JP2005280348A - Manufacturing method of fiber-reinforcing substrate and of composite material using the substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a fiber-reinforcing substrate by which a composite material superior in a surface quality or a quality stability of dynamic characteristics can be obtained in a high productivity and a manufacturing method of a composite material in which the fiber-reinforcing substrate is impregnated by a matrix resin. <P>SOLUTION: The manufacturing method of a carbon fiber-reinforcing substrate is passed through at least steps of (A) to (C) as follows. (A) A drawing step for drawing the reinforcing fiber thread with an original thread width Wo, (B) a spreading step for spreading a thread width to a spread width Ws with a width of >100% and <500% of the original thread width Wo, (C) a narrowing step for narrowing the thread width to ≤97% of the spread width Ws and also to an objective targeted width Wt being 100-300 % of the original thread width Wo. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing a reinforced fiber base material capable of obtaining a composite material excellent in surface quality and quality stability of mechanical properties (small variation) with good productivity, and a method for producing a composite material using the reinforced fiber base material About.

  Composite materials using reinforced fibers (hereinafter referred to as FRP) have been used mainly for aerospace, sports and sports applications because they satisfy the required mechanical properties and required properties such as weight reduction. Examples of the molding method excellent in productivity of these FRPs include resin transfer molding (RTM). In such RTM, a dry reinforcing fiber base material not impregnated with a matrix resin is placed in a mold, and a liquid matrix resin is forcibly injected to impregnate the reinforcing fibers with the matrix resin. Mold FRP.

  However, although this RTM is generally excellent in productivity of FRP, when the opening ratio of the reinforcing fiber base to be used (dry reinforcing fiber woven fabric or the like) is high, not only the mechanical properties are lowered, but also the obtained FRP. There was a problem of poor surface quality. With respect to the above problem, Patent Document 1 describes the use of flat carbon fiber yarns, Patent Document 2 describes the use of healds that do not narrow the width in the mail of the loom, and Patent Document 3 describes heat. There is a description of a woven fabric using reinforcing fibers coated with a plastic emulsion, and Patent Document 4 describes a multiaxial stitch base material in which yarns widened at a desired pitch are arranged.

  However, it is difficult to uniformly control such a reinforcing fiber base material in the state in which the yarn width of the reinforcing fiber, that is, the cover factor in the base material is increased, and the gap between the reinforcing fibers is reduced. The quality was unstable. Here, that the cover factor is non-uniform means that a void next to the reinforcing fiber yarn may or may not exist. In other words, the problem of void formation due to the difference in the impregnation rate of the matrix resin between the region where the reinforcing fiber is present and the region where the void is not present, as well as relatively meandering and bending are induced, and its straightness is locally It was causing problems to hinder. As a result, the properties of the reinforcing fiber cannot be fully expressed, and the mechanical properties (particularly the compressive strength) of the FRP are impaired. This is due to the fact that there is no idea to stably control the yarn width by simply expanding the reinforcing fiber to the desired yarn width at once.

In other words, according to the conventional proposal, a composite material having particularly excellent compressive strength and surface quality can be obtained with high productivity, and a method for producing a reinforced fiber base material having excellent quality stability has not been established. Realization was desired.
Japanese Patent Laid-Open No. 6-136632 (second page, claim 1) JP 2001-303384 A (page 4, paragraphs 0027 to 0037) JP 2001-226850 A (2nd page, claim 10) International Publication No. WO01 / 63033 (Claims 14 to 27)

  The present invention provides a method for producing a reinforced fiber base material capable of obtaining a composite material excellent in surface quality and quality stability of mechanical properties (particularly compressive strength) with good productivity, and a method for producing a composite material using the reinforced fiber base material. provide.

  The present invention employs the following means in order to solve such problems. That is, the method for producing a reinforcing fiber substrate of the present invention is a method for producing a reinforcing fiber substrate composed of reinforcing fiber yarns arranged in parallel in at least one direction, and includes the following (A) to (C ).

(A) Pulling-out process of pulling out the reinforcing fiber yarn of the original yarn width Wo (B) Widening step of widening the yarn width to a widening width Ws of more than 100% and less than 500% of the original yarn width Wo (C) Thread width Narrowing step of narrowing the width to a target width Wt of 97% or less of the widening width Ws and 100 to 300% of the original yarn width Wo. The manufacturing method of the composite material of the present invention is at least a reinforced fiber manufactured by the above method A method for producing a composite material using a substrate, which is characterized by undergoing the following steps (F) to (H).
(F) A setting step of forming a cavity by placing a reinforcing fiber base in a mold (G) An injection step of injecting a matrix resin into the cavity and impregnating the reinforcing fiber base with the matrix resin (H) Matrix resin Solidification process to solidify the composite material

According to the production method of the present invention, the yarn width can be accurately and stably controlled. Therefore, the variation rate CV of the yarn width of the reinforcing fiber yarn, the cover factor, and the gap (gap) between the yarns are desired. A reinforcing fiber base material that can be uniformly controlled within the range, meandering and bending of the reinforcing fiber yarns is suppressed, and excellent in straightness can be obtained.
Thus, it is possible to provide a reinforced fiber base material and a composite material which can obtain a composite material excellent in surface quality and quality stability of mechanical properties (small variation) with good productivity.

  The method for producing a reinforcing fiber substrate of the present invention undergoes at least the following steps (A), (B) and (C). Moreover, in order to express the effect of this invention more highly, the following (D) re-widening process can be included after the (C) narrowing process. Furthermore, the following (E) fixing step can be included simultaneously with or after the narrowing step (C) or the re-widening step (D).

(A) Pulling-out process for drawing out the reinforcing fiber yarn of the original yarn width Wo (B) Widening step of widening the yarn width to a widening width Ws of more than 100% and less than 500% of the original yarn width Wo (C) Narrowing step of narrowing to a target width Wt of 97% or less of the widening width Ws and 100 to 300% of the original yarn width Wo (D) The yarn width is 103% or more of the target width Wt and the original yarn width Wo (E) A resin material of 0.1 to 20% by weight is attached to 100% by weight of the reinforcing fiber base, and the width of the reinforcing fiber yarn is reduced. Fixing process to fix

  In the present invention, the reinforcing fiber base means a fabric composed of reinforcing fiber yarns arranged in parallel in at least one direction, as will be described in detail later.

  The original yarn width Wo is the yarn width before drawing on the bobbin around which the reinforcing fiber yarn is wound or on the beam in the later-described (A) drawing step, and extends over the entire width direction of the reinforcing fiber substrate. It means the average value of 50 selected at equal intervals.

  In addition, the yarn width means that the reinforcing fiber yarn may pass through a three-dimensional yarn path, so that the width that is widest in the vertical direction of the longitudinal direction of the reinforcing fiber yarn at that point is reinforced. This means an average value of 50 selected at regular intervals over the entire width direction of the fiber substrate.

  Generally, it is rare to prepare a reinforcing fiber yarn dedicated to a specific application, and it is general to use a commercially available one for each application. The present invention may be a reinforcing fiber yarn (warp yarn, weft yarn, insertion yarn) having an original yarn width Wo in the case of manufacturing a reinforcing fiber base having a target width Wt equal to or greater than the original yarn width Wo. ) Is widened to a widening width Ws of more than 100% and less than 500% of the original yarn width Wo, then 97% or less of Ws and a target width Wt that is 100 to 300% of the original yarn width Wo. Thus, the inventors have found that the problems of the present invention can be solved. That is, if the yarn width is directly controlled to the target width Wt without controlling the original yarn width Wo to the widening width Ws, not only the target width Wt cannot be accurately controlled but also its stability is inferior. The problem cannot be solved. By setting the target width Wt through the widening step (B) and the narrowing step (C), the target width Wt can be accurately and stably controlled. This makes it possible to uniformly control the variation rate CV of the yarn width of the reinforcing fiber yarn, which will be described later, and the cover factor of the reinforcing fiber substrate within a desired range, and to suppress meandering and bending of the reinforcing fiber yarn. A fiber substrate can be obtained. The composite material using the reinforcing fiber substrate thus obtained has a feature that is excellent in surface quality and quality stability of mechanical properties. In particular, when injection molding is performed, an unexpected effect of suppressing variation in impregnation is also exhibited.

  FIG. 1 is a schematic process diagram for explaining the flow of the manufacturing process of the present invention. Each step will be described in detail below.

(A) Drawing process (1 in FIG. 1)
The reinforcing fiber yarn having the original yarn width Wo is pulled out, for example, directly from a bobbin hung on a creel stand or pulled out from a partially warped beam or the like. Since the width of the reinforcing fiber base is usually 0.1 m to 2.54 m, there are many reinforcements in the warp in the woven fabric and in the warp yarn (0 ° direction) and the weft yarn (direction other than 0 °) in the multiaxial sheet described later. It is common to use fiber yarns. It is common to use a single weft in a woven fabric.

  Generally, the reinforcing fiber yarn is wound while traversing with a predetermined number of winds. In particular, when the reinforcing fiber yarns are flat, the flat yarn is bent in the width direction at the traverse reversal portion when wound on the bobbin while traversing. In other words, the filament close to the inner angle of the bend is loosened, and the filament close to the outer bend is wound in a tension state and temporarily set in that state. When such a reinforcing fiber yarn bobbin is unwound, a flat yarn is easy to twist and often induces false twist or fine yarn. From this point of view, when using a flat one as the reinforcing fiber yarn, the reinforcing fiber yarn is unwound at a substantially constant speed while contacting the contact roller with the bobbin around which the reinforcing fiber yarn is wound. It is preferable to pull out. By adopting such an embodiment, it is possible to minimize false twists and fine yarns from being mixed into the reinforcing fiber yarn. Such an embodiment can be used for both the warp and the weft, but the effect is maximized particularly when used for the weft.

(B) Widening process (2 in FIG. 1)
The yarn width is widened to a widening width Ws of more than 100% and less than 500% of the original yarn width Wo. More preferable Ws is 110 to 300% of Wo, more preferably 120 to 200% of Wo. If this Ws is 100% or less of Wo, this step and the narrow step (C) described below do not make sense. On the other hand, if it is 500% or more of Ws, not only Wt cannot be accurately controlled in the narrow width step (C) described later, but fluff is likely to be generated from the reinforcing fiber yarns, which may cause difficulty in production. is there.

  As a means for widening the yarn width to Ws, a method suitable for the reinforcing fiber yarn can be selected as appropriate, and an area for blowing gas or fluid, an area for sucking gas or fluid, a roll (vibrating roll, oscillating roll) , Passing through tension changing rolls (eg, egg-shaped cross section rolls, rolls whose axis is not straight), rubbing rolls (fixed rolls that do not rotate freely), pressure rolls, heating rolls, combinations thereof, etc. Vibration (ultrasonic wave etc.) application, pressurization, combinations thereof, and the like. Among these, a method of passing a gas blowing area in the yarn thickness direction, a method of passing a gas suction area in the yarn thickness direction, a roll having a contact angle of 10 ° or more (especially heating and rubbing) It is effective to pass the roll. When heating the roll, it is important for widening to heat to a temperature that sufficiently softens the sizing agent previously applied to the reinforcing fiber yarn, and heating to a range of 40 to 150 ° C. preferable. From such a viewpoint, the adhesion amount of the sizing agent for the reinforcing fiber yarn described later is preferably in the range of 0.2 to 2% by weight. More preferably, it is in the range of 0.5 to 1.5% by weight.

  In a roll having a contact angle of 10 ° or more (preferably 30 to 180 °, more preferably 45 to 90 °), a method of passing adjacent reinforcing fiber yarns through different rolls is preferable. When the fiber yarn passes through different rolls, the effect is maximized. This is because when adjacent reinforcing fiber yarns pass through the same roll, adjacent reinforcing fiber yarns become an obstacle to widening and cannot be widened to a width of Wo or more. Further, it is effective to combine this with a pressure roll (nip roll or the like). Such a method relates in particular to warp yarns in woven fabrics or warp yarns and weft yarns in multiaxial sheets. On the other hand, weft yarns in woven fabrics are generally driven into a single yarn to form a fabric. Therefore, the effect of this aspect is unlikely to occur, so gas or fluid is blown in a direction penetrating in the thickness direction of the yarn. A method of passing through the region and a method of passing through a region where gas or fluid is sucked in a direction penetrating in the thickness direction of the yarn are particularly effective.

  In addition to this, it is possible to prevent the reinforcing fiber yarn from passing through a portion having a size smaller than Wo, that is, to set the size of the passing portion to Wo or more.

(C) Narrow width process (3 in FIG. 1)
The yarn width is narrowed to a target width Wt of 97% or less of the widening width Ws and 100 to 300% of the original yarn width Wo. More preferable Wt is 95% or less of Ws, 110 to 200% of Wo, more preferably 90% or less of Ws, and 115 to 180% of Wo. When the Wt is 97% or less of Ws or less than 100% of Wo, the meaning of this step is diminished and it is difficult to obtain the effects of the present invention. On the other hand, if it exceeds 300%, the yarn width varies after the yarn width has been narrowed and cannot be accurately controlled to Wt.

  As a means for narrowing the yarn width to Wt, it is possible to use a regulation guide, a surface tension when drying by applying a liquid, a narrowing using a tension for pulling a substrate, or a gap between reinforcing fiber yarns. The above-mentioned warp knitting, needle up-and-down movement, a combination thereof, and the like are preferable, and a method of passing the reinforcing fiber yarn through the regulation guide is preferable. At least one regulation guide may be passed, but a plurality of regulation guides are preferably passed to make the regulation width more accurate. When passing a plurality of regulation guides, it is effective to use a regulation guide that greatly exceeds the target width Wt and a regulation guide that slightly exceeds the target width Wt.

  Examples of such a regulation guide include combs, grooves, saddles, and the like. Especially in looms, cocoons or cocoons can be used as regulation guides, which can be said to be a preferable mode (particularly for warp yarns). . The weft yarn is preferably narrowed using a grooved roll or a group of guide rollers in which a vertical roller and a horizontal roller are combined.

  According to the manufacturing method of the present invention through the above steps (A), (B), and (C), the target width Wt can be accurately and stably controlled. This also makes it possible to uniformly control the variation rate CV of the yarn width described later, the cover factor, and the gap (gap) between the yarns within a desired range. The composite material made of the reinforcing fiber base thus obtained has the effects of excellent quality stability (small variation) in mechanical properties and excellent surface quality.

(D) Re-widening process (4 in FIG. 1)
In the production method of the present invention, if the re-widening step described below is performed after the narrowing step (C), a more excellent effect can be obtained. That is, in the re-widening step here, the yarn width is re-widened to a re-widening width Wss of 103% or more of the target width Wt and 250% or less of the original yarn width Wo. More preferable Wss is 105% or more of Wt, 105 to 180% of Wo, more preferably 110% or more of Wt, and 110 to 150% of Wo. When the Wss is less than 103% of Wt or less than 100% of Wo, the meaning of widening in this step is diminished, and the effect of the present invention is reduced. On the other hand, if it exceeds 250%, fluff is likely to be generated from the reinforcing fiber yarn, which may cause difficulty in production.

  Examples of means for widening the yarn width to Wt include the method exemplified in the widening step (B). Among them, it is preferable that the yarn is passed through any one of a gas suction zone and a heating roll zone. In this re-widening step, means that could not be used in the widening step of (B), for example, means for opening the reinforcing fiber yarn by passing the reinforcing fiber base material through a needle (hereinafter abbreviated as stitching means), etc. Can also be adopted. This is because, in the present invention, since the narrowing step (C) is essential after the widening step (B), it cannot be fixed so that the yarn width of the reinforcing fiber yarn does not change. After the re-widening step, the selection width of the means is greatly increased because the yarn width of the reinforcing fiber yarn can be fixed at any time so as not to change. In such stitching means, the stitch yarn can be knitted, placed without knitting like tufting, removed after stitching, or simply needling without inserting the stitch yarn. The stitch yarn is preferably knitted so that it can also serve as a fixing step (E) described later.

  Among the means for re-widening, it is preferable to pressurize or widen the reinforcing fiber yarn by stitch means. Specifically, the pressurization includes continuous pressurization with a roll or intermittent pressurization with an indenter (for example, a flat plate).

(E) Fixing process (5 in FIG. 1)
The manufacturing method of the present invention can obtain a more excellent effect if the fixing step described below is further performed simultaneously with or after the narrowing step (C) or the re-widening step (D). it can. That is, in the fixing step here, a resin material is attached to fix the width of the reinforcing fiber yarn. Such a resin material is preferably 0.1 to 20% by weight with respect to 100% by weight of the reinforcing fiber substrate. If the amount is less than 0.1% by weight, the form stability of the base material is inferior when the reinforcing fiber base material is handled. If it exceeds 20% by weight, impregnation of the matrix resin may be hindered when a composite material is obtained. Furthermore, the mechanical properties of the resulting composite material may be impaired.

  Such a resin material may be attached to the surface of the reinforcing fiber base (which may be either one or both sides), or may be covered and attached over the entire surface of the reinforcing fiber base. Furthermore, you may arrange | position through the reinforcing fiber base material. The adhesion referred to in the present invention means that the resin material and the reinforcing fiber base are integrated. Specifically, the reinforcing fiber base material and the resin material may be bonded together by entanglement or braiding so as not to be separated, and microscopically, the reinforcing fiber yarn and the resin material are bound together. May not be bonded.

In the case where the resin material is attached to the surface of the reinforcing fiber base, examples of preferable means include the following methods (d1) and (d2).
(D1) After applying or bonding the solid resin material, the resin material is melted and adhered to the reinforcing fiber yarn. In this case, a nonwoven fabric, a woven fabric, a knitted fabric, fibers, particles, or the like can be used as the resin material. It is preferable to use a non-woven fabric as the resin material because the amount of the resin material can be easily controlled. On the other hand, it is preferable to use particles because microscopically uniform dispersion is possible. As a particle coating apparatus, a charged spray, a fluidized bed, a contact roll (kiss roll, dot roll, etc.), a non-contact roll (scraping roll, etc.), etc. can be used. FIG. 2 is a plan view of an embodiment of a reinforcing fiber base produced by the production method of the present invention, in which a particulate resin material is adhered to a bidirectional fabric by the method (d1). On the reinforcing fiber base 21 composed of the warp yarns 22 and the weft yarns 23 which are reinforcing fiber yarns, the resin material 24 is dispersed discontinuously in the form of dots.
(D2) A molten resin material is applied and adhered to the reinforcing fiber yarn. In this case, for example, when a melt blow method or a spun bond method is used, a nonwoven fabric can be formed and adhered directly and simultaneously to the surface of the reinforcing fiber base, which can be an efficient process.

  In the case of the methods (d1) and (d2), the resin material is preferably 2 to 20% by weight with respect to 100% by weight of the reinforcing fiber base. When the resin material is attached to the surface of the reinforcing fiber substrate by such a method, not only the width of the reinforcing fiber yarn is fixed and the shape stability of the substrate is expressed, but also the resin material is interposed between the substrate layers of the composite material. By being a crack stopper, it is possible to suppress damage between layers when subjected to an impact, and to exhibit an effect of being excellent in impact resistance characteristics (particularly, compression after impact, hereinafter abbreviated as CAI). Furthermore, the resin material itself becomes a spacer to form a flow path when impregnating the matrix resin, not only when impregnating, especially when subjected to injection molding, but also the impregnation speed is increased and the composite is increased. Unexpected effects such as excellent material productivity are also exhibited.

On the other hand, in the case where the resin material is coated and adhered over the entire surface of the reinforcing fiber base, a preferable means is, for example, the following method (d3).
(D3) After applying a resin material dissolved or dispersed in a solvent, the solvent is removed and adhered to the reinforcing fiber yarn. In this case, it is preferable to use a liquid in which the resin material is dissolved or dispersed at a high concentration because the solvent can be easily and inexpensively removed. In order to increase the concentration, an emulsifier or the like can be used as long as the mechanical properties are not adversely affected. Moreover, as a coating device, printing apparatuses, such as an inkjet and a screen, a spray, a contact roll (a kiss roll, a touch roll, etc.), etc. can be used. In addition, a solvent here is a generic name of the liquid which can melt | dissolve or disperse | distribute resin materials, such as an inorganic solvent, an organic solvent, and water.

  In this case, the resin material is preferably 0.5 to 5% by weight with respect to 100% by weight of the reinforcing fiber base. When the resin material is coated and adhered over the entire surface of the reinforcing fiber substrate by such a method, the width of the reinforcing fiber yarn can be fixed with a smaller amount of the resin material, and higher morphological stability of the substrate can be obtained. .

  In addition to this, as a preferable means for arranging the resin material through the reinforcing fiber base, for example, the above-described stitching means may be mentioned. When the stitching means is used, a through hole is formed in the thickness direction of the base material, so that an unexpected effect that the resin impregnation property is extremely excellent is exhibited. In the stitch means, stitch yarns and knot yarns described later correspond to the resin material.

  Here, when simultaneously performing the re-widening step of (D) and the fixing step of (E), the means for controlling the yarn width is continuously pressed with a roll having a glass transition point Tg or higher of the resin material, or It is preferable to intermittently pressurize with an indenter (for example, a flat plate). With this means, the yarn width can be easily controlled within the scope of the present invention even when the resin material described later is used.

  From another point of view, when the (D) re-widening step and the (E) fixing step are performed simultaneously, it is preferably a stitch means as described above. With the stitch means, the yarn width can be easily controlled within the scope of the present invention while efficiently obtaining the reinforcing fiber base material, and the impregnation property can be further improved. The stitch means may be employed because it does not fulfill the role of the re-widening step (D) but only the fixing step (E).

  In the present invention, the reinforcing fiber yarn for controlling the yarn width may be used as a warp yarn of a reinforcing fiber base material or as a weft yarn. As the reinforcing fiber base, it is preferable that both the warp and the weft are controlled and the problem of the present invention can be solved in any direction. The warp yarn in the present invention refers to reinforcing fiber yarns arranged in parallel to the longitudinal direction (0 ° direction, warp direction) of the reinforcing fiber base, and the weft yarn refers to the other direction (for example, 90 ° Direction, 45 ° direction, etc.).

  The reinforcing fiber base according to the present invention is, for example, a two-dimensional unidirectional, bi-directional, or more directional fabric, a three-dimensional multi-directional woven fabric, a knitted fabric (for example, warp knitting or weft knitting). Reinforced fiber yarns), multiaxial insert base material, reinforced fiber sheets aligned in one direction (for example, the unidirectional sheet described above) are cross-laminated in two or more directions and integrated. A multiaxial sheet may be mentioned, and these may be joined by stitch yarns, knot yarns, resin components, or the like, and a plurality of them may be integrated.

  Among them, at least a reinforced fiber yarn is used as a warp yarn, and an auxiliary fiber yarn is used as a weft yarn (in particular, a non-crimp fabric using a warp auxiliary yarn is preferable), or at least a reinforcing fiber yarn is used as a warp yarn. The unidirectional sheet is preferable because very high mechanical properties (particularly compressive strength) at the level required for the primary structural member of an aircraft can be easily achieved. This high mechanical property is caused by the fact that no bending (crimp) is formed at the intersection of the warp and weft generated in the bi-directional fabric. Furthermore, the same effect is likely to be manifested even if the unidirectional warp knitted fabric is formed by binding at least the reinforcing fiber yarn to the warp insertion yarn and the auxiliary fiber yarn forming the warp knitting structure and binding the reinforcing fiber yarn.

  From another point of view, in the case of a base material in which reinforcing fiber yarns are oriented in two directions or in multiple directions, in a unidirectional base material, two or more layers must be laminated when molding a composite material. Since it is sufficient to stack layers, it is preferable because a composite material can be obtained with high productivity (low cost). Further, a bi-directional woven fabric using warp yarns and weft yarns as reinforcing fiber yarns is more preferable because of excellent design properties.

  Furthermore, from another point of view, a multiaxial sheet obtained by laminating sheets formed of reinforcing fiber yarns in multiple directions is preferable because the labor of lamination can be further reduced. In addition, when the multiaxial sheet is a base material integrated with stitch yarns, it is possible to obtain a reinforced fiber base material that is extremely excellent in impregnation as described above. It is particularly preferable because a composite material can be obtained.

  According to the present invention, the target width Wt is accurately regulated, and as a result, the yarn width variation rate CV, the cover factor, and the gap in the reinforcing fiber base can be controlled accurately and stably.

  The reinforcing fiber base produced by the production method of the present invention is preferably such that the variation rate CV of the yarn width of the reinforcing fiber yarn in the reinforcing fiber base is controlled to 0 to 10%. More preferably, it is 0-8%, More preferably, it is 0-6%. When it exceeds 10%, when forming into a composite material, a void is formed between a portion where the reinforcing fiber yarn is thin and a thick portion, or the reinforcing fiber yarn is relatively meandered and bent to be straight. Or locally inhibit. Here, the reinforcing fiber yarn width refers to the width of the reinforcing fiber base made into a planar shape when viewed from the perpendicular direction, and an average value of 50 selected at equal intervals over the entire width direction of the reinforcing fiber base was used. . Further, the fluctuation rate of the yarn width is determined by measuring 20 yarn widths at intervals of 25 mm in the longitudinal direction of the reinforcing fiber yarn, and using these standard deviation and average value, (variation rate) = (standard deviation) × Calculated at 100 / (average value).

The reinforcing fiber base produced by the production method of the present invention is preferably controlled so that the cover factor is 95% or more. More preferably 97% or more, still more preferably 99% or more. If the composite material is less than 95%, pits (unfilled part of the resin) are generated on the surface and surface quality and mechanical properties (especially environmental durability and compressive strength under humid and heat environment) are stable. May be inferior. Here, the cover factor refers to the reinforcing fiber yarn (auxiliary fiber yarn, warp auxiliary fiber yarn) in the base material in a unit area of 200 mm × 200 mm when the flat reinforcing fiber substrate is viewed from the perpendicular direction. This indicates the percentage of the closed portion where (excluding strips, stitch yarns, etc.) is present (covered), and the value calculated by cover factor (%) = total area of closed portion (mm ² ) / 400. In this invention, it represented by the average value measured four places at equal intervals over the full width direction of the reinforced fiber base material. Such a closed portion can be calculated based on an image optically captured by a CCD camera, a scanner, or the like.

In particular, in such a multiaxial sheet, the sheet may be laminated in multiple directions, and thus the above cover factor may not be substantially meaningful. For example, when four or more layers are laminated, in almost all cases, it becomes about 100%. Therefore, as an index of quality stability when a multiaxial sheet is made of a composite material, the frequency of gaps (gaps) between reinforcing fiber yarns exceeding 2 mm in each layer arranged in multiple directions in the reinforcing fiber substrate. Is mentioned. The frequency of the gap (the value obtained by averaging the values for each layer in all layers) is preferably 0.5 pieces / m ² or less. If it exceeds 0.5 pieces / m ² , pits (unfilled part of the resin) are generated on the surface when the composite material is used, and the surface quality is inferior. On the other hand, a resin-rich layer is formed and mechanical properties ( In particular, it may be inferior in environmental stability and quality stability of compressive strength in a moist heat environment), which is undesirable depending on the application.

  Examples of the reinforcing fiber yarn used in the present invention include carbon fiber, graphite fiber, glass fiber, organic fiber (aramid, paraphenylene benzobisoxazole, polyvinyl alcohol, high-strength polyethylene, polyimide, etc.), and two types of these. What used the above together can be used. Among these, carbon fibers are excellent in specific strength and specific elastic modulus, and are therefore preferably used as reinforcing fibers for aircraft applications.

  Such reinforcing fiber yarns can be used either untwisted or twisted, but are preferably substantially untwisted from the viewpoint of mechanical properties (tensile, compression, etc.). The fineness is preferably 300 to 5,000 tex. More preferably, it is 600-2,000 tex. If it is smaller than this range, in the case of making a woven fabric, there are too many intersection points and not only the crimp but also the number thereof becomes large, and the mechanical properties may be inferior. If it is larger than this range, there are cases where the number of crossing points is too small and the form stability of the reinforcing fiber base is inferior.

In particular, when a reinforcing fiber yarn having such a fineness is used, the basis weight of the reinforcing fiber yarn that maximizes the effect of the present invention is 50 to 350 g / m ² , preferably 140 to 270 g / m ² . The effect of the present invention is further enhanced when a reinforcing fiber substrate having such a weight per unit area is obtained using reinforcing fiber yarns in the above fineness range. This is because when a carbon fiber yarn having a high fineness is used to obtain a base material with a low basis weight, the number of yarns of the reinforcing fiber yarn to be used is reduced (the woven density is reduced), and thus the cover factor is likely to be reduced. This can be understood from the fact that the gap between the reinforcing fiber yarns tends to be large.

In particular, in the multiaxial sheet, the basis weight of the reinforcing fiber yarn on the base material varies greatly depending on how many layers are laminated. From such a viewpoint, in the multiaxial sheet, the basis weight of the reinforcing fiber yarns in each layer is preferably 50 to 350 g / m ² . More preferably, it is 60-150 g / m < ² >, More preferably, it is 70-120 g / m < ² >. The effect of the present invention is exhibited to the maximum when the range of the basis weight is manufactured using the reinforcing fiber yarn having the fineness range. That is, when the basis weight of the reinforcing fiber yarns in each layer exceeds 350 g / m ² , the significance of the present invention is diminished. Moreover, it becomes difficult to produce a prepreg impregnated with a resin in advance. On the other hand, if it is less than 50 g / m ^{2, when} it is desired to obtain a desired strength in the composite material, it is necessary to laminate too many layers, which may result in poor productivity.

  The auxiliary fiber yarn of the present invention refers to a yarn having a fineness of 15% or less of the reinforcing fiber yarn used. More preferably, the fineness is less than 5%, more preferably less than 1%. The smaller the fineness of the auxiliary fiber yarn, the smaller the influence due to its presence. That is, it is possible to express the mechanical properties that the reinforcing fiber yarns essentially have. In addition, there is no restriction | limiting in particular in the material of the auxiliary fiber yarn to be used, The same thing as a reinforced fiber yarn can be used. Among these, inorganic fibers (particularly carbon fibers and glass fibers) are preferable because they are excellent in specific strength and specific elastic modulus and have few problems due to shrinkage. From another viewpoint, synthetic fibers (particularly polyamide resins and polyester resins) are preferable because the fineness can be reduced.

  The resin material used in the present invention is not particularly limited as long as it improves the morphological stability of the reinforcing fiber base and does not impair or improve the mechanical properties of the composite material, and is not particularly limited. Alternatively, a thermoplastic resin can be used.

  As the thermosetting resin, for example, epoxy, phenol, polybenzimidazole, cyanate ester, unsaturated polyester, vinyl ester, urea, melamine, bismaleimide and the like, copolymers, modified products, and two or more kinds thereof are blended. Resin or the like can be used. Furthermore, those to which an elastomer, a rubber component, a curing agent, a curing accelerator, a catalyst and the like are added can also be used.

  Examples of the thermoplastic resin include polyester, polyolefin, polyamide, polyurethane, polycarbonate, polyphenylene sulfide, polyphenylene ether, polyetherimide, polysulfone, polyarylate, polyethersulfone, polyetherethersulfone, polyketone, polyetherketone, polyether. Ether ketone, polyether ketone, polyether nitrile, phenol (novolak type), phenoxy resin, styrene resin, acrylic resin, fluorine resin, and their copolymers, modified products, and resins blended with two or more types Can be used.

  As a preferable example of the resin material that can fully express the subject of the present invention, a thermosetting resin and a thermoplastic resin are mixed, preferably compatibilized, and the glass transition point Tg thereof is more preferably 30 to 100 ° C. May be those adjusted to 50 to 90 ° C. Such a resin material not only easily adheres to the reinforcing fiber substrate, but also exhibits an excellent mechanical property improvement effect when an epoxy resin is used as a matrix resin described later. The measurement of the glass transition point Tg indicates a value obtained by measuring an absolutely dry state using a differential scanning calorimeter (DSC) at a heating rate of 20 ° C./min. In the present invention, Pyris 1 DSC manufactured by Perkin Elmer was used.

  The method for producing a composite material of the present invention may be autoclave molding, press molding, or sheet wind molding using a prepreg. As a more preferable aspect, the following steps (F) to (H) are performed. Can be molded.

(F) Set process The reinforcing fiber base produced by the above method is placed in a mold to form a cavity. In this step, when a male mold and a female mold are used as the mold, a composite material that is excellent in dimensional accuracy and cheaper than conventional autoclave molding can be molded.

  On the other hand, if either a male mold or a female mold and a bag material are used as the mold, the cost of the mold can be reduced and the cost can be further reduced, which is preferable. Examples of the bag material include a film and a flexible rubber material. Since the bag material is usually flexible, a plate for imparting rigidity to the surface on the bag material side can be used in combination. The combined use of such plates makes it possible to achieve the same level of dimensional accuracy as when using molds on both sides.

  In the latter case, since it is not possible to inject the matrix resin by applying pressure, it is preferable to dispose a resin diffusion medium that promotes the impregnation of the matrix resin in the cavity. Such a resin diffusion medium refers to a medium having a high space holding ability (having irregularities on the surface) and a flow resistance of the matrix resin having a low resistance of 1/10 or less of that of the reinforcing fiber base. Examples thereof include non-woven fabrics.

(G) Injection step A matrix resin is injected into the cavity to impregnate the reinforcing fiber substrate with the matrix resin. In this process, degassing with a vacuum pump or the like and injecting the matrix resin while keeping the inside of the cavity at a reduced pressure facilitates the impregnation of the matrix resin into the reinforcing fiber base material, and shortens the cycle of a higher quality composite material. This is preferable because it can be molded with a lower molding cost.

(H) Solidification process The matrix resin is solidified (cured or polymerized) to obtain a composite material. Here, when the matrix resin is solidified, it is preferably heated to increase the solidification efficiency. If necessary, in order to further solidify the matrix resin, a secondary solidification step in which the composite material is heated again and further solidified may be passed.

  The matrix resin used in the present invention is preferably a thermosetting resin from the viewpoint of moldability and mechanical properties, and those exemplified in the resin material are preferably used. The difference from the resin material is that when it is used for injection molding, it must be liquid at the injection temperature. The thermosetting resin having such characteristics is preferably epoxy, bismaleimide, phenol, vinyl ester, unsaturated polyester, or cyanate ester. Those obtained by further adding an elastomer, a rubber component, a curing agent, a curing accelerator, a catalyst, or the like to these resins can also be used. Among them, epoxy, bismaleimide or cyanate ester is preferable, and epoxy is particularly preferable in order to achieve very high mechanical properties required for aircraft primary structural members and the like.

  It is preferable to select different materials for the matrix resin and the resin material in consideration of their different roles.

  That is, a matrix resin having excellent impregnation properties (a resin viscosity is low at the injection temperature and a gelation time is long) and a resin material that improves the shape stability of the reinforcing fiber base are selected and used. Is preferred. Of course, in the matrix resin and the resin material, there is no limitation to using the same component for a part thereof, which can be said to be a preferable form from the viewpoint of compatibility between the two.

Example 1
FIG. 3 is a schematic process diagram illustrating a preferred embodiment of the present invention, and shows a state in which a reinforcing fiber base is manufactured using a loom 31. Next, each step will be described in detail.

  (A) Drawing process: 120 warp yarns 32 were arranged in parallel and alternately, and were drawn directly from each bobbin so as to have a width of 1 m. The yarn width (original yarn width Wo) on the bobbin of the reinforcing fiber yarn was 5.8 mm for both the warp yarn and the weft yarn.

  The warp yarn 32 is a polyacrylonitrile (PAN) -based carbon fiber yarn (12,000 filament, fineness 800 tex, tensile strength 4,800 MPa, tensile elastic modulus 240 GPa, sizing agent 0.5% by weight), which is a reinforcing fiber yarn. Was used. The same weft 33 described later was also used. When unraveling the weft yarn, the bobbin was unwound and pulled out at a substantially constant speed while contacting the contact roller (not shown).

  (B) Widening step: On the roll 38 having the maximum contact angle by passing three rolls 39 (the contact angle of the second roll 38 of the three is 190 °) different from each other in the adjacent warp threads 32. Thus, the warp yarn 32 was widened to 10 mm of the widening width Ws (172% of the original yarn width Wo). On the other hand, the weft yarn sucks air in a direction penetrating the thickness direction of the carbon fiber yarn (not shown) in a state in which tension is not substantially applied, and the weft yarn 33 is 11 mm of the widening width Ws (of the original yarn width Wo). 190%).

  (C) Narrowing step: The widened warp yarn 32 is opened and closed while passing through the heel 34a (the inner size of the mail 34b is 9 mm), and 1.2 ra / cm is used using the rapier 36 in the formed heel. Weft yarn 33 was driven in at a weaving density, and warp yarn and weft yarn were crossed. Next, the warp yarn 35 (the inner dimension of the portion through which the yarn passes (the wrinkle gap) is 8.2 mm) is passed through to pass the warp yarn 32 to 7.9 mm of the target width Wt (79% of the widening width Ws, the original yarn). The bi-directional woven fabric was narrowed to 136% of the width Wo. The weft 33 was passed through a grooved roller (not shown) and narrowed to 8 mm of the target width Wt (73% of the widening width Ws and 138% of the original yarn width Wo).

The basis weight of the reinforcing fiber yarn in the obtained reinforcing fiber base was 193 g / m ² , the variation rate CV of the yarn width of the warp yarn 32 was 7%, and the cover factor was 99.7%.

Example 2
The reinforcing fiber base material, which is the bidirectional fabric obtained in Example 1, was subsequently re-expanded in the following (D) re-widening step.

  (D) Re-widening step: A pressure roller 37 (heated to 80 ° C.) that moves back and forth in the take-up direction of the base material is pressed while weaving the reinforcing fiber base material, and the warp yarn 32 is re-expanded width 8. The paper was re-expanded to 2 mm (104% of the target width Wt, 141% of the original yarn width Wo) and wound up once.

  In the obtained reinforcing fiber base material, the variation rate CV of the yarn width of the warp yarn 32 was 5%, and the cover factor was 99.9%.

Example 3
In the following (E) fixing step, the resin material was applied and bonded to the reinforcing fiber base material, which is the bidirectional fabric obtained in Example 2, to fix the width of the reinforcing fiber yarn.

(E) Fixing step: The resin material that is in the form of particles is naturally dropped while being measured with an embossing roll and a doctor blade, and uniformly dispersed through a vibration net, while being 7.5 g / m ² (resin material) on one surface 4% by weight with respect to 100% by weight of the reinforcing fiber substrate after application). Then, the far-infrared heater was passed at 185 degreeC, and the resin material was made to adhere only to the one surface of a reinforced fiber base material.

  As the particulate resin material, a pellet obtained by freeze-pulverizing pellets obtained by kneading and compatibilizing 60% by weight of a polyethersulfone resin and 40% by weight of an epoxy resin composition was used. The particulate resin material had an average particle diameter D50 (laser diffraction / scattering method) of 115 μm and a glass transition point of 68 ° C.

  The obtained reinforcing fiber base was remarkably improved in shape stability by the resin material, easier to handle than that of Example 1, and the reinforcing fiber yarn was excellent in straightness. Further, the yarn width was stable in the longitudinal direction and the width direction, and was excellent in quality stability.

Example 4
(A) Drawing process: 150 warp yarns and 150 warp auxiliary fiber yarns were arranged in parallel and alternately, and were drawn directly from each bobbin so as to have a width of 1 m. The carbon fiber yarn used in Example 1 as the warp yarn, the glass fiber yarn (ECE225 1/0) as the warp auxiliary fiber yarn, and the polyamide fiber yarn (7 filaments) as the weft yarn (auxiliary fiber yarn) , Fineness 1.7 tex) was used.

  (B) Widening step: The warp yarn is passed through a widening width Ws of 8. The width of the warp yarn is 8 so that adjacent warp yarns pass through three rolls (the same configuration as that used in Example 1 and without the nip roll 41). The width was increased to 9 mm (153% of the original yarn width Wo).

  (C) Narrowing step: The widened warp yarn is passed through a heel (inner dimension of the mail is 7.5 mm) and moved by opening and closing, and a rapier is used to form the weft at a weave density of 3 / cm. And warp auxiliary fiber yarns and weft yarns were interlaced to hold the warp yarns together (warp yarns and weft yarns were not interlaced). Next, the warp yarn is passed through the target width Wt by 6.2 mm (70% of the widened width and 107% of the original yarn width Wo) by passing through the reed (the inner dimension of the portion through which the yarn passes (the wrinkle gap) is 7 mm). ) To form a unidirectional non-crimp fabric.

The basis weight of the reinforcing fiber yarn in the obtained reinforcing fiber substrate was 144 g / m ² , the variation rate CV of the yarn width of the warp yarn 32 was 6%, and the cover factor was 95%.

Example 5
The reinforcing fiber base material, which is the unidirectional non-crimp fabric obtained in Example 4, was subsequently re-widened in the following (D) re-widening step.

  (D) Re-widening step: pressurizing while weaving the reinforcing fiber base with a pressure roller (heated to 80 ° C.) moving back and forth in the take-up direction of the base, and the warp yarn is 6.5 mm of the re-widening width Wss The paper was re-expanded and wound up (105% of the target width Wt, 112% of the original yarn width Wo).

  The variation rate CV of the warp yarn width in the obtained reinforcing fiber substrate was 4%, and the cover factor was 98%.

Example 6
In the following (E) fixing process, the resin material was applied and adhered to the reinforcing fiber base material, which was the unidirectional non-crimp fabric obtained in Example 5, to fix the width of the reinforcing fiber yarn.

(E) Fixing step: The resin material that is in the form of particles is naturally dropped while being measured with an embossing roll and a doctor blade, and is uniformly dispersed through a vibration net while being 21 g / m ² (after the resin material is attached) Of 13% by weight based on 100% by weight of the reinforcing fiber substrate). Then, the far infrared heater was passed at 185 degreeC, and the resin material was adhere | attached only on the one surface of the reinforced fiber base material. In addition, the same thing as Example 3 was used as a particulate resin material.

  The obtained reinforcing fiber base was remarkably improved in shape stability by the resin material, easier to handle than that of Example 4, and the reinforcing fiber yarn was excellent in straightness. Further, the yarn width was stable in the longitudinal direction and the width direction, and was excellent in quality stability.

Example 7
FIG. 4 is a schematic process diagram for explaining another preferred embodiment of the present invention, and shows a state in which a multi-axis sheet is manufactured using a multi-axis laminator 42. Next, each step will be described in detail.

  (A) Drawing process: 180 warp threads 43 were arranged in parallel and alternately, and were directly drawn out from each bobbin so as to have a width of 1.2 m. When unwinding the warp yarn, the warp yarn was unwound and pulled out at a substantially constant speed while contacting the bobbin with the contact roller. On the other hand, 18 weft yarns (stacked at different locations a and b in the + 45 ° direction and −45 ° direction with respect to the warp yarns, respectively) (not shown) are arranged in parallel and alternately, resulting in a width of 0.1 m. Was pulled directly from each bobbin. When unraveling the weft yarn, the weft yarn was unwound and pulled out at a substantially constant speed while contacting the bobbin with the contact roller in the same manner as the warp yarn. The yarn width (original yarn width Wo) on the bobbin of the reinforcing fiber yarn was 5.8 mm for both the warp yarn and the weft yarn. The same warp yarn 43 and weft yarn (not shown) as in Example 1 were used.

  (B) Widening step: On the roll 44 having the maximum contact angle by passing three rolls 45 (the contact angle of the second roll 44 is 190 ° among the three) different from the adjacent warp threads 43. Thus, the warp yarn 43 was widened to 9 mm of the widening width Ws (155% of the original yarn width Wo). On the other hand, the weft yarn is widened to 8.3 mm of the widening width Ws (143% of the original yarn width Wo) by passing a roll (contact angle is 180 °) (not shown) having different weft yarns. did.

  (C) Narrowing step: The widened warp yarn 43 is passed through a comb-shaped guide 47 (the inner dimension of the comb gap where the yarn passes is 7 mm), so that the warp yarn 43 is 6.7 mm (target width Wt). A unidirectional warp sheet 48 was formed narrowed to 74% of the widening width Ws and 116% of the original yarn width Wo. On the other hand, the weft yarn is similarly passed through a comb-shaped guide (not shown) to narrow the weft yarn to 6.7 mm of the target width Wt (81% of the widened width Ws and 116% of the original yarn width Wo). A weft sheet (not shown) was formed.

  (E) Fixing process: warp yarn and weft yarn by taking chain stitches with stitch device c using stitch yarn (polyester multifilament yarn) which is a resin material while taking a laminate of warp yarn sheet and weft yarn sheet The strip width was fixed and wound up.

The basis weight of the reinforcing fiber yarn of each layer in the obtained multiaxial sheet is 120 g / m ² , the variation rate CV of the warp and weft yarn width is 6%, and the reinforcing fiber yarn exceeds 2 mm in each layer of the multiaxial sheet. The frequency of the gap between each other was 0.2 to 0.3 / m ² . Forming a chain stitch structure with stitch yarns significantly improves shape stability, is easier to handle than that of Example 1, and forms a base material in which reinforcing fiber yarns are oriented in three layers I was able to.

Example 8
Using the reinforcing fiber base produced through Examples 1-3, 6, and 7, it was molded into a composite material by the following method. In addition, the laminated configuration was 12 sheets in the first to third examples, 7 sheets in Example 6, and 4 sheets in Example 7.

  A reinforcing fiber base material was laminated on the surface of the aluminum mold. A peel ply (polyester fiber release treated fabric) and a resin diffusion medium (polypropylene mesh sheet) were sequentially disposed on the outermost surface, and an aluminum cowl plate was further disposed thereon. A plurality of edge breathers (polyester fiber non-woven fabrics) were laminated and stretched around the periphery of the laminated reinforcing fiber substrate in contact with the mold. The maximum outer shape in plan view of the resin diffusion medium is larger than the maximum outer shape in plan view of the reinforcing fiber substrate on the surface of the resin diffusion medium so that the distance from the vacuum suction port or edge breather to the nearest resin diffusion medium is 10 mm or more. It arrange | positioned so that it might become small about 10-50 mm. The whole was covered with a bag material (nylon film), and the periphery of the bag material and the mold was sealed with a sealing material to form a cavity. The resin injection port was attached so as to be in contact with the resin diffusion medium and sealed with a sealing material. The vacuum suction port was mounted on the edge breather farthest from the resin injection port and sealed in the same manner. Suction was performed from the vacuum suction port, and the inside of the cavity was vacuumed. The entire apparatus was heated to the matrix resin injection temperature (80 ° C.). While the vacuum suction was continued, the reinforcing fiber substrate was held for 1 hour after reaching the injection temperature. Thereafter, the valve of the resin injection port was released, and the required amount of matrix resin prepared in a state ready for injection after mixing and defoaming was injected from the resin diffusion medium. When the impregnation was completed, the injection was stopped by closing the valve of the resin injection port. Vacuum suction was continued until the matrix resin gelled (1.5 hours from the start of injection). Thereafter, the temperature was raised to the curing temperature (130 ° C.) of the matrix resin and held for 2 hours to cure the matrix resin. When the curing temperature was reached, the vacuum suction port was closed to stop the suction, and the bag material was kept in a vacuum state.

  Thereafter, the temperature was lowered to room temperature, the bag material, the peel ply and the resin impregnated medium were removed, and secondary curing was performed again at a free stand (180 ° C.) to obtain a composite material. In addition, the epoxy resin composition (The polyamine is used as a hardening | curing agent, The viscosity by an E-type viscosity meter in 80 degreeC: 55 mPa * s) was used as matrix resin.

  When the obtained composite material was inspected, no pinholes or voids were found, and it was confirmed that excellent molding was performed with excellent appearance quality.

  Next, the change rate CV of the compressive strength was measured for the test piece along the SACMA-SRM-1R-94 from the composite material.

Comparative Example 1
(B) No widening without passing through the three rolls in the widening step (yarn width is 5.2 mm, 90% of the original yarn width Wo), (C) the inner dimensions of the mail in the narrowing step A bi-directional woven fabric was obtained in the same manner as in Example 1 except that the width was reduced by using a 4 mm wrinkle (69% of the original yarn width Wo). The final yarn width was 6.5 mm.

The resulting reinforcing fiber substrate has a basis weight of the reinforcing fiber yarn of 193 g / m ² , a variation rate CV of the yarn width of 14%, a cover factor of 95%, and the gap between the reinforcing fiber yarns is not uniform. Furthermore, the quality stability was inferior.

Comparative Example 2
A composite material was molded and evaluated in the same manner as in Example 8 except that the reinforcing fiber base produced through Comparative Example 1 was used. When the obtained composite material was inspected, voids were not found, but the unevenness was large at the open portions and the appearance quality was poor.
The above results are summarized in Table 1. In Table 1, the evaluation for each item is a four-level evaluation, “very good” is “◎”, “excellent” is “○”, “ordinary” is “△”, “Inferior” was indicated as “×”.

As can be seen from Table 1, regarding the mechanical properties of the composite material, the examples of the present invention showed a very low rate of change in compressive strength, and among them, the examples 3 and 6 have particularly excellent characteristics. Yes.
On the other hand, the comparative example 1 has a larger variation rate CV of the compressive strength and a larger variation than the examples.

Regarding the impregnation property, quality stability and shape stability of the matrix resin of the reinforcing fiber base, those of Examples 3 and 6 have excellent characteristics. In addition, since the thing of Example 1 did not use the resin material, it was the following form stability of Example 2, 3. In addition, the thing of Example 7 was excellent in especially the impregnation property. That is, Example 3 or 6 is mentioned as one of the most preferable embodiments of the present invention.
In the above description of the present invention, the frequency of the gaps (gap) between reinforcing fiber yarns exceeding 2 mm in each layer arranged in multiple directions in the reinforcing fiber substrate (the number present per 1 m ² ) is as follows: It is the value measured in this way. And each value for every layer obtained by this measuring method is further averaged for all layers.
First, the number of gaps exceeding 2 mm width existing on the outermost layer of the measurement sample is counted. Specifically, regarding the gap between the reinforcing fiber yarns A and B, if there is even one place exceeding 2 mm, the gap is counted as one. As the width of the gap, a gap measured with a caliper in the plane direction of the sample is used. The measurement range is within an arbitrary 1 m width × 1 m length (1 m ² ) excluding 5 cm at the end of the sample. However, when the sample width is narrower than 1.1 m, the range is (width excluding 5 cm at the end of the sample) × (length determined so that the measurement range is 1 m ² ). This measurement is repeated three times and an average value is taken as the gap frequency of the layer. Next, the stitching yarn is unwound in the case of an integration means, for example, in the case of a stitch yarn, and in the case of a molten resin, the adhesion is released by heating, the inner layer of the measurement sample is exposed, and each layer is counted in the same manner as described above. The frequency of gaps in each layer obtained by such measurement is averaged to obtain the frequency of gaps in the reinforcing fiber substrate.

  According to the reinforcing fiber base material manufactured by the method of the present invention, a reinforcing fiber base material and a composite material capable of obtaining a composite material excellent in surface quality and quality stability of mechanical properties (particularly compressive strength) with good productivity are provided. The present invention can be used very effectively in the composite material industry.

  Such a composite material is suitable for primary structural members, secondary structural members, exterior parts, interior parts or parts thereof in transportation equipment such as aircraft, automobiles, and ships.

It is a schematic process drawing explaining the flow of the manufacturing process in the manufacturing method of the reinforced fiber base material of this invention. It is a plane schematic diagram of one embodiment of the reinforcing fiber base manufactured with the manufacturing method of the reinforcing fiber base of the present invention. It is a process schematic diagram explaining an example of the preferable embodiment of the manufacturing method of the reinforced fiber base material of this invention. It is a process schematic diagram explaining another example of the preferable embodiment of the manufacturing method of the reinforced fiber base material of this invention.

Explanation of symbols

1: Drawing step 2: Widening step 3: Narrowing step 4: Re-widening step 5: Fixing step 21: Reinforcing fiber base materials 22, 32, 43: Warp yarn 23, 33: Weft yarn 24: Resin material 31: Loom 34a: Wrinkle 34b: Mail 35: 筬 36: Rapier 37: Pressing roll 38 moving back and forth, 44: Roll 39 having the largest contact angle among three rolls, 45: Three rolls 40: Dancer rolls 41, 46: Nip rolls 42: Multi-axis laminating machine 47: Comb guide 48: Unidirectional warp sheet a: Weft stacking position in + 45 ° direction b: Weft stacking position in −45 ° direction c: Stitch device

Claims (26)

A method for producing a reinforcing fiber substrate composed of reinforcing fiber yarns arranged in parallel in at least one direction, wherein the reinforcing fiber substrate is subjected to the following steps (A) to (C): Manufacturing method.
(A) Pulling-out process for drawing out the reinforcing fiber yarn of the original yarn width Wo (B) Widening step of widening the yarn width to a widening width Ws of more than 100% and less than 500% of the original yarn width Wo (C) The narrowing step of narrowing to a target width Wt of 97% or less of the widening width Ws and 100 to 300% of the original yarn width Wo The method for producing a reinforcing fiber substrate according to claim 1, wherein after the narrowing step (C), the following re-widening step (D) is performed.
(D) Re-widening step of re-widening the yarn width to a re-widening Wss of 103% or more of the target width Wt and 250% or less of the original yarn width Wo The reinforcing fiber substrate according to claim 1 or 2, further comprising the following (E) fixing step simultaneously with or after the narrowing step (C) or the re-widening step (D). Manufacturing method.
(E) A fixing step in which 0.1 to 20% by weight of a resin material is attached to 100% by weight of the reinforcing fiber base to fix the width of the reinforcing fiber yarn.   The drawing process of (A) is characterized in that the reinforcing fiber yarn is unwound and pulled out at a substantially constant speed while contacting the contact roller with the bobbin around which the reinforcing fiber yarn is wound. The manufacturing method of the reinforced fiber base material in any one of Claims 1-3.   The widening step of (B) is performed by passing the yarn through a roll having a contact angle of 10 ° or more, and adjacent reinforcing fiber yarns pass through different rolls. The manufacturing method of the reinforced fiber base material in any one of 1-4.   The method for producing a reinforcing fiber substrate according to claim 5, wherein the roll having a contact angle of 10 ° or more is heated in a range of 40 ° C to 150 ° C.   The re-widening step of (D) is performed by passing the yarn through any one of a gas blowing area, a vibrating roll, a swinging roll, and a pressure roll. The manufacturing method of the reinforced fiber base material in any one of -6.   The re-widening step of (D) is performed by allowing the yarn to pass through any one of a gas suction zone and a heating roll zone. A method for producing a reinforcing fiber substrate.   In the fixing step (E), after applying or bonding a solid resin material to the yarn, the resin material is melted, and within a range of 2 to 20% by weight with respect to 100% by weight of the reinforcing fiber substrate The method for producing a reinforcing fiber base material according to any one of claims 3 to 8, wherein the resin material is adhered to the reinforcing fiber yarn.   The fixing step (E) applies a molten resin material and adheres it to the reinforcing fiber yarn within a range of 2 to 20% by weight with respect to 100% by weight of the reinforcing fiber substrate. The manufacturing method of the reinforced fiber base material in any one of Claims 3-8 characterized by the above-mentioned.   In the fixing step (E), the resin material dissolved or dispersed in the solvent is applied and then the solvent is removed, and the reinforcing fiber yarn is within a range of 0.5 to 5% by weight with respect to 100% by weight of the reinforcing fiber substrate. The method for producing a reinforcing fiber substrate according to any one of claims 3 to 9, wherein the reinforcing fiber substrate is attached to a strip.   The re-widening step of (D) or the fixing step of (E) is continuously pressurized with a roll having a glass transition point Tg or higher of the resin material, or intermittently pressurized with an indenter. The manufacturing method of the reinforced fiber base material in any one of 11.   The re-widening step of (D) or the fixing step of (E) is to allow the needle to penetrate the reinforcing fiber substrate, The production of the reinforcing fiber substrate according to any one of claims 2 to 12 Method.   The reinforcing fiber base material according to any one of claims 1 to 13, wherein the reinforcing fiber base material is a unidirectional woven fabric having at least a reinforcing fiber yarn as a warp and an auxiliary fiber yarn as a weft. Production method.   A unidirectional warp knitted fabric in which a reinforcing fiber base is used, wherein at least a reinforcing fiber yarn is used as a warp yarn insertion yarn, and a warp knitting structure formed by an auxiliary fiber yarn is formed by binding the reinforcing fiber yarns. It exists, The manufacturing method of the reinforced fiber base material in any one of Claims 1-13 characterized by the above-mentioned.   The method for producing a reinforced fiber base material according to any one of claims 1 to 13, wherein the reinforced fiber base material is a unidirectional sheet having at least a reinforced fiber yarn as a warp.   The method for producing a reinforcing fiber substrate according to any one of claims 1 to 13, wherein the reinforcing fiber substrate is a bi-directional woven fabric using warp yarns and weft yarns as reinforcing fiber yarns.   The variation rate CV of the yarn width of the reinforcing fiber yarn in the reinforcing fiber base is 0 to 10%, and the cover factor of the reinforcing fiber base is 95% or more. The manufacturing method of the reinforced fiber base material in any one. The fineness of the reinforcing fiber yarn is 300 to 5,000 tex, and the basis weight of the reinforcing fiber yarn in the reinforcing fiber base is 50 to 350 g / m ² . The manufacturing method of the reinforced fiber base material of description.   The method for producing a reinforcing fiber base material according to any one of claims 1 to 13, wherein the reinforcing fiber base material is a multiaxial sheet obtained by laminating sheets formed of reinforcing fiber yarns in multiple directions. In a multiaxial sheet, the average number of gaps between reinforcing fiber yarns exceeding 2 mm in each layer arranged in multiple directions in the reinforcing fiber substrate is 0.5 pieces / m ² or less in all layers. The manufacturing method of the reinforced fiber base material of Claim 20 characterized by the above-mentioned. In the multiaxial sheet, the fineness of the reinforcing fiber yarn is 300 to 5,000 tex, and the basis weight of the reinforcing fiber yarn of each layer arranged in multiple directions in the reinforcing fiber base is 50 to 350 g / m ² . The method for producing a reinforcing fiber substrate according to claim 20 or 21, wherein:   The method for producing a reinforcing fiber substrate according to any one of claims 1 to 22, wherein the reinforcing fiber yarn is used as a warp yarn of the reinforcing fiber substrate.   The method for producing a reinforcing fiber base according to any one of claims 1 to 23, wherein the reinforcing fiber yarn is used as a weft of the reinforcing fiber base. It is a manufacturing method of the composite material using the reinforced fiber base material manufactured by the method in any one of Claims 1-24, Comprising: The composite_body | complex characterized by passing through the process of following (F)-(H). Material manufacturing method.
(F) A setting step of forming a cavity by placing a reinforcing fiber base in a mold (G) An injection step of injecting a matrix resin into the cavity and impregnating the reinforcing fiber base with the matrix resin (H) Matrix resin Solidification process to solidify the composite material   (F) The setting process uses either a male mold or a female mold as a mold and a bag material, and a resin diffusion medium is disposed in the cavity. (G) An injection process is performed in the cavity. 26. The method for producing a composite material according to claim 25, wherein the matrix resin is injected while maintaining a reduced pressure state.

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