JP2008231291A - Molding material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molding material from which a molded article having high dynamic characteristics and containing reinforcing fibers well dispersed in the molded article on an injection molding without deteriorating the economy and productivity of the molding material in a process for producing the molding material. <P>SOLUTION: This molding material comprising 1 to 50 wt.% of continuous reinforcing fiber bundles (A), 0.1 to 10 wt.% of a polyarylene sulfide polymer (B) containing a cyclic polyarylene sulfide in an amount of at least 50 wt.% and having a weight-average mol.wt. of <10,000, and 40 to 98.9 wt.% of a thermoplastic resin (C), is characterized in that the component (C) is adhered to a composite material comprising the component (A) and the component (B). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a long fiber reinforced thermoplastic resin molding material. More specifically, the present invention relates to a molding material that has good dispersion of reinforcing fibers in a molded product during injection molding, has excellent fluidity and handleability, and can easily produce a molded product having high mechanical properties.

  As a molding material having a continuous reinforcing fiber bundle and a thermoplastic resin as a matrix, a wide variety of forms such as thermoplastic prepreg, yarn, and glass mat (GMT) are known. Such molding materials are easy to mold by using the properties of thermoplastic resins, do not require storage load like thermosetting resins, and the resulting molded products have high toughness and are recyclable. It has the feature of being excellent. In particular, a molding material processed into a pellet can be applied to a molding method having excellent economic efficiency and productivity such as injection molding and stamping molding, and is useful as an industrial material.

  However, in the process of producing a molding material, impregnating a continuous reinforcing fiber bundle with a thermoplastic resin has a problem in terms of economy and productivity and is not widely used at present. For example, it is well known that the higher the melt viscosity of the resin, the more difficult the impregnation of the reinforcing fiber bundle is. Thermoplastic resins with excellent mechanical properties such as toughness and elongation are high molecular weight polymers, have higher viscosity than thermosetting resins, and require higher processing temperatures, making molding materials easier. In addition, it is unsuitable for manufacturing with good productivity.

  On the other hand, when a low molecular weight, that is, a low viscosity thermoplastic resin is used for the matrix resin due to the ease of impregnation, there is a problem that the mechanical properties of the obtained molded product are significantly lowered. A molding material is disclosed in which a high molecular weight thermoplastic resin is placed in contact with a composite composed of a low molecular weight thermoplastic polymer and continuous reinforcing fibers (for example, Patent Document 1).

  In this molding material, a low molecular weight material is used separately for impregnation into a continuous reinforcing fiber bundle, and a high molecular weight material is used for the matrix resin, thereby achieving both economic efficiency, productivity and mechanical properties. Also, when this molding material is molded by injection molding, it is easily mixed with matrix resin while minimizing breakage of reinforcing fibers at the stage of material plasticization during molding, and molding with excellent fiber dispersibility Product can be manufactured. Therefore, the obtained molded product can increase the fiber length of the reinforcing fiber as compared with the conventional one, and can have both good mechanical properties and excellent appearance quality.

In recent years, however, fiber-reinforced composite materials have gained a lot of attention, and their applications have been subdivided into various fields, requiring molding materials with excellent moldability, handleability, and mechanical properties of the resulting molded products. In addition, industrially higher economic efficiency and productivity have become necessary. For example, by increasing the low molecular weight impregnation property, reducing the process load, proposing a molding material with higher heat resistance, and improving the fiber dispersibility during molding, the fiber length It has become necessary to develop a wide variety of technologies, such as further increasing the mechanical properties and further improving the surface appearance.
Japanese Patent Laid-Open No. 10-138379

  The present invention attempts to improve the problems of the prior art, and in a molding material composed of a continuous reinforcing fiber bundle and a thermoplastic resin, molding is performed by using a thermoplastic resin having better impregnation into the reinforcing fiber bundle. Without impairing the economy and productivity in the process of manufacturing the material, and when performing injection molding, the dispersion of the reinforcing fiber in the molded product is good, and the fluidity and handleability are excellent. An object of the present invention is to provide a molding material capable of easily producing a molded product having characteristics.

The present invention for solving such problems has the following configuration. That is,
(1) Polyarylene sulfide prepolymer (B) 0 containing 1 to 50% by weight of continuous reinforcing fiber bundle (A), containing at least 50% by weight of cyclic polyarylene sulfide and having a weight average molecular weight of less than 10,000 A molding material comprising 1 to 10% by weight and 40 to 98.9% by weight of a thermoplastic resin (C), wherein a composite comprising the component (A) and the component (B) is mixed with the component (C ) Is a molding material.

  (2) Molding material as described in (1) whose melting | fusing point of the said component (B) is 100-250 degreeC.

  (3) The molding material according to any one of (1) and (2), wherein the component (A) contains at least 10,000 single carbon fibers.

  (4) The molding material according to any one of (1) to (3), wherein the component (C) is at least one selected from a polyamide resin, a polyester resin, and a polyphenylene sulfide resin.

  (5) The component (A) is arranged substantially parallel to the axial direction, and the length of the component (A) is substantially the same as the length of the molding material (1) to (4) The molding material in any one of.

  (6) The complex composed of the component (A) and the component (B) has a core structure, and the component (C) has a core-sheath structure covering the periphery of the complex. Molding material.

  (7) The molding material according to (6), wherein the molding material is in the form of long fiber pellets.

  (8) The molding material in any one of (1)-(7) whose length exists in the range of 1-50 mm.

  By using the molding material of the present invention, the economics and productivity of the obtained molded product are further improved, and the dispersion of reinforcing fibers in the molded product is good when performing injection molding, and the mechanical properties are excellent. A molded product can be manufactured easily.

  The molding material of the present invention comprises a continuous reinforcing fiber bundle (A), a polyarylene sulfide prepolymer (B), and a thermoplastic resin (C). First, each component will be described.

  The reinforcing fiber used in the present invention is not particularly limited, but carbon fiber, glass fiber, aramid fiber, boron fiber, alumina fiber, mineral fiber, silicon carbide fiber and the like can be used, and two or more of these fibers are mixed. You can also.

  In particular, carbon fibers are preferable from the viewpoint of excellent specific strength and specific rigidity, and improving the mechanical properties of the molded product. Among these, from the viewpoint of obtaining a molded article having a light weight, high strength, and high elastic modulus, it is preferable to use carbon fibers, and it is particularly preferable to use carbon fibers having a tensile elastic modulus of 200 to 700 GPa. Furthermore, carbon fibers and reinforcing fibers coated with metal have high conductivity, and thus have the effect of improving the conductivity of the molded product. For example, for housing applications such as electronic devices that require electromagnetic shielding properties. Is particularly preferred.

  As a more preferred embodiment of the carbon fiber, the amount of surface functional groups (O / C), which is the ratio of the number of atoms of oxygen (O) and carbon (C) on the fiber surface measured by X-ray photoelectron spectroscopy, is 0. The range is from 0.05 to 0.4. The higher the O / C, the greater the functional group amount on the carbon fiber surface, and the higher the adhesiveness with the matrix resin. On the other hand, if O / C is too high, there is a concern about the destruction of the crystal structure on the surface of the carbon fiber. Within the preferable range of O / C, it is possible to obtain a molded product particularly excellent in the balance of mechanical properties.

The surface functional group amount (O / C) is determined by the following procedure by X-ray photoelectron spectroscopy. First, the carbon fibers from which the sizing agent and the like have been removed with a solvent are cut and spread and arranged on a copper sample support, and then the photoelectron escape angle is set to 90 °, MgK _α1,2 is used as the X-ray source, and the sample chamber Keep the inside at 1 × 10 ⁻⁸ Torr. As a correction of the peak accompanying charging during measurement, the kinetic energy value (KE) of the main peak of C1S is adjusted to 969 eV. The C1S peak area is the K.S. E. Is obtained by drawing a straight base line in the range of 958 to 972 eV. The O1S peak area E. It is obtained by drawing a straight base line in the range of 714 to 726 eV. Here, the surface functional group amount (O / C) is calculated as an atomic ratio from the ratio of the O1S peak area to the C1S peak area using a sensitivity correction value unique to the apparatus.

  In the reinforcing fiber bundle, the more the number of single yarns of reinforcing fibers is, the more economical is advantageous. Therefore, the number of single fibers is preferably 10,000 or more. On the other hand, as the number of single yarns of the reinforcing fibers tends to be disadvantageous for the impregnation of the matrix resin, when using a carbon fiber bundle as the reinforcing fiber bundle, from the viewpoint of achieving both economy and impregnation, More preferably from 000 to 100,000, more preferably from 20,000 to 50,000. In particular, the advantages of the present invention are the excellent impregnation of the thermoplastic resin in the process of producing the molding material, and the good dispersion of the reinforcing fibers in the molded product during injection molding. It is possible to cope with a reinforcing fiber bundle having a larger number of fibers.

  Furthermore, a sizing agent may be used separately from the component (B) of the present invention for the purpose of bundling single fibers into a reinforcing fiber bundle. This is because the sizing agent is attached to the reinforcing fiber bundle to improve the handleability at the time of transferring the reinforcing fiber and the processability in the process of producing the molding material. One or more commonly known sizing agents such as resins, urethane resins, acrylic resins and various thermoplastic resins can be used in combination.

  The continuous reinforcing fiber bundle (A) used in the molding material of the present invention means that a reinforcing fiber bundle in which single fibers are arranged in one direction is in a continuous state in the length direction. It is not necessary for all the single fibers of the fiber bundle to be continuous over the entire length, and some of the single fibers may be divided in the middle. Examples of such continuous reinforcing fiber bundles include unidirectional fiber bundles, bi-directional fiber bundles, and multidirectional fiber bundles, but from the viewpoint of productivity in the process of manufacturing a molding material, unidirectional The fiber bundle can be used more preferably.

  The polyarylene sulfide prepolymer (B) used in the present invention contains at least 50% by weight of cyclic polyarylene sulfide and has a weight average molecular weight of less than 10,000. Here, the cyclic polyarylene sulfide is a cyclic compound having a repeating unit of formula: — (Ar—S) — as a main constituent unit, preferably 80% by weight or more, more preferably 90% by weight of the repeating unit. % Or more, more preferably 95% by weight or more of the compound represented by the following general formula (a). Ar includes units represented by the above formulas (b) to (l), among which the formula (b) is particularly preferable.

In the cyclic polyarylene sulfide, the repeating units such as the above formulas (b) to (l) may be included randomly, may be included in blocks, or may be any mixture thereof. Typical examples of these include cyclic polyphenylene sulfide (formula (b), formula (c), formula (g) to formula (l)), cyclic polyphenylene sulfide sulfone (formula (e)), cyclic Examples thereof include polyphenylene sulfide ketone (formula (d)), cyclic polyphenylene sulfide ether (formula (f)), cyclic random copolymers, cyclic block copolymers and mixtures thereof. Particularly preferred cyclic polyarylene sulfides include p-phenylene sulfide units as the main structural unit.

Is a cyclic polyphenylene sulfide containing 80% by weight or more, particularly 90% by weight or more in a cyclic compound having a repeating unit of-(Ar-S)-as a main structural unit (hereinafter sometimes abbreviated as cyclic PPS) Is mentioned.

  Although there is no restriction | limiting in particular in the repeating number m in the said (A) formula of cyclic polyarylene sulfide, 2-50 are preferable, 2-25 are more preferable, and 3-20 can be illustrated as a more preferable range. When m is 50 or more, the melting temperature of the cyclic polyarylene sulfide increases, and impregnation of the reinforcing fiber base may be difficult.

  The cyclic polyarylene sulfide may be either a single compound having a single repeating number or a mixture of cyclic polyarylene sulfides having different repeating numbers, but may be a mixture of cyclic polyarylene sulfides having different repeating numbers. This is preferable because the melt solution temperature tends to be lower than that of a single compound having a single number of repetitions, and the reinforcing fiber substrate is easily impregnated.

  The component other than the cyclic polyarylene sulfide in the polyarylene sulfide prepolymer in the present invention is particularly preferably a linear polyarylene sulfide oligomer. Here, the linear polyarylene sulfide oligomer is a homo-oligomer or co-oligomer having a repeating unit of the formula:-(Ar-S)-as the main constituent unit, preferably containing 80 mol% or more of the repeating unit. is there. Ar includes units represented by the above-described formulas (b) to (l), among which the formula (b) is particularly preferable. The linear polyarylene sulfide oligomer can contain a small amount of branching units or crosslinking units represented by the above formulas (m) to (o) as long as these repeating units are the main constituent units. The amount of copolymerization of these branched units or cross-linked units is preferably in the range of 0 to 1 mol% with respect to 1 mol of-(Ar-S)-units. The linear polyarylene sulfide oligomer may be any of a random copolymer, a block copolymer and a mixture thereof containing the above repeating unit.

  Typical examples of these include polyphenylene sulfide oligomers, polyphenylene sulfide sulfone oligomers, polyphenylene sulfide ketone oligomers, polyphenylene sulfide ether oligomers, random copolymers, block copolymers, and mixtures thereof. Particularly preferred linear polyarylene sulfide oligomers include linear polyphenylene sulfide oligomers containing 80 mol% or more, particularly 90 mol% or more of p-phenylene sulfide units as the main structural unit of the polymer.

  The polyarylene sulfide prepolymer in the present invention contains at least 50% by weight of cyclic polyarylene sulfide, preferably 70% by weight or more, more preferably 80% by weight or more, and further preferably 90% by weight or more. . The upper limit value of the cyclic polyarylene sulfide contained in the polyarylene sulfide prepolymer is not particularly limited, but 98% by weight or less, preferably 95% by weight or less can be exemplified as a preferred range. Usually, the higher the weight ratio of the cyclic polyarylene sulfide in the polyarylene sulfide prepolymer, the more effective is the fluidity of the molding material, which is preferable.

  The upper limit of the molecular weight of the polyarylene sulfide prepolymer in the present invention is less than 10,000 in terms of weight average molecular weight, preferably 5,000 or less, more preferably 3,000 or less, while the lower limit is the weight average molecular weight. 300 or more are preferable, 400 or more are preferable, and 500 or more are more preferable. When the weight average molecular weight is 10,000 or more, the impregnation property for the reinforcing fiber bundle is insufficient, and the productivity may be impaired, or the reinforcing fiber bundle may fall off from the molding material and the handling property may be lowered.

  The melting point of the cyclic polyarylene sulfide (B) used in the molding material of the present invention is preferably 100 to 250 ° C., more preferably 130 to 230 ° C., most preferably from the viewpoint of moldability of the molding material. 150-230 ° C.

  By having a melting point within the above range, not only can it be handled as a solid at room temperature, but also a continuous reinforcing fiber bundle (A) combined with a known impregnation die, coater, filmer, etc. without requiring severe process temperatures. The body can be formed.

  The present invention is not limited to this, but a cyclic polyphenylene sulfide is taken as an example of the cyclic polyarylene sulfide, and the details will be described below.

  The cyclic polyphenylene sulfide compound of the present invention is a cyclic polyphenylene sulfide compound represented by the following formula (r) and represented by an integer of m = 4 to 20, and m may be a mixture of 4 to 20.

(M may be an integer of 4 to 20, m may be a mixture of 4 to 20)
The repeating unit m in the above formula is an integer of 4 to 20, preferably 4 to 15, and more preferably 4 to 12.

Moreover, although the cyclic polyphenylene sulfide simple substance with a single m has a difference in the crystallization ease, since it is obtained as a crystal | crystallization, melting | fusing point tends to become high. On the other hand, in the case of a mixture having different m, the melting temperature is specifically lowered and the melt processing temperature can be reduced as compared with the cyclic polyphenylene sulfide alone, and the cyclic polyphenylene sulfide compound (mixture of m = 4 to 20) ) Is added to the crystalline resin, the fluidity improvement effect during injection molding, which is the object of the present invention, and the improvement effect of crystallization characteristics are particularly excellent. It means that a molded product can be easily obtained at a lower heating temperature when molding.
For example, since cyclic polyphenylene sulfide alone (cyclohexa (p-phenylene sulfide)) of m = 6 has a high melting point of 348 ° C., the processing temperature is set to a molten state in the course of compounding with the continuous reinforcing fiber bundle (A). It is necessary to adopt a method in which the temperature is excessively increased or a method in which cyclic polyphenylene sulfide is dissolved in a solvent.

  Due to the characteristics of such cyclic polyphenylene sulfide compounds, the cyclic polyphenylene sulfide compounds used in the present invention are cyclic polyphenylene sulfide compounds having different m from the viewpoint of production, moldability, and improvement of crystallization characteristics. preferable.

  The content of cyclic polyphenylene sulfide of m = 6 with respect to the cyclic polyphenylene sulfide compound is preferably less than 50% by weight, more preferably less than 10% by weight (m = 6 cyclic polyphenylene sulfide alone (weight) / cyclic polyphenylene sulfide compound. (Weight) × 100). Here, the content of m = 6 cyclic polyphenylene sulfide alone in the cyclic polyphenylene sulfide mixture has a polyphenylene sulfide structure when the cyclic polyphenylene sulfide mixture is divided into components by high performance liquid chromatography equipped with a UV detector. It can be determined as the ratio of the peak area attributed to m = 6 cyclic polyphenylene sulfide alone to the total peak area attributed to the compound. Here, the compound having a polyphenylene sulfide structure is a compound having at least a phenylene sulfide structure, such as a cyclic polyphenylene sulfide compound or a linear polyphenylene sulfide, and has a structure other than phenylene sulfide (for example, The compound (as a terminal structure) also belongs to the compound having a polyphenylene sulfide structure referred to herein. In addition, the qualitative characteristics of each peak divided into components by this high performance liquid chromatography can be obtained by separating each peak by preparative liquid chromatography and performing an absorption spectrum or mass analysis in infrared spectroscopic analysis.

  Examples of the method for obtaining the polyarylene sulfide prepolymer in the present invention include the following methods.

  (1) Granules separated by 80 mesh sieve (aperture 0.125 mm) by polymerizing polyarylene sulfide resin by heating a mixture containing at least a polyhalogenated aromatic compound, a sulfidizing agent and an organic polar solvent A mixture containing a PAS resin, a PAS component produced by polymerization and other than the granular PAS resin (referred to as polyarylene sulfide oligomer), an organic polar solvent, water, and an alkali metal halide salt; A method of obtaining a polyarylene sulfide prepolymer by separating and recovering the polyarylene sulfide oligomer contained therein and subjecting it to a purification operation.

  (2) heating a mixture containing at least a polyhalogenated aromatic compound, a sulfidizing agent and an organic polar solvent to polymerize a polyarylene sulfide resin, and removing the organic polar solvent by a known method after the completion of the polymerization; A polyarylene sulfide resin containing a polyarylene sulfide prepolymer obtained by preparing a mixture containing a polyarylene sulfide resin, water, and an alkali metal halide salt and purifying the mixture by a known method is obtained. In particular, the polyarylene sulfide prepolymer is not dissolved but the polyarylene sulfide prepolymer is extracted using a solvent that is dissolved to recover the polyarylene sulfide prepolymer.

  The thermoplastic resin (C) used in the present invention is not particularly limited, and a known thermoplastic resin can be used. That is, polyester resins such as polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, polytrimethylene terephthalate (PTT) resin, polyethylene naphthalate (PENp) resin, liquid crystal polyester, polyethylene (PE) resin, polypropylene (PP) resin, polyolefin resin such as polybutylene resin, styrene resin, urethane resin, polyoxymethylene (POM) resin, polyamide (PA) resin, polycarbonate (PC) resin, polymethyl 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, polyethersulfone (PES) resin, polyketone (PK) resin, polyetherketone (PEK) resin, polyetheretherketone (PEEK) resin, poly Fluorine resins such as ether ketone ketone (PEKK) resin, polyarylate (PAR) resin, polyether nitrile (PEN) resin, phenolic resin, phenoxy resin, polytetrafluoroethylene, copolymers thereof, modified products, and Two or more kinds of blended resins may be used.

  Among them, the cyclic polyarylene sulfide (B) component used in the present invention is preferably a crystalline resin from the viewpoint of further drawing out the effect of improving the fluidity during molding, and further the melting point of the crystalline resin is 120 ° C. or higher. More preferably, it is particularly preferably 180 ° C. or higher. In addition, the melting point here means that after the endothermic peak temperature (Tm) observed at a temperature rising condition of 20 ° C./min in the differential calorimetry is maintained for 1 minute at a temperature of 320 ° C. It refers to the endothermic peak temperature observed when it is once cooled to 100 ° C. under a temperature drop condition of 20 ° C./minute, held for 1 minute, and then measured again under a temperature rise condition of 20 ° C./minute. Specific examples include polyamide resin, polyester resin, and polyphenylene sulfide resin.

  The molecular weight of the thermoplastic resin (C) used in the present invention is preferably 10,000 or more in terms of weight average molecular weight, more preferably from the viewpoint of mechanical properties of a molded product obtained by molding a molding material. It is 20,000 or more, and particularly preferably 30,000 or more. This is more advantageous from the viewpoint of increasing the strength and elongation of the matrix resin as the weight average molecular weight increases. On the other hand, although there is no restriction | limiting in particular about the upper limit of a weight average molecular weight, From a viewpoint of the fluidity at the time of shaping | molding, Preferably it is 1,000,000 or less, More preferably, 500,000 or less can be illustrated. In addition, the said weight average molecular weight can be calculated | required using generally well-known GPC (gel permeation chromatography), such as said SEC (size exclusion chromatography).

  The thermoplastic resin composition exemplified in the above group contains an impact resistance improver such as a fiber reinforcing agent, an elastomer or a rubber component, and other fillers and additives as long as the object of the present invention is not impaired. Also good. Examples of these include inorganic fillers, flame retardants, conductivity imparting agents, crystal nucleating agents, ultraviolet absorbers, antioxidants, vibration damping agents, antibacterial agents, insect repellents, deodorants, anti-coloring agents, heat stabilizers. , Release agents, antistatic agents, plasticizers, lubricants, colorants, pigments, dyes, foaming agents, antifoaming agents, or coupling agents.

  The molding material of the present invention is composed of a reinforcing fiber bundle (A), a polyarylene sulfide prepolymer (B), and a thermoplastic resin (C), and the total of each component is 100% by weight.

  Among these, the reinforcing fiber bundle (A) is 1 to 50% by weight, preferably 5 to 45% by weight, and more preferably 10 to 40% by weight. If the reinforcing fiber bundle (A) is less than 1% by weight, the resulting molded article may have insufficient mechanical properties, and if it exceeds 50% by weight, the fluidity may be reduced during injection molding.

  Moreover, a polyarylene sulfide prepolymer (B) is 0.1 to 10 weight%, Preferably it is 0.5 to 8 weight%, More preferably, it is 1 to 6 weight%. If the polyarylene sulfide prepolymer (B) is less than 0.1% by weight, the moldability and handleability of the molding material may be insufficient. If it exceeds 10% by weight, a large amount of gas is generated during injection molding. As a result, voids remain in the molded product, and the mechanical properties may deteriorate.

  Furthermore, the thermoplastic resin (C) is 40 to 98.9% by weight, preferably 47 to 94.5% by weight, more preferably 54 to 89% by weight. Can be achieved.

  The molding material of the present invention is a molding material configured by being arranged so that the thermoplastic resin (C) adheres to a composite composed of a continuous reinforcing fiber bundle (A) and a polyarylene sulfide prepolymer (B). .

  A composite of the reinforcing fiber bundle (A) and the polyarylene sulfide prepolymer (B) is formed by the two. The form of this composite is as shown in FIG. 1, and the polyarylene sulfide prepolymer (B) is filled between the single fibers of the reinforcing fiber bundle (A). That is, the reinforcing fibers (A) are dispersed like islands in the sea of the polyarylene sulfide prepolymer (B). Specifically, the composite is formed by heating and melting the cyclic polyarylene sulfide (B) and impregnating the reinforcing fiber bundle (A).

  In the molding material of the present invention, the thermoplastic resin (C) is obtained by forming a composite in which the reinforcing fiber bundle (A) is well impregnated with the polyarylene sulfide prepolymer (B) having good fluidity and excellent impregnation properties. For example, when the molding material of the present invention is injection-molded, the polyarylene sulfide prepolymer (B) having good fluidity melt-kneaded in the cylinder of the injection molding machine becomes a thermoplastic resin ( C) is diffused to help the reinforcing fiber bundle (A) be dispersed in the thermoplastic resin (C), and at the same time, the thermoplastic resin (C) helps to replace and impregnate the reinforcing fiber bundle (A). It plays the role of impregnation aid and dispersion aid.

  As a preferred embodiment in the molding material of the present invention, as shown in FIG. 2, the reinforcing fiber bundle (A) is arranged substantially parallel to the axial direction of the molding material, and the length of the reinforcing fiber bundle (A) is The length is substantially the same as the length of the molding material.

  Here, “arranged substantially in parallel” means that the long axis of the reinforcing fiber bundle and the long axis of the molding material are oriented in the same direction. The angle shift is preferably 20 ° or less, more preferably 10 ° or less, and further preferably 5 ° or less. In addition, “substantially the same length” means that, for example, in a pellet-shaped molding material, a reinforcing fiber bundle is cut in the middle of the pellet, or a reinforcing fiber bundle substantially shorter than the entire length of the pellet is substantially included. It is not done. In particular, the amount of reinforcing fiber bundle shorter than the total length of the pellet is not specified, but when the content of reinforcing fiber having a length of 50% or less of the total length of the pellet is 30% by weight or less, the pellet It is evaluated that the reinforcing fiber bundle significantly shorter than the full length is not substantially contained. Furthermore, the content of reinforcing fibers having a length of 50% or less of the total length of the pellet is preferably 20% by weight or less. In addition, a pellet full length is the length of the reinforcing fiber orientation direction in a pellet. Since the reinforcing fiber bundle (A) has a length equivalent to that of the molding material, the reinforcing fiber length in the molded product can be increased, so that excellent mechanical properties can be obtained.

  3 to 6 schematically show examples of the shape of the cross section in the axial center direction of the molding material of the present invention, and FIGS. 7 to 10 show examples of the shape of the cross section in the orthogonal direction of the molding material of the present invention. This is a schematic representation.

  The shape of the cross-section of the molding material is shown in the figure if the thermoplastic resin (C) is disposed so as to adhere to the composite composed of the reinforcing fiber bundle (A) and the polyarylene sulfide prepolymer (B). Although it is not limited to a thing, Preferably the structure by which a composite_body | complex becomes a core material and is pinched | interposed and laminated | stacked by the thermoplastic resin (C) as FIG. 3-5 which is an axial center cross section is preferable.

  Moreover, as FIG. 7-9 which is a cross section of an orthogonal | vertical direction shows, the structure arrange | positioned at the core sheath structure that a thermoplastic resin (C) coat | covers the circumference | surroundings with respect to a core is preferable. When arranging a plurality of composites as shown in FIG. 11 so as to cover the thermoplastic resin (C), the number of composites is preferably about 2 to 6.

  The boundary between the composite and the thermoplastic resin (C) is bonded, and the thermoplastic resin (C) partially enters the part of the composite near the boundary to form a phase with the cyclic polyarylene sulfide (B) in the composite. It may be in a state where it is melted or impregnated in a reinforcing fiber.

  The axial direction of the molding material may be continuous while maintaining substantially the same cross-sectional shape. Depending on the molding method, such a continuous molding material may be cut into a certain length.

  The molding material of the present invention is obtained by kneading the thermoplastic resin (C) into a composite comprising the reinforcing fiber bundle (A) and the polyarylene sulfide prepolymer (B) by a technique such as injection molding or press molding. Can be produced. From the viewpoint of the handling property of the molding material, it is important that the composite and the thermoplastic resin (C) are not separated until molding is performed and the shape as described above is maintained. Since the polyarylene sulfide prepolymer (B) has a low molecular weight, it is usually a relatively fragile and easily crushed solid at room temperature. For this reason, the thermoplastic resin (C) is disposed so as to protect the composite, and the polyarylene sulfide prepolymer (B) is crushed and scattered by transportation of the material until molding, shock at the time of handling, rubbing, etc. It is desirable not to do so.

  Therefore, as illustrated in FIGS. 7 to 9, the thermoplastic resin (C) covers the periphery of the composite composed of the reinforcing fiber bundle (A) that is the reinforcing fiber and the cyclic polyarylene sulfide. In other words, the composite composed of the reinforcing fiber bundle (A) and the cyclic polyarylene sulfide (B), which are reinforcing fibers, has a core structure, and the thermoplastic resin (C) is the composite of the composite. A core-sheath structure covering the periphery is preferable.

  With such an arrangement, the high molecular weight thermoplastic resin (C) encloses the cyclic polyarylene sulfide that is easily crushed or is arranged on a surface that is easily rubbed, so that the shape is maintained as a molding material. Cheap. Further, the thermoplastic resin (C) is disposed so as to cover the periphery of the composite composed of the reinforcing fiber bundle (A) and the polyarylene sulfide prepolymer (B), or the composite and the thermoplastic resin (C). Is arranged in a layered manner or which is advantageous is determined so that the thermoplastic resin (C) covers the periphery of the composite from the viewpoint of ease of manufacture and ease of handling of the material. It is more preferable.

  As described above, it is desirable that the reinforcing fiber bundle (A) is completely impregnated with the polyarylene sulfide prepolymer (B). However, in reality, this is difficult, and a composite composed of reinforcing fibers and cyclic polyarylene sulfide is difficult. There are some voids in the body. In particular, when the reinforcing fiber content is large, the number of voids increases, but even when a certain amount of voids are present, the effect of promoting impregnation and fiber dispersion of the present invention is shown. However, if the void ratio exceeds 40%, the effect of promoting impregnation and fiber dispersion is remarkably reduced. Therefore, the void ratio is preferably in the range of 0 to 40%. A more preferable void ratio range is 20% or less. The void fraction is measured on the part of the composite by the ASTM D2734 (1997) test method.

  The molding material of the present invention is preferably used after being cut to a length in the range of 1 to 50 mm. By adjusting to the above length, the fluidity and handleability during molding can be sufficiently enhanced. A particularly preferred embodiment of the molding material cut to an appropriate length in this way can be exemplified by long fiber pellets for injection molding.

  Further, the molding material of the present invention can be used depending on the molding method even if it is continuous or long. For example, as a thermoplastic yarn prepreg, it can be wound around a mandrel while heating to obtain a roll-shaped molded product. Examples of such molded products include liquefied natural gas tanks. It is also possible to produce a unidirectional thermoplastic prepreg by heating and fusing a plurality of molding materials of the present invention in one direction. Such a prepreg can be applied to fields where high strength, elastic modulus, and impact resistance are required, for example, aircraft members.

  The molding material of the present invention can be processed into a final product by a known molding method. Examples of the molding method include press molding, transfer molding, injection molding, and combinations thereof. Examples of molded products include cylinder head covers, bearing retainers, intake manifolds, automobile parts such as pedals, tools such as monkeys and wrenches, and small items such as gears. Moreover, since the molding material of this invention is excellent in fluidity | liquidity, the thin molded product whose thickness of a molded product is 0.5-2 mm can be obtained comparatively easily. Such thin-wall molding is required to be represented by, for example, a casing used for a personal computer, a mobile phone, or a keyboard support that is a member that supports the keyboard inside the personal computer. Examples of members for electrical and electronic equipment. In such a member for an electric / electronic device, when carbon fiber having conductivity is used as the reinforcing fiber, electromagnetic shielding properties are imparted, which is more preferable.

  The molding material described above can be used as an injection molding pellet. In injection molding, when plasticizing a pellet-shaped molding material, temperature, pressure, and kneading are added. According to the present invention, polyarylene sulfide prepolymer (B) is used as a dispersion / impregnation aid. Demonstrate great effect. In this case, a normal in-line screw type injection molding machine can be used, such as using a screw with a low compression ratio or setting a low back pressure during material plasticization. Even when the kneading effect by is weak, the reinforcing fiber is well dispersed in the matrix resin, and a molded product in which the fiber is impregnated with the resin can be obtained.

  The following examples illustrate the present invention more specifically.

  The evaluation method used in the present invention is described below.

(1) Weight average molecular weight of polyarylene sulfide prepolymer The weight average molecular weight of polyarylene sulfide was calculated as polystyrene-reduced weight average molecular weight (Mw) using gel permeation chromatography (GPC). The measurement conditions for GPC are shown below.
Apparatus: Senshu Science SSC-7100 (Column name: Senshu Science GPC3506)
Eluent: 1-chloronaphthalene, flow rate: 1.0 mL / min
Column temperature: 210 ° C., detector temperature: 210 ° C.

(2) Melting point of polyarylene sulfide prepolymer In accordance with JIS K7121 (1987), DSC system TA3000 (manufactured by METTLER) was used and measured at a heating rate of 10 ° C./min, and the melting peak temperature was taken as the melting point.

(3) Average fiber length of reinforcing fibers contained in a molded product obtained by using a molding material A part of the molded product is cut out and heated in an electric furnace at 500 ° C. for 30 minutes in an air, so that sufficient thermoplastic resin is obtained. The reinforcing fibers were separated by incineration. At least 400 separated reinforcing fibers are randomly extracted, and the length is measured to the 1 μm unit with an optical microscope. The weight average fiber length (Lw) and the number average fiber length (Ln) are calculated according to the following equations. Ask.
Weight average fiber length (Lw) = Σ (Li × Wi / 100)
Number average fiber length (Ln) = (ΣLi) / Ntotal
Li: measured fiber length (i = 1, 2, 3,..., N)
Wi: Weight fraction of fiber having fiber length Li (i = 1, 2, 3,..., N)
Ntotal: the total number of fibers measured.

(4) Density of molded product obtained using molding material Measured according to method A (underwater substitution method) described in 5 of JIS K7112 (1999). A test piece of 1 cm × 1 cm was cut out from the molded article, put into a heat-resistant glass container, this container was vacuum-dried at a temperature of 80 ° C. for 12 hours, and cooled to room temperature with a desiccator so as not to absorb moisture. Ethanol was used as the immersion liquid.

(5) Bending test of molded product obtained using molding material In accordance with ASTM D790 (1997), a support span is set to 100 mm using a three-point bending test jig (indenter 10 mm, fulcrum 10 mm), and crosshead Bending strength and flexural modulus were measured under the test conditions of a speed of 5.3 mm / min. As a testing machine, “Instron” (registered trademark) universal testing machine 4201 type (manufactured by Instron) was used.

(6) Izod Impact Test of Molded Product Obtained Using Molding Material An Izod impact test with a mold notch was performed according to ASTM D256 (1993). The Izod impact strength (J / m) was measured when the thickness of the used test piece was 3.2 mm and the moisture content of the test piece was 0.1% by weight or less.

(7) Appearance evaluation of molded product obtained by using molding material The surface of a thin flat plate molded product having a width of 150 mm × length of 150 mm × thickness of 1.2 mm obtained by injection molding is visually observed to disperse reinforcing fibers. The number of defective defects (floating, swollen) was measured. The measurement was performed for 20 samples, and the evaluation was performed in the following four stages using the average number of defects obtained by dividing the total number of defective dispersion points by the number of samples as a criterion.

  ◯: Dispersion defects are not observed at all in all molded products. Excellent surface appearance.

  ○: The average number of defects is less than 0.1 / sheet. Excellent surface appearance.

  Δ: The average number of defects is 0.1 to 0.5 / sheet. Slightly inferior in surface appearance.

  X: The average number of defects exceeds 0.5 / sheet, and dispersion failure is observed in all molded products. The surface appearance is inferior.

(Reference Example 1)
<Preparation of polyphenylene sulfide prepolymer>
In a 1000 liter autoclave equipped with a stirrer, 47.5% sodium hydrosulfide 118 kg (1000 mol), 96% sodium hydroxide 42.3 kg (1014 mol), N-methyl-2-pyrrolidone (hereinafter sometimes abbreviated as NMP) 163 kg (1646 mol) of sodium acetate, 24.6 kg (300 mol) of sodium acetate, and 150 kg of ion-exchanged water, and gradually heated to 240 ° C. over 3 hours while passing nitrogen at normal pressure. After distilling 211 kg of water and 4 kg of NMP, the reaction vessel was cooled to 160 ° C. In addition, 0.02 mol of hydrogen sulfide per 1 mol of the sulfur component charged during this liquid removal operation was scattered out of the system.

Next, 147 kg (1004 mol) of p-dichlorobenzene and 129 kg (1300 mol) of NMP were added, and the reaction vessel was sealed under nitrogen gas. While stirring at 240 rpm, the temperature was raised to 270 ° C. at a rate of 0.6 ° C./min and held at this temperature for 140 minutes. Water was cooled to 250 ° C. at a rate of 1.3 ° C./min while 18 kg (1000 mol) of water was injected over 15 minutes. Thereafter, the slurry was cooled to 220 ° C. at a rate of 0.4 ° C./min, and then rapidly cooled to near room temperature to obtain a slurry (A). This slurry (A) was diluted with 376 kg of NMP to obtain a slurry (B).
14.3 kg of slurry (B) heated to 80 ° C. was filtered off with a sieve (80 mesh, opening 0.175 mm) to obtain 10 kg of crude PPS resin and slurry (C). The slurry (C) was charged into a rotary evaporator, replaced with nitrogen, treated at 100 to 160 ° C. under reduced pressure for 1.5 hours, and then treated at 160 ° C. for 1 hour in a vacuum dryer. The amount of NMP in the obtained solid was 3% by weight.

  After adding 12 kg of ion-exchanged water (1.2 times the amount of slurry (C)) to this solid, it was stirred at 70 ° C. for 30 minutes to make a slurry again. This slurry was subjected to suction filtration with a glass filter having an opening of 10 to 16 μm. 12 kg of ion-exchanged water was added to the obtained white cake, and the mixture was stirred again at 70 ° C. for 30 minutes to make a slurry again. Similarly, after suction filtration, vacuum drying was performed at 70 ° C. for 5 hours to obtain 100 g of a polyphenylene sulfide oligomer. The above operation was repeated until the polyphenylene sulfide prepolymer reached a predetermined amount.

  4 g of the obtained polyphenylene sulfide oligomer was collected and subjected to Soxhlet extraction with 120 g of chloroform for 3 hours. Chloroform was distilled off from the obtained extract, and 20 g of chloroform was again added to the resulting solid, which was dissolved at room temperature to obtain a slurry-like mixture. This was slowly added dropwise to 250 g of methanol while stirring, and the precipitate was suction filtered through a glass filter having an opening of 10 to 16 μm, and the resulting white cake was vacuum dried at 70 ° C. for 3 hours to obtain a white powder.

  The weight average molecular weight of this white powder was 900. The absorption spectrum in the infrared spectroscopic analysis of this white powder revealed that the white powder was polyphenylene sulfide (PAS). Moreover, as a result of analyzing the thermal characteristics of this white powder using a differential scanning calorimeter (temperature increase rate 40 ° C./min), it shows a broad endotherm at about 200 to 260 ° C., and the peak temperature is 215 ° C. I understood it.

  In addition, this white powder was obtained from cyclic polyphenylene sulfide having 4 to 11 repeating units and cyclic polyphenylene sulfide having 2 to 11 repeating units, based on mass spectral analysis of components separated by high performance liquid chromatography and molecular weight information by MALDI-TOF-MS. It was a mixture of chain polyphenylene sulfide, and the weight ratio of cyclic polyphenylene sulfide to linear polyphenylene sulfide was found to be 9: 1.

(Reference Example 2)
In a 20 liter autoclave with a stirrer and a valve at the bottom, 2383 g (20.0 mol) of 47% sodium hydrosulfide (Sankyo Kasei), 831 g (19.9 mol) of 96% sodium hydroxide, 3960 g of NMP (40.0) Mol) and 3000 g of ion-exchanged water, and gradually heated to 225 ° C. over 3 hours while passing nitrogen at normal pressure. After distilling out 4200 g of water and 80 g of NMP, the reaction vessel was cooled to 160 ° C. The residual water content in the system per mole of the alkali metal sulfide charged was 0.17 mole. The amount of hydrogen sulfide scattered per mole of the alkali metal sulfide charged was 0.021 mol.

  Next, 2942 g (20.0 mol) of p-dichlorobenzene (Sigma Aldrich) and 1515 g (15.3 mol) of NMP were added, and the reaction vessel was sealed under nitrogen gas. Then, while stirring at 400 rpm, the temperature was increased from 200 ° C. to 227 ° C. at a rate of 0.8 ° C./min, then increased to 274 ° C. at a rate of 0.6 ° C./min, and held at 274 ° C. for 50 minutes. Then, the temperature was raised to 282 ° C. Open the extraction valve at the bottom of the autoclave, pressurize with nitrogen, flush the contents to a vessel with a stirrer over 15 minutes, stir at 250 ° C for a while to remove most of the NMP, and contain polyphenylene sulfide and salts The solid was collected.

  The obtained solid and 15120 g of ion-exchanged water were put in an autoclave equipped with a stirrer, washed at 70 ° C. for 30 minutes, and then suction filtered through a glass filter. Next, 17280 g of ion-exchanged water heated to 70 ° C. was poured into a glass filter, and suction filtered to obtain a cake. The obtained cake and 11880 g of ion-exchanged water were charged into an autoclave equipped with a stirrer, and the inside of the autoclave was replaced with nitrogen, and then the temperature was raised to 192 ° C. and held for 30 minutes. Thereafter, the autoclave was cooled and the contents were taken out. The contents were subjected to suction filtration with a glass filter, and then 17280 g of ion-exchanged water at 70 ° C. was poured into the contents, followed by suction filtration to obtain a cake. The obtained cake was dried with hot air at 80 ° C. and further vacuum-dried at 120 ° C. for 24 hours to obtain a dried polyphenylene sulfide.

  The obtained polyphenylene sulfide (PPS) had a weight average molecular weight of 20,000.

(Example 1)
The polyphenylene sulfide prepolymer prepared in Reference Example 1 is melted in a 240 ° C. melting bath and supplied to the kiss coater with a gear pump. A polyphenylene sulfide prepolymer was applied from a kiss coater on a roll heated to 230 ° C. to form a film.

  On this roll, carbon fiber trading card (registered trademark) T700S-24K (manufactured by Toray Industries, Inc.) was passed while contacting to adhere a certain amount of polyphenylene sulfide prepolymer per unit length of the carbon fiber bundle.

  The carbon fiber to which the polyphenylene sulfide prepolymer is attached is passed between 10 rolls (φ50 mm) alternately rotated up and down on a straight line freely rotating by a bearing heated to 230 ° C., and component (B) Was sufficiently impregnated into the component (A).

  Subsequently, the polyphenylene sulfide (PPS) prepared in Reference Example 2 was melted at 320 ° C. with a single screw extruder and extruded into a crosshead die attached to the tip of the extruder, and at the same time, continuously strengthened through the above operations. The fiber bundle (A) was also continuously fed into the crosshead die so that the melted component (C) was coated on the composite of component (A) and component (B). At this time, the amount of the component (C) was adjusted so that the content of the reinforcing fiber was 20% by weight.

  The strand obtained by the method described above was cooled and then cut into a length of 7 mm with a cutter to obtain a core-sheath columnar pellet (long fiber pellet).

  The above long fiber pellets were continuously produced online. The obtained long fiber pellets showed no fuzz due to transportation and showed good handleability. The obtained molding material was dried under vacuum at 140 ° C. for 5 hours or more. The obtained molding material was molded using a mold for each test piece using a J150EII-P type injection molding machine manufactured by Nippon Steel Works. The conditions were as follows: cylinder temperature: 350 ° C., mold temperature: 140 ° C., and cooling time 30 seconds. After the molding, the test piece was dried at 80 ° C. for 12 hours under vacuum, and the dried test piece was stored in a desiccator at room temperature for 3 hours. The evaluation results are summarized in Table 1.

(Comparative Example 1)
In the same manner as in Example 1 except that the polyphenylene sulfide prepolymer was not used, the polyphenylene sulfide prepared in Reference Example 2 was melted at 320 ° C. with a single screw extruder and placed in a crosshead die attached to the tip of the extruder. Simultaneously with the extrusion, a continuous reinforcing fiber bundle (A) was also continuously fed into the crosshead die so that the molten component (C) was coated on the component (A). At this time, the amount of the component (C) was adjusted so that the content of the reinforcing fiber was 20% by weight.

  The strand obtained by the method described above is cooled and then cut into a length of 7 mm with a cutter to form a core-sheath columnar pellet. The polyphenylene sulfide does not impregnate the reinforcing fiber bundle and is reinforced from the cut surface. The fibers dropped out and fluffing of the pellets occurred. When this was transported for injection molding, there was more fluff and it was at a level that could not be handled as a molding material.

(Comparative Example 2)
With the composition shown in Table 1, a core-sheath columnar pellet (long fiber pellet) was obtained in the same manner as in Example 1. Moreover, the obtained molding material was injection-molded similarly and used for each evaluation. Table 1 shows the process conditions and evaluation results.

(Example 2)
Using Amilan CM3001 (nylon 66 manufactured by Toray Industries, Inc., melting point 265 ° C.) as the thermoplastic resin (C), a columnar pellet (long fiber pellet) having a core-sheath structure is obtained in the same manner as in Example 1. It was. Moreover, the obtained molding material was injection-molded similarly and used for each evaluation. Table 1 shows the process conditions and evaluation results.

(Example 3)
By using Toraycon 1100S (Toray Industries, Inc. PBT, melting point 226 ° C.) as the thermoplastic resin (C), a core-sheath columnar pellet (long fiber pellet) was obtained in the same manner as in Example 1. . Moreover, the obtained molding material was injection-molded similarly and used for each evaluation. Table 1 shows the process conditions and evaluation results.

  The molding materials obtained in Examples 1 to 3 and Comparative Example 2 were all free of fuzz due to transportation and exhibited good handling properties.

  From the examples and comparative examples in Table 1, the following is clear. In the molding materials of Examples 1 to 3, the appropriate amount of the polyphenylene sulfide prepolymer (B) is impregnated in the reinforcing fiber bundle (A). Therefore, compared with the comparative example, the handling property of the molding material and the obtained molded product It is clear that it has excellent mechanical properties and appearance quality.

It is the schematic which shows an example of the form of the composite_body | complex which consists of a reinforced fiber bundle (A) and a polyarylene sulfide prepolymer (B). It is the schematic which shows an example of the preferable aspect of the molding material of this invention. It is the schematic which shows an example of the shape of the axial direction cross section of the preferable aspect of the molding material of this invention. It is the schematic which shows an example of the shape of the axial direction cross section of the preferable aspect of the molding material of this invention. It is the schematic which shows an example of the shape of the axial direction cross section of the preferable aspect of the molding material of this invention. It is the schematic which shows an example of the shape of the axial direction cross section of the preferable aspect of the molding material of this invention. It is the schematic which shows an example of the shape of the orthogonal cross section of the preferable aspect of the molding material of this invention. It is the schematic which shows an example of the shape of the orthogonal cross section of the preferable aspect of the molding material of this invention. It is the schematic which shows an example of the shape of the orthogonal cross section of the preferable aspect of the molding material of this invention. It is the schematic which shows an example of the shape of the orthogonal cross section of the preferable aspect of the molding material of this invention. It is the schematic which shows an example of the shape of the orthogonal cross section of the preferable aspect of the molding material of this invention.

Explanation of symbols

1 Reinforcing fiber bundle (A)
2 Polyarylene sulfide prepolymer (B)
3 Composite made of reinforcing fiber bundle (A) and polyarylene sulfide prepolymer (B) 4 Thermoplastic resin (C)

  The molding material of the present invention is excellent in fluidity and handleability, and when injection molding is performed, the dispersion of reinforcing fibers in the molded product is good, and a molded product having excellent mechanical properties is easily produced. Therefore, it can be applied not only to molding methods such as injection molding, blow molding, and insert molding, but also to a wide range of molding methods such as plunger molding, press molding, stamping molding, etc. It is not done.

Claims (8)

Polyarylene sulfide prepolymer (B) 0.1 to 50% by weight of continuous reinforcing fiber bundle (A), containing at least 50% by weight of cyclic polyarylene sulfide and having a weight average molecular weight of less than 10,000 A molding material comprising 10% by weight and thermoplastic resin (C) 40 to 98.9% by weight, wherein the component (C) is bonded to the composite comprising the component (A) and the component (B) Molding material made. The molding material of Claim 1 whose melting | fusing point of the said component (B) is 100-250 degreeC. The molding material according to claim 1, wherein the component (A) contains at least 10,000 single fibers of carbon fibers. The molding material in any one of Claims 1-3 whose said component (C) is at least 1 sort (s) selected from a polyamide resin, a polyester resin, and a polyphenylene sulfide resin. The component (A) is arranged substantially parallel to the axial direction, and the length of the component (A) is substantially the same as the length of the molding material. Molding material. The molding material according to claim 5, wherein the composite composed of the component (A) and the component (B) has a core structure, and the component (C) has a core-sheath structure covering the periphery of the composite. The molding material of Claim 6 whose form of a molding material is a long fiber pellet. The molding material in any one of Claims 1-7 whose length exists in the range of 1-50 mm.

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