JP2015193118A - Production method of composite molding article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of a composite molding article using an UD tape formed of a continuous fiber and thermoplastic resin, capable of preventing positional deviation of the UD tape itself and disarray of the continuous fiber in the UD tape, and capable of efficiently and easily producing a composite molding article having high design flexibility.SOLUTION: Provided is a production method of a composite molding article, in which thermoplastic resin is injected and molded in a mold cavity on which the UD tape is disposed in advance, and when the thermoplastic resin contacts the UD tape, it contacts first the top face of the UD tape.

Description

  The present invention relates to a method for producing a composite molded article using a UD tape and a thermoplastic resin using continuous fibers.

  In recent years, fiber reinforced resins reinforced with glass fibers, carbon fibers, and the like, taking advantage of their light weight and high strength, have been widely used in fields such as automobiles, aircraft, and electrical electronics. In particular, in the automobile field, it is expected to be used as a metal substitute with the aim of improving fuel efficiency by reducing vehicle weight. The biggest point in expanding the use as a metal substitute is the further increase in strength and rigidity. However, since the fiber reinforced resin for injection molding that is usually used is a short fiber in which the reinforcing fiber contained is discontinuous, the effect of improving strength and rigidity is limited.

  In order to overcome these limitations, a method has been found that improves the mechanical properties of the structure by inserting continuous fibers having higher strength and rigidity than short fibers into the molded body. Specifically, there are many methods of manufacturing a composite molded product in which a UD tape composed of unidirectional continuous fibers is preliminarily placed in a mold cavity and a thermoplastic resin is injection-molded and joined together. ing. Unidirectional continuous fibers are extremely excellent in tensile strength and elastic modulus in the fiber direction, and give excellent mechanical properties that cannot be obtained by short fiber reinforcement to composite molded articles produced by the above method. be able to.

  The UD tape is a unidirectional tape in which a continuous fiber arranged in one direction is impregnated and solidified with a thermoplastic resin and processed into a tape shape. Since a thermoplastic resin is used as the impregnating resin, the impregnating resin is melted by the heat of the injected thermoplastic resin, and then re-solidified to form a good adhesive layer. Thereby, the composite molded product excellent in the adhesiveness of an impregnation resin and a thermoplastic resin can be obtained. On the other hand, in the process of melting the impregnating resin, the fiber restraining force of the impregnating resin is reduced, so that the continuous fibers are disturbed by shearing of the flowing thermoplastic resin (the continuous fibers are not aligned in one direction). Or the UD tape itself is displaced and it is very difficult to obtain a good molded product.

  As a prior art for this problem, Patent Document 1 uses a fixing jig to sandwich one end of a UD tape, and sets it in a mold cavity having a digging shape that can be accommodated by the fixing jig. A method of manufacturing a composite molded article by injection molding a molten thermoplastic resin is disclosed.

JP 2013-252644 A

  However, according to the manufacturing method described in Patent Document 1, although disturbance of continuous fibers and positional deviation of the UD tape can be suppressed to some extent, one end of the UD tape is clamped with a fixing jig every cycle, This requires a pre-operation of setting in the housing part in the mold cavity, and the production efficiency is not good. In addition, the one end sandwiched by the fixing jig is structurally not filled with the thermoplastic resin and protrudes from the molded product. Therefore, post-processing is required to remove that portion. Similarly, production efficiency is not good.

  In addition to this, it is necessary to provide a holding part for a fixing jig as a mold structure, and it is assumed in molding of a large molded product, and it is difficult to insert a UD tape in a place far from the end of the molded product. There are many restrictions on the shape of the molded product.

  In addition, an increase in the number of parts due to the use of the fixing jig, a complicated shape of the mold due to the provision of the fixing jig accommodating portion, and a decrease in the maintainability of the mold due to these are also problems.

  In view of such problems of the prior art, the present invention is more efficient without deteriorating the maintainability of the mold by suppressing the disturbance of continuous fibers and the positional deviation of the UD tape by devising the arrangement method in the UD tape. It is another object of the present invention to provide a manufacturing method for manufacturing a composite molded product of a UD tape and a thermoplastic resin.

To achieve the above object, the present invention adopts the following configuration. That is,
(1) A method of manufacturing a composite molded product in which a thermoplastic resin is injected into a mold cavity after a UD tape having a cut surface is placed in the mold cavity, and the thermoplastic resin is brought into contact with the UD tape. And a method of manufacturing a composite molded article, wherein the thermoplastic resin is first brought into contact with the upper surface of the UD tape.
(2) When the UD tape is disposed in the mold cavity, the UD tape is disposed such that the cut surface of the UD tape is within 1 mm from the mold cavity surface. .
(3) The UD tape is disposed such that at least a part of the cut surface of the UD tape is brought into contact with the mold cavity surface in advance when the UD tape is disposed in the mold cavity. Manufacturing method of composite molded article.
(4) When the thermoplastic resin is first brought into contact with the upper surface of the UD tape, the contact position is an upper surface within 10 mm in the orientation direction of the continuous fibers constituting the UD tape from the cut surface of the UD tape. (3) The manufacturing method of the composite molded article in any one of.
(5) The method for producing a composite molded article according to any one of (1) to (4), wherein the continuous fibers constituting the UD tape are carbon fibers.

  According to the method for producing a composite molded product according to the present invention, the UD tape is devised and arranged, which causes a problem in the composite injection molding using the UD tape, and the disturbance of the continuous fibers in the UD tape and the UD tape itself. Thus, a composite molded product of the UD tape and the thermoplastic resin can be manufactured without causing the positional deviation. In addition, since there is no need to provide a special mold structure without using a fixing jig, it is possible to easily manufacture a composite molded product without impairing the maintainability of the mold. Furthermore, since there is no need for a pre-work such as clamping the UD tape in advance, or a post-processing work for removing the end of the UD tape protruding from the composite molded product, the composite molded product can be manufactured more efficiently. . In addition to these, since there is no restriction on the shape of the composite molded product, it is possible to manufacture a composite molded product with a high degree of design freedom.

It is sectional drawing which shows one embodiment of this invention. It is sectional drawing of other one Embodiment of this invention. It is sectional drawing of other one Embodiment of this invention. It is sectional drawing which shows other one embodiment of this invention. It is sectional drawing which shows other one embodiment of this invention. It is sectional drawing which shows other one embodiment of this invention. It is sectional drawing which shows other one embodiment of this invention. It is sectional drawing which shows other one embodiment of this invention. It is sectional drawing which shows the aspect at the time of implementing the comparative example 1. FIG. FIG. 2 is a perspective view of one embodiment of FIG. 1.

(UD tape)
As described above, the UD tape is a member obtained by impregnating and solidifying a continuous fiber aligned in one direction with a thermoplastic resin and processing it into a tape shape. As the reinforcing fibers used in the UD tape, various inorganic fibers or organic fibers such as carbon fibers, aramid fibers, nylon fibers, high-strength polyester fibers, glass fibers, boron fibers, alumina fibers, and silicon nitride fibers can be used. Among these, carbon fibers are preferable in that they are excellent in specific strength and specific elastic modulus.

  Moreover, a well-known thing is mentioned as a thermoplastic resin to impregnate. For example, polyethylene terephthalate resin (PET), polybutylene terephthalate resin (PBT), polytrimethylene terephthalate resin (PTT), polyethylene naphthalate resin (PEN), polyester resin such as liquid crystal polyester, polyethylene resin (PE), polypropylene resin (PP), polyolefin resins such as polybutylene, styrene resins, polyoxymethylene resins (POM), polyamide resins (PA), polycarbonate resins (PC), polymethylene methacrylate resins (PMMA), polyvinyl chloride resins ( PVC), polyphenylene sulfide resin (PPS), polyphenylene ether resin (PPE), modified PPE resin, polyimide resin (PI), polyamideimide resin (PAI), polyetherimide resin ( EI), polysulfone resin (PSU), modified PSU resin, polyethersulfone resin (PES), polyketone resin (PK), polyetherketone resin (PEK), polyetheretherketone resin (PEEK), polyetherketoneketone resin ( PEKK), polyarylate resin (PAR), polyether nitrile resin (PEN), thermoplastic phenol resin, phenoxy resin, polytetrafluoroethylene and other fluorine resins, polystyrene resin, polyolefin resin, polyurethane resin, Examples thereof include thermoplastic resins such as polyester-based resins, polyamide-based resins, polybutadiene-based resins, polyisoprene-based resins, and fluorine-based resins, copolymers thereof, modified products, and resins obtained by blending two or more types. Among these, from the viewpoint of affinity and adhesiveness, the same type of resin as the thermoplastic resin used for injection molding is preferable.

  Further, the fiber volume content (Vf:%) indicating the proportion of continuous fibers in the UD tape can be appropriately selected depending on the required characteristics of the composite molded product, but is preferably 15 to 65%, more preferably. 30 to 60%, more preferably 40 to 55%. The elastic modulus of the UD tape is preferably 40 GPa or more, more preferably 50 GPa or more, and even more preferably 60 GPa or more. If the fiber volume content is less than 15%, the reinforcing effect by the continuous fibers may not be sufficiently exhibited. On the other hand, if it exceeds 65%, the adhesive strength with a thermoplastic resin for injection molding described later may not be sufficiently exhibited.

(Thermoplastic resin)
As the thermoplastic resin to be injection-molded in the mold, the thermoplastic resin exemplified above or an alloy resin formed by combining these resins can be used, and the adhesiveness with the impregnating resin used for the UD tape can be used. These resins can be changed as appropriate in consideration.

  In addition, in order to increase the strength and rigidity of the composite molded product, those obtained by adding reinforcing fibers to these resins may be used. Carbon fiber, glass fiber, potassium titanate whisker, zinc oxide whisker, calcium carbonate whisker, wollastonite whisker, aluminum borate whisker, aramid fiber, alumina fiber, silicon carbide fiber, ceramic fiber, asbestos fiber, stone koji fiber And metal fibers.

  Furthermore, according to the required characteristic, you may contain another filler and additive in the range which does not impair the objective of this invention. For example, flame retardants, conductivity imparting agents, crystal nucleating agents, ultraviolet absorbers, antioxidants, vibration damping agents, antibacterial agents, insect repellents, deodorants, coloring inhibitors, heat stabilizers, mold release agents, antistatic agents , Plasticizers, lubricants, colorants, pigments, dyes, foaming agents, antifoaming agents, coupling agents and the like.

(Production method for composite molded products)
A method for producing a composite molded article composed of a UD tape having the above composition and a thermoplastic resin will be described in detail below.

  A first embodiment of the present invention is shown in FIG. As shown in FIG. 1, the manufacturing method of the present invention is a method for manufacturing a composite molded product in which a UD tape 1 having a cut surface 1c is arranged in a mold cavity and then a thermoplastic resin 2 is injected into the mold cavity 4. In this case, when the thermoplastic resin 2 is brought into contact with the UD tape 1, the thermoplastic resin 2 is first brought into contact with the upper surface 1a of the UD tape to obtain a composite molded product. Here, the cut surface 1c means a surface cut in a direction substantially orthogonal to the orientation direction of the continuous fibers of the UD tape 1.

  At this time, the impregnated resin of the UD tape 1 is melted by the heat of the injected thermoplastic resin 2, so that a good adhesive layer is formed between the thermoplastic resin 2 and the impregnated resin, and composite molding having excellent adhesive strength. You can get goods. However, in the process in which the injected thermoplastic resin 2 and the impregnated resin are melted and bonded, the fiber restraint force of the impregnated resin is reduced, so that depending on how the thermoplastic resin 2 contacts the UD tape 1, the UD tape 1 Phenomena such as disturbance of the fibers inside and positional deviation of the UD tape 1 itself may occur. In insert molding of the UD tape 1 using the thermoplastic resin 2 as an impregnating resin, how to suppress this phenomenon is one of the major technical problems.

  As a method of arranging the UD tape 1 in the mold cavity 4, the UD tape 1 manufactured in a desired specific width is cut into a specific length to obtain a sheet-like material having a desired size, and this is used as a metal mold. The mold cavity surface 3 is positioned by overlapping a surface along the orientation direction of the continuous fibers constituting the UD tape 1. Examples of the positioning method include adhesives such as double-sided tape, suction by negative pressure, and the like, but may be appropriately selected according to the mold design and the shape of the UD tape 1. Here, regarding the UD tape 1 to be disposed, the surface fixed to the mold cavity surface 3 is referred to as a lower surface 1b, and the opposite surface is referred to as an upper surface 1a.

  As shown in FIG. 1, when the flow path of the injected thermoplastic resin 2 is provided in a direction substantially perpendicular to the upper surface 1 a of the UD tape 1, the thermoplastic resin 2 is always in contact with the UD tape 1. Will be contacted first. Thereby, the pressure of the thermoplastic resin 2 is applied to the UD tape 1 from the opposite side of the mold cavity surface 3, and the UD tape 1 is pressed firmly against the mold cavity surface 3 to be firmly fixed. The UD tape 1 fixed in this way is joined and integrated as positioned on the mold cavity surface 3 without any fiber disturbance or positional displacement of the UD tape in the subsequent filling process of the thermoplastic resin 2. A molded product can be obtained. 1, the flow path of the thermoplastic resin 2 is provided obliquely above the upper surface 1a of the UD tape 1 as shown in FIG. 2, or a plurality of thermoplastic resins 2 as shown in FIG. 3. 4 is provided, the injected thermoplastic resin 2 is formed as in the case where the plurality of thermoplastic resin flow paths are provided obliquely above the upper surface 1a of the UD tape 1 as shown in FIG. As long as it first contacts the upper surface 1a, it can be said that all are preferred embodiments.

  Next, a second embodiment of the present invention is shown in FIG. In FIG. 5, the cavity surface 3 on which the UD tape 1 is arranged is provided at a position one level lower than the flow path of the thermoplastic resin 2. At this time, when placing the UD tape 1 in the mold cavity 4, it is preferable to place the UD tape 1 so that the cut surface 1 c of the UD tape 1 is within 1 mm from the mold cavity surface 3. Further, when the UD tape 1 is disposed in the mold cavity 4, it is more preferable to dispose the UD tape 1 so that at least a part of the cut surface 1 c of the UD tape 1 is brought into contact with the mold cavity surface 3 in advance.

  When the injected thermoplastic resin 2 has the flow direction 2 b shown in FIG. 5, the thermoplastic resin 2 changes its flow direction very close to the cut surface 1 c of the UD tape 1. Without coming into direct contact with the cut surface 1c, the upper surface 1a of the UD tape 1 comes into contact with the side close to the cut surface 1c. In such a contact mode of the thermoplastic resin 2, since the formation of the skin layer, that is, the fixation starts from the vicinity of the cut surface 1 c of the UD tape 1, fiber disturbance or UD tape due to the thermoplastic resin 2 is less likely to occur. preferable. At this time, if the mold cavity surface 3 with which the thermoplastic resin 2 contacts is at a distance within 1 mm from the cut surface 1c, such a preferred embodiment can be taken, but this distance is more preferable as it is closer, More preferably, at least a part of the cut surface 1c is in contact with the mold cavity surface 3. 5 and the case where the flow path of the thermoplastic resin 2 is provided above the cut surface 1c of the UD tape 1 as shown in FIG. 6, or the thermoplastic resin 2 as shown in FIGS. As long as the flow path is provided obliquely above the cut surface 1c of the UD tape 1, as long as the injected thermoplastic resin 2 is in contact with the cut surface 1c, it can be said that both are preferred embodiments.

  Furthermore, when the thermoplastic resin 2 is first brought into contact with the upper surface 1 a of the UD tape 1, the contact position is an upper surface within 10 mm from the cut surface 1 c of the UD tape 1 in the orientation direction of the continuous fibers constituting the UD tape 1. The aspect which performs is further preferable. According to such a method for manufacturing a composite molded product, it is not necessary to fix one end of the UD tape 1 in advance with a fixing jig or the like. Therefore, the UD tape 1 fixed by the flow of the thermoplastic resin 2 does not protrude from the obtained composite molded product, and post-processing such as removing the protruding portion is not necessary. Further, since the positioning of the UD tape 1 before injection molding can be performed by a simple method, it is not necessary to perform a prior work for sandwiching the fixing jig between the UD tape 1. According to such a method of manufacturing a composite molded product, a composite molded product can be manufactured with high production efficiency. Furthermore, it is not necessary to provide the mold with a special structure that accommodates the fixing jig, and the number of parts does not increase, so that maintainability of the mold is not impaired. Moreover, the composite molded product obtained by such a method of manufacturing a composite molded product can insert the UD tape 1 on the floating island, has a high degree of freedom in shape, and efficiently reinforces a desired part. It is possible.

  The present invention will be described more specifically with reference to the following examples. However, the following examples are not intended to limit the present invention, and modifications within the scope of the present invention may be made without departing from the spirit of the present invention. It is a range.

(Example 1)
A UD tape (carbon fiber content 40% by weight, manufactured by Toray Industries, Inc., base resin: nylon 6 resin) previously cut to a length of 100 mm is used as a gate-side mold in a film gate mold as shown in FIG. The cut surface was placed in contact with the cavity surface. A thermoplastic resin CM1011G45 (base resin: nylon 6, containing 45% by weight of glass fiber) was injection molded into the mold cavity, and a UD tape and a thermoplastic resin were joined and integrated to produce a composite molded product. This composite molded article was a molded body in which the UD tape was inserted in the desired shape and position without any disturbance of the continuous fibers in the UD tape and displacement of the UD tape itself. At this time, since no fixing jig was used and no special mold was introduced, it was possible to manufacture a composite injection molded product very efficiently.

(Comparative Example 1)
A UD tape (carbon fiber content 40% by weight, base resin: nylon 6 resin, manufactured by Toray Industries, Inc.) cut to the same length as in Example 1 was used as a gate-side mold in a film gate mold as shown in FIG. The cavity surface was placed at a position 20.0 mm from the gate. In the mold cavity, a thermoplastic resin CM1011G45 (base resin: nylon 6, containing 45% by weight of glass fiber) was injection molded, and a UD tape and a thermoplastic resin were joined to produce a composite injection molded product. A large disturbance of continuous fibers and a large displacement of the UD tape itself were observed.

DESCRIPTION OF SYMBOLS 1 UD tape 1a Upper surface 1b Lower surface 1c Cutting surface 2 Thermoplastic resin 2a Flow front 2b Flow direction 3 Mold cavity surface 4 In mold cavity

Claims (5)

A method of manufacturing a composite molded article in which a thermoplastic resin is injected into a mold cavity after a UD tape having a cut surface is placed in the mold cavity, and when the thermoplastic resin is brought into contact with the UD tape, A method for producing a composite molded article, wherein a plastic resin is first brought into contact with an upper surface of a UD tape. The method for producing a composite molded article according to claim 1, wherein when the UD tape is disposed in the mold cavity, the UD tape is disposed such that a cut surface of the UD tape is within 1 mm from the mold cavity surface. 3. The composite molded article according to claim 1, wherein when the UD tape is disposed in the mold cavity, the UD tape is disposed so that at least a part of a cut surface of the UD tape is brought into contact with the mold cavity surface in advance. Production method. Any one of claims 1 to 3, wherein when the thermoplastic resin is first brought into contact with the upper surface of the UD tape, the contact position is the upper surface within 10 mm from the cut surface of the UD tape in the orientation direction of the continuous fibers constituting the UD tape. A method for producing a composite molded product according to claim 1. The manufacturing method of the composite molded product in any one of Claims 1-4 whose continuous fiber which comprises a UD tape is carbon fiber.