JP6581680B2 - Method for producing resin-impregnated fiber bundle - Google Patents

Description

  The present invention relates to a method for producing a resin-impregnated fiber bundle in which a fiber bundle is impregnated with resin.

  In general, in a reinforcing sheet, high performance is expressed by impregnating a resin in a reinforcing fiber bundle and integrating the resin and the reinforcing fiber.

  Examples of the resin impregnated in the reinforcing fiber bundle include a thermosetting resin and a thermoplastic resin. A high molecular weight thermosetting resin or a general thermoplastic resin has a high melt viscosity. It is not easy to impregnate a reinforcing fiber bundle with a resin having a high melt viscosity.

  As a method of impregnating a reinforcing fiber bundle with a resin having a high melt viscosity, the reinforcing fiber is compressed by compressing the laminated body for a long time at a high pressure in the state of a laminated body in which the molten resin and the reinforcing fiber bundle are in contact There is a method of impregnating a resin in a bundle.

  Patent Document 1 discloses a double belt press method. In this method, a material is sandwiched between thick stainless steel belts, and after heating, the belt is moved and moved. Since a thick stainless steel belt is used, the material can be pressed over a long period of time with a large area and high compression force.

JP, 2014-212490, A

  The double belt press method is actually widely recognized in the industry, and many reinforced sheets are manufactured using this method. However, drawbacks have been pointed out with this method.

  A generally used stainless steel belt has a thickness of 1 mm or more, and the stainless steel belt is thick. For example, thick stainless steel belts must be heated and cooled during the process. Since the heat capacity of the thick stainless steel belt is large, the heating and cooling costs of the manufacturing process are high. On the other hand, if a thin stainless steel belt is used, effective compression cannot be performed.

  The conventional resin impregnation method has the above-described problems, and there is a great advantage in providing a new method capable of easily and sufficiently impregnating a fiber bundle with resin.

  An object of the present invention is to provide a method for producing a resin-impregnated fiber bundle that allows a fiber bundle to be easily and sufficiently impregnated with a resin.

  According to a wide aspect of the present invention, a laminated body having a fiber bundle and a first resin portion laminated on a first surface of the fiber bundle is conveyed while contacting a plurality of heating rolls, and the fiber bundle A step of impregnating the resin of the first resin portion with the plurality of heating rolls, the first heating roll, and the second heating roll with which the laminate is in contact with the first heating roll. The first heating roll and the second heating roll are made while generating tension in the laminate by making the rotation speed of the second heating roll faster than the rotation speed of the first heating roll. A method for producing a resin-impregnated fiber bundle is provided in which the laminate is brought into contact with a heating roll.

  In a specific aspect of the present invention, the ratio of the rotation speed of the second heating roll to the rotation speed of the first heating roll is set to 1.001 or more and 1.010 or less.

  In a specific aspect of the present invention, a first surface of the laminate is brought into contact with the first heating roll, and a second opposite to the first surface of the laminate is brought into contact with the second heating roll. Contact the surface of.

  In a specific aspect of the present invention, the flow direction of the laminate is changed by the first heating roll, and the flow direction of the laminate is changed by the second heating roll.

  In a specific aspect of the present invention, the flow direction of the laminate is changed by 45 degrees or more by the first heating roll, and the flow direction of the laminate is changed by 45 degrees or more by the second heating roll.

  In a specific aspect of the present invention, the plurality of heating rolls include a third heating roll that comes into contact with the laminated body next to the second heating roll, and the rotation speed of the third heating roll is set to the rotation speed of the third heating roll. By making it faster than the rotation speed of the second heating roll, the laminate is brought into contact with the third heating roll while generating tension in the laminate.

  In a specific aspect of the present invention, the ratio of the rotation speed of the third heating roll to the rotation speed of the second heating roll is set to 1.001 or more and 1.010 or less.

  In a specific aspect of the present invention, the first surface of the laminate is brought into contact with the first heating roll, the second surface of the laminate is brought into contact with the second heating roll, The first surface of the laminate is brought into contact with a third heating roll.

  On the specific situation of this invention, the flow direction of the said laminated body is changed with the said 3rd heating roll.

  In a specific aspect of the present invention, the plurality of heating rolls include a fourth heating roll that comes into contact with the laminate next to the third heating roll, and the rotational speed of the fourth heating roll is set to By making it faster than the rotation speed of the third heating roll, the laminate is brought into contact with the fourth heating roll while generating tension in the laminated body, and the laminate is brought into contact with the first heating roll. Contacting the first surface, contacting the second surface of the laminate with the second heating roll, contacting the first surface of the laminate with the third heating roll, and The second surface of the laminate is brought into contact with a fourth heating roll, and the ratio of the rotation speed of the fourth heating roll to the rotation speed of the third heating roll is 1.001 or more and 1.010 or less. And the product is heated by the fourth heating roll. Changing the flow direction of the body.

  On the specific situation with this invention, the laminated body which has a 1st release sheet arrange | positioned on the surface side opposite to the said fiber bundle side of said 1st resin part is used as said laminated body.

  In a specific aspect of the present invention, as the laminate, a laminate having a second resin portion that is laminated on a second surface opposite to the first surface of the fiber bundle is used, and the fiber is used. The bundle is impregnated with the resin of the first resin portion and the resin of the second resin portion.

  In a specific aspect of the present invention, as the laminate, a first release sheet disposed on a surface side opposite to the fiber bundle side of the first resin part, and a second resin part A laminate having a second release sheet disposed on the surface side opposite to the fiber bundle side is used.

  In a specific aspect of the present invention, the fiber bundle includes spacer particles that increase the interfiber distance.

  In the method for producing a resin-impregnated fiber bundle according to the present invention, a laminate having a fiber bundle and a first resin portion laminated on the first surface of the fiber bundle is conveyed while contacting a plurality of heating rolls. A step of impregnating the fiber bundle with the resin of the first resin portion, wherein the plurality of heating rolls are in contact with the first heating roll and the laminated body next to the first heating roll. The first heating roll while generating tension in the laminate by making the rotation speed of the second heating roll faster than the rotation speed of the first heating roll. Since the laminate is brought into contact with the second heating roll, the fiber bundle can be easily and sufficiently impregnated with the resin.

Drawing 1 is a mimetic diagram showing the state at the time of manufacture in the manufacturing method of the resin impregnation fiber bundle concerning one embodiment of the present invention. FIG. 2 is a cross-sectional view showing a laminate used for a resin-impregnated fiber bundle according to an embodiment of the present invention.

  Details of the present invention will be described below.

  In the method for producing a resin-impregnated fiber bundle according to the present invention, a laminate having a fiber bundle and a first resin portion laminated on the first surface of the fiber bundle is used. The method for producing a resin-impregnated fiber bundle according to the present invention includes a step of causing the laminate to be conveyed while being in contact with a plurality of heating rolls, and impregnating the fiber bundle with the resin of the first resin portion.

  In the method for producing a resin-impregnated fiber bundle according to the present invention, the plurality of heating rolls include a first heating roll and a second heating roll that comes into contact with the laminate next to the first heating roll. . The plurality of heating rolls may include a third heating roll that comes in contact with the laminated body next to the second heating roll, and the second heating roll comes into contact with the laminated body next to the third heating roll. 4 heating rolls may be provided, and a fifth heating roll that the laminated body contacts may be provided next to the fourth heating roll, and an nth heating roll (n is 5 or more). You may provide the (n + 1) th heating roll which the said laminated body contacts after an integer.

  In the method for producing a resin-impregnated fiber bundle according to the present invention, the rotational speed of the second heating roll is made faster than the rotational speed of the first heating roll, thereby generating tension in the laminate, The laminate is brought into contact with the first heating roll and the second heating roll.

  In the present invention, since the above configuration is provided, the fiber bundle can be easily and sufficiently impregnated with resin. In the present invention, in the specific laminate having the fiber bundle and the first resin portion, the above method is employed in order to impregnate the fiber bundle with resin. In general, it may be difficult to impregnate the fiber bundle with resin. For example, it is difficult to impregnate a fiber bundle with a high molecular weight thermosetting resin (for example, a weight average molecular weight of 5000 or more, the weight average molecular weight is converted to polystyrene by gel permeation chromatography) or a thermoplastic resin. On the other hand, by adopting the above method in the present invention, the laminate can be effectively pressed against the heating roll by the difference in rotational speed between the first heating roll and the second heating roll. . As a result, the fiber bundle can be easily and sufficiently impregnated with the resin.

  In the present invention, the impregnation of the resin can be promoted by pressing the laminate to the heating roll by a simple method in which the laminate is brought into contact with a plurality of heating rolls having different speeds and conveyed.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

  First, the laminated body used for the resin impregnated fiber bundle which concerns on one Embodiment of this invention is demonstrated. FIG. 2 is a cross-sectional view showing a laminate used for a resin-impregnated fiber bundle according to an embodiment of the present invention.

  A laminated body 21 shown in FIG. 2 includes a fiber bundle 22, a first resin portion 23 laminated on the first surface of the fiber bundle 22, and a second opposite to the first surface of the fiber bundle 22. And a second resin portion 24 laminated on the surface. Note that the second resin portion 24 is not essential. From the viewpoint of efficiently impregnating the fiber bundle with resin, and from the viewpoint of increasing the strength of the resin-impregnated fiber bundle on both sides, the laminate preferably has a second resin portion.

  The laminate 21 includes a first release sheet 25 disposed on the surface side opposite to the fiber bundle 22 side of the first resin portion 23, and a fiber bundle 22 side of the second resin portion 24. And a second release sheet 26 disposed on the opposite surface side.

  The first release sheet 25 is not essential, and the second release sheet 26 is not essential. From the viewpoint of enhancing the handleability of the laminate, preventing contamination of rolls, etc., and effectively impregnating the fiber bundle with resin, the laminate preferably has the first release sheet. It is preferable to have two release sheets, and it is more preferable to have a first release sheet and a second release sheet.

  Moreover, the 1st release sheet may be laminated | stacked on the 1st resin part, and may be laminated | stacked on the 1st resin part via the other member. The second release sheet may be laminated on the fiber bundle, may be laminated on the second resin portion, or may be laminated on the fiber bundle or the second resin portion via another member. May be.

  Although not shown, the fiber bundle 22 includes spacer particles that increase the interfiber distance. The spacer particles are in contact with the fibers in the fiber bundle 22. The spacer particles have an increased interfiber distance compared to when spacer particles are not used.

  Next, a method for producing a resin-impregnated fiber bundle according to an embodiment of the present invention will be described. Drawing 1 is a mimetic diagram showing the state at the time of manufacture in the manufacturing method of the resin impregnation fiber bundle concerning one embodiment of the present invention.

  As shown in FIG. 1, the first release sheet 25, the first resin portion 23 (first resin sheet before melting), the fiber bundle 22, and the second resin portion 24 (first resin before melting). 2 resin sheet) and the second release sheet 26 are respectively conveyed and integrated to obtain the laminate 21. In FIG. 1, the laminate 21 is obtained on the surface of the transport roll 31. In the present embodiment, the transport roll 31 is not a heating roll.

  On the downstream side of the transport roll 31, the heating roll 1, the heating roll 2, the heating roll 3, the heating roll 4, the heating roll 5, the heating roll 6, the heating roll 7, the heating roll 8, and the heating roll. 9 and the heating roll 10 are arranged from the upstream side to the downstream side. These heating rolls 1 to 10 are separated from each other by adjacent heating rolls.

  The laminated body 21 is conveyed by the heating rolls 1 to 10 from the upstream side toward the downstream side. The resin of the first resin part 23 and the second resin part 24 is melted by the heating roll 1 and the heating roll 2. The laminated body 21 is conveyed while being brought into contact with the plurality of heating rolls 1 to 10, and the fiber bundle 22 is impregnated with the resin of the first resin portion 23 and the resin of the second resin portion 24.

  In this embodiment, the rotation speeds of the heating roll 2 and the heating roll 1 are the same, the rotation speed of the heating roll 3 is faster than the rotation speed of the heating roll 2, and the rotation speed of the heating roll 4 is the rotation speed of the heating roll 3. The rotational speed of the heating roll 5 is higher than the rotational speed of the heating roll 4, the rotational speed of the heating roll 6 is higher than the rotational speed of the heating roll 5, and the rotational speed of the heating roll 7 is The rotation speed of the heating roll 8 is higher than the rotation speed of the heating roll 7, the rotation speed of the heating roll 9 is higher than the rotation speed of the heating roll 8, and the rotation speed of the heating roll 10 is higher than the rotation speed of the heating roll 9. Faster than the rotation speed. In the continuous heating rolls 2 to 10, the rotation speed is gradually increased. As a result, the laminate 21 is brought into pressure contact with the heating rolls 1 to 10, and the fiber bundle 22 is impregnated with the resin of the first resin portion 23 and the resin of the second resin portion 24.

  Although the rotation speeds of the heating roll 2 and the heating roll 1 are the same, the rotation speed of the heating roll 2 may be higher than the rotation speed of the heating roll 1. For example, the rotation speed of the heating roll 10 may not be faster than the rotation speed of the heating roll 9. The plurality of heating rolls may include a heating roll having a lower rotational speed than the upstream heating roll on the downstream side of the upstream heating roll.

  In this embodiment, the heating roll 2 may be the first heating roll, the heating roll 3 may be the first heating roll, the heating roll 4 may be the first heating roll, and the heating roll. 5 may be the first heating roll, the heating roll 6 may be the first heating roll, the heating roll 7 may be the first heating roll, and the heating roll 8 is the first heating roll. The heating roll 9 may be the first heating roll. Furthermore, the heating roll 1 may be the first heating roll.

  By making the rotation speed of the second heating roll faster than the rotation speed of the first heating roll, the laminate is brought into contact with the first heating roll and the second heating roll while generating tension in the laminate. be able to. It is preferable to bring the laminate into contact with the third heating roll while generating tension on the laminate by making the rotation speed of the third heating roll faster than the rotation speed of the second heating roll. More preferably, the rotational speed of the heating roll is made higher than the rotational speed of the third heating roll so that the laminated body is brought into contact with the fourth heating roll while generating tension in the laminated body. More preferably, the rotational speed of the heating roll is made higher than the rotational speed of the fourth heating roll so that the laminated body is brought into contact with the fifth heating roll while generating tension in the laminated body. The heating roll (n is an integer greater than or equal to 5) is made faster than the rotation speed of the n-th heating roll, so that tension is generated in the laminated body and the laminate is placed on the (n + 1) -th heating roll. Especially preferred to contact There.

  In at least two continuous heating rolls (adjacent heating rolls), the rotational speed of the downstream heating roll may be made faster than the rotational speed of the upstream heating roll. In at least three continuous heating rolls, the rotation speed of the downstream heating roll is preferably higher than the rotation speed of the upstream heating roll, and in at least four continuous heating rolls, the downstream heating roll More preferably, the rotational speed of the upstream heating roll is higher than the rotational speed of the upstream heating roll, and the rotational speed of the downstream heating roll is set to be higher than the rotational speed of the upstream heating roll in at least five consecutive heating rolls. It is more preferable to make it faster, and in at least n + 1 (n is an integer of 5 or more) continuous heating rolls, it is particularly preferable to make the rotation speed of the downstream heating roll faster than the rotation speed of the upstream heating roll. .

  The upper limit of n is not particularly limited. n may be 29 or less, 19 or less, 9 or less, or 5 or less.

  By increasing the number of heating rolls, the laminate can be brought into contact with the heating roll over a wide area for a long time, and the resin impregnation property can be further enhanced.

  The total number of heating rolls may be 30 or less, 20 or less, or 10 or less.

  From the viewpoint of suppressing the slackness of the laminated body and appropriately increasing the tension of the laminated body, appropriately pressing the laminated body on the heating roll, and effectively impregnating the fiber bundle with resin, the rotation of the second heating roll Ratio of speed to rotation speed of first heating roll (rotation speed ratio), ratio of rotation speed of third heating roll to rotation speed of second heating roll (rotation speed ratio), rotation of fourth heating roll Ratio of speed to rotation speed of third heating roll (rotation speed ratio), ratio of rotation speed of fifth heating roll to rotation speed of fourth heating roll (rotation speed ratio), (n + 1) th heating roll The ratio (rotational speed ratio) of the rotational speed of (n is an integer of 5 or more) to the rotational speed of the n-th heating roll (rotational speed ratio) is preferably more than 1, more preferably 1.001 or more. From the viewpoint of preventing the fiber bundle from being damaged by the friction of the laminate with the heating roll, the rotational speed ratio is preferably 1.050 or less, more preferably 1.020 or less, and still more preferably 1.010 or less. is there.

  The said rotational speed is a moving speed of the surface of a heating roll, and affects the conveyance speed of a laminated body.

  From the viewpoint of suppressing the slackness of the laminate, as well as appropriately increasing the tension of the laminate, suitably pressing the laminate to the heating roll, and effectively impregnating the fiber bundle with the resin, the first heating roll The rotation speed is preferably 0.1 m / min or more, more preferably 0.5 m / min or more. From the viewpoint of preventing the fiber bundle from being damaged by the friction of the laminated body with respect to the heating roll, the rotational speed of the first heating roll is preferably 10 m / min or less, more preferably 5 m / min or less.

  From the viewpoint of effectively impregnating the fiber bundle with resin, the flow direction of the laminate is preferably changed by the first heating roll, the flow direction of the laminate is preferably changed by the second heating roll, It is preferable to change the flow direction of the laminated body by the heating roll, and it is preferable to change the flow direction of the laminated body by the fourth heating roll, preferably to change the flow direction of the laminated body by the fifth heating roll, It is preferable to change the flow direction of the laminate by (n + 1) heating rolls (n is an integer of 5 or more). It is preferable to change the flow direction of the laminated body by contact with the heating roll.

  From the viewpoint of effectively impregnating the fiber bundle with resin, the first heating roll, the second heating roll, the third heating roll, the fourth heating roll, the fifth heating roll, and the (n + 1) th heating roll It is preferable to change the flow direction of the laminate by 10 degrees or more, preferably 30 degrees or more, and preferably 45 degrees or more, depending on each heating roll (n is an integer of 5 or more). The flow direction of the laminate is changed by each of the first heating roll, the second heating roll, the third heating roll, the fourth heating roll, and the (n + 1) th heating roll (n is an integer of 5 or more). 270 degrees or less may be changed, 225 degrees or less may be changed, and 180 degrees or less may be changed.

  The angle at which the flow direction changes is an angle formed by the flow direction of the laminate before contacting the heating roll and the flow direction of the laminate after contacting the heating roll with respect to one heating roll.

  From the viewpoint of effectively impregnating the fiber bundle with the resin, the first surface of the laminate is brought into contact with the first heating roll, and the second heating roll is opposite to the first surface of the laminate. It is preferable to contact the surface of each other. From the viewpoint of effectively impregnating the fiber bundle with the resin, when the first surface of the laminate is brought into contact with the first heating roll, the second surface of the laminate is brought into contact with the second heating roll. It is preferable that the first surface of the laminate is brought into contact with the third heating roll, the second surface of the laminate is preferably brought into contact with the fourth heating roll, and the fifth heating roll is laminated. It is preferred to contact the first surface of the body. From the viewpoint of effectively impregnating the fiber bundle with resin, it is preferable to alternately contact the first surface and the second surface of the laminate in a plurality of continuous heating rolls. In particular, when the laminate has the first resin portion and the second resin portion, it is preferable to alternately contact the first surface and the second surface of the laminate in a plurality of continuous heating rolls. . It is preferable to contact the laminate in a zigzag manner with respect to a plurality of continuous heating rolls. However, in all or a part of the continuous heating rolls, the first surface of the laminate may be in continuous contact, or the second surface of the laminate may be in continuous contact.

  In the laminate 21, the first release sheet 25 side may be the first surface of the laminate 21, and the first release sheet 25 side may be the second surface of the laminate 21. In the laminate 21, the second release sheet 26 side may be the first surface of the laminate 21, and the second release sheet 26 side may be the second surface of the laminate 21.

  The laminated body 21 is cooled by the cooling rolls 32 and 33 downstream of the heating roll 10. The cooling rolls 32 and 33 are a pair of rolls. The laminated body 21 can be effectively cooled by allowing the laminated body 21 to pass between the cooling rolls 32 and 33. By cooling, the molten resin is solidified, and the resin-impregnated fiber bundle 11 is obtained. In addition, as a cooling method, you may use methods other than the method of using a cooling roll.

  In this embodiment, the 1st release sheet 25 and the 2nd release sheet 26 are peeled downstream of the cooling rolls 32 and 33, and the resin impregnated fiber bundle 11 is wound up. As a result, the resin-impregnated fiber bundle 11 not having the first release sheet 25 and the second release sheet 26 is obtained.

  From the viewpoint of improving the handleability and the protective property, the resin-impregnated fiber bundle 11 may be wound in a state covered with the first release sheet 25 and the second release sheet 26.

  Moreover, in this embodiment, the peeled 1st release sheet 25 and the 2nd release sheet 26 are each wound up separately. The wound first release sheet 25 and second release sheet 26 may be reused.

  Hereinafter, the detail of the constituent material of a laminated body is demonstrated.

(Fiber bundle)
The fiber bundle is, for example, a reinforcing fiber bundle. The elastic modulus of the fiber bundle, particularly the elastic modulus of the reinforcing fiber bundle is relatively high. For this reason, a large stress can be generated in the fiber bundle even if the continuous heating roll is slightly increased. Using this stress, the laminate including the molten resin and the fiber bundle is pressed against the heating roll. For this reason, the impregnation of the resin proceeds efficiently.

  Specific examples of the material for the fiber bundle include glass fiber and carbon fiber. From the viewpoint of increasing the strength, the material of the fiber bundle is preferably glass fiber or carbon fiber.

  Preferable examples of the carbon fiber include PAN-based carbon fiber and PITCH-based carbon fiber. Preferable examples of the glass fiber include E glass fiber.

  The average fiber diameter in the fiber bundle is preferably 6 μm or more, and preferably 27 μm or less. The average fiber diameter is obtained by averaging fiber diameters (maximum diameters) at arbitrary 10 or more locations.

  The number of fibers in the fiber bundle is not particularly limited. The number of fibers in the fiber bundle is preferably 1000 or more, and preferably 50000 or less. When the material of the fiber bundle is carbon fiber, the number of fibers in the fiber bundle is preferably 1000 or more, and preferably 50000 or less. When the material of the fiber bundle is glass fiber, the number of fibers in the fiber bundle is preferably 1000 or more, and preferably 20000 or less.

  The fiber bundle is a bundle of a plurality of fibers. The form of the fiber bundle is not particularly limited. The fiber bundle may be a fiber sheet formed by stitches or the like.

One index of the performance of the fiber sheet is the weight per unit area (usually 1 m square), and the performance is expressed as a basis weight. The basis weight of the fiber sheet is preferably 100 g / m ² or more, and preferably 400 g / m ² or less. When the basis weight is not less than the above lower limit, the strength of the fiber bundle is further increased. When the basis weight is not more than the above upper limit, the impregnation property of the resin is further enhanced.

  Tension is applied to each fiber constituting the fiber bundle. When tension is applied to the fibers, the distance between the fibers tends to be narrowed. For this reason, it is preferable that the fiber bundle is processed to increase the inter-fiber distance. The fiber bundle preferably includes spacer particles that increase the distance between the fibers. By widening the distance between the fibers in this way, even when a high tension is applied to the fibers, the distance between the fibers is widened in advance, so that the impregnation of the resin is facilitated. Moreover, even if tension is applied to the fibers, the distance between the fibers is not easily reduced.

  The material of the spacer particles is not particularly limited. The material of the spacer particles is preferably a material in which the spacer particles are not excessively deformed by the temperature and pressure at the time of impregnation.

  As a material for the spacer particles, naphthoxazine resin is preferable. The naphthoxazine resin is easily carbonized and is not easily softened even when a high temperature or pressure is applied. For this reason, the distance between fibers is sufficiently secured, and the impregnation property of the resin is further enhanced.

  The spacer particles are preferably naphthoxazine resin particles or inorganic particles. The spacer particles are preferably inorganic particles, and more preferably inorganic particles excluding metal particles. Regarding the inorganic particles, the colloidal inorganic particle dispersion may be subjected to a treatment such as salting out to agglomerate the particles to adjust the particles to a size suitable as a spacer.

(First resin part and second resin part)
The resin that is a material of the first resin portion and the second resin portion (also simply referred to as a resin portion) is preferably a thermosetting resin or a thermoplastic resin, and is preferably a thermoplastic resin.

  As the thermoplastic resin, a thermoplastic resin having an appropriate viscosity under necessary heating conditions is preferable. Specific examples of the thermoplastic resin include polyolefin resin, polyamide resin, polycarbonate resin, polystyrene resin, and polyester resin. Examples of the polyolefin resin include polyethylene resin and polypropylene resin. Examples of the polyamide resin include aliphatic polyamide resins, and specific examples include polyamide 66, polyamide 6, and polyamide 12. Examples of the polystyrene resin include styrene polymer resin, AS resin and ABS resin. As said polyester resin, an aliphatic polyester resin is mentioned, Specifically, a polylactic acid resin etc. are mentioned.

  Polyolefin resins are preferred from the viewpoints of excellent physical properties and resin impregnation properties.

  The resin part before melting is preferably a resin sheet. The method for forming the resin into a sheet is not particularly limited. For example, after a thermoplastic resin is supplied to an extruder and heated and melted, it is extruded into a sheet using a coat hanger die or the like, and cooled with a cooling roll, whereby a resin sheet with excellent thickness accuracy can be obtained. The thickness of the resin sheet and the resin part is preferably 50 μm or more, and preferably 200 μm or less. When the thickness of the resin sheet and the resin portion is equal to or more than the above lower limit, the resin impregnation property is further enhanced. When the thickness of the resin sheet and the resin part is not more than the above upper limit, the resin hardly deteriorates the performance of the fiber bundle.

(First release sheet and second release sheet)
It is preferable that the first release sheet and the second release sheet (also simply referred to as a release sheet) have strength even when heated to a high temperature. Examples of the material for the release sheet include fluororesin, polyimide resin, and polyethylene terephthalate (PET) resin.

  The thickness of the release sheet is preferably 50 μm or more, and preferably 100 μm or less. When the thickness of the release sheet is not less than the above lower limit, the strength of the release sheet is further increased. When the thickness of the release sheet is not more than the above upper limit, the heating efficiency and cooling efficiency of the laminate are further increased, and the heating and cooling costs are further suppressed.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. The present invention is not limited only to the following examples.

Example 1
(1) Fiber bundle A reinforcing fiber bundle (“Carbon fiber bundle TC35-24K” manufactured by Taiwan Plastics Co., Ltd., 24,000 fibers) was used.

(2) Resin sheet A high-density polyethylene resin ("J108" manufactured by Prime Polymer Co., Ltd.) is supplied to a single-screw extruder (φ40 mm) to which a coat hanger type sheet molding die is connected, and melt-kneaded at about 200 ° C. It extruded to the sheet form and cooled with the cooling roll, and produced the resin sheet (thickness 0.1mm).

(3) Release sheet A PET sheet (“Melinex” manufactured by Teijin DuPont Films, Inc., thickness 100 μm) was used.

(4) Production of resin-impregnated fiber bundle As shown in FIG. 1, an apparatus was prepared in which 10 iron heating rolls were arranged adjacent to each other. Ten heating rolls were connected by a gear and were driven using one motor. Each roll was adjusted to rotate at different speeds by slightly changing the diameter of the roll. The rotation speed is shown in Table 1. The 10 rolls were heated by direct application of hot air, and the surface temperature of the heating roll was adjusted to 200 ° C.

  A release sheet, a resin sheet, a reinforcing fiber bundle, a resin sheet, and a release sheet were laminated in this order to produce a laminate. As shown in FIG. 1, after passing this laminated body through a zigzag-shaped pass line with respect to a plurality of heating rolls, the laminated body was conveyed while the motor was driven and brought into contact with the heating rolls. With each heating roll, the flow direction of the laminate was changed by 45 degrees or more.

  Since the heating roll was slightly increased in speed, tension was applied to the laminate, and it was observed that the laminate was being pressed against each heating roll.

  After the laminated body discharged from the apparatus was sufficiently cooled with a cooling roll, the release sheet was peeled off to obtain a resin-impregnated fiber bundle in which the reinforcing fiber bundle was impregnated with resin.

  In Example 1, the heating roll 2 corresponds to the first heating roll. The heating rolls 3 to 10 correspond to second to ninth heating rolls.

(Example 2)
A resin-impregnated fiber bundle was obtained in the same manner as in Example 1 except that the reinforcing fiber bundle was changed to the following reinforcing fiber bundle.

  20 g of ethanol (“057-00456” manufactured by Wako Pure Chemical Industries, Ltd.), 2.0 g of 1,5-dihydroxynaphthalene (“048-02342” manufactured by Wako Pure Chemical Industries, Ltd.), 40% methylamine aqueous solution (Wako Pure Chemical Industries, Ltd.) 1.0 g of “132-01857” manufactured by the company) and 2.0 g of 37% formaldehyde aqueous solution (“064-00406” manufactured by Wako Pure Chemical Industries, Ltd.) were added in this order to the beaker and stirred to prepare a solution. Next, the above solution is soaked into a reinforcing fiber bundle (“Carbon Fiber Bundle TC35-24K” manufactured by Taiwan Plastics Co., Ltd., 24,000 fibers) and pinched between rubber rollers to discharge excess solution from the carbon fiber bundle. I let you. This carbon fiber bundle was allowed to stand at 25 ° C. for 1 hour, and ethanol as a solvent was slowly evaporated. Next, the carbon fiber bundle was placed in a hot air oven at 170 ° C. for 20 minutes, and heat treatment was performed to obtain a reinforcing fiber bundle.

  When the inside of the obtained reinforcing fiber bundle was observed with an optical microscope, spacer particles having a diameter of 1 μm to 10 μm were adhered between the fibers. By this treatment, it was confirmed that a gap (space) about the diameter of the spacer particles was secured between the carbon fibers.

(Comparative Example 1)
Resin impregnation in the same manner as in Example 1 except that only the diameters of the 10 heating rolls were changed and the diameters of the 10 heating rolls were adjusted to 50 mm in order to align the rotation speed of the 10 heating rolls. A fiber bundle was obtained. Since each heating roll rotates at the same speed, it is considered that the tension is not applied to the fiber bundle as in Example 1.

(Evaluation)
Tensile test:
Using “Autograph AB-10TB” manufactured by Shimadzu Corporation, the tensile strength in the fiber extending direction of a strip-shaped resin-impregnated fiber bundle having a width of 10 mm and a span of 50 mm was measured. The results are shown in Table 1 below. The tensile speed was 5 mm / min.

  The rotational speed of the 10 heating rolls and the tensile strength of the obtained resin-impregnated fiber bundle are shown in Table 1 below.

  From the results shown in Table 1 above, according to the method for producing a reinforced sheet of the present invention, a resin is applied to a fiber bundle by a simple method of conveying a laminate while contacting a plurality of heating rolls slightly different in speed. It can be seen that a resin-impregnated fiber bundle excellent in strength can be obtained as a result. In this case, since a conveying belt having a large heat capacity such as a stainless belt is not used, heating and cooling costs in the manufacturing process of the resin-impregnated fiber bundle can be reduced.

  In the present invention, since a plurality of heating rolls rotate at different speeds, a large tension may be applied to the fiber bundle. Since the fiber bundle includes spacer particles that extend the distance between the fibers, the impregnation of the resin into the fiber bundle can be promoted even in a state where each fiber is strongly stretched, and as a result, a resin that is more excellent in strength An impregnated fiber bundle is obtained.

DESCRIPTION OF SYMBOLS 1-10 ... Heating roll 11 ... Resin impregnated fiber bundle 21 ... Laminate 22 ... Fiber bundle 23 ... 1st resin part 24 ... 2nd resin part 25 ... 1st release sheet 26 ... 2nd release sheet 31 ... Conveying roll 32, 33 ... Cooling roll

Claims (14)

A laminate having a fiber bundle and a first resin portion laminated on the first surface of the fiber bundle is conveyed while being in contact with a plurality of heating rolls, and the resin of the first resin portion is conveyed to the fiber bundle. Comprising the step of impregnating
The material of the fiber bundle is carbon fiber,
The resin of the first resin portion is a thermoplastic resin,
The plurality of heating rolls include a first heating roll and a second heating roll that comes in contact with the laminate next to the first heating roll,
By making the rotation speed of the second heating roll faster than the rotation speed of the first heating roll, the first heating roll and the second heating roll are generated while generating tension in the laminate. A method for producing a resin-impregnated fiber bundle, wherein the laminate is contacted.   The method for producing a resin-impregnated fiber bundle according to claim 1, wherein a ratio of a rotation speed of the second heating roll to a rotation speed of the first heating roll is set to 1.001 or more and 1.010 or less.   The first surface of the laminate is brought into contact with the first heating roll, and the second surface opposite to the first surface of the laminate is brought into contact with the second heating roll. Or the manufacturing method of the resin impregnation fiber bundle of 2.   The resin-impregnated fiber bundle according to any one of claims 1 to 3, wherein the flow direction of the laminate is changed by the first heating roll, and the flow direction of the laminate is changed by the second heating roll. Production method.   The production of the resin-impregnated fiber bundle according to claim 4, wherein the flow direction of the laminate is changed by 45 degrees or more by the first heating roll, and the flow direction of the laminate is changed by 45 degrees or more by the second heating roll. Method. The plurality of heating rolls include a third heating roll that comes in contact with the laminate next to the second heating roll,
By causing the rotation speed of the third heating roll to be higher than the rotation speed of the second heating roll, while generating tension in the laminate, the laminate is brought into contact with the third heating roll. The manufacturing method of the resin impregnated fiber bundle of any one of Claims 1-5.   The method for producing a resin-impregnated fiber bundle according to claim 6, wherein a ratio of a rotation speed of the third heating roll to a rotation speed of the second heating roll is set to 1.001 or more and 1.010 or less. The first surface of the laminate is brought into contact with the first heating roll, the second surface opposite to the first surface of the laminate is brought into contact with the second heating roll, and the third The method for producing a resin-impregnated fiber bundle according to claim 6 or 7, wherein the first surface of the laminate is brought into contact with a heating roll.   The method for producing a resin-impregnated fiber bundle according to any one of claims 6 to 8, wherein the flow direction of the laminate is changed by the third heating roll. The plurality of heating rolls include a fourth heating roll that comes in contact with the laminate next to the third heating roll,
By making the rotation speed of the fourth heating roll faster than the rotation speed of the third heating roll, the laminate is brought into contact with the fourth heating roll while generating tension in the laminate.
The first surface of the laminate is brought into contact with the first heating roll, the second surface opposite to the first surface of the laminate is brought into contact with the second heating roll, and the third Contacting the first surface of the laminate to the heating roll, and contacting the second surface of the laminate to the fourth heating roll,
The ratio of the rotation speed of the fourth heating roll to the rotation speed of the third heating roll is 1.001 or more and 1.010 or less,
The method for producing a resin-impregnated fiber bundle according to any one of claims 6 to 9, wherein the flow direction of the laminate is changed by the fourth heating roll.   The laminate according to any one of claims 1 to 10, wherein a laminate having a first release sheet disposed on a surface opposite to the fiber bundle side of the first resin portion is used as the laminate. A method for producing the resin-impregnated fiber bundle as described. As the laminate, a laminate having a second resin portion laminated on a second surface opposite to the first surface of the fiber bundle is used.
The method for producing a resin-impregnated fiber bundle according to any one of claims 1 to 11, wherein the fiber bundle is impregnated with the resin of the first resin portion and the resin of the second resin portion.   As the laminate, a first release sheet disposed on the surface side opposite to the fiber bundle side of the first resin part, and a surface opposite to the fiber bundle side of the second resin part The manufacturing method of the resin impregnation fiber bundle of Claim 12 using the laminated body which has a 2nd mold release sheet arrange | positioned at the side.   The method for producing a resin-impregnated fiber bundle according to any one of claims 1 to 13, wherein the fiber bundle includes spacer particles that increase a distance between fibers.

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