects gas or liquid into the core that is also installed in the mold and pressurizes it, 3D printing method that heats and pressurizes the molding material and forms a three-dimensional shape while melting and laminating. Can be mentioned. In particular, a 3D printing method suitable for molding complex shapes is preferably used.

Examples are shown below, and the present invention will be described in more detail, but the present invention is not limited to the description of these examples. The characteristic evaluation in each Example and Comparative Example was performed according to the following method.

1. 1. Roundness (i) Take a photograph of the cross section perpendicular to the axial direction of the fiber-reinforced thermoplastic resin filament.
(Ii) Draw an inscribed circle and a circumscribed circle of the filament in the cross-sectional image, and obtain the diameter and length of each.
(Iii) The roundness parameter s defined by the following equation (11) is calculated.
(Iv) The procedure of (i) to (iii) is repeated at a plurality of locations of the fiber-reinforced thermoplastic resin filament, and the average value S of the roundness parameter s is calculated.
Roundness parameter s = diameter of inscribed circle / diameter of circumscribed circle x 100 ... (11)

(Evaluation method of coefficient of variation)
The fiber-reinforced thermoplastic resin filament as a sample is embedded in an epoxy resin "Epoquick" (registered trademark: manufactured by Buehler) and cured at room temperature for 24 hours, and then in the orientation direction of the reinforcing fiber in the fiber-reinforced thermoplastic resin filament. The vertical cross section is polished, and then the polished surface is magnified 300 times using an ultra-deep color 3D shape measuring microscope VHX-6000 (controller part) / VH-ZST (measuring part) (manufactured by Keyence Co., Ltd.). Taken at. The imaging range was the range in which the entire cross section of the fiber-reinforced thermoplastic resin filament was captured.

A circle inscribed in the outer shape of the filament and a circle inscribed in the outer shape of the filament were drawn on the cross-sectional photograph of the photographed fiber thermoplastic resin filament, the diameter length of each was obtained, and the roundness parameter s was calculated by the formula (11). While changing the cross-sectional observation position of the fiber-reinforced thermoplastic resin filament, the polished surface was photographed over 20 or more sheets, and the average value S and the plurality of roundness parameters s used for calculating the average value S were taken. The coefficient of variation of was calculated.

2. 2. Fiber volume content (Vf)
For the fiber volume content Vf of the fiber-reinforced thermoplastic resin filaments obtained in each Example and Comparative Example, after measuring the mass W0 of the fiber-reinforced thermoplastic resin filament, the fiber-reinforced thermoplastic resin filament was placed in the air at 550 ° C. The thermoplastic resin component was burned off by heating for 3 hours, and the mass W1 of the remaining reinforcing fibers was measured and calculated by the formula (12).
Vf (volume%) = (W1 / ρf) / {W1 / ρf + (W0-W1) / ρr} × 100 ... (12)
ρf: Density of reinforcing fibers (g / cm ³ )
ρr: Thermoplastic resin density (g / cm ³ )
3. 3. Thickness

The thickness of the fiber-reinforced thermoplastic resin filament obtained in each Example and Comparative Example was measured by measuring 20 points at arbitrary positions of the fiber-reinforced thermoplastic resin filament with a caliper and obtaining the average value.

4. Impregnation property The cross section of the fiber-reinforced thermoplastic resin filament obtained in each Example and Comparative Example in the thickness direction was observed as follows. After embedding the fiber-reinforced thermoplastic resin filament in the epoxy resin "Epoquick" (registered trademark: manufactured by Buehler) and curing it at room temperature for 24 hours, the thickness direction cross section of the fiber-reinforced thermoplastic resin filament can be observed well. The sample was polished until it became. The polished sample was photographed at a magnification of 300 times using an ultra-depth color 3D shape measurement microscope VHX-6000 (controller unit) / VH-ZST (measurement unit) (manufactured by KEYENCE CORPORATION). The imaging range was the range in which the entire cross section of the fiber-reinforced thermoplastic resin filament was captured. In the photographed image, the total cross-sectional area of the fiber-reinforced thermoplastic resin filament and the area of the portion having voids (voids) were obtained, and the void ratio was calculated by the formula (13) (the impregnation rate is the reciprocal of the void ratio).
Void ratio (%) = 100 × (total area occupied by voids) / (total area of fiber-reinforced thermoplastic resin filament) ... (13)

5. Uniformity (i) Take a photograph of the cross section perpendicular to the axial direction of the filament so that the entire cross section of the fiber-reinforced thermoplastic resin filament can be seen.
(Ii) The entire cross-sectional image is divided into square units having a side length defined by the formula (14).
(Iii) The variance parameter d defined by the equation (15) is calculated.
(Iv) The procedure of (i) to (iii) is repeated at a plurality of locations of the fiber-reinforced thermoplastic resin filament for the 3D printer, and the average value D of the dispersion parameter d is calculated.
1.5a ≤ t ≤ 2.5a (a: fiber diameter, t: length of one side of the unit) ... (14)
Dispersion parameter d (%) = number of units containing reinforcing fibers in the evaluation section / number of all units including even a part of filament in the evaluation section × 100 ... (15)

(Evaluation method of variance parameter d and mean value D)
The fiber-reinforced thermoplastic resin filament as a sample is embedded in an epoxy resin "Epoquick" (registered trademark: manufactured by Buehler) and cured at room temperature for 24 hours, and then in the orientation direction of the reinforcing fiber in the fiber-reinforced thermoplastic resin filament. The vertical cross section is polished, and then the polished surface is magnified 300 times using an ultra-deep color 3D shape measuring microscope VHX-6000 (controller part) / VH-ZST (measuring part) (manufactured by Keyence Co., Ltd.). Taken at. The imaging range was the range in which the entire cross section of the fiber-reinforced thermoplastic resin filament was captured. Image analysis was performed on the photographed cross-sectional view of the fiber thermoplastic resin filament using Imagej, and the photograph was divided into substantially square units having the length of one side and not overlapping with each other. The substantially square units were image-analyzed in order, the units containing the reinforcing fibers in the substantially square units were counted, and the dispersion parameter d was calculated from the equation (15).

The dispersion parameter d thus obtained was photographed over 20 or more polished surfaces while changing the cross-sectional observation position of the fiber-reinforced thermoplastic resin filament, and the average value D and the average value D were calculated. The coefficient of variation of the plurality of variance parameters d was calculated.

6. Straightness The fiber-reinforced thermoplastic resin filaments obtained in each Example and Comparative Example were sampled to a length of 20 mm, embedded in an epoxy resin "Epoquick" (registered trademark: manufactured by Buehler), and cured at room temperature for 24 hours. Then, the vertical cross section of the fiber-reinforced thermoplastic resin filament, which was substantially parallel to the orientation direction of the reinforcing fibers, was polished to half the filament thickness. Next, the polished surface is imaged using an ultra-deep color 3D shape measurement microscope VHX-6000 (controller unit) / VH-ZST (measurement unit) (manufactured by KEYENCE CORPORATION) so that the entire vertical cross section with a length of 20 mm can be captured. The image was taken at a magnification of 200 times using the connection function.

The image angle was adjusted so that the filament axial direction was horizontal (0 degree) using the image processing software GIMP for the photograph of the longitudinal cross section of the photographed fiber thermoplastic resin filament. Then, using the image processing software Image j, binarization processing was performed at a value at which the contour of the reinforcing fiber could be clearly discriminated. Image j was used to approximate an ellipse to the image subjected to the binarization treatment, and the orientation angle (Angle) of the ellipse was obtained. Regarding the result of ellipse approximation, in order to exclude polishing debris and noise at the time of binarization, the result of the major axis (Major) value smaller than 50 was deleted, and only the result of ellipse approximation of the reinforcing fiber was extracted. After converting the orientation angle of the reinforcing fibers into the display of −90 degrees to 90 degrees for the extracted result, the absolute value was obtained, and a histogram was created to obtain the ratio of the predetermined orientation angle.

7. Flexural Rigidity The flexural rigidity of the fiber-reinforced thermoplastic resin filaments obtained in each Example and Comparative Example was calculated by the following formula (16).
Flexural rigidity = E × I ... (16)
here,
E: Flexural modulus of fiber-reinforced thermoplastic resin filament I: Moment of inertia of area.

The flexural modulus of the fiber-reinforced thermoplastic resin filament was measured according to JIS K7074 (2012). The measurement was performed by a bending test along the axial direction of the filament.

8. Handleability For the handleability of the fiber-reinforced thermoplastic resin filaments obtained in each Example and Comparative Example, the fiber-reinforced thermoplastic resin filament is wound around a roll having an inner diameter of 150 mm, and the broken or slack of the wound fiber-reinforced thermoplastic resin filament is judged. Based on the criteria, the evaluation was made in the following two stages, and 〇 was passed. 〇: No breakage, no bending ×: Folding, bending

Formability by 9.3D printer [1]
The fiber-reinforced thermoplastic resin filaments obtained in each Example and Comparative Example were molded using a commercially available FDM 3D printer (Ultimaker S5 manufactured by Ultimaker) at the melting point of the thermoplastic resin used for the filament + 30 ° C. The adhesion between the filaments was visually confirmed and evaluated in the following two stages, and 〇 was evaluated as acceptable. As the nozzle of the 3D printer, a commercially available nozzle was additionally machined so that the diameter of the tip ejection port was +0.1 mm in thickness of the fiber-reinforced thermoplastic resin filament obtained in each Example and Comparative Example.
〇 (Good): The adhesion between the filaments after molding is high and the gap between the filaments is almost unknown. × (Defective): The adhesion between the filaments after molding is poor and the gap between the filaments can be clearly seen.

Formability by 10.3D printer [2]
The fiber-reinforced thermoplastic resin filaments obtained in each Example and Comparative Example are used in a commercially available FDM 3D printer (Ultimaker S5 manufactured by Ultimaker) at the melting point of the thermoplastic resin used for the filament + 30 ° C., for example. It was modeled by the modeling path as shown in 4. Twisting and twisting of the fibers were visually confirmed at the folded portion after modeling, and the evaluation was made in the following two stages, and 〇 was evaluated as acceptable. As the nozzle of the 3D printer, a commercially available nozzle was additionally machined so that the diameter of the tip ejection port was +0.1 mm in thickness of the fiber-reinforced thermoplastic resin filament obtained in each Example and Comparative Example.
〇 (Good): The folded part after modeling is in a state where the fiber is not twisted or twisted and is neatly shaped. Not in the state

11.3 Passability by D Printer The thermoplasticity of the fiber-reinforced thermoplastic resin filaments obtained in each example and comparative example is used in the filament using a commercially available FDM 3D printer (Ultimaker S5 manufactured by Ultimaker). It was confirmed whether clogging occurred when the filament was molded to a length of 2 m at the melting point of the resin + 30 ° C. The above test was repeated 20 times and evaluated in the following two stages, and 〇 was judged as a pass. As the nozzle of the 3D printer, a commercially available nozzle was additionally machined so that the diameter of the tip ejection port was +0.1 mm in thickness of the fiber-reinforced thermoplastic resin filament obtained in each Example and Comparative Example.
〇 (Good): The number of times of clogging occurs 0 to 2 times × (Defective): The number of times of clogging occurs 3 times or more

[material]
In Examples and Comparative Examples, the raw materials shown below were used.
(Carbon fiber bundle)
PAN-based carbon fiber (CF) "Trading Card (registered trademark)" manufactured by Toray Industries, Inc.
(Thermoplastic resin)
-Polyphenylene sulfide (PPS) resin "Trelina (registered trademark)" manufactured by Toray Industries, Inc.
-Victrex Japan Co., Ltd. polyetheretherketone (PEEK) resin "VICTREX (registered trademark)"
-Polyetherketone ketone (PEKK) resin manufactured by Arkema Co., Ltd. "KEPSTAN (registered trader, polyetherimide (PEI) resin manufactured by SABIC Co., Ltd." ULTEM (registered trademark) "

[Example 1]
One bobbin wrapped with a carbon fiber bundle was prepared, and the carbon fiber bundle was continuously sent out from each bobbin through a thread guide. The continuously delivered carbon fiber bundle was impregnated with the PPS resin quantitatively supplied from the filled feeder in the impregnation die. The carbon fibers impregnated in the impregnated die were continuously withdrawn from the nozzle of the impregnated die using a take-up roll at a drawing speed of 1 m / min. The drawn carbon fiber bundle is passed through a cooling die to cool and solidify the PPS resin, and after making a cut through a rotary cutter equipped with multiple blades, it is wound as a continuous fiber-reinforced thermoplastic resin filament for a 3D printer. It was taken up by the machine. The obtained fiber-reinforced thermoplastic resin filaments for 3D printers had a circular cross-sectional shape, and the reinforcing fiber directions were arranged in one direction. Moreover, the notch as shown in FIG. 1 was made. The characteristics of the obtained fiber-reinforced thermoplastic resin filament, the cutting angle θ, the cutting depth H, the cutting length T, the length L of the reinforcing fiber after cutting, and the evaluation results are as shown in Table 1, and are easy to handle. It was excellent in formability, process passability, and straightness of the reinforcing fiber.

[Examples 2 and 3]
Fiber reinforcement heat by the same method as in Example 1 except that the fiber volume content, the filament thickness, the cutting angle θ, the cutting depth H, the cutting length T, and the length L of the reinforcing fiber after cutting are changed. A plastic resin filament was prepared. The characteristics and evaluation results of the obtained fiber-reinforced thermoplastic resin filaments are shown in Table 1, and they are excellent in handleability, formability, process passability, and straightness.

[Example 4]
A fiber-reinforced thermoplastic resin filament was produced in the same manner as in Example 1 except that the thermoplastic resin was changed to PEEK resin. The characteristics and evaluation results of the obtained fiber-reinforced thermoplastic resin filaments are shown in Table 1, and they are excellent in handleability, formability, process passability, and straightness of the reinforced fiber.

[Comparative Example 1]
One bobbin wrapped with a carbon fiber bundle was prepared, and the carbon fiber bundle was continuously sent out from each bobbin through a thread guide. The continuously delivered carbon fiber bundle was impregnated with the PPS resin quantitatively supplied from the filled feeder in the impregnation die. The carbon fibers impregnated in the impregnated die were continuously withdrawn from the nozzle of the impregnated die using a take-up roll at a drawing speed of 5 m / min. The drawn carbon fiber bundle passed through a cooling die to cool and solidify the PPS resin, and was wound up by a winder as a continuous fiber-reinforced thermoplastic resin filament for a 3D printer without making a notch. The obtained fiber-reinforced thermoplastic resin filaments for 3D printers had an elliptical cross-sectional shape, and the reinforcing fiber directions were arranged in one direction. The results are shown in Table 1, and although the handleability was excellent, the formability, process passability, void ratio, uniformity of the reinforcing fibers, and straightness of the reinforcing fibers were inferior.

[Examples 5 to 7]
Fiber reinforcement heat by the same method as in Example 1 except that the fiber volume content, the filament thickness, the cutting angle θ, the cutting depth H, the cutting length T, and the length L of the reinforcing fiber after cutting are changed. A plastic resin filament was prepared. The characteristics and evaluation results of the obtained fiber-reinforced thermoplastic resin filaments are shown in Table 2, and they are excellent in handleability, formability, process passability, and straightness.

[Comparative Example 2]
A fiber-reinforced thermoplastic resin filament was produced in the same manner as in Example 1 except that no cut was made. The characteristics and evaluation results of the obtained fiber-reinforced thermoplastic resin filaments are shown in Table 2. Although they are excellent in handleability, they are excellent in formability, process passability, void ratio, uniformity of reinforcing fibers, and straightness of reinforcing fibers. Was inferior.

The fiber-reinforced thermoplastic resin filament according to the present invention can be molded into a desired shape by any method such as a press molding method or a 3D printing method. In particular, the 3D printing method has a high reinforcing effect and handleability at the time of molding. It is necessary to achieve both, and it is suitable as a method for molding the fiber-reinforced thermoplastic resin filament of the present invention. The molded product obtained by molding the fiber-reinforced thermoplastic resin filament according to the present invention is, for example, an aircraft engine peripheral part, an aircraft interior part, an aircraft exterior part, a vehicle frame, an automobile engine peripheral part, an automobile underhood part, and an automobile gear. It is effective for automobile applications such as parts, automobile interior parts, automobile exterior parts, intake / exhaust system parts, engine cooling water system parts, automobile electrical components, and electrical / electronic parts such as LED reflectors and SMT connectors.

The fiber-reinforced thermoplastic resin filament of the present invention and its molded products are, among other things, aircraft engine peripheral parts, aircraft parts exterior parts, automobile body parts, vehicle frames, automobile engine peripheral parts, and automobile underhoods, which require stable mechanical properties. It is particularly preferably used for parts, automobile gear parts, automobile interior parts, automobile exterior parts, intake / exhaust system parts, engine cooling water system parts, automobile electrical components, and electric / electronic parts. Specifically, the fiber-reinforced thermoplastic resin filament of the present invention and its molded product are used for aircraft engine peripheral parts such as fan blades, landing gear pods, winglets, spoilers, edges, rudder, elevators, failing, ribs and the like. Aircraft related parts, various seats, front body, underbody, various pillars, various members, various frames, various beams, various supports, various rails, various hinges and other automobile body parts, engine covers, air intake pipes, timing belt covers, Automotive engine peripheral parts such as intake manifold, filler cap, throttle body, cooling fan, cooling fan, radiator tank top and base, cylinder head cover, oil pan, brake piping, fuel piping tube, waste gas system parts, etc. Hood parts, gears, actuators, bearing retainers, bearing cages, chain guides, automobile gear parts such as chain tensioners, shift lever brackets, steering lock brackets, key cylinders, door inner handles, door handle cowls, interior mirror brackets, air conditioner switches, Automotive interior parts such as instrumental panels, console boxes, glove boxes, steering wheels, trims, front fenders, rear fenders, fuel lids, door panels, cylinder head covers, door mirror stays, tailgate panels, licensed garnishes, roof rails, engine mount brackets, rear Car exterior parts such as garnish, rear spoiler, trunk lid, rocker molding, molding, lamp housing, front grill, mudguard, side bumper, air intake manifold, intercooler inlet, turbocharger, exhaust pipe cover, inner bush, bearing retainer, engine Intake and exhaust system parts such as mounts, engine head covers, resonators, and throttle bodies, engine cooling water system parts such as chain covers, thermostat housings, outlet pipes, radiator tanks, alternators, and delivery pipes, connectors, wire harness connectors, motor parts, etc. Automotive electrical components such as lamp sockets, sensor in-vehicle switches, combination switches, electricity / electricity As child parts, for example, generators, electric motors, transformers, current transformers, voltage regulators, rectifiers, resistors, inverters, relays, power contacts, switches, switches, switches, knife switches, and other pole rods. , Motor case, TV housing, laptop housing and internal parts, CRT display housing and internal parts, printer housing and internal parts, mobile terminal housing and internal parts such as mobile phones, mobile PCs, handheld mobiles, IC and LED compatible housings , Condenser seat plate, fuse holder, various gears, various cases, cabinets and other electrical parts, connectors, SMT compatible connectors, card connectors, jacks, coils, coil bobbins, sensors, LED lamps, sockets, resistors, relays, relay cases , Reflectors, small switches, power supply parts, coil bobbins, condensers, variable condenser cases, optical pickup chassis, oscillators, various terminal boards, transformers, plugs, printed boards, tuners, speakers, microphones, headphones, small motors, magnetic head bases, It is preferably used for electronic parts such as power modules, Si power modules, SiC power modules, semiconductors, liquid crystals, FDD carriages, FDD chassis, motor brush holders, transformer members, parabolic antennas, and computer-related parts.

1: Fiber longitudinal direction 2: Fiber orthogonal direction 3: Reinforcing fiber 4: Notch 5: Angle between the notch and the fiber direction θ
6: Fiber length L divided by a pair of notches in the fiber direction
7: Fiber reinforced thermoplastic resin filament

Claims (9)

A fiber-reinforced thermoplastic resin filament for a 3D printer in which a plurality of continuous reinforcing fibers are aligned in one direction to form a reinforcing fiber bundle and impregnated with a thermoplastic resin between the reinforcing fibers, and a notch crossing the continuous reinforcing fibers. A fiber-reinforced thermoplastic resin filament for a 3D printer, which comprises a plurality of fibers. The fiber-reinforced thermoplastic resin filament for a 3D printer according to claim 1, wherein the fiber length of the reinforcing fiber cut by the notch is 3 mm or more and 100 mm or less. The fiber-reinforced thermoplastic resin filament for a 3D printer according to claim 1 or 2, wherein the depth of cut is 0.05 mm or more and less than 1 mm. The fiber-reinforced thermoplastic resin for a 3D printer according to any one of claims 1 to 3, wherein the absolute value θ of the angle formed by the notch and the reinforcing fiber in the longitudinal direction is 2 ° or more and 25 ° or less. filament. The fiber-reinforced thermoplastic resin filament for a 3D printer according to any one of claims 1 to 4, wherein the notch length is 0.05 mm or more and 25 mm or less. The fiber reinforcing heat for a 3D printer according to any one of claims 1 to 5, wherein the volume ratio of the reinforcing fiber is 15 to 85%, and the volume ratio of the thermoplastic resin is 85 to 15%. Thermoplastic filament. The fiber-reinforced thermoplastic resin filament for a 3D printer according to any one of claims 1 to 6, wherein the reinforcing fiber is at least one selected from carbon fiber, glass fiber, and aramid fiber. At least the thermoplastic resin is selected from polyphenylene sulfide (PPS) resin, polyetherimide (PEI) resin, polyphenylene ether ether ketone (PEEK) resin, polyphenylene ether ketone (PEK) resin, and polyetherketone ketone (PEKK) resin. The fiber-reinforced thermoplastic resin filament for a 3D printer according to any one of claims 1 to 7, which is one type. A molded product obtained by using the fiber-reinforced thermoplastic resin filament for a 3D printer according to any one of claims 1 to 8.

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