JP2020142390A - Injection molding machine and method for manufacturing resin molded body using the same - Google Patents

Abstract

To provide an injection molding machine capable of manufacturing a resin molded body which includes a reinforcing fiber with a long fiber length, and in which a base resin and reinforcing fiber are firmly adhered to each other, and in addition, which has high strength and high rigidity, and also has excellent wear resistance and fatigue resistance, and a method for manufacturing a resin molded body using the injection molding machine.SOLUTION: An injection molding machine 1 includes: a resin supply unit 5 which is disposed at a proximal end side of a cylinder 3, and is supplied with a base resin 2; a fiber supply unit 15 which is disposed at a downstream side of the resin supply unit, and is continuously supplied with a roving 14; and additive supply units 15, 18 and 19 which are disposed on the downstream side and upstream of the fiber supply unit or at the same position, and supplied with a compatibilizer and/or a reactive compound, as an additive 20. The method for producing the resin molded body 7 comprises the steps of: supplying an additive and roving into the base resin 1 plasticized in the cylinder 3 of the injection molding machine 1 to prepare a fiber reinforced resin 16; and filling a metallic mold 8 with the prepared fiber reinforced resin.SELECTED DRAWING: Figure 1

Description

The present invention relates to an injection molding machine used for producing a resin molded product made of a fiber reinforced resin, and a method for producing a resin molded product using the injection molding machine.

As structural parts of automobiles, resin molded bodies are often used for the purpose of reducing the weight of automobiles and improving quietness. In particular, parts that require strength and rigidity are generally formed of a resin molded body made of a fiber-reinforced resin containing reinforcing fibers such as glass fiber, carbon fiber, and aramid fiber in the base resin. .. Examples of these parts include gears, roller parts, bearing cages, housings for electric power steering devices, housings for electric oil pumps, and the like.

As the fiber reinforced resin, for example, it is common to use a short fiber compound in which short fiber-like reinforcing fibers are mixed with a base resin and kneaded under high temperature and high pressure using a kneading disc of a twin-screw kneader or the like. Is.
However, in recent years, with the demand for smaller size and higher output of automobile equipment, the above-mentioned various parts also have higher strength, higher rigidity, and improved wear resistance and fatigue resistance. Etc. are being sought.

In the case of a resin molded body made of a fiber-reinforced resin, it is known that it is effective to increase the fiber length of the reinforcing fibers contained in the resin molded body in order to meet these demands. Therefore, various methods for producing the resin molded product have been studied in order to increase the fiber length of the reinforcing fibers contained in the resin molded product.
For example, in Patent Document 1, a fiber-reinforced resin prepared by continuously supplying a long roving to a base resin being conveyed in a cylinder of an injection molding machine while maintaining a long length is nozzleed at the tip of the cylinder. The resin molded body is manufactured by filling the inner space of the mold connected via the above.

Specifically, first, the base resin is supplied into the cylinder from the resin supply unit provided on the base end side of the cylinder. Then, the supplied base resin is heated and plasticized in the cylinder while being transported in the transport direction toward the tip portion as the screw rotatably inserted into the cylinder rotates.
At the same time, a long roving is continuously supplied into the cylinder from a fiber supply unit provided in the middle of the cylinder. Then, the supplied roving is continuously drawn into the cylinder as the base resin is conveyed by the rotation of the screw, and is continuously kneaded with the base resin, whereby the fiber reinforced resin is prepared.

The prepared fiber-reinforced resin is filled in the mold inner space of the mold connected to the tip of the cylinder via a nozzle to manufacture a resin molded product.
According to the above manufacturing method, although it is cut and shortened by kneading during injection molding, the fiber length of the reinforcing fibers contained in the resin molded body can be lengthened as compared with the case where the short fiber compound is used. it can.

Japanese Unexamined Patent Publication No. 2014-166712

However, according to the study of the inventor, the manufacturing method described in Patent Document 1 [Direct Fiber Feeding Injection Molding (DFIM), hereinafter referred to as “direct roving method” may be described. ], The effect of increasing the fiber length of the reinforcing fiber may not be sufficiently obtained.
That is, despite the fact that the fiber length of the reinforcing fiber is increased, the resin molded body is sufficiently strengthened and made highly rigid, and has abrasion resistance and fatigue resistance, etc., as compared with the one made of a short fiber compound. May not be fully improved.

When preparing a conventional short fiber compound, as described above, the base resin and the short fiber-like reinforcing fibers are sufficiently kneaded under high temperature and high pressure using a kneading disc of a twin-screw kneader or the like. .. Also during injection molding, the short fiber compound is kneaded and heated over the entire length of the cylinder of the injection molding machine. In other words, the short fiber compound is provided with sufficient shearing force and calorific value from preparation to molding.

Therefore, the base resin and the short fiber reinforcing fibers can be firmly adhered to each other by the shearing force and the amount of heat.
On the other hand, in the manufacturing method described in Patent Document 1, a resin molded body is manufactured by filling the mold in a short time after supplying roving from the middle of the cylinder of the injection molding machine, and therefore during kneading. There is a tendency for the shear force and the amount of heat to be insufficient.

Therefore, the base resin and the reinforcing fiber cannot be firmly adhered to each other, and as a result, the resin molded body is sufficiently strengthened and made highly rigid despite the lengthening of the reinforcing fiber. In some cases, it may not be possible to sufficiently improve wear resistance and fatigue resistance.
An object of the present invention is that the base resin and the reinforcing fiber are firmly adhered to each other in addition to containing the reinforcing fiber having a long fiber length, and the strength and rigidity are higher than those of the present state, and the abrasion resistance and fatigue resistance are also obtained. It is an object of the present invention to provide an injection molding machine capable of producing an excellent resin molded product, and a method for producing a resin molded product using the injection molding machine.

The present invention includes a cylinder (3) that plasticizes the base resin (2) while being conveyed in one direction, and the cylinder has a resin supply unit (5) to which the base resin is supplied to the base end side. A fiber supply in which a long roving (14) in which reinforcing fibers (22) are focused by a sizing agent (23) is continuously supplied from the resin supply unit to the downstream side in the transport direction (F) of the base resin. Section (15), on the downstream side of the resin supply section in the transport direction, on the upstream side of the fiber supply section, or at the same position as the fiber supply section.
A compatibilizer that compatibles the base resin with the sizing agent, and a reactive compound having a functional group that can chemically bond with the surface of the base resin and the reinforcing fiber.
An injection molding machine (1) including an additive supply unit (15), (18), and (19) to which at least one additive (20) selected from the group consisting of is supplied (claim 1).

According to the above configuration, in the base resin supplied from the resin supply unit and transported in one direction in the cylinder, a long roving is performed from the fiber supply unit provided on the downstream side in the transport direction of the base resin. , The fiber-reinforced resin is prepared by being continuously supplied as it is long.
Therefore, the fiber length of the reinforcing fibers contained in the resin molded body formed by using the prepared fiber-reinforced resin can be lengthened.

Moreover, according to the above configuration, the compatibilizer and / or the reactivity are supplied as an additive from the additive supply unit provided on the downstream side of the resin supply unit and on the upstream side or the same position as the fiber supply unit. Due to the function of the compound, even if the shearing force and the amount of heat at the time of kneading are insufficient, the base resin and the reinforcing fiber can be adhered more firmly.
For example, the compatibilizer can make the base resin compatible with the sizing agent that bundles the reinforcing fibers in the roving, so that the roving can be defibrated in the base resin by the individual reinforcing fibers. It functions to disperse well in the base resin.

However, when the compatibilizer is supplied from the resin supply unit at the same time as the base resin into the cylinder in a state of being compounded or pelletized with the base resin, for example, before the roving is supplied from the fiber supply unit, As the plasticization of the base resin progresses, it may be widely and thinly diluted in the base resin. Then, in that case, the function of roving by the compatibilizer to defibrate the individual reinforcing fibers satisfactorily and uniformly disperse the roving in the base resin may not be sufficiently obtained.

On the other hand, when the compatibilizer is supplied from the additive supply unit provided at the predetermined position immediately before or at the same time as the roving is supplied from the fiber supply unit, the compatibilizer is concentrated at a higher concentration. In this state, the base resin and roving can be brought into contact with each other, so that the functions of the compatibilizer described above can be satisfactorily exhibited. That is, due to the function of the compatibilizer, the roving supplied from the fiber supply unit can be satisfactorily defibrated by the individual reinforcing fibers and uniformly dispersed in the base resin.

Therefore, even if the shearing force and the amount of heat during the subsequent kneading are insufficient, the base resin and the reinforcing fibers can be firmly adhered to each other by the short kneading. In addition to containing reinforcing fibers with a long fiber length, the base resin and the reinforcing fibers are firmly adhered to each other, and the strength and rigidity are higher than the current state, and the wear resistance and fatigue resistance are also excellent. It is possible to manufacture a resin molded product.

Further, the reactive compound functions to chemically bond with the surface of the base resin and the reinforcing fibers to firmly adhere the reinforcing fibers dispersed in the base resin and the base resin.
However, when the reactive compound is supplied from the resin supply unit at the same time as the base resin, for example, in a compounded or pelletized state together with the base resin, in the cylinder before the reinforcing fibers are supplied, the base resin is supplied. It may react with chisel to increase the molecular weight of the base resin and increase its melt viscosity. Then, in that case, it may not be possible to defibrate the rovings well in the individual reinforcing fibers and uniformly disperse them in the base resin.

On the other hand, when the reactive compound is supplied from the additive supply unit provided at the predetermined position immediately before or at the same time as the roving is supplied from the fiber supply unit, the base resin by the reaction with the reactive compound. It is possible to suppress an increase in the melt viscosity of. Then, the base resin is maintained in a low viscosity state, and the roving supplied from the fiber supply unit is defibrated well by each reinforcing fiber and uniformly dispersed in the base resin, and is reactive. Due to the function of the compound, the defibrated reinforcing fiber and the base resin can be satisfactorily reacted and firmly adhered to each other.

Further, in a state where the reinforcing fibers are sufficiently dispersed, the base resins can be reacted with each other via a reactive compound or directly to increase the molecular weight.
Therefore, in addition to containing reinforcing fibers with a long fiber length, the base resin and the reinforcing fibers are firmly adhered to each other, and the strength and rigidity are higher than the current state, and the wear resistance and fatigue resistance are also improved. An excellent resin molded product can be produced.

It is preferable that the fiber supply unit (15) also serves as the additive supply unit (claim 2).
According to this configuration, the number of openings of each supply portion provided in the cylinder can be reduced, and it is possible to prevent the base resin during transportation in the cylinder from leaking to the outside, that is, so-called vent-up.

It is preferable that the additive supply units (15), (18) and (19) include a cooling unit (21) that supplies the additive (20) into the cylinder (3) while cooling the additive (20) (claim). 3).
According to this configuration, when a compatibilizer or a reactive compound having a normally low melting point is supplied into a cylinder from an additive supply unit, it is prevented from agglomerating or welding due to heat in the cylinder. It can be suppressed and supplied quantitatively and stably into the cylinder.

As the compatibilizer, a polymer containing a block having a structure similar to that of the base resin (2) and a block having a structure similar to that of the sizing agent (23) in the molecule is preferable (claim 4, claim 4. 7).
When the base resin (2) is a polyamide resin and the reinforcing fibers (22) are reinforcing fibers having an amino group introduced on the surface, the reactive compound includes an amino group at the end of the polyamide resin. And a polymer having a functional group that reacts with an amino group on the surface of the reinforcing fiber is preferable (claims 5 and 8).

The present invention is a method for producing a resin molded body (7) made of a fiber-reinforced resin (16) containing a base resin (2) and a reinforcing fiber (22), according to the injection molding machine (1) of the present invention. The base resin is supplied from the resin supply unit (5) into the cylinder (3), and the supplied base resin is plasticized while being transported in the transport direction (F) in the cylinder. , The at least one additive (20) selected from the group consisting of the compatibilizer and the reactive compound, from the additive supply unit (15) (18) (19) (21). The long roving (14), which is supplied into the base resin in the cylinder, is continuously supplied from the fiber supply unit (15) into the base resin in the cylinder as long as it is. The step of preparing the fiber-reinforced resin and the prepared fiber-reinforced resin are filled in the mold inner space of the mold (8) connected to the downstream side in the transport direction of the cylinder to mold the resin. A method for producing a resin molded product, which comprises a step of molding the body (claim 6).

According to this configuration, based on the effect of using the injection molding machine described above, the reinforcing fibers having a long fiber length are included, and the base resin and the reinforcing fibers are firmly adhered to each other, resulting in higher strength than the current state. It is possible to produce a resin molded product having high rigidity and excellent wear resistance and fatigue resistance.
In this section, the numbers in parentheses and the like represent the reference codes of the corresponding components in the embodiments described later, but these reference codes do not mean to limit the scope of claims.

It is sectional drawing explaining the outline of an example of Embodiment of the injection molding machine of this invention. FIGS. (A) to (c) are cross-sectional views illustrating the mechanism of defibration and dispersion of reinforcing fibers from roving in the base resin. It is a graph which shows the result of having measured the tensile strength of the resin molded article produced in the Example and the comparative example of this invention.

<Injection molding machine>
FIG. 1 is a cross-sectional view illustrating an outline of an example of an embodiment of the injection molding machine 1 of the present invention.
With reference to FIG. 1, the injection molding machine 1 includes a cylinder 3 that heats and plasticizes the base resin 2 while transporting it in the transport direction F indicated by the white arrow in the figure. The cylinder 3 is formed in a tubular shape.

A hopper 4 for accommodating the pellet-shaped base resin 2 is connected to the vicinity of the base end of the cylinder 3 on the upstream side (right side in the drawing) of the transport direction F via a resin supply device 5. .. The resin supply device 5 is an example of a resin supply unit that supplies the base resin 2 housed in the hopper 4 to the cylinder 3 in a preset supply amount, for example.
A nozzle 6 is connected to the tip of the cylinder 3 on the downstream side (left side in the drawing) of the transport direction F, and a mold 8 corresponding to the shape of the resin molded body 7 to be manufactured is connected via the nozzle 6. ing. As shown in the figure, the nozzle 6 is connected to the sprue of the mold 8 at least during injection molding.

On the outer circumference of the cylinder 3, a plurality of tubular heaters 9 for heating and plasticizing the base resin 2 conveyed in the cylinder 3 are provided along the conveying direction F of the base resin 2, and the outer circumference of the cylinder 3 is provided. It is provided so as to surround. For example, the temperature of the plurality of heaters 9 may be adjusted collectively or individually.
Inside the cylinder 3, a screw 10 for transporting the base resin 2 in the transport direction F while kneading the base resin 2 in the cylinder 3 is provided. The screw 10 includes a rotating shaft 11 over substantially the entire length of the cylinder 3 and a spiral flight 12 projecting outward from the outer peripheral surface of the rotating shaft 11. The rotation shaft 11 and the flight 12 are integrally formed, for example.

The screw 10 is rotatably inserted into the cylinder 3 with the central axis of the rotating shaft 11 aligned with the axis X of the cylinder 3.
The rotating shaft 11 has a diameter smaller than that of the inner peripheral surface of the cylinder 3 over substantially the entire length of the base resin 2 in the transport direction F.
The outer edge of the flight 12 in the radial direction has a shape projected onto a plane orthogonal to the axis X as a circle centered on the axis X, and the circle of the flight 12 is arranged concentrically with the rotation axis 11. ..

The circular outer diameter of the flight 12 is slightly smaller than the inner diameter of the inner peripheral surface of the cylinder 3. Therefore, in the arrangement state of the figure in which the central axis of the rotating shaft 11 is aligned with the axis X of the cylinder 3, the radial outer edge of the flight 12 extends over the inner peripheral surface of the cylinder 3 and the entire circumference thereof. , They are facing each other with a predetermined clearance.
Further, on the outer circumference of the screw 10, a spiral groove 13 for accommodating and transporting the base resin 2 between the outer peripheral surface of the rotating shaft 11 and the flight 12 and the inner peripheral surface of the cylinder 3 is provided. It is configured.

The base resin 2 is supplied from the hopper 4 into the recess 13 via the resin supply device 5.
The screw 10 is rotated in one direction by a rotation mechanism (not shown) as shown by a solid arrow in the figure. Then, the base resin 2 supplied from the hopper 4 into the concave groove 13 is conveyed in the transfer direction F indicated by the white arrow while being kneaded by receiving a shearing force from the flight 12 as the screw 10 rotates. At the same time, it is heated by the heat from the heater 9 and gradually plasticized.

A fiber supply port 15 as a fiber supply unit for continuously supplying a long roving 14 into the cylinder 3 is provided in the middle of the cylinder 3 in the transport direction F of the base resin 2 by connecting the inside and the outside. Has been done.
The roving 14 continuously supplied through the fiber supply port 15 into the base resin 2 being conveyed in the cylinder 3 receives a shearing force from the flight 12 as the screw 10 rotates, and is kneaded with the base resin 2. Will be done. As a result, the fiber-reinforced resin 16 that is the basis of the resin molded body 7 is prepared in the cylinder 3 from the fiber supply port 15 to the nozzle 6.

Further, in the fiber supply port 15, a hopper 17 containing a compatibilizer and / or a reactive compound as an additive 20 provides an additive supply device 18 and an additive supply pipe (pipe, hose, tube, etc.) 19 Connected via.
The additive supply device 18 supplies the additive 20 housed in the hopper 17 through the additive supply pipe 19 as shown by the arrow of the alternate long and short dash line in the drawing, for example, in a preset supply amount. It is supplied to the cylinder 3 from the port 15.

The additive supply pipe 19 includes a cooling jacket 21, and the cooling jacket 21 cools the additive supply pipe 19 to, for example, below the melting point of a compatibilizer or a reactive compound as an additive. As a result, the compatibilizer and the reactive compound can be suppressed from being aggregated or welded by the heat in the cylinder 3 and can be quantitatively and stably supplied into the cylinder 3.

The additive supply device 18, the additive supply pipe 19, and the cooling jacket 21 are examples of the additive supply unit together with the fiber supply port 15. The cooling jacket 21 is an example of a cooling unit.
The fiber supply port 15, which is a fiber supply unit, also serves as an additive supply unit. The fiber supply port 15 also functions as a vent port for removing gas, moisture, and the like generated when the base resin 2 is heated and plasticized.

However, it is important that the base resin 2 during transportation does not leak from the fiber supply port 15 in the cylinder 3, so-called vent-up does not occur. Therefore, in the example of FIG. 1, the fiber supply port 15 is used not only as a fiber supply unit but also as an additive supply unit, and the number of openings of each supply unit provided in the cylinder 3 is set to one to vent. It suppresses the occurrence of ups.

Further, in order to suppress the occurrence of vent-up, for example, any one or more of the following means may be used in combination.
The transport speed of the base resin 2 is faster on the downstream side of the fiber supply port 15 than on the upstream side, and / or the transport amount of the base resin 2 is higher on the downstream side of the fiber supply port 15 than on the upstream side. The outer diameter of the rotating shaft 11 of the screw 10 and the pitch of the flight 12 are set.
-The heating temperature of the heater 9 is set to a different temperature on the upstream side and the downstream side of the fiber supply port 15.
-The amount of the base resin 2 supplied from the hopper 4 is adjusted by the resin supply device 5.
-In addition, a conventionally known method of suppressing the occurrence of vent-up will be adopted.

Further, in the present invention, it is also important that the reinforcing fibers in the roving 14 supplied from the fiber supply port 15 are contained in the resin molded body 7 while maintaining the state of long fibers as much as possible. For that purpose, for example, it is preferable to adopt any one or more of the following means.
-Adjust the clearance between the inner peripheral surface of the cylinder 3 and the radial outer edge of the flight 12.
-Increase the nozzle diameter of the nozzle 6 and the runner diameter of the mold 8 more than usual.
-In addition, a conventionally known method of lengthening the fiber length of the reinforcing fibers contained in the resin molded body 7 is adopted.

By adopting these means, the step of preparing the fiber reinforced resin 16 and the step of molding the resin molded body 7 are continuously carried out by using the injection molding machine 1 of FIG. The fiber length of the reinforcing fibers contained in the molded body 7 can be increased to, for example, about 1 mm or more.
In the example of FIG. 1, the mold 8 includes an outer mold (cavity) 8a corresponding to the external shape of the resin molded body 7 and an inner mold (core) 8b corresponding to the internal shape of the resin molded body 7. However, the shape and structure of the mold 8 can be arbitrarily set according to the shape of the resin molded body 7 to be manufactured.

The fiber reinforced resin 16 plasticized in the cylinder 3 is injected and filled in the in-mold space between the cavity 8a and the core 8b of the mold 8 through the nozzle 6. Then, the resin molded body 7 corresponding to the shape of the space inside the mold is molded.
<Manufacturing method of resin molded product>
In order to manufacture the resin molded body 7 by the manufacturing method of the present invention using the injection molding machine 1 and the mold 8, the base resin 2 is first supplied to the hopper 4. In addition, a long continuous roving 14 is prepared. Further, the hopper 17 is supplied with a compatibilizer and / or a reactive compound as an additive 20.

As the base resin 2, various resins that can form the fiber-reinforced resin 16 that is the forming material of the resin molded body 7 can be used. In particular, examples of the base resin 2 for forming the resin molded body 7 that is required to have the above-mentioned strength, rigidity, abrasion resistance, etc. include polyamide (PA) and polyphenylene sulfide (PPS).
Specific examples of the polyamide include aliphatic polyamides such as PA6, PA66, PA46, PA12, PA612, PA610, PA11 and PA410, aromatic polyamides such as PA6T, PA9T, PA10T and PAMXD6. The base resin 2 may be supplied in the form of pellets or the like as in the conventional case.

Examples of the reinforcing fibers constituting the roving 14 include glass fibers, carbon fibers, and aramid fibers. The roving 14 is produced by bundling a large number of reinforcing fibers with a sizing agent as in the conventional case.
That is, the roving 14 is produced, for example, by applying a liquid sizing agent to the reinforcing fibers using a coating roller or the like, drying the fibers at a high temperature, and further aligning and winding a predetermined number of strands. be able to.

Examples of the sizing agent include urethane-based resin, acrylic-based resin, epoxy-based resin, and polyether-based resin.
Further, the reinforcing fibers are preferably used for producing the roving 14 in a state of being treated with a coupling agent in advance in order to firmly adhere the sizing agent. Examples of the coupling agent include a silane coupling agent, a titanate coupling agent and the like. Further, examples of the silane coupling agent include an aminosilane coupling agent and a ureidosilane coupling agent.

Examples of the compatibilizer among the additives 20 include polymers containing a block having a structure similar to that of the base resin and a block having a structure similar to that of the sizing agent in the molecule. For example, when the base resin is a polyamide resin and the sizing agent is any one of the above resins, the compatibilizer includes a block having a structure similar to that of the polyamide resin in the molecule and similar to any of the sizing agents. A block copolyamide or the like including a block having the above-mentioned structure is used.

Further, as the block copolymer, it is preferable to use one having a high proportion of blocks having a structure similar to that of the polyamide resin. A block copolymer having a higher proportion of blocks having a structure similar to that of a polyamide resin can improve the strength of the resin molded product and the like, as is clear from the results of Examples described later.
Examples of the reactive compound include a base resin and various reactive compounds having a functional group capable of chemically bonding to the surface of the reinforcing fiber.

For example, when the base resin is a polyamide resin and the reinforcing fiber is a reinforcing fiber in which an amino group (-NH ₂ ) is introduced on the surface by treating with an aminosilane coupling agent or the like, the reactive compound is a polyamide resin. A polymer having a functional group that reacts with the amino group at the end of the fiber and the amino group introduced into the surface of the reinforcing fiber is preferable.
Examples of the functional group include a carboxyl group (-COOH) and the like. Further, examples of the polymer that is the source of the reactive compound include a polymer having good compatibility with the base resin.

For example, when the base resin is a polyamide resin, the reactive compound has a main chain of polyolefin having good compatibility with the polyamide resin, and has a carboxyl group in the side chain or a segment containing the carboxyl group, such as maleic anhydride. So-called acid-modified polyolefins or the like into which a polyvalent carboxylic acid segment, a maleic anhydride segment such as maleic anhydride, etc. are introduced are used.

Further, as the acid-modified polyolefin, it is preferable to use one in which the above-mentioned carboxyl group is masked (blocked) to suppress the reactivity. When the acid-modified polyolefin is used, as is clear from the results of Examples described later, the strength of the resin molded product can be improved as compared with the acid-modified polyolefin in which the carboxyl group is not masked (blocked). ..

Next, in the manufacturing method of the present invention, the resin supply device 5 is operated while controlling the temperature of each of the plurality of heaters 9, for example, and the base resin 2 housed in the hopper 4 is supplied in a preset amount. Therefore, the supply to the cylinder 3 is started. Then, as described above, the supplied base resin 2 is conveyed in the transfer direction F indicated by the white arrow while being kneaded by receiving a shearing force from the flight 12 as the screw 10 rotates, and the heater. It is heated by the heat from 9 and gradually plasticized.

In this state, the additive supply device 18 is operated to supply the additives contained in the hopper 17 to the additive supply pipe 19 cooled by the cooling jacket 21 and the fiber supply port with a preset supply amount. Through 15, the inside of the cylinder 3 is supplied into the base resin 2 during transportation.
Further, the roving 14 is continuously supplied into the base resin 2 which is being conveyed in the cylinder 3 through the same fiber supply port 15.

2 (a) to 2 (c) are cross-sectional views illustrating the outline of the mechanism of defibration and dispersion of the reinforcing fibers 22 from the roving 14 in the base resin 2.
With reference to FIG. 2A, the roving 14 is produced by bundling a large number of reinforcing fibers 22 with a sizing agent 23 as described above.
With reference to FIGS. 1 and 2 (a) and 2 (b), the roving 14 supplied into the base resin 2 being conveyed in the cylinder 3 receives a shearing force from the flight 12 as the screw 10 rotates. The sizing agent 23 is gradually compatible with the surrounding base resin 2 and is defibrated into individual reinforcing fibers 22.

Then, referring to FIGS. 1 and 2 (c), the defibrated reinforcing fibers 22 are further kneaded with the base resin 2 while being further conveyed in the cylinder 3, so that the defibrated reinforcing fibers 22 are further kneaded into the base resin 2. The fiber-reinforced resin 16 that is uniformly dispersed and is the basis of the resin molded body 7 is prepared.
When the additive 20 supplied into the base resin 2 together with the roving 14 is a compatibilizer, the compatibilizer is an individual reinforcing fiber as shown in FIG. 2 (b) by the roving 14 in FIG. 2 (a). It functions to assist in being crushed into 22. Then, the roving 14 can be defibrated well by the individual reinforcing fibers 22 and uniformly dispersed in the base resin 2 as shown in FIG. 2 (c).

Therefore, even if the shearing force and the amount of heat during the subsequent kneading are insufficient, the base resin 2 and the reinforcing fibers 22 can be firmly adhered to each other by the short kneading. In addition to containing the reinforcing fiber 22 having a long fiber length, the base resin 2 and the reinforcing fiber 22 are firmly adhered to each other, and have higher strength and rigidity than the current state, and also have abrasion resistance and fatigue resistance. It is also possible to produce an excellent resin molded body 7.

Further, when the additive 20 supplied into the base resin 2 together with the roving 14 is a reactive compound, the reactive compound is substantially the same as the roving 14 being supplied from the fiber supply port 15 also serving as the additive supply unit. Since it is supplied at the same time, it is unlikely that the melt viscosity will increase due to the increase in the molecular weight of the base resin.
Then, the supplied reactive compound is well chemically bonded to the surface of each defibrated reinforcing fiber 22 and the base resin 2 as shown in FIG. 2 (b), and dispersed in the base resin 2. It functions to firmly adhere the reinforcing fiber and the base resin.

Therefore, even if the shearing force and the amount of heat during the subsequent kneading are insufficient, the base resin 2 and the reinforcing fibers 22 can be firmly adhered to each other by the short kneading. In addition to containing the reinforcing fiber 22 having a long fiber length, the base resin 2 and the reinforcing fiber 22 are firmly adhered to each other, and have higher strength and rigidity than the current state, and also have abrasion resistance and fatigue resistance. It is also possible to produce an excellent resin molded body 7.

As shown in FIGS. 2A and 2B, a small amount of the sizing agent 23 may remain on the surface of the reinforcing fiber 22. The remaining sizing agent 23, depending on the combination with the base resin 2, enhances the dispersibility of the reinforcing fibers 22 in the base resin 2 together with the compatibilizer, and the base resin 2 and the reinforcing fibers together with the reactive compound. It functions to improve the adhesion with 22.
With reference to FIG. 1, the prepared fiber reinforced resin 16 is injected and filled in the in-mold space between the cavity 8a and the core 8b of the mold 8 through the nozzle 6 as described above. Then, the resin molded body 7 corresponding to the shape of the space inside the mold is molded.

After that, the resin molded product 7 taken out from the mold 8 can be heated in a non-oxidizing atmosphere or annealed in the air, if necessary. Examples of the non-oxidizing atmosphere include a reduced pressure atmosphere, an inert gas atmosphere, a reduced pressure atmosphere + an inert gas atmosphere, and the like.
The polyamide resin is made into a high molecular weight by the reaction of the carboxyl group (-COOH) remaining at the terminal and the amino group (-NH ₂ ) by heating the produced resin molded product 7 in a non-oxidizing atmosphere. Further, the above heating causes the carboxyl group and the amino group to react with the reinforcing fiber to further firmly adhere to the reinforcing fiber.

However, in the present invention, as described above, by supplying the compatibilizer and / or the reactive compound from the fiber supply port 15, the adhesion between the base resin 2 and the reinforcing fiber 22 can be enhanced. Further, in particular, when the reactive compound is supplied as the additive 20, the polyamides can be bonded to each other via the reactive compound or directly to increase the molecular weight. Therefore, the heating step can be omitted (excluded), the heating time can be shortened, and the productivity of the resin molded product 7 can be improved.

The configuration of the present invention is not limited to the examples of the drawings described above. For example, the additive supply unit is located on the cylinder 3 in the transport direction F of the base resin 2 on the downstream side of the resin supply device (resin supply unit) 5 and on the upstream side of the fiber supply port (fiber supply unit) 15. , May be formed separately from the fiber supply port 15.
In addition, various design changes can be made within the scope of the matters described in the claims.

Hereinafter, the present invention will be further described based on Examples and Comparative Examples, but the configuration of the present invention is not limited to these Examples and Comparative Examples.
<Example 1>
Using the injection molding machine 1 of FIG. 1, the ISO multipurpose test piece A type (thickness: 4 mm, width of narrow portion: 10 mm) specified in the International Organization for Standardization standard ISO3167 was manufactured as a resin molded body 7.

That is, the compatibilizer (I) as the additive 20 is supplied from the fiber supply port 15 provided in the cylinder 3 of the injection molding machine 1 into the base resin 2 during transportation in the cylinder 3, and is long. The fiber-reinforced resin 16 was prepared by continuously supplying the roving 14 as it was long. Then, the prepared fiber-reinforced resin 16 was filled into the inner space of the mold 8 connected to the tip of the cylinder 3 via the nozzle 6 to form the resin molded body 7.

As the base resin 2, non-reinforced PA66 [Leona (registered trademark) 1402S manufactured by Asahi Kasei Corporation] is used, and as the roving 14, glass fiber whose surface is treated with an aminosilane coupling agent is used as a sizing agent. Robbing focused with an ether resin was used. The ratio of the glass fiber was 30% by mass of the total amount of the glass fiber and the base resin.
The compatibilizer (I) is a block copolyma containing a block having a structure similar to that of a polyamide resin and a block having a structure similar to that of a polyether resin, which is a roving sizing agent, in the molecule.

<Example 2>
The resin molded product 7 was molded in the same manner as in Example 1 except that the compatibilizer (II) was used instead of the compatibilizer (I).
Similar to the compatibilizer (I), the compatibilizer (II) includes a block having a structure similar to that of the polyamide resin and a block having a structure similar to that of the polyether resin, and the compatibilizer (I). ), The block copolyma has a higher proportion of blocks having a structure similar to that of the polyamide resin.

<Example 3>
The resin molded product 7 was molded in the same manner as in Example 1 except that the reactive compound (i) was used instead of the compatibilizer (I).
The reactive compound (i) has a polyolefin as the main chain, and an carboxylic acid anhydride segment is introduced into the side chain thereof, and the carboxyl group of the carboxylic acid anhydride segment is masked (blocked) to suppress the reactivity. It is a polyolefin.

<Example 4>
The resin molded product 7 was molded in the same manner as in Example 1 except that the reactive compound (ii) was used instead of the compatibilizer (I).
Like the reactive compound (i), the reactive compound (ii) has a polyolefin as a main chain, an carboxylic acid anhydride segment is introduced into the side chain thereof, and the carboxyl group of the carboxylic acid anhydride segment is masked ( It is an acid-modified polyolefin that is not blocking).

<Comparative example 1>
The resin molded body 7 was molded in the same manner as in Example 1 except that the compatibilizer (I) was not supplied into the base resin 2 during transportation in the cylinder 3.
<Tensile strength measurement>
The tensile strength of the resin molded product (ISO multipurpose test piece A type) produced in each Example and Comparative Example was measured according to the measuring method described in the International Organization for Standardization standard ISO527.

As a result, as shown in FIG. 3, according to Examples 1 to 4, it was found that the tensile strength of the resin molded product could be improved as compared with Comparative Example 1.
Further, from the results of Examples 1 and 2, it is necessary to use a block copolymer as a compatibilizer having a high proportion of blocks having a structure similar to that of the polyamide resin in order to improve the tensile strength of the resin molded product. It turned out to be particularly preferable.

Further, from the results of Examples 3 and 4, it is particularly preferable to use an acid-modified polyolefin having a carboxyl group masked (blocking) as the reactive compound in order to improve the tensile strength of the resin molded product. It turned out.

1: Injection molding machine 2: Base resin 3: Cylinder 5: Resin supply device (resin supply unit), 7: Resin molded body, 8: Mold, 14: Robbing, 15: Fiber supply port (fiber supply unit) , Additive supply part), 16: Fiber reinforced plastic, 18: Additive supply device (additive supply part), 19: Additive supply pipe (additive supply part), 20: Additive, 21: Cooling jacket (addition) Agent supply unit, cooling unit), 22: Reinforcing fiber, 23: Focusing agent, F: Transport direction

Claims (8)

Includes a cylinder that plasticizes the base resin while transporting it in one direction.
The cylinder
A resin supply unit to which the base resin is supplied to the base end side,
A fiber supply unit in which a long roving in which reinforcing fibers are bundled with a sizing agent is continuously supplied from the resin supply unit to the downstream side in the transport direction of the base resin.
Downstream of the resin supply section in the transport direction, upstream of the fiber supply section, or at the same position as the fiber supply section.
A compatibilizer that compatibles the base resin with the sizing agent, and a reactive compound having a functional group that can chemically bond with the surface of the base resin and the reinforcing fiber.
Additive supply unit, to which at least one additive selected from the group consisting of
Injection molding machine including. The injection molding machine according to claim 1, wherein the fiber supply unit also serves as the additive supply unit. The injection molding machine according to claim 1 or 2, wherein the additive supply unit includes a cooling unit that supplies the additive into the cylinder while cooling the additive. The aspect of any one of claims 1 to 3, wherein the compatibilizer is a polymer containing a block having a structure similar to that of the base resin and a block having a structure similar to that of the sizing agent in the molecule. Injection molding machine. The base resin is a polyamide resin, the reinforcing fiber is a reinforcing fiber having an amino group introduced on the surface, and the reactive compound is an amino group at the end of the polyamide resin and an amino group on the surface of the reinforcing fiber. The injection molding machine according to any one of claims 1 to 4, which is a polymer having a functional group that reacts. A method for manufacturing a resin molded product made of a fiber-reinforced resin containing a base resin and a reinforcing fiber.
The base resin is supplied from the resin supply unit into the cylinder of the injection molding machine according to any one of claims 1 to 5, and the supplied base resin is conveyed in the cylinder. While being transported in the direction, it is plasticized, and at least one of the additives selected from the group consisting of the compatibilizer and the reactive compound is transferred from the additive supply unit to the base resin in the cylinder. A step of preparing the fiber-reinforced resin by continuously supplying the long roving from the fiber supply unit into the base resin in the cylinder as it is long. The step of filling the inner space of the mold connected to the downstream side of the cylinder in the transport direction with the fiber-reinforced resin to form the resin molded product.
A method for producing a resin molded product containing. The method for producing a resin molded product according to claim 6, wherein the compatibilizer is a polymer containing a block having a structure similar to the base resin and a block having a structure similar to the sizing agent in the molecule. .. The base resin is a polyamide resin, the reinforcing fiber is a reinforcing fiber having an amino group introduced on the surface, and the reactive compound is an amino group at the end of the polyamide resin and an amino group on the surface of the reinforcing fiber. The method for producing a resin molded product according to claim 6 or 7, which is a polymer having a reactive functional group.

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