JP2008045247A - Method for producing carbon fiber woven fabric and fiber-reinforced plastic - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing carbon fiber woven fabric to which filling treatment capable of suppressing collapse of structure of carbon fiber and tangle in cutting and effective for retention of shape of weave structure suppressed in gap and excellent in appearance and quality appearance when molded into fiber-reinforced plastic is applied and to provide a method for producing a fiber-reinforced plastic. <P>SOLUTION: The method for producing a carbon fiber woven fabric by which at least either one of warp and weft is composed of yarn of carbon fiber and by which filling treatment for retaining shape of weave structure is applied through (A) a drawing process for introducing warp into a loom, (B) an attaching process for at least partially moistening the weft with a resin solution, emulsion and suspension in which a solvent or a dispersion medium is water, (C) a weaving process for weaving the weft at least partially moistened and the warp in a crossed state into a woven fabric, (D) a drying process for heating and drying the woven fabric and (E) a rolling process for rolling the woven fabric into a roll. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a carbon fiber fabric and a method for producing a fiber reinforced plastic. More specifically, it is possible to suppress the collapse of the structure of the carbon fiber fabric (bending of the weaving yarn) and the unraveling at the time of cutting, and it is effective for maintaining the shape of the woven structure with reduced gaps, and is formed into a fiber reinforced plastic. The present invention relates to a method for producing a carbon fiber fabric and a method for producing a fiber reinforced plastic that have been subjected to a crushing process that is sometimes excellent in appearance quality (particularly surface smoothness).

  Conventionally, reinforced fibers such as carbon fibers have a high specific strength and specific elastic modulus, so that they can be used as a fiber reinforced plastic (hereinafter sometimes referred to as FRP) for sports / leisure products, which have a large weight reduction effect, It is often used for general industries. Such FRP molding methods include various methods such as hand lay-up molding, autoclave molding, and RTM molding, and are appropriately selected depending on the shape and number of molded products, required characteristics, and the like. In these molding methods, reinforcing fibers are often used in the form of a woven fabric as an intermediate substrate. In such a woven fabric, there is a problem of misalignment when the fabric is deformed or the weaving yarn is displaced, and there is a problem that the weaving yarn is easily unraveled when the fabric is cut.

  To prevent such problems, weaving reinforcement fibers and thermoplastic fibers and heating them, or applying particles to the fabric, aiming at the intersection of the warp and weft with thermoplastic fibers and particles, and the ability to suppress the release There have been proposals to provide a form-stable function (see, for example, Patent Documents 1 and 2).

  In these proposals, there is a description that the sheet is heated after passing through the guide roll and then wound through the pressing roll. However, since the woven fabric is heated after passing through a plurality of rolls, the fabric may already have a collapsed structure (weaving of the yarn), resulting in a fabric in which the yarn is arranged in a straight line. There was no problem. Such a phenomenon is particularly prominent in a unidirectional woven fabric in which the reinforcing fiber is a warp and the auxiliary fiber is finer than the reinforcing fiber.

  In addition, as a squeezing agent, a thermoplastic fiber or particle having a relatively large size was used, and the compatibility between the squeezing agent and the matrix resin was not taken into consideration. , The sizing agent forms a domain having a dimension that can be visually observed in the matrix resin (the squeezing agent and the matrix resin are incompatible), and the appearance quality of the FRP, in particular, the surface smoothness is inferior. there were. Furthermore, when the obtained FRP is used in a high temperature environment, there is also a problem that the squeezing agent itself bleeds (elutes) from the domain of the squeezing agent formed on the FRP surface.

  On the other hand, the proposal which uses resin emulsion etc. as a squeezing agent is made | formed (for example, refer patent document 3, 4 etc.). However, in Patent Document 3, since the resin emulsion is applied to the woven fabric after weaving, the woven fabric itself becomes hard, and the drapeability is inferior and difficult to handle. There was an unnecessarily large problem. Further, in Patent Document 4, since the woven yarn is preliminarily applied and fixed and woven in a state in which the woven yarn is opened, an extra process for preliminarily applying and opening the woven yarn is increased. There was a problem that there were too many unnecessarily.

  On the other hand, in a method for producing a carbon fiber fabric, a proposal has been made to apply a liquid to warp yarns and weft yarns in order to suppress fluff generated from carbon fibers during weaving (see, for example, Patent Documents 5 and 6). In these proposals, there is a description that fluff can be suppressed by applying water or a paste (polyethylene glycol, water, and methanol). However, such a proposal has the effect of suppressing fluff, and is effective in maintaining the form of the woven structure, the form of the squeezing material necessary for obtaining an FRP having an excellent appearance quality, and the sizing. There is no description about the compatibility between the agent and the matrix resin. Further, Patent Document 5 refocuses the weft yarn. However, in the carbon fiber woven fabric, it means that the crimp of the woven fabric is enlarged and expresses the strength and elastic modulus inherent to the carbon fiber. In addition to hindering, there was also a problem that the opening (gap) of the fabric was increased and the appearance quality of the resulting FRP was inferior.

In other words, the technique proposed above provides a method for producing a woven fabric that is effective in maintaining the shape of the woven fabric and that completely suppresses the collapse of the woven fabric fabric (bending of the woven yarn) and the unraveling during cutting. It was not done. In other words, the reinforced fiber fabric obtained by the prior art cannot easily exhibit the original mechanical characteristics in the FRP because the carbon fibers are easily misaligned, and is inferior in the appearance quality of the obtained FRP, particularly in the surface smoothness. It was.
Japanese Patent Laid-Open No. 63-152637 (FIG. 11) JP 2004-256930 A (FIG. 1) Japanese Patent Laid-Open No. 08-158207 (FIG. 1) JP 2001-226850 A (FIG. 1) JP 05-005252 A (FIG. 1) JP 2002-115145 A (FIG. 1)

  The object of the present invention is to solve the above-mentioned problems of the prior art, to suppress the collapse of the carbon fiber woven fabric (bending of the weaving yarn) and the unraveling at the time of cutting, and to reduce the gap. To provide a method for producing a carbon fiber fabric and a method for producing a fiber reinforced plastic that are effective for holding and subjected to a squeezing treatment that is excellent in appearance quality (particularly surface smoothness) when molded into a fiber reinforced plastic. is there.

In order to achieve the above object, the present invention adopts the following configuration. That is,
(1) A method for producing a carbon fiber woven fabric in which at least one of the warp yarn or the weft yarn is made of carbon fiber yarns and is subjected to a crushing treatment that maintains the shape of the woven structure, and includes the following (A) to (E The method for producing a carbon fiber woven fabric, characterized in that it undergoes the step of
(A) Pulling out the warp yarn to the loom (B) Adhering step (C) At least partially wet the weft yarn at least partially with a resin solution, emulsion or suspension in which the solvent or dispersion medium is water Weaving process of wetting the weft yarn with the warp yarn to weave the fabric (D) Drying step of heating and drying the woven fabric (E) Winding step of winding the fabric into a roll (2) Between the drying process of (D) and the winding-up process of (E), the manufacturing method of the carbon fiber fabric as described in said (1) which passes through the process of the following (F).
(F) A cooling step of cooling the heat-dried woven fabric below the melting point of the agitating resin that is a solute or dispersoid of a resin solution, emulsion or suspension. (3) The drawing step of (A) above ( The method for producing a carbon fiber woven fabric according to the above (1) or (2), which undergoes the following step (G) between the weaving step C).
(G) Second adhering step in which the warp yarn is at least partially wetted with a resin solution, emulsion or suspension whose solvent or dispersion medium is water. (4) In the weaving step of (C), the weft yarn is intercepted. And the manufacturing method of the carbon fiber fabric in any one of said (1)-(3) which drives into a shed without mixing untwisting.

  (5) The carbon according to any one of (1) to (4), wherein in the weaving step of (C), the weft width retention of the weft yarn after being at least partially wetted is 70% or more. A method for producing a textile fabric.

  (6) The agitating resin that is the solute or dispersoid of the resin solution, emulsion or suspension is solid at room temperature (25 ° C.) in the carbon fiber fabric after the drying step (D) described later. The manufacturing method of the carbon fiber fabric in any one of said (1)-(5).

  (7) Any one of the resin resins, emulsions, or suspension solutes or dispersoids is at least one selected from epoxy, unsaturated polyester, and vinyl ester. A method for producing a carbon fiber fabric according to claim 1.

  (8) The aforesaid resin that is a solute or dispersoid of a resin solution, emulsion or suspension is at least one selected from polyamide, polyester, polyolefin, polyvinyl formal, and polyether sulfone (1) The manufacturing method of the carbon fiber fabric in any one of (6)-(6).

  (9) A unidirectional fabric in which the carbon fiber fabric uses a flat carbon fiber yarn having a flatness ratio of 20 to 200 as a warp, and an auxiliary fiber yarn having a finer degree than the carbon fiber yarn. The manufacturing method of the carbon fiber fabric in any one of said (1)-(8) which is.

  (10) The method for producing a carbon fiber woven fabric according to (9), wherein the auxiliary fiber yarn that is the weft of the unidirectional woven fabric has a melting point of 300 ° C or lower.

  (11) Any of the above (1) to (8), wherein the carbon fiber woven fabric is a bi-directional woven fabric having a flat carbon fiber yarn having a flatness ratio of 20 to 200 as a warp and a weft. A method for producing a carbon fiber fabric according to claim 1.

  (12) A method for producing a fiber reinforced plastic comprising a carbon fiber woven fabric obtained by the production method according to any one of (1) to (11) above and a matrix resin, A method for producing a fiber-reinforced plastic, comprising: making a resin that is a solute or dispersoid of a resin solution, emulsion or suspension contained in a fiber fabric, compatible with a matrix resin.

  In the present invention, the weft yarn is at least partially wetted with a resin solution, emulsion or suspension, and the solvent or dispersion medium is dried after weaving. This makes it possible to perform a crushing process effective for maintaining the shape of the woven structure.

  The carbon fiber woven fabric obtained by such a manufacturing method can exhibit original mechanical properties when formed into FRP because the carbon fibers are not misaligned. In addition, since it is agitated with an agitating resin that is a solute or dispersoid of a resin solution, emulsion, or suspension that is compatible with the matrix resin, it is possible to obtain an FRP having excellent appearance quality. it can. This effect is exerted to the maximum extent in a bidirectional fabric.

  The method for producing a carbon fiber woven fabric of the present invention is a method for producing a carbon fiber woven fabric in which at least one of the warp yarn or the weft yarn is a carbon fiber yarn and is subjected to a squeezing treatment that maintains the shape of the woven structure, The following steps (A) to (E) are performed. Preferably, the following step (F) can be performed between the following (D) heat drying step and (E) winding step. More preferably, the following step (G) can be performed between the drawing step (A) below and the weaving step (C). Below, each process is demonstrated in order.

    (A) A drawing process for guiding the warp yarn to the loom.

    (B) An attaching step in which the weft is at least partially wetted with a resin solution, emulsion or suspension whose solvent or dispersion medium is water.

    (G) a second attachment step wherein the warp yarn is at least partially wetted with a resin solution, emulsion or suspension in which the solvent or dispersion medium is water.

    (C) a weaving step of weaving a woven fabric by interweaving at least partially wet weft yarns with warp yarns.

    (D) A drying step of heating and drying the woven fabric.

    (F) A cooling step of cooling the heat-dried fabric to a temperature lower than the melting point of the resin that is the solute or dispersoid of the resin solution, emulsion or suspension.

    (E) A winding process in which the fabric is wound into a roll.

(A) Draw process This process is a process of guiding the warp yarn to the loom. When carbon fiber yarns are used for warp yarns, it is preferable that the carbon fiber yarns are unwound from the bobbins and aligned, and then guided directly to a loom for weaving. Once the bobbin carbon fiber yarns are warped or partially warped (beamed), when the sheet warp group is aligned and guided to the loom, the fineness is particularly 350 to 3,500 tex. When carbon fiber yarns having a large fineness are used, unevenness in the thickness of each carbon fiber yarn is likely to occur, so that there is often a difference in yarn length between yarns. The above problem can be solved by drawing and weaving carbon fiber yarns from each bobbin directly to a loom without performing warping or partial warping.

In this step, it is preferable that the warp yarn is taken and guided to the loom without mixing the untwisted yarn. As described above, by guiding the carbon fiber yarn which is a warp yarn without twisting, for example, even when a flat carbon fiber yarn having a flatness ratio of 20 to 200 is used, the carbon fiber having an opening ratio of less than 5%. A woven fabric can be easily obtained. The flatness in the present invention is expressed as a percentage of the division of the yarn thickness and the yarn width when the carbon fiber yarn is viewed in a plane. In actual measurement, five carbon fiber yarns to be used are taken out at intervals of 1 m, and the yarn thicknesses of the taken out yarns are read and calculated with a dial gauge and the yarn width with a caliper (n = 5 average value). Further, the aperture ratio in the present invention is expressed as a percentage obtained by dividing the area of the void portion where the carbon fiber yarn does not exist and the inspection area when the carbon fiber fabric is viewed in a plane. In actual measurement, 5 squares of 15 cm × 15 cm (inspection area 225 cm ² ) were cut out at equal intervals in the width direction, and the area of the voids was read and calculated with an optical microscope (average value of n = 5). .

(B) Adhesion process In this process, weft is dispersed in a resin solution (solution: a liquid in which a solute is dissolved in a solvent) or an emulsion (emulsion: a liquid dispersoid) in which the solvent or dispersion medium is water. A liquid dispersed in a medium) or a suspension (suspension: a liquid in which a solid dispersoid is dispersed in a dispersion medium). By this step, a clogging resin which is a solute or dispersoid of such a resin solution, emulsion or suspension is applied, and the warp yarn is interlaced with the warp yarn in a wet state in the weaving step (C) described later. Then, it can be awakened in the drying step (D) described later. By this step, since a minimum amount of the crushing resin can be attached to a place required for crushing, the shape of the woven structure with a reduced crevice can be maintained. In addition, since the carbon fiber woven fabric can be selected from a close resin compatible with the matrix resin without being limited in its form, an FRP having excellent appearance quality can be obtained at low cost.

  Here, when the resin is a solid or fine resin, it is not only limited in the selection of the fine resin, but the size of the fine resin can be visually observed in the matrix resin. It will form a domain. Further, if the material is applied and fixed after weaving, the fabric itself becomes hard and the drapeability becomes inferior, making it difficult to handle, and the amount of clogging resin applied is excessively increased. Furthermore, if weaving yarns that have been applied and fixed in advance before weaving and awakening again, not only will extra processes be added, but also no awakening resin is required. Too much. This conventional technique does not exhibit the effect of the present invention.

  In this step, the means for at least partially wetting the weft thread is (b1) contact roll means for contacting the roll wet with the resin solution, emulsion or suspension, (b2) the resin solution, emulsion or Porous body contact means for contacting a porous body capable of holding the liquid wetted with the suspension, (b3) dropping means for dropping the resin solution, emulsion or suspension, (b4) resin solution, milk It is preferably any one of spray means for spraying a turbid liquid or suspension, and (b5) a combination of (b1) to (b4).

  In the case of the contact roll means (b1), a liquid that is a resin solution, an emulsion or a suspension can be quantitatively supplied with a simple device. Further, in this means, if the contact roll is rotated by the movement of the weft yarn, there is an advantage that no special device is required to follow the intermittent movement of the weft yarn. In particular, when a flat carbon fiber yarn having a flatness ratio of 20 to 200 is used, or when a weft yarn is intercepted and driven, the carbon fiber yarn is not narrowed and can be said to be a particularly preferable means.

  In the case of the porous body contact means (b2), a liquid which is a resin solution, an emulsion or a suspension can be quantitatively supplied with a simple device. In particular, it is preferable that the porous body is flexible because it can follow a slight change in the yarn path of the weft yarn. Examples of such a flexible porous body include sponges, nets, and the like made of a material excellent in scratch resistance (eg, polyamide, polyacetal, etc.). In addition, this means has an advantage that no special device is required to follow the intermittent movement of the weft yarn. From the viewpoint of evenly adhering to the weft yarn, it can be said to be a particularly preferable means.

  In the case of the dropping means (b3), the liquid can be quantitatively supplied with a simple apparatus by using a liquid quantitative supply means such as a load cell or a metering pump. By inputting a signal from the weaving machine for driving the weft yarn to such a quantitative supply means, it is possible to follow the intermittent movement of the weft yarn. From the viewpoint of adhering to a predetermined portion of the weft yarn, it can be said to be a particularly preferable means.

  In the case of the spraying means (b4), the amount of the fine resin to be applied to the weft yarn can be accurately controlled by using a liquid quantitative supply means such as a load cell or a metering pump. By inputting a signal from the weaving machine for driving the weft yarn to such a quantitative supply means, it is possible to follow the intermittent movement of the weft yarn. According to this means, the weft yarn does not come into contact. Therefore, when using a flat carbon fiber yarn in the range of a flatness ratio of 20 to 200, or when wefting the weft yarn and driving it, the carbon fiber yarn is used. It can be said that it is a particularly preferable means without narrowing.

  As the resin that is a solute or dispersoid of the resin solution, emulsion or suspension, a thermosetting resin or a thermoplastic resin can be used, for example, compatibility with a matrix resin described later. It is appropriately selected depending on each purpose. Such a fine resin is preferably solid at room temperature (25 ° C.) in the carbon fiber woven fabric after the drying step described later (D). If it is a solid at room temperature, it can exhibit a high acuity effect. In the case of a liquid at room temperature, when an external force that moves at the intersection of the warp and the weft is applied because it is liquid, resistance to the external force is hardly exhibited. Further, it is more preferable that the agitating resin is a room temperature solid in a state where it is dissolved in a solvent or dispersed in a dispersion medium. In this case, it is preferable to use a resin solution or suspension.

  It is preferable that the thermosetting resin is at least one selected from epoxy, unsaturated polyester, vinyl ester, phenol, benzoxazine, acrylic, and vinyl acetate. When such a thermosetting resin is used, it exhibits excellent compatibility when a thermosetting resin is used as a matrix resin to be described later, and when it is molded into FRP, it has excellent appearance quality, particularly surface smoothness. Can do.

  The thermoplastic resin is preferably at least one selected from polyamide, polyester, polyolefin, polyvinyl formal, and polyether sulfone. In particular, polyamide and polyester are preferable because water can be used as a solvent or dispersion medium without using an emulsifier (an emulsifier is often required for other resins). However, when a thermosetting resin is used as the matrix resin described later, the appearance quality is often inferior to the case where the above-mentioned thermosetting resin is used as an abrupt resin, so a thermoplastic resin is used as the matrix resin. It can be said that it is preferable when used.

(G) Second attachment step This step is a step of at least partially wetting the warp yarn with a resin solution, emulsion or suspension whose solvent or dispersion medium is water. By this step, weft and warp yarns are both wet in the weaving step (C) described later and are awakened in the drying step (D) described later, thereby making them more awake. An effect can be expressed highly. Further, in this step as well as the attaching step (B), since the minimum amount of the agitation resin can be adhered to the location required for the agitation, the shape of the woven structure with a reduced gap is maintained. be able to.

  The resin used as the solute or dispersoid of the resin solution, emulsion or suspension is preferably the same as that used in the attaching step (B). The concentration of the resin solution, emulsion or suspension can be appropriately different from the weft. For warp yarns that have a lower bobbin replacement frequency than weft yarns, it is preferable to minimize dirt on the yarn path, and from this point of view, the concentration of the resin solution, emulsion or suspension that partially wets the weft yarns. It is preferred that the one that partially wets the warp yarn is lower.

  Further, the means for at least partially wetting the warp yarn can be the same means as the attaching step (B). Specifically, (g1) contact roll means for contacting a roll wetted with a resin solution, emulsion or suspension, (g2) a liquid wetted with a resin solution, emulsion or suspension A porous body contact means for contacting a porous body capable of holding a liquid; (g3) a dropping means for dropping a resin solution, emulsion or suspension; (g4) spraying a resin solution, emulsion or suspension; The spray means is preferably any one of (g5) (g1) to (g4). In particular, when applying to a warp yarn in which a large number of yarns are drawn and aligned, the contact roll means (g1) is preferred.

(C) Weaving process This process is a process of weaving a woven fabric by crossing at least partially wet weft yarns with warp yarns. Preferably, the warp yarn is also at least partially wetted. A weaving machine (for example, a shuttle loom, a rapier loom, a needle loom, a water jet loom, an air jet loom, etc.) is used for the intersection of the weft and the warp.

  Examples of the interlaced structure include plain weave, twill weave, satin weave, combinations thereof, or changed structures. It is preferable that the woven structure is a twill weave, a satin weave, a combination thereof, or a changed structure in which the effect of loosening and a maximum effect is exhibited. As the woven form, a unidirectional woven fabric using carbon fiber yarns as warp yarns and auxiliary fiber yarns having finer finer than carbon fiber yarns as weft yarns, bi-directional woven fabric using carbon fiber yarns as warp yarns and weft yarns, or It is possible to weave a multi-directional fabric, a three-dimensional fabric in which carbon fiber yarns or auxiliary fiber yarns are arranged in the fabric thickness direction (Z direction). Among them, a unidirectional woven fabric having a flat carbon fiber yarn in the range of flatness 20 to 200 as a warp and an auxiliary fiber yarn having a finer fineness than the carbon fiber yarn, or a flatness 20 to 20 A bi-directional woven fabric having a flat carbon fiber yarn within the range of 200 as warp and weft is preferable. By using a flat carbon fiber yarn having a flatness in the range of 20 to 200, crimping at the crossing point of the fabric can be minimized, and an FRP excellent in mechanical properties (tensile and compression) can be obtained. it can.

  In particular, in the case of a unidirectional woven fabric, when the melting point of the auxiliary fiber yarn, which is a weft yarn, is within the range of 100 to 300 ° C., the effect of the present invention can be maximized because it can be awakened at a relatively low temperature. The That is, in the present invention, it is only necessary to dry the water that is the solvent or the dispersion medium. Due to this effect, it is possible to suppress the auxiliary fiber yarns from being thermally contracted in the high-temperature squeezing process and impairing the dimensional stability in the width direction of the woven fabric to a minimum. A more preferable melting point is in the range of 120 to 260 ° C, and more preferably 140 to 230 ° C. The melting point in the present invention is measured at a rate of temperature increase of 20 ° C./min in an absolutely dry state using a DSC (differential scanning calorimeter) according to JIS K7121 (1987) “Method for measuring transition temperature of plastic”. Refers to the melting temperature.

  In this step, it is preferable that the weft yarn is intercepted and driven into the shed without mixing untwisting. As described above, a carbon fiber having an opening ratio of less than 5% is obtained by driving a carbon fiber yarn which is a weft yarn without twisting, for example, even when a flat carbon fiber yarn having a flatness of 20 to 200 is used. A woven fabric can be easily obtained. The same applies to the warp yarn as described in the drawing step (A).

  In this step, it is preferable that the weft width retention of the weft yarn after being at least partially wetted is in the range of 70 to 100%. More preferably, it is 80-100%, More preferably, it exists in the range of 90-100%. Here, the yarn width retention rate refers to the weft yarn width Wd before wetting (dry state) and the weft yarn width Ww after at least partial wetting, and the yarn width retention rate = (at least It refers to the value obtained by weft width Ww after being partially wetted x 100 / (weft width Wd before being wetted). When weft yarns having a yarn width reduction rate of less than 70% are used, a large gap that cannot be eliminated is formed between the weft yarns in the woven carbon fiber fabric. For example, when a flat carbon fiber yarn having a flatness ratio of 20 to 200 is used, such a gap is formed remarkably, and a carbon fiber woven fabric having an opening ratio of less than 5% tends to be formed. The above-described yarn width retention rate is related to the weft yarn. However, when the warp yarn is at least partially wetted, the yarn width retention rate is preferably in the range of 70 to 100% for the same reason as the weft yarn. More preferably, it is 80-100%, More preferably, it exists in the range of 90-100%.

(D) Drying step In this step, the woven fabric is heated and dried. In this step, warp yarns and weft yarns are awakened. The woven fabric is preferably heated to a temperature equal to or higher than the melting point of the agitating resin, which is a solute or dispersoid of a resin solution, emulsion or suspension. In the case where the agitating resin does not have a melting point, it is preferable to heat to the softening point or higher instead of the melting point. Generally, the upper limit of the heating temperature is lower than the decomposition temperature of the abrupt resin. The softening point in the present invention refers to a value measured according to JIS K7234 (1986) “Testing method for softening point of epoxy resin”. The decomposition temperature refers to a temperature at which the heat loss measured by a TG (thermogravimetric analysis) method in a nitrogen atmosphere at a heating rate of 10 ° C./min exceeds 30%.

  In this step, means for heating the woven fabric is (d1) non-contact heating means for radiating or blowing heat in a state where it is not in contact with the roll, (d2) radiating heat in a state where it is in contact with the roll, or Pseudo contact heating means for blowing air, (d3) contact heating means for direct contact with a heating source, (d4) a combination of (d1) to (d3) are preferable.

  In the case of (d1), it is preferable to heat before contacting the take-up roll, that is, before weaving. In such an embodiment, not only can the angle where the warp yarn and the weft yarn are interwoven be woven, but the resin solution can be applied to rolls including a take-up roll of a loom, It is possible to minimize the adhesion or contamination of the emulsion or suspension. Moreover, from another viewpoint, you may heat between the winding rolls after passing a take-up roll. Such an embodiment is particularly excellent in workability of weaving. From the viewpoint of maintaining an accurate crossing angle and minimizing contamination, it can be said to be a particularly preferable means.

  In the case of (d2), the roll is preferably a take-up roll of a loom. With such an embodiment, it is possible to awaken in a state where the warp and the weft are in reliable contact. It can be said that it is a particularly preferable means from the viewpoint of aiming firmly.

  In the case of (d3), the heating source is preferably a roll, particularly a take-up roll of a loom. In this mode, as in (d2) above, not only can warp in a state where the warp yarn and the weft yarn are in reliable contact but also excellent heat transfer efficiency because of direct contact. It can be said to be a particularly preferable means from the viewpoint of energy saving and energy saving.

  In the case of (d4), the equipment cost increases, but there is an advantage that each advantage can be reflected.

(F) Cooling step This step is a step of cooling the heated fabric below the melting point of the agitating resin that is the solute or dispersoid of the resin solution, emulsion or suspension. In addition, when the agitating resin does not have a melting point, it is cooled to below the softening point instead of the melting point. When the winding is performed at a temperature equal to or higher than the melting point of the fine resin, the fabrics may be bonded to each other in the roll, and the fabric may not be smoothly unwound from the roll. By passing through this step, it is possible to solve the problem that the fabrics adhere to each other in the winding step (E) below.

(E) Winding process This process is a process of winding a fabric into a roll.

  The carbon fiber fabric obtained by the present invention preferably has an opening ratio of less than 5%. When the aperture ratio is 5% or more, not only is it difficult to obtain a resin-rich portion in the FRP when molded into the FRP which is the subject of the present invention, and excellent appearance quality, particularly surface smoothness, It may be inferior in lightness, durability (fatigue strength), environmental resistance and the like.

  The FRP production method of the present invention is an FRP composed of a carbon fiber woven fabric obtained by the above-described production method and a matrix resin, and a solute of a resin solution, emulsion or suspension contained in the carbon fiber woven fabric or It is preferable that the fine resin as a dispersoid is compatible with the matrix resin. By appropriately selecting the combination of the agitating resin and the matrix resin, both can be made compatible. Due to the compatibility between the agitating resin and the matrix resin, not only the appearance quality, particularly the surface smoothness, but also the mechanical properties can be obtained when molded into FRP.

  In the present invention, the compatibility means that a model resin composition containing 10 wt% of the awake resin and 90 wt% of the matrix resin was cured and solidified by giving the same thermal history as the FRP molding conditions. The glass transition point of the cured product measured at a heating rate of 20 ° C./min in an absolutely dry state according to JIS K7121 (1987) “Method for measuring the transition temperature of plastics” using a DSC (differential scanning calorimeter) is 1 In addition, the cured resin is cured and solidified by applying the same thermal history as the FRP molding conditions, and the matrix resin is cured and solidified by applying the same thermal history as the FRP molding conditions. It is not the same as the glass transition point of each cured product, and is located between the two.

  As a method of forming a FRP by impregnating a carbon fiber fabric with a matrix resin, an autoclave method using a prepreg (a hot melt method, a wet method, etc.) in which the carbon fiber fabric is impregnated with a matrix resin in advance, or a carbon fiber fabric is used. Forming a remodel (pre-formed body) to form a cavity (a double-sided mold in which a male mold and a female mold are molds), one of the male mold and female mold is a mold and the other is a flexible bag film And a direct injection method in which the matrix resin is directly impregnated in a single-sided mold that is a mold). Among them, the latter (particularly the RTM method using a double-sided type) is preferable because it is excellent in productivity and easy to reduce costs.

  The carbon fiber yarn used in the present invention is a polyacrylonitrile fiber having a fiber diameter of 5 to 10 μm, and exhibits high mechanical properties by being a multifilament having a tensile strength of 3 to 7 GPa and a tensile modulus of 200 to 500 GPa. It is preferable because FRP is obtained. Since such carbon fiber yarns can generally provide a low-cost textile substrate because the production cost is lower as the fineness increases, the carbon fiber yarn used in the present invention has a fineness yarn of 350 to 3,500 tex. Is preferred. In the case of a fine yarn having a fineness of carbon fiber yarn of less than 350 tex, the number of crossing points of the warp and weft yarn is large, so that the woven form is stable, and it is not necessary to awaken and it is not subjected to the heat treatment of the present invention. Can be used. In the case of a carbon fiber yarn having a thicker fineness than this, the number of crossing points of the warp and weft yarns is small, and the fabric is easily misaligned. However, when the carbon fiber yarn has a fineness exceeding 3,500 tex, there is a problem that a woven fabric with uniform fiber dispersion cannot be obtained unless the yarn width is uniformly expanded. May be difficult.

(Example 1)
Carbon fiber yarns (flat carbon fiber yarns having a tensile strength of 4,900 MPa, a tensile modulus of elasticity of 234 GPa, a fineness of 800 tex, a twist of 0 turns / m, and a flatness of 70 measured according to JIS R7601) are used for the warp. A polyester fiber (melting point 260 ° C., fineness 55 dtex) is used for the weft yarn, and the warp yarn density is 2.5 yarns / cm and the weft yarn density is 3 yarns / cm (carbon fiber basis weight 200 g / m ² ). Was woven. Detailed steps are described below.

  (A) Drawing process: Carbon fiber yarns were used as warp yarns, taken from each bobbin, unwound and drawn, and led to a loom without warping to be woven. In addition, as the carbon fiber yarn, a flat one having a flatness ratio of 70 was used.

  (B) Adhesion step: Wet the weft thread that has been unraveled vertically with resin solution 1 (water-soluble polyamide resin, 7% by weight, AQ nylon manufactured by Toray Industries, Inc.) in which polyamide resin is dissolved in water. It was. A porous body contact means was used as a means for wetting the weft yarn. Specifically, a polyamide sponge is used as the porous body, the weft thread is in contact with the upper part of the sponge, the emulsion 1 is immersed in the lower part of the sponge, and the emulsion 1 is supplied to the upper part of the sponge by the osmotic pressure of the sponge. The weft thread is taken out from the upper part where the weft thread comes into contact.

  (C) Weaving process: Weft yarn was interwoven with warp yarn and woven with a rapier loom.

  (D) Drying step: Fineness 800 tex obtained by drying water, which is a dispersion medium, of a woven fabric by a non-contact heating means. Specifically, it was heated to 120 ° C. using a far infrared heater before weaving (before contacting the take-up roll).

  (E) Winding step: The fabric was wound into a roll.

  The obtained unidirectional woven fabric 1 was excellent in handleability because the polyamide resin adhered to the warp yarn and the weft yarn linearly along the weft yarn. Moreover, the aperture ratio was 4%.

(Example 2)
Carbon fiber yarns having a fineness of 800 tex (flat carbon fiber yarns having a tensile strength of 4,900 MPa measured in accordance with JIS R7601, a tensile modulus of elasticity of 234 GPa, a twist of 0 turns / m, and a flatness of 70 are used for warp and weft. ), A bi-directional woven fabric (carbon fiber basis weight 200 g / m ² ) having a warp yarn density and a weft yarn density of 3.1 yarns / cm was woven using a rapier loom. In weaving,
In the adhesion step (B), an emulsion 1 obtained by emulsifying an epoxy resin in water with an emulsifier (emulsion type epoxy resin, concentration is 12% by weight, manufactured by Dainippon Ink & Chemicals, Inc., Epicron EM-82-75W) A contact roll means that wets only one side of a flat carbon fiber yarn having a flatness ratio of 70 and wets the weft thread as a means for wetting the weft thread.
In the drying step (D), contact heating means (100 ° C. in the order of contact with each other while directly contacting the three heating rolls and the fabric disposed between the take-up roll after passing through the take-up roll of the loom) , Heated to 110 ° C. and 130 ° C.)
(F) The cooling process which cools the heated textile fabric to less than 35 degreeC (below melting | fusing point and softening point of the awakening resin which is an epoxy resin) with an air blower (electric fan),
Except for the above, a carbon fiber fabric was obtained in the same manner as in Example 1.

  The obtained bi-directional woven fabric 2 was excellent in handleability because the epoxy resin adhered to the warp yarn and the weft yarn in a band shape along the weft yarn. Further, the aperture ratio was 1.2%, and the appearance quality was very excellent.

(Example 3)
When weaving a bidirectional fabric having the same woven structure as in Example 2 with a rapier loom,
Emulsion 2 in which epoxy resin is emulsified in water with an emulsifier in the adhesion step (B) (emulsion type epoxy resin, concentration is 12 wt%, Japan Epoxy Resins Co., Ltd. Epiletz 3540WY55 diluted with water) Then, the weft thread that had been unrolled was wetted only on one side of the flat carbon fiber yarn having a flatness ratio of 70, and spray means were used as means for wetting the weft thread,
(G) Second adhesion using contact roll means that wets only one side of the flat carbon fiber yarn having a flatness ratio of 70 with the emulsion 2 and makes contact with the roll as means for wetting the warp yarn with the emulsion 2 Adding a process,
In the drying step of (D), the woven fabric is heated to non-contact heating means (heated to 150 ° C. with a far infrared heater before weaving) and contact heating means (up to the winding roll after passing through the take-up roll of the loom). Heating and drying at 100 ° C., 110 ° C., and 130 ° C. in the order of contact, while directly contacting the three heating rolls and the woven fabric disposed between them,
Except for the above, a carbon fiber fabric was obtained in the same manner as in Example 2.

  The obtained bi-directional woven fabric 3 is made of an epoxy resin that adheres the warp and the weft to a band along the warp and the weft. The bi-directional woven fabric 3 is more handleable than the bi-directional woven fabric 2 of Example 2. outstanding. The opening ratio was 2%, which was slightly larger than that of the bi-directional fabric 2 of Example 2. However, the appearance quality was satisfactory.

Example 4
The unidirectional woven fabric 1 and the bidirectional woven fabrics 2 and 3 obtained in Examples 1, 2, and 3 were each cut into a 30 cm × 30 cm square. The warp and weft yarns did not fall apart at the time of cutting, and each carbon fiber fabric obtained was sufficiently awakened. A total of eight cut carbon fiber fabrics were laminated in the same direction, and heated and pressed with an iron (160 ° C.) to obtain a preform. In the obtained preform, the bi-directional woven fabric did not fall apart, and was adhered by a clogging resin. This preform is placed in a cavity formed by a double-sided mold (mould) of male and female molds, and epoxy resin (Epicoat 630 (main agent) manufactured by Japan Epoxy Resin Co., Ltd., EpiCure W) is used as a matrix resin. (Hardening agent mixed at a mixing ratio of 0.464) is impregnated and heated to 180 ° C. at 1.5 ° C./min, and after reaching 180 ° C., held for 120 minutes to cure, 2.5 ° C. The temperature was lowered to 25 ° C./min to obtain FRP.

  The obtained FRPs were extremely excellent in surface smoothness, without the mesh resin forming a domain. In addition, since the opening ratio of the bidirectional fabric 2 was slightly lower than that of the bidirectional fabric 3, the surface smoothness was improved accordingly.

(Comparative Example 1)
In the adhesion step (B), the low melting point polyamide fiber (“Elder” (registered trademark) 110 dtex manufactured by Toray Industries, Inc.) was aligned with the weft yarn that was unraveled and removed without using the emulsion 1.
In the weaving step (C), the bi-directional fabric 1 is obtained in the same manner as in Example 2 except that the weft yarn released from the longitudinal direction and the low-melting polyamide fiber are aligned and weaved together. It was.

  The obtained bi-directional woven fabric 1 does not have the polyamide resin, which is a crush resin, stably arranged, and there are places that are not cleaved depending on the intersection of the warp and the weft. The variation was large. Further, the opening ratio was 6%, which was considerably larger than the bidirectional fabrics 2 and 3 of Examples 2 and 3, and there was a problem in terms of appearance quality.

(Comparative Example 2)
For the weft yarn, a twisted yarn in which glass fiber (ECE225 1/2, glass fiber yarn having a flatness ratio of less than 20) and low melting point polyamide fiber (“Elder” (registered trademark) 330 dtex manufactured by Toray Industries, Inc.) was combined was used. thing,
The resin solution 1 was not used in the adhesion step (B),
In the drying step (D), a unidirectional fabric 2 was obtained in the same manner as in Example 1 except that non-contact heating means (170 ° C. with a far-infrared heater before winding) was used.

  In the obtained unidirectional fabric 2, the polyamide resin adhered to the warp yarn and the weft yarn linearly along the weft yarn. However, a higher temperature than Example 1 was required to awaken.

(Comparative Example 3)
FRP was molded in the same manner as in Example 4 using the bidirectional fabric 1 and the unidirectional fabric 2 obtained in Comparative Examples 1 and 2.

  In the obtained FRP, the polyamide resin, which is an abrupt resin, formed a domain, and the surface smoothness was very inferior (the polyamide resin was dissolved).

  The present invention is a resin solution, milk, which can be subjected to a squeezing treatment effective in maintaining the shape of the woven structure by suppressing the collapse of the structure of the reinforcing fiber fabric and cutting, and being compatible with the matrix resin. FRP with excellent appearance quality can be obtained because it is agitated with an agitating resin that is a solute or dispersoid of a suspension or suspension. Such FRP is particularly suitable for exterior members for automobiles and aircrafts where surface smoothness requirements are severe.

Claims (12)

A method for producing a carbon fiber woven fabric in which at least one of warp yarns and weft yarns is made of carbon fiber yarns and has been subjected to a clogging treatment that maintains the shape of the woven structure, the following steps (A) to (E) A process for producing a carbon fiber woven fabric, characterized in that
(A) Pulling out the warp yarn to the loom (B) Adhering step (C) At least partially wet the weft yarn at least partially with a resin solution, emulsion or suspension in which the solvent or dispersion medium is water Weaving process in which wet weft yarn is interlaced with warp yarn to weave the fabric (D) Drying step in which the woven fabric is heated to dry (E) Winding step in which the fabric is wound into a roll The manufacturing method of the carbon fiber fabric of Claim 1 which passes through the process of following (F) between the drying process of said (D), and the winding process of (E).
(F) A cooling step for cooling the heat-dried fabric to a temperature lower than the melting point of the agitating resin that is the solute or dispersoid of the resin solution, emulsion or suspension. The manufacturing method of the carbon fiber fabric of Claim 1 or 2 which passes through the process of following (G) between the drawing-out process of the said (A), and the weaving process of (C).
(G) Second attachment step in which the warp yarn is at least partially wetted with a resin solution, emulsion or suspension in which the solvent or dispersion medium is water. The method for producing a carbon fiber woven fabric according to any one of claims 1 to 3, wherein in the weaving step (C), the weft is intercepted and driven into the shed without mixing untwisting. The method for producing a carbon fiber fabric according to any one of claims 1 to 4, wherein in the weaving step (C), the yarn width retention of the weft yarn after being at least partially wetted is 70% or more. Any one of Claims 1-5 which are the normal temperature solids in the carbon fiber fabric after the drying process of the below-mentioned (D) are the lime resin which is a solute or dispersoid of a resin solution, emulsion, or suspension. A method for producing a carbon fiber fabric according to claim 1. 7. A close-up resin which is a solute or dispersoid of a resin solution, emulsion or suspension is at least one selected from epoxy, unsaturated polyester, and vinyl ester. Carbon fiber fabric manufacturing method. The close-up resin that is a solute or dispersoid of a resin solution, emulsion or suspension is at least one selected from polyamide, polyester, polyolefin, polyvinyl formal, and polyether sulfone. The manufacturing method of the carbon fiber fabric in any one. The carbon fiber woven fabric is a unidirectional woven fabric having a flat carbon fiber yarn within the range of a flatness ratio of 20 to 200 as a warp and an auxiliary fiber yarn having a finer degree than the carbon fiber yarn as a weft. The manufacturing method of the carbon fiber fabric in any one of Claims 1-8. The manufacturing method of the carbon fiber fabric of Claim 9 whose melting | fusing point of the auxiliary fiber yarn which is the weft of the said unidirectional fabric is 300 degrees C or less. The method for producing a carbon fiber woven fabric according to any one of claims 1 to 8, wherein the carbon fiber woven fabric is a bi-directional woven fabric using a flat carbon fiber yarn having a flatness ratio of 20 to 200 as a warp and a weft. . It is a manufacturing method of the fiber reinforced plastic comprised by the carbon fiber fabric obtained by the manufacturing method in any one of Claims 1-11, and matrix resin, Comprising: In fiber reinforced plastic, resin contained in a carbon fiber fabric A method for producing a fiber reinforced plastic, characterized in that an agitating resin, which is a solute or dispersoid of a solution, emulsion or suspension, is dissolved in a matrix resin.