JP2015166417A - Method for producing thermoplastic prepreg - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a thermoplastic prepreg, in which the thermoplastic prepreg having high quality can be produced stably.SOLUTION: The method for producing the thermoplastic prepreg, in which a thermoplastic resin and a reinforcing fiber bundle are heated and then cooled by using a heating roll 11, a first cooling roll 12, and a second cooling roll 13 to produce the thermoplastic prepreg, comprises: a step (1) of superposing the fibrillated fiber bundle on the thermoplastic resin to form a laminate and conveying the laminate to such a position while heating the laminate by the heating roll 11 that the laminate is brought into contact with the first cooling roll 12; a step (2) of pressurizing the laminate, which is heated at the step (1), between the heating roll 11 and the first cooling roll 12 to obtain a thermoplastic resin-impregnated reinforcing fiber molding; and a step (3) of conveying the molding, which is obtained at the step (2), to such another position that the molding is brought into contact with the second cooling roll 13 and pressurizing the conveyed molding between the first cooling roll 12 and the second cooling roll 13 to obtain the thermoplastic prepreg.

Description

  The present invention relates to a method for producing a thermoplastic prepreg.

When manufacturing a thermoplastic prepreg, as a method for impregnating a thermoplastic resin into a reinforcing fiber bundle, two methods using a roll are known as described in the prior art of Patent Document 1, for example. Yes.
In the first method, first, a thermoplastic resin is superimposed on a bundle of reinforcing fibers opened in a sheet shape to form a molding material, and a pressure roll and a heater for heating are provided above and below the conveyance path of the molding material. Is disposed. And the said to-be-molded material is passed in the state pinched | interposed into a pair of release sheet between a pair of upper and lower pressure rolls. In this way, the material to be molded is pressed with a pair of upper and lower pressure rolls and heated with a heater for heating, whereby the reinforcing fiber bundle is continuously impregnated with the thermoplastic resin to produce a prepreg sheet material.

  In the second method, first, a thermoplastic resin is superimposed on a reinforcing fiber bundle opened in a sheet shape to obtain a material to be molded. And after pinching this to-be-molded material between a pair of release sheets, it pulls along with a heating roll. In this way, the material to be molded is pressed against the heating roll with the above-described tensile force (tension), whereby the reinforcing fiber bundle is impregnated with the thermoplastic resin to produce a prepreg sheet material.

JP 2003-181832 A

However, in the first method, the pressure is applied with a pair of rolls, but the pressurization time is instantaneous. Therefore, a preheating portion for preheating the resin is required, and the apparatus is enlarged.
On the other hand, in the second method, since the object to be molded is brought into contact with the heating roll, preheating is not required and the pressing time can be lengthened. However, the pressing force depends on the tension of the reinforcing fiber bundle. become weak.

In addition, since both the first method and the second method use a pair of release sheets as a support, it is necessary to heat and preheat the release sheet when heating or preheating the molding material. Therefore, the thermal efficiency in the process is lowered. Furthermore, since the processing temperature depends on the heat resistance of the release sheet, the temperature condition of the roll is limited to the release sheet.
Then, this inventor examined the method of manufacturing a thermoplastic prepreg using a roll, without using a release sheet. However, if pressure is applied with a roll without using a release sheet, disorder of the reinforcing fibers occurs or the thermoplastic resin adheres to the roll and the separation of the thermoplastic prepreg (molded body) from the roll is stable. Therefore, it has been difficult to stably produce the thermoplastic prepreg.

  The present invention has been made in view of the above circumstances, and the purpose thereof is to stabilize the peeling of the thermoplastic prepreg from the roll when performing roll pressurization without using a release sheet, Accordingly, an object of the present invention is to provide a method for producing a thermoplastic prepreg, which is capable of stably producing a high-quality thermoplastic prepreg having good impregnation properties.

The method for producing a thermoplastic prepreg of the present invention includes a heating roll, a first cooling roll arranged to be paired with the heating roll, and the first cooling roll without being paired with the heating roll. Using the second cooling rolls arranged in a pair, the thermoplastic resin and the reinforcing fiber bundle are heated and further cooled to produce a prepreg including the thermoplastic resin and the reinforcing fiber bundle. A manufacturing method, comprising at least the following steps (1) to (3).
(1) A reinforcing fiber bundle opened in a web shape and a thermoplastic resin are laminated to form a laminate comprising a reinforcing fiber bundle layer and a thermoplastic resin layer, and the thermoplastic resin layer of the laminate is When the thermoplastic resin is a crystalline resin having a melting point, in the temperature range of + 40 ° C. to + 90 ° C. with respect to the melting point of the thermoplastic resin, and when the thermoplastic resin is an amorphous resin having no melting point, While heating the thermoplastic resin layer while being held in contact with the heating roll heated to a temperature range of + 40 ° C. to + 90 ° C. with respect to the glass transition temperature of the thermoplastic resin, the laminate is Transporting to a position in contact with the first cooling roll;
(2) Between the 1st cooling roll which set the laminated body heated at the said process (1) to the temperature range of -60 degreeC--10 degreeC with respect to the temperature of the said heating roll and this heating roll. A step of applying a linear pressure in the range of 10 kg / cm to 30 kg / cm to obtain a thermoplastic resin-impregnated reinforcing fiber molded body.
(3) The second cooling is performed by holding the thermoplastic resin-impregnated reinforcing fiber molded body obtained in the step (2) in contact with the first cooling roll set in the temperature range. The process which conveys to the position which touches a roll, and pressurizes in the range of 10 kg / cm-30 kg / cm of linear pressure between the said 1st cooling roll and the said 2nd cooling roll, and obtains a thermoplastic prepreg.

  In the step (1), the viscosity of the thermoplastic resin layer is set to 1 Pa · s to 400 Pa · s by heating with the heating roll.

  Further, in the step (3), the thermoplastic resin-impregnated reinforcing fiber molded body obtained in the step (2) is held in contact with the first cooling roll, and the second cooling roll is used. By transporting to the contact position, the viscosity of the thermoplastic resin in the thermoplastic resin-impregnated reinforcing fiber molded body is 50 Pa · s to 500 Pa · s higher than the viscosity of the thermoplastic resin after completion of the step (1). It is characterized by.

  Further, the temperature of the second cooling roll is set to a temperature range of −150 ° C. to −100 ° C. with respect to the melting point of the thermoplastic resin when the thermoplastic resin has a melting point. When the resin is an amorphous resin having no melting point, the resin is characterized by having a temperature range of −150 ° C. to −100 ° C. with respect to the glass transition temperature of the thermoplastic resin.

  In addition, the holding angle of the heating roll in the step (1) is set to 45 ° to 300 °, the holding angle of the first cooling roll in the step (3) is set to 45 ° to 300 °, and the second The holding angle of the cooling roll is set to 10 ° to 180 °.

  The thermoplastic resin is one or more thermoplastic resins selected from polypropylene resins, polyamide resins, polyphenylene sulfide resins, polyetherimide resins, and modified resins of these resins.

  Further, the reinforcing fiber bundle is a carbon fiber bundle.

  According to the method for producing a thermoplastic prepreg of the present invention, it is possible to stabilize the peeling of the thermoplastic prepreg from the roll when the roll is pressed without using a release sheet, and thereby the impregnation property is good. A high-quality thermoplastic prepreg can be stably produced.

It is a figure which shows schematic structure of an example of the prepreg manufacturing apparatus for enforcing the manufacturing method of the thermoplastic prepreg which concerns on this invention. It is a figure which shows schematic structure of an example of the roll apparatus which comprises the prepreg manufacturing apparatus shown in FIG.

Hereinafter, the present invention will be described in detail with reference to the drawings. In the following drawings, the scale of each member is appropriately changed to make each member a recognizable size.
FIG. 1 is a diagram showing a schematic configuration of an example of a prepreg apparatus for carrying out the method for manufacturing a thermoplastic prepreg according to the present invention, and FIG. 2 is an example of a roll apparatus constituting the prepreg manufacturing apparatus shown in FIG. It is a figure which shows schematic structure.

  In FIG. 1, reference numeral 1 denotes a prepreg apparatus. The prepreg apparatus 1 covers a spread portion 2 for opening the reinforcing fiber bundle 20 and a spread thermoplastic fiber 22 so as to overlap the opened reinforcing fiber bundle 21. A roll device 4 for forming a continuous sheet-like thermoplastic prepreg 24 by heating and pressurizing the covering portion 3 for forming and the sheet-like reinforcing fiber (molded material) 23 coated with the molten thermoplastic resin 22; The sheet-shaped thermoplastic prepreg 24 is configured to include a winding unit 5 including a winding roller and the like.

With such a prepreg manufacturing apparatus 1, the method for manufacturing a thermoplastic prepreg according to the present invention is implemented.
That is, in this embodiment, the prepreg manufacturing apparatus 1 is continuously used until the reinforcing fiber bundle 20 prepared in advance and wound up by a winding roll or the like is finally wound up by a winding roller or the like of the winding unit 5. In this process, a sheet-like thermoplastic prepreg 24 is formed.

  First, the reinforcing fiber bundle 20 taken up by a take-up roll or the like is sent to the opening part 2 by the take-up force of the take-up part 5 and opened into a web shape here. The opening part 2 has a plurality of opening bars (spreader bars) 2a in the example shown in FIG. 1, and these are arranged stepwise in the vertical direction. The opening bar 2a is formed by a cylindrical rod having a small diameter, and both ends thereof are fixed to a fixing portion (not shown) so that they cannot rotate or rotate at a speed lower than the take-up speed of the reinforcing fiber bundle 20 and cannot move. Yes. In such a configuration, the reinforcing fiber bundle 20 flows (runs) between the opening bars 2a of the opening portion 2 and thereby the opening force is successively applied by the tensile force of each opening bar 2a. And spreads in the form of a web.

  The opening bar 2a is a thin cylindrical bar in the present embodiment, but may be an elongated flat bar. However, if the opening bar 2a has acute corners, the reinforcing fibers constituting the reinforcing fiber bundle 20 may be damaged by the corners. Therefore, the opening bar 2a has a columnar shape without corners. Is preferred. In addition, the number of spread bars (spreader bars) 2a constituting the spread part 2 is preferably 3 or more because the reinforcing fiber bundle 20 can be opened more favorably and spread into a web shape. . Further, the opening bar 2a is preferably configured to be heatable by a heating means such as a heater. By configuring so that heating is possible, the reinforcing fiber bundle 20 can be preheated before the molten thermoplastic resin is applied to the reinforcing fiber bundle 20. Here, the last stage opening bar 2a of the opening bars 2a also serves as a guide 6 on the upstream side of the covering portion 3 as described later.

  As the reinforcing fiber bundle 20 that is opened in a web shape at the opening portion 2, the number of bundles that are simultaneously unwound and supplied to the opening portion 2 is determined in accordance with the width of the sheet-like thermoplastic prepreg to be manufactured. The That is, the reinforcing fiber bundle 20 is supplied to the fiber opening unit 2 in an appropriate amount (number of bundles) from one bundle to several tens of bundles, and is opened in a web shape.

  The reinforcing fiber constituting such a reinforcing fiber bundle is not particularly limited, but inorganic fiber, organic fiber, metal fiber, or a hybrid reinforcing fiber combining these can be used. Examples of the inorganic fiber include carbon fiber, graphite fiber, silicon carbide fiber, alumina fiber, tungsten carbide fiber, boron fiber, and glass fiber. Examples of organic fibers include aramid fibers, high density polyethylene fibers, other general nylon fibers, and polyesters. Examples of metal fibers include fibers such as stainless steel and iron, and carbon fibers coated with metal may be used. Among these, carbon fibers are preferable in view of mechanical properties (mechanical properties) such as strength of the final molded product. Moreover, it is preferable that the average fiber diameter of a reinforced fiber is 1-50 micrometers, and it is still more preferable that it is 5-20 micrometers.

  Next, the reinforcing fiber bundle 21 opened in a web shape is sent to the covering portion 3. The covering portion 3 includes two guides 6 and 7 disposed along the flow direction of the reinforcing fiber bundle 21 and a die 8 disposed between the guides 6 and 7. The upstream guide 6 is constituted by the last stage opening bar 2a in the opening part 2 as described above. That is, the last stage opening bar 2 a in the opening part 2 also serves as the upstream guide 6 in the covering part 3. Accordingly, the guide 6 is also configured such that both ends thereof are fixed and cannot rotate or rotate at a lower speed than the take-up speed of the reinforcing fiber bundle 20 and cannot move.

  The downstream guide 7 is formed of a cylindrical roll having a diameter larger than that of the guide 6 (opening bar 2a). Both ends of the guide 6 are fixed and cannot rotate or are slower than the take-up speed of the reinforcing fiber bundle 20. It is configured to be rotatable and immovable. However, the guide 7 of the covering portion 3 may be configured to be rotatable according to the movement (flow) of the reinforcing fiber bundle 21 unlike the fiber opening bar 2a.

  Next, the molten thermoplastic resin 22 is discharged and applied from the die 8 to the reinforcing fiber bundle 21 that has been sent to the covering portion 3 and opened in a web shape, and the molten thermoplastic resin 22 is applied to the reinforcing fiber bundle. Reinforcement in which a reinforcing fiber bundle 21 and a thermoplastic resin 22 are laminated in a sheet shape, that is, a sheet-like reinforcing fiber 23 which is covered with one surface (upper surface) 21 and is formed into a molding material. A laminate composed of a fiber bundle layer and a thermoplastic resin layer is formed.

  The die 8 is disposed vertically above the upper surface of the reinforcing fiber bundle 21 that moves (flows) between the guides 6 and 7 and includes heating means such as a heater. The die 8 is supplied with a thermoplastic resin from a resin storage section (not shown), and heats the supplied thermoplastic resin to a predetermined temperature to form a molten thermoplastic resin, which is discharged from a lip 8a serving as a discharge port with a predetermined discharge pressure. The molten thermoplastic resin 22 is applied to and coated on the upper surface of the reinforcing fiber bundle 21 that is discharged and moved between the guides 6 and 7. The die 8 is formed to have a width that is substantially the same as or slightly wider than the width of the reinforcing fiber bundle 21 to which the lip 8a moves. Therefore, the molten thermoplastic resin is uniformly applied to the reinforcing fiber bundle 21 in the width direction. It can be applied.

  Examples of the thermoplastic resin to be discharged, that is, the thermoplastic resin for covering the reinforcing fiber bundle 21 include polyamide (nylon 6, nylon 66, etc.), polyolefin (polyethylene, polypropylene, etc.), modified polyolefin, polyester (polyethylene terephthalate, polybutylene). Terephthalate, etc.), polycarbonate, polyamideimide, polyphenylene oxide, polysulfone, polyethersulfone, polyetheretherketone, polyetherimide, polystyrene, ABS, polyphenylene sulfide, liquid crystal polyester, and a copolymer of acrylonitrile and styrene. it can. Moreover, you may use these mixtures. Further, a copolymer of nylon 6 and nylon 66, such as nylon, may be used. Among such thermoplastic resins, in the present invention, it is particularly preferable to use one or more thermoplastic resins selected from polypropylene resins, polyamide resins, polyphenylene sulfide resins, polyetherimide resins, and modified resins of these resins. . If these resins are used, various properties such as physical properties of the obtained thermoplastic prepreg can be further improved. Depending on the required properties of the molded product to be obtained, flame retardants, weather resistance improvers, other antioxidants, heat stabilizers, UV absorbers, plasticizers, lubricants, colorants, compatibilizers, conductive fillers, etc. Can also be added.

  The molten thermoplastic resin discharged from the die 8 is preferably heated to an appropriate temperature according to the type of the resin so that the viscosity (melt viscosity) is, for example, 100 Pa · s or more and 1000 Pa · s or less. By discharging with a viscosity in such a range, the molten thermoplastic resin 22 spreads well with respect to the reinforcing fiber bundle 21 and securely fixes the reinforcing fibers opened in a web shape.

  Next, the sheet-like reinforcing fibers 23 led out from the downstream guide 7, that is, as shown in FIG. 2, a sheet-like reinforcing fiber (covered) as a laminate comprising the reinforcing fiber bundle layer 21 a and the thermoplastic resin layer 22 a. The molding material 23 is supplied to the roll device 4. The roll device 4 is a device for carrying out the main process of the method for producing a thermoplastic prepreg according to the present invention, and includes a heating roll 11 and a first cooling unit disposed so as to be paired with the heating roll 11. A roll 12, a second cooling roll 13 arranged to be paired with the first cooling roll 12 without being paired with the heating roll 11, the heating roll 11, the first cooling roll 12, A rotation mechanism (not shown) that rotates each of the second cooling rolls 13 at a preset speed is provided. The rotating mechanism includes a connecting member such as a gear connected to the rotation shaft of each of the rolls 11, 12, 13, a driving unit such as a motor connected via the connecting member, and a control device that controls the operation of the driving unit, , Having a known configuration. The rotation mechanism is driven for each of the rolls 11, 12, and 13. Or it may be driven by having a drive part in any one or more of rolls 11, 12, and 13 and pressurizing a roll which does not have a drive part to a roll which has a drive part.

  In the present embodiment, a laminate (sheet-like reinforcing fiber 23) composed of the thermoplastic resin layer 22a (thermoplastic resin 22) and the reinforcing fiber bundle layer 21a (reinforcing fiber bundle 21) by the roll device 4 having such a configuration. Is heated and further cooled to produce a prepreg (continuous sheet-like prepreg 24) containing a thermoplastic resin and a reinforcing fiber bundle.

  That is, in the roll device 4, as the step (1), the thermoplastic resin layer 22 a of the sheet-like reinforcing fiber 23 (laminated body) is held in contact with the heating roll 11, and the thermoplastic resin While heating the layer 22a, the sheet-like reinforcing fibers 23 are conveyed to a position in contact with the first cooling roll 12. At that time, the heating roll 11 is heated to a predetermined temperature range in advance according to the type of the thermoplastic resin 22 (thermoplastic resin layer 22a). Specifically, in the case where the thermoplastic resin 22 is a crystalline resin having a melting point, the temperature ranges from + 40 ° C. to + 90 ° C. with respect to the melting point of the thermoplastic resin 22, and the thermoplastic resin 22 has a melting point. In the case of an amorphous resin that is not used, it is heated to a temperature range of + 40 ° C. or higher and + 90 ° C. or lower with respect to the glass transition temperature of the thermoplastic resin 22.

Below, melting | fusing point or glass transition temperature of a typical thermoplastic resin is described.
"Polyolefin resin"
・ Low density polyethylene: 95-130 ° C (melting point)
-High density polyethylene: 120-140 ° C (melting point)
-Polypropylene: 168 ° C (melting point)
"Modified polypropylene resin"
: 160-165 ° C. (melting point)
"Polyamide resin"
Polyamide 6: 220 ° C. (melting point)
Polyamide 66: 260 ° C. (melting point)
Polyamide 12: 175 ° C (melting point)
-Polyamide MXD6: 237 ° C (melting point)
"Polycarbonate resin"
: 145 ° C (glass transition temperature)
However, the melting point (glass transition temperature) of each resin varies somewhat due to differences in resin density, crystal structure, degree of modification, and the like.

By heating the heating roll 11 to a temperature range of + 40 ° C. or higher and + 90 ° C. or lower with respect to the melting point or glass transition temperature of the thermoplastic resin 22 in the sheet-like reinforcing fiber 23 to be processed, The thermoplastic resin layer 22a in the laminate (reinforcing fiber 23) can be reliably melted, and the reinforcing fiber 23 can be satisfactorily impregnated with the thermoplastic resin 22.
That is, by heating the heating roll 11 to the above temperature range, the viscosity of the thermoplastic resin layer 22a can be set to 1 Pa · s or more and 400 Pa · s or less. By making the thermoplastic resin layer 22a have such a viscosity, the thermoplastic resin 22 superimposed on one surface of the reinforcing fiber bundle layer 21a can be easily placed between the fibers of the reinforcing fiber bundle layer 21a (reinforcing fiber 23). Infiltrate into the reinforcing fiber 23.

  When the temperature of the heating roll 11 is less than + 40 ° C. with respect to the melting point or glass transition temperature of the thermoplastic resin 22, the viscosity of the thermoplastic resin layer 22 a often exceeds 400 Pa · s, and the reinforcing fiber 23 The impregnation of the thermoplastic resin 22 into the inside may be insufficient. On the other hand, when the temperature of the heating roll 11 exceeds + 90 ° C. with respect to the melting point or glass transition temperature of the thermoplastic resin 22, the thermoplastic resin 22 may be altered or decomposed. Further, the viscosity of the thermoplastic resin layer 22a becomes too low and the fluidity becomes high, and there is a possibility that the thermoplastic resin 22 adheres to the heating roll 11 in a large amount.

  In the step (1) of heating with the heating roll 11, the holding angle α of the heating roll 11 indicating the range in which the laminate (reinforced fiber 23) is in contact with the heating roll 11 is 45 ° or more and 300 ° or less. It is preferable to do this. By setting the holding angle α in such an angle range, the thermoplastic resin layer 22a is reliably melted on the heating roll 11, and the thermoplastic resin 22 is applied to the reinforcing fibers 23 in the step (2) described later. It can be impregnated well.

  Subsequently, as step (2), the laminate (reinforced fiber 23) heated in step (1) is subjected to a linear pressure of 10 kg / cm to 30 kg / cm between the heating roll 11 and the first cooling roll 12. Pressure is applied in the following range to obtain a thermoplastic resin-impregnated reinforcing fiber molded body 23a. By pressing the laminate (reinforcing fiber 23) heated in the step (1) with a linear pressure in the above range, the thermoplastic resin 22 melted in the step (1) is impregnated in the reinforcing fiber 23. When the linear pressure is less than 10 kg / cm, impregnation of the thermoplastic resin 22 into the reinforcing fiber 23 becomes insufficient. If the linear pressure exceeds 30 kg / cm, the reinforcing fibers constituting the reinforcing fiber bundle layer 21a of the laminate may be disturbed by pressurization and meander on the first cooling roll 12.

  At this time, the first cooling roll 12 is preheated to a predetermined temperature range in accordance with the temperature of the heating roll 11, that is, according to the type of the thermoplastic resin 22 (thermoplastic resin layer 22a). Specifically, it is set (heated) in a temperature range of −60 ° C. or more and −10 ° C. or less with respect to the temperature of the heating roll 11. If it is less than -60 degreeC with respect to the temperature of the heating roll 11, the impregnation of the thermoplastic resin 22 in the reinforcing fiber 23 will become inadequate. Moreover, when it exceeds -10 degreeC, peeling to the heating roll 11 of a laminated body (reinforcing fiber 23) will not be stabilized, and there exists a possibility that a laminated body may wind around the heating roll 11. FIG.

  Subsequently, as the step (3), the thermoplastic resin-impregnated reinforcing fiber molded body 23a obtained in the step (2) is held in a state of being in contact with the first cooling roll 12 set in the temperature range. The sheet is conveyed to a position in contact with the second cooling roll 13. And the continuous sheet-like thermoplastic prepreg 24 is obtained by pressurizing in the range of 10 kg / cm or more and 30 kg / cm or less of linear pressure between the 1st cooling roll and the 2nd cooling roll. .

The thermoplastic resin-impregnated reinforced fiber molded body 23a is held in contact with the first cooling roll 12 and conveyed to a position in contact with the second cooling roll 13, whereby the thermoplastic resin-impregnated reinforced fiber molded body 23a is conveyed. Can be cooled close to the temperature of the second cooling roll 13. Thereby, the viscosity of the thermoplastic resin 22 in the thermoplastic resin-impregnated reinforcing fiber molded body 23a is higher than the viscosity of the thermoplastic resin 22 after the end of the step (1) in a range of about 50 Pa · s to 500 Pa · s. Therefore, the peelability of the thermoplastic resin-impregnated reinforcing fiber molded body 23a with respect to the first cooling roll 12 can be improved.
When the viscosity of the thermoplastic resin 22 in the thermoplastic resin-impregnated reinforcing fiber molded body 23a becomes higher than the viscosity of the thermoplastic resin 22 after the completion of the step (1) is less than 50 Pa · s, the reinforcing fiber 23 is entered. The impregnation of the thermoplastic resin 22 is not sufficiently uniform. Moreover, if it exceeds 500 Pa · s, the peeling point of the laminate may not be determined, and the reinforcing fibers constituting the reinforcing fiber bundle layer 21 a of the laminate may be disturbed and meander on the first cooling roll 12.

  Further, the cooling with the first cooling roll 12 is performed by setting the holding angle β of the first cooling roll 12 indicating the range in which the thermoplastic resin-impregnated reinforcing fiber molded body 23a is in contact with the first cooling roll 12, It is preferable to set it to 45 ° or more and 300 ° or less. By setting the holding angle β in such an angle range, the thermoplastic resin-impregnated reinforcing fiber molded body 23a is cooled more favorably on the first cooling roll 12, and the viscosity of the thermoplastic resin 22 falls within the above range. Can be adjusted.

  Therefore, when the linear pressure is applied between the first cooling roll 12 and the second cooling roll 13 in the range of 10 kg / cm or more and 30 kg / cm or less, the thermoplastic resin-impregnated reinforcing fiber molded body 23a is formed into the first. Can be reliably delivered from the cooling roll 12 side to the second cooling roll 13 side. The smoothness of the prepreg 24 can be improved by pressurization between the first cooling roll 12 and the second cooling roll 13.

  When the linear pressure in pressurization between the first cooling roll 12 and the second cooling roll 13 is less than 10 kg / cm, the peeling point of the formed prepreg 24 from the second cooling roll 13 is stabilized. Therefore, sufficiently stable operation (manufacturing) becomes difficult, and the resulting prepreg 24 also lacks smoothness. Further, if the linear pressure exceeds 30 kg / cm, the reinforcing fibers constituting the reinforcing fiber bundle layer 21a of the laminate may be disturbed by pressurization, and the second cooling roll 13 may be meandered.

  At this time, the second cooling roll 13 is set (heated) in a predetermined temperature range in advance according to the type of the thermoplastic resin 22 (thermoplastic resin layer 22a). Specifically, when the thermoplastic resin 22 is a crystalline resin having a melting point, the thermoplastic resin 22 has a temperature range of −150 ° C. to −100 ° C. with respect to the melting point of the thermoplastic resin 22, and the thermoplastic resin 22 has a melting point. In the case of an amorphous resin that does not have a temperature, it is set (heated) in a temperature range of −150 ° C. or higher and −100 ° C. or lower with respect to the glass transition temperature of the thermoplastic resin 22.

  The second cooling roll 13 is set (heated) in a temperature range of −150 ° C. or more and −100 ° C. or less with respect to the melting point or glass transition temperature of the thermoplastic resin 22 in the sheet-like reinforcing fiber 23 to be processed. Thus, the thermoplastic resin 22 in the thermoplastic resin-impregnated reinforcing fiber molded body 23 a can be reliably solidified by the second cooling roll 13, and the thermoplastic resin 22 can be integrated with the reinforcing fiber 23. Thereby, the peelability of the thermoplastic resin-impregnated reinforcing fiber molded body 23a with respect to the second cooling roll 13 can be improved.

  Further, the cooling with the second cooling roll 13 is performed by setting the holding angle γ of the second cooling roll 13 indicating the range in which the thermoplastic resin-impregnated reinforcing fiber molded body 23a is in contact with the second cooling roll 13, The angle is preferably 10 ° or more and 180 ° or less. By setting the holding angle γ within such an angle range, the thermoplastic resin-impregnated reinforcing fiber molded body 23a can be cooled more satisfactorily on the second cooling roll 13, and the peelability can be improved.

That is, since the peelability can be improved in this way, it is possible to stably obtain a continuous sheet-like thermoplastic prepreg 24 in which the thermoplastic resin-impregnated reinforcing fiber molded body 23a is pressurized and cooled. it can.
Then, the continuous sheet-like thermoplastic prepreg 24 is wound up by the winding-up part 5, and the process in the prepreg manufacturing apparatus 1 is complete | finished. In addition, a thermoplastic prepreg can be obtained by cutting the continuous sheet-like thermoplastic prepreg 24 formed in this way into a predetermined size with another cutting device.

  In such a method for producing a thermoplastic prepreg, without using a release sheet as in the prior art by the roll device 4 provided with the heating roll 11, the first cooling roll 12, and the second cooling roll 13, Since the continuous sheet-like thermoplastic prepreg 24 is manufactured by heating, pressurization, and cooling by the rolls 11, 12, and 13, the heating roll 11 particularly improves the impregnation of the thermoplastic resin 22. Furthermore, the peelability of the molded body 23a and the thermoplastic prepreg 24 from the first cooling roll 12 and the second cooling roll 13 can be stabilized. Therefore, it is possible to stably produce a high-quality thermoplastic prepreg having good impregnation of the thermoplastic resin 22.

As mentioned above, although preferred embodiment of this invention was described referring drawings, this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are merely examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.
For example, the apparatus for carrying out the manufacturing method of the present invention is not limited to the prepreg manufacturing apparatus 1 shown in FIG. 1, and any manufacturing apparatus provided with the roll apparatus 4 shown in FIG. It can be suitably used as an apparatus for carrying out the manufacturing method of the invention.

Hereinafter, the present invention will be described more specifically with reference to examples.
Example 1
A thermoplastic prepreg was manufactured by using the opening portion 2 of the prepreg manufacturing apparatus 1 shown in FIG. 1 and the roll apparatus 4 shown in FIG.
As the reinforcing fibers, 20 bundles of carbon fibers (manufactured by Mitsubishi Rayon Co., Ltd., product name: TR50S15L, basis weight: 1000 mg / m, tensile strength: 4.90 GPa, tensile elastic modulus: 240 GPa) were used. While the reinforcing fiber bundle made of these carbon fibers was maintained at a tension of 2000 g per bundle in the opening portion 2, the four opening bars 2a were sequentially moved (runned) at a speed of 1 m / min. By sequentially rubbing the four open bars 2a in this manner, the reinforcing fiber bundles are aligned in one direction, the width per fiber bundle is 10 mm, and the weight of the web-like reinforcing fiber bundle 21 is 100 g / sm. It was.

A polypropylene (modified polypropylene, manufactured by Mitsubishi Chemical Corporation, product name: Modic [registered trademark]) film is heated at 200 ° C. with respect to the reinforcing fiber bundle 21 thus opened, and the heated polypropylene is Laminated on the reinforcing fiber bundle 21.
Then, this laminated body (sheet-like reinforcing fiber 23) was used for the heating roll 11, and the layer of polypropylene was heated with this heating roll. The heating roll 11 was previously heated to 205 ° C. Moreover, the laminated body was hold | maintained with the heating roll 11, and it heated so that the holding angle of the heating roll 11 might be 210 degrees.

Next, the laminate is pressed between the heating roll 11 and the first cooling roll 12 at a linear pressure of 20 kg / cm, and then the laminate is taken up by the first cooling roll 12 and the first The holding angle of one cooling roll 12 was held in contact with the cooling roll 12 at 180 °. At that time, the first cooling roll 12 was heated (set) to a temperature of 160 ° C. in advance.
Next, the formed molded body 23a is passed between the first cooling roll 12 and the second cooling roll 13 and pressurized with a linear pressure of 20 kg / cm. Subsequently, the molded body 23a is pressed with the second cooling roll. 13 and the second cooling roll 13 was held in contact with the second cooling roll 13 so that the holding angle was 90 °. At that time, the temperature of the second cooling roll 13 was set to 30 ° C. in advance.
Thereafter, the formed sheet-like prepreg 24 was pulled out from the second cooling roll 13 and peeled off.

  About the obtained sheet-like prepreg 24, the following items were evaluated and the results are shown in Table 1 together with the prepreg production conditions.

"Impregnated state"
The obtained prepreg 24 was cut in the width direction, and the impregnated state of the thermoplastic resin was evaluated by observing and analyzing the cut cross section, and the quality of the impregnated state was determined. At that time, when the area ratio of the voids was 2% or less, it was determined that “impregnation was good”, and in Table 1, it was indicated as “◯”. Further, when it exceeded 2%, it was determined that “impregnation property was not good”, and in Table 1, “x” was described. In Example 1, the impregnation property was good.

"Fiber disturbance"
The method for visually confirming how the reinforcing fibers of the obtained prepreg 24 are aligned is visually inconsistent with that of the reinforcing fibers aligned in the 0 ° direction with ± 1 ° or more. No, that is, “good” was determined, and in Table 1, “good” was indicated. In addition, those in which the disturbance (meandering) of the reinforcing fiber of ± 1 ° or more was observed were judged as having a fiber disturbance, that is, “defective”, and indicated as “X” in Table 1. In Example 1, there was no disorder of the fiber.

"Smoothness of prepreg"
The smoothness of the obtained sheet-like prepreg 24 was visually confirmed to determine whether the smoothness was good or bad. Those having good smoothness are indicated by ○ in Table 1, and those having poor smoothness are indicated by × in Table 1. In Example 1, the smoothness was good.
“Stable operation for 2 hours or more”
It was confirmed whether or not a continuous operation could be stably performed for 2 hours (hours) or longer. In the case where stable operation could be performed stably for 2 hours (hours) or longer, it was determined as “good”, and in Table 1, “O” was indicated. In addition, when the continuous operation could not be stably performed for 2 hours (hours) or more, it was determined as “bad”, and in Table 1, “x” was described. In Example 1, continuous operation could be performed sufficiently stably for a long time of 2 h (hours) or longer. In Table 1, since continuous operation was stably possible for the longest time compared with other examples, it was described as “◎”.

(Example 2)
The temperature of the heating roll 11 was 230 ° C., and the temperature of the first cooling roll 12 was 180 ° C. Except for these points, a sheet-like prepreg 24 was produced in the same manner as in Example 1. Evaluation was conducted in the same manner as in Example 1, and the results obtained are also shown in Table 1. In Example 2, the “impregnated state” was the best as compared with the other examples, and therefore “◎” is shown in Table 1.

(Example 3)
Polyamide (melting point 225 ° C.) was used as the thermoplastic resin, the temperature of the heating roll 11 was 280 ° C., and the temperature of the first cooling roll 12 was 250 ° C. Except for these points, a sheet-like prepreg 24 was produced in the same manner as in Example 1. Evaluation was conducted in the same manner as in Example 1, and the results obtained are also shown in Table 1.

(Comparative Example 1)
The temperature of the heating roll 11 was 180 ° C., and the temperature of the first cooling roll 12 was 140 ° C. Except for these points, a sheet-like prepreg 24 was produced in the same manner as in Example 1. Evaluation was conducted in the same manner as in Example 1, and the results obtained are also shown in Table 1.
As shown in Table 1, since the temperature of the heating roll 11 is less than + 40 ° C. from the melting point of the thermoplastic resin, the “impregnation state” is poor, and “stable operation of 2 hours or more” is also bad. It was.

(Comparative Example 2)
The temperature of the heating roll 11 was 230 ° C., and the temperature of the first cooling roll 12 was 230 ° C. Except for these points, a sheet-like prepreg 24 was produced in the same manner as in Example 1. Evaluation was conducted in the same manner as in Example 1, and the results obtained are also shown in Table 1.
As shown in Table 1, since the temperature of the first cooling roll 12 exceeds −10 ° C. from the temperature of the heating roll 11, “fiber disturbance” is poor, and “stable operation for 2 hours or more” Was also bad.

(Comparative Example 3)
The temperature of the heating roll 11 was 230 ° C., and the temperature of the first cooling roll 12 was 120 ° C. Except for these points, a sheet-like prepreg 24 was produced in the same manner as in Example 1. Evaluation was conducted in the same manner as in Example 1, and the results obtained are also shown in Table 1.
As shown in Table 1, since the temperature of the 1st cooling roll 12 was less than -60 degreeC from the temperature of the heating roll 11, "impregnation state" was unsatisfactory.

(Comparative Example 4)
The temperature of the heating roll 11 is 230 ° C., the temperature of the first cooling roll 12 is 180 ° C., and the linear pressure when pressurizing between the heating roll 11 and the first cooling roll 12 is 5 kg / cm. . Except for these points, a sheet-like prepreg 24 was produced in the same manner as in Example 1. Evaluation was conducted in the same manner as in Example 1, and the results obtained are also shown in Table 1.
As shown in Table 1, the “impregnation state” was poor because the linear pressure between the heating roll 11 and the first cooling roll 12 was less than 10 kg / cm.

(Comparative Example 5)
The temperature of the heating roll 11 is 230 ° C., the temperature of the first cooling roll 12 is 180 ° C., and the linear pressure when pressurizing between the heating roll 11 and the first cooling roll 12 is 35 kg / cm. . Except for these points, a sheet-like prepreg 24 was produced in the same manner as in Example 1. Evaluation was conducted in the same manner as in Example 1, and the results obtained are also shown in Table 1.
As shown in Table 1, since the linear pressure between the heating roll 11 and the first cooling roll 12 exceeded 30 kg / cm, “fiber disturbance” was poor.

(Comparative Example 6)
The temperature of the heating roll 11 is 230 ° C., the temperature of the first cooling roll 12 is 180 ° C., and the linear pressure when pressurizing between the first cooling roll 12 and the second cooling roll 13 is 5 kg / cm. Except for these points, a sheet-like prepreg 24 was produced in the same manner as in Example 1. Evaluation was conducted in the same manner as in Example 1, and the results obtained are also shown in Table 1.
As shown in Table 1, since the linear pressure between the first cooling roll 12 and the second cooling roll 13 was less than 10 kg / cm, the “smoothness of the prepreg” was poor.

(Comparative Example 7)
The temperature of the heating roll 11 is 230 ° C., the temperature of the first cooling roll 12 is 180 ° C., and the linear pressure when pressing between the first cooling roll 12 and the second cooling roll 13 is 35 kg / cm. Except for these points, a sheet-like prepreg 24 was produced in the same manner as in Example 1. Evaluation was conducted in the same manner as in Example 1, and the results obtained are also shown in Table 1.
As shown in Table 1, since the linear pressure between the first cooling roll 12 and the second cooling roll 13 was 35 kg / cm, “fiber disturbance” was poor.

DESCRIPTION OF SYMBOLS 1 ... Prepreg manufacturing apparatus, 4 ... Roll apparatus, 11 ... Heating roll, 12 ... 1st cooling roll, 13 ... 2nd cooling roll, 20 ... Reinforcement fiber bundle, 21 ... Opened reinforcement fiber bundle, 21 ... Reinforcement Fiber bundle layer, 22 ... molten thermoplastic resin, 22a ... thermoplastic resin, 23 ... sheet-like reinforcing fiber bundle, 23a ... thermoplastic resin-impregnated reinforcing fiber molding, 24 ... sheet-like prepreg

Claims (7)

A heating roll, a first cooling roll arranged to be paired with the heating roll, and a second arranged to be paired with the first cooling roll without being paired with the heating roll A manufacturing method for manufacturing a prepreg including the thermoplastic resin and the reinforcing fiber bundle by heating and further cooling the thermoplastic resin and the reinforcing fiber bundle using a cooling roll, and comprising at least the following (1): A process for producing a thermoplastic prepreg comprising the steps of (3) to (3).
(1) A reinforcing fiber bundle opened in a web shape and a thermoplastic resin are laminated to form a laminate comprising a reinforcing fiber bundle layer and a thermoplastic resin layer, and the thermoplastic resin layer of the laminate is When the thermoplastic resin is a crystalline resin having a melting point, in the temperature range of + 40 ° C. to + 90 ° C. with respect to the melting point of the thermoplastic resin, and when the thermoplastic resin is an amorphous resin having no melting point, While heating the thermoplastic resin layer while being held in contact with the heating roll heated to a temperature range of + 40 ° C. to + 90 ° C. with respect to the glass transition temperature of the thermoplastic resin, the laminate is Transporting to a position in contact with the first cooling roll;
(2) Between the 1st cooling roll which set the laminated body heated at the said process (1) to the temperature range of -60 degreeC--10 degreeC with respect to the temperature of the said heating roll and this heating roll. A step of applying a linear pressure in the range of 10 kg / cm to 30 kg / cm to obtain a thermoplastic resin-impregnated reinforcing fiber molded body.
(3) The second cooling is performed by holding the thermoplastic resin-impregnated reinforcing fiber molded body obtained in the step (2) in contact with the first cooling roll set in the temperature range. The process which conveys to the position which touches a roll, and pressurizes in the range of 10 kg / cm-30 kg / cm of linear pressure between the said 1st cooling roll and the said 2nd cooling roll, and obtains a thermoplastic prepreg.   The method for producing a thermoplastic prepreg according to claim 1, wherein, in the step (1), the viscosity of the thermoplastic resin layer is set to 1 Pa · s to 400 Pa · s by heating with the heating roll. .   In the step (3), the thermoplastic resin-impregnated reinforcing fiber molded body obtained in the step (2) is held in contact with the first cooling roll and is in contact with the second cooling roll. The viscosity of the thermoplastic resin in the thermoplastic resin-impregnated reinforcing fiber molded body is set to a value 50 Pa · s to 500 Pa · s higher than the viscosity of the thermoplastic resin after the completion of the step (1). The method for producing a thermoplastic prepreg according to claim 1 or 2.   When the temperature of the second cooling roll is a crystalline resin having a melting point of the thermoplastic resin, a temperature range of −150 ° C. to −100 ° C. with respect to the melting point of the thermoplastic resin, The amorphous resin having no melting point is set to a temperature range of -150 ° C to -100 ° C with respect to the glass transition temperature of the thermoplastic resin. A method for producing the thermoplastic prepreg according to 1.   The holding angle of the heating roll in the step (1) is set to 45 ° to 300 °, the holding angle of the first cooling roll in the step (3) is set to 45 ° to 300 °, and the second cooling is performed. The method for producing a thermoplastic prepreg according to claim 1, wherein the holding angle of the roll is 10 ° to 180 °.   6. The thermoplastic resin according to claim 1, wherein the thermoplastic resin is one or more thermoplastic resins selected from polypropylene resins, polyamide resins, polyphenylene sulfide resins, polyetherimide resins, and modified resins of these resins. The manufacturing method of the thermoplastic prepreg as described in any one of Claims.   The method for producing a thermoplastic prepreg according to any one of claims 1 to 6, wherein the reinforcing fiber bundle is a carbon fiber bundle.

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