JP2001145958A - Method of manufacturing fiber reinforced resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for meanufacturing a fiber reinforced resin, especially, molding fiber reinforced pellets with excellent productivity by enhancing the impregnating properties of fiber bundles with a resin and increasing a taking-over speed to a large extent without performing pretreatment. SOLUTION: In manufacturing a fiber reinforced resin from fiber bundles and a molten thermoplastic resin, the fiber bundles and the thermoplastic resin are brought into contact with each other and compressed by rolls while the thermoplastic resin is held to a molten state before shaped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a fiber reinforced resin, and more particularly, to a method for improving the impregnation of a fiber bundle with a resin and greatly improving the take-up speed. The present invention relates to a method for producing fiber-reinforced pellets having excellent handling, moldability, and fiber dispersibility.

[0002]

2. Description of the Related Art Conventionally, a fiber reinforced resin obtained by impregnating a fiber bundle (a roving in which filaments are collected) with a thermoplastic resin gives a molded article having excellent mechanical properties. Widely used as a material.

As a method for producing such a fiber-reinforced resin, for example, a fiber bundle is impregnated with a thermoplastic resin by a melt drawing method (melt drawing method).
By cutting into pellets of about 00mm length,
Various methods for producing a fiber reinforced resin have been proposed. However, in this method, it is generally difficult to sufficiently impregnate the fiber bundle with the resin because the melt of the thermoplastic resin has a high viscosity. Therefore, various measures have been taken in order to improve this. Has been taken.

[0004] For example, as disclosed in JP-B-63-37694, the molecular weight of a resin is reduced and the viscosity is remarkably reduced to promote impregnation. Also, as disclosed in US Pat. No. Re. 32,772. In order to improve the impregnation, a method has been proposed in which a die is devised, pressure is applied to rub the fiber bundle, and impregnation is promoted.

[0005] Although the impregnation of the resin into the fiber bundle is greatly improved by these methods, it is not sufficiently satisfactory. There were problems such as the occurrence of serious troubles at the empty line at the molding site.

Further, in these methods, the pull-out resistance is large, and as shown in the example of JP-B-63-37694, the pull-out speed is only about several tens cm / min, and the productivity is low. There are fundamental drawbacks. If an attempt is made to increase the drawing speed, the impregnation property is unavoidably reduced, and the fibers are damaged, the fibers are cut, and the production stability is reduced.

Therefore, in order to solve these problems,
Japanese Patent Application Laid-Open No. 8-90659 discloses a fiber reinforced composite material in which a fiber bundle is passed through an aqueous emulsion to improve the wettability between the fiber bundle and the molten resin, thereby improving productivity and having good resin impregnation. Manufacturing methods have been proposed. However, in this method, it is necessary to dry out the medium attached to the fiber bundle before the fiber bundle comes into contact with the molten resin in the die, and thus not only requires a considerably long drying oven but also a drying method. There are problems such as high costs including processing costs, and they have not always been fully satisfactory.

To improve this, Japanese Patent Application Laid-Open Nos. 11-9519 and 11-138534 propose a method of treating a fiber bundle in advance with a liquid material having a high boiling point such as liquid paraffin. I have. This method is an excellent manufacturing method in which the drawing speed is greatly improved in combination with the improvement in the conventional impregnation die. However, further improvement in productivity is required.

Japanese Patent No. 2586078 discloses a technique for improving a pressing method for impregnating a resin into a fiber bundle.
JP-A-58-138616, JP-A-6-2548
The inventions described in JP-A-57-57, JP-A-6-254976 and the like are known, but all of them have problems such as insufficient impregnation and take-up speed.

Further, Japanese Patent Application Laid-Open No. 1-214408 discloses that the filling rate of a fibrous reinforcing material is 50 to 90% by weight,
A molding material in which the surface of at least 90% by mass of short fibers (filaments) is coated with a thermoplastic resin is described. As a specific manufacturing method, there is shown a method in which rovings are aligned between belts coated with a molten polypropylene resin and passed while applying tension. However, as is clear from the examples, the speed was 50 cm / min.
Very slow.

Japanese Unexamined Patent Publication (Kokai) No. 1-317751 discloses that a roving of a fiber which has been expanded by applying tension is impregnated with a thermoplastic polymer for anchoring in a first die, and then passed through a tension applying area to cover the fiber. There is disclosed a two-step method of coating with a reinforcing thermoplastic polymer on a heating die. However, as is apparent from the example, it is considered that this is due to the pull-out resistance in the tension application area, but the pull-out speed is at a level of 4.6 m / min, and the productivity is not sufficient.

[0012] In addition, it has been proposed to impregnate a fiber bundle such as glass fiber with a molten resin in a die, draw it out of the die, and then compress it with a roll. Although it is possible, it is a final step for shaping and is limited to the shape of the fiber-reinforced resin, and is not always suitable for the production of pellets, and has low versatility. When the fiber content is low, the degree of compression is greatly limited, and is limited to a special product field such as a film.

[0013]

SUMMARY OF THE INVENTION The present invention overcomes the drawbacks of the prior art, enhances the impregnation of the fiber bundle with the resin, and does not require pretreatment of the fiber bundle.
It is an object of the present invention to provide a method for producing a fiber-reinforced resin which can significantly improve a take-up speed and is excellent in productivity, particularly, a fiber-reinforced pellet as a molding material.

[0014]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, have departed from the conventional idea of impregnating a fiber bundle with a molten resin in a die. It was found that separation by a compression roll outside the die, a separate process, followed by molding with a shaping die, did not damage fibers such as glass fibers, and could significantly improve the take-up speed. The present invention
It has been completed based on such knowledge.

That is, the present invention provides: (1) In producing a fiber-reinforced resin from a fiber bundle and a molten thermoplastic resin, the fiber bundle is brought into contact with the thermoplastic resin, and then roll-compressed in a molten state of the thermoplastic resin; A method for producing a fiber-reinforced resin, which is then introduced into a shaping die and taken off. (2) The fiber according to (1), wherein the fiber bundle and the molten thermoplastic resin are brought into contact with each other with a first die, and the partially impregnated intermediate material is roll-compressed, and then introduced into a second die for shaping and taken up. Manufacturing method of reinforced resin. (3) The method for producing a fiber-reinforced resin according to (2), wherein the outlets of the first die and the second die are divided into a plurality. (4) The method for producing a fiber-reinforced resin according to (2) or (3), wherein the molten resin is supplied to the first die and the second die. (5) The method for producing a fiber-reinforced resin according to any one of (1) to (4), wherein the fiber bundle is treated with a liquid having a boiling point higher than the melting temperature of the thermoplastic resin. (6) After introduction into the shaping die, take-off speed 20-100m
The method for producing a fiber-reinforced resin according to any one of (1) to (5), wherein the fiber-reinforced resin is taken up in a strand shape at a rate of 1 / min, cut into a length of 3 to 100 mm, and pelletized. (7) The thermoplastic resin is any one of a polypropylene resin, a styrene resin, a polyamide resin, a polycarbonate resin, and a polyester resin containing an acid-modified resin, and the fiber is any one of glass fiber, carbon fiber, and metal fiber The present invention relates to the method for producing a fiber-reinforced resin according to any one of (1) to (6), wherein the fiber-reinforced resin contains 15 to 80% by mass of a fiber.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The thermoplastic resin used in the method for producing a fiber-reinforced resin of the present invention is not particularly limited, and examples thereof include polypropylene, propylene-ethylene block copolymer, and propylene-ethylene random copolymer. , Polyolefin resins such as polyethylene, polystyrene, rubber-modified impact-resistant polystyrene, polystyrene resins such as polystyrene having a syndiotactic structure, ABS resins, polyvinyl chloride resins, polyamide resins, polyester resins, polyacetal resins ,
Examples thereof include a polycarbonate resin, a polyaromatic ether or thioether resin, a polyaromatic ester resin, a polysulfone resin, and an acrylate resin. Here, the thermoplastic resin may be used alone, or two or more kinds may be used in combination.

Among such thermoplastic resins, polypropylene resins such as polypropylene, block copolymers of propylene and other olefins, random copolymers, or mixtures thereof, styrene resins, polyamide resins, Polycarbonate resins and polyester resins are preferred, and polypropylene resins are particularly preferred. Further, these thermoplastic resins may also contain an acid-modified resin.

Here, the polypropylene resin includes an acid-modified polyolefin resin modified with an unsaturated carboxylic acid such as maleic anhydride and fumaric acid, or a derivative thereof;
Particularly, a polypropylene resin containing an acid-modified polypropylene resin is preferable. In addition, polypropylene resins include high-density polyethylene, low-density polyethylene, ethylene-α-olefin copolymer resin, other thermoplastic resins such as polyamide resin, and impact strength improvement of ethylene-α-olefin copolymer elastomer. For this purpose, an elastomer may be compounded.

The polypropylene resin is not particularly limited, and a wide range of molecular weights (melt index) can be used. However, from the viewpoint of long-term heat stability, the melt index (MI) [based on JIS K7210. (Temperature 230 ° C, load 2.16kg) 10 to 1,000g / 1
0 minutes, preferably 20 to 500 g / 10 minutes. Furthermore, those containing an acid-modified polyolefin resin have improved interface strength between glass fiber and polypropylene resin,
It is preferable because the tensile strength and the like are greatly improved, and the resin impregnation property of the fiber bundle is promoted.

Examples of the polyolefin resin used for the acid-modified polyolefin resin include, for example, polypropylene, polyethylene, ethylene-α-olefin copolymer rubber, ethylene-α-olefin-nonconjugated diene compound copolymer (eg, EPDM, etc.). ), Ethylene-aromatic monovinyl compound-conjugated diene compound copolymer rubber, and the like. Examples of the α-olefin include propylene; butene-1; pentene-1; hexene-1; 4-methylpentene-1 and the like, and these may be used alone or in combination of two or more. You may. Among these polyolefin-based resins, polypropylene and polyethylene are preferred, and polypropylene is most preferred.

The unsaturated carboxylic acids used for the acid modification include unsaturated carboxylic acids and derivatives thereof. Examples of the unsaturated carboxylic acids include acrylic acid, methacrylic acid, maleic acid, fumaric acid, and itaconic acid. Acid, crotonic acid, citraconic acid, sorbic acid, mesaconic acid, angelic acid and the like; and derivatives thereof include acid anhydrides, esters, amides, imides, metal salts and the like. For example, maleic anhydride, itaconic anhydride Acid, citraconic anhydride, methyl acrylate, methyl methacrylate, ethyl acrylate, butyl acrylate, monoethyl maleate, acrylamide, maleic monoamide, maleimide, N-butylmaleimide, sodium acrylate, sodium methacrylate, etc. Can be mentioned. Among these, unsaturated dicarboxylic acids and derivatives thereof are preferred, and maleic anhydride and fumaric acid are particularly preferred.

These unsaturated carboxylic acids and derivatives thereof may be used alone or in combination of two or more when modifying the polyolefin resin. The modification method is not particularly limited, and various conventionally known methods can be used. For example, a method of dissolving the polyolefin resin in an appropriate organic solvent, adding an unsaturated carboxylic acid or a derivative thereof and a radical generator, stirring and heating, or supplying the respective components to an extruder to carry out graft copolymerization. A method for performing the method can be used.

As the acid-modified polyolefin resin, the unsaturated carboxylic acid or the derivative thereof is added in an amount of 0.1 to 0.1%.
The content is preferably in the range of from 01 to 20% by mass, and preferably in the range of from 0.05 to 10% by mass. Particularly, maleic anhydride and fumaric acid-modified polypropylene are suitable.

The fibers constituting the fiber bundle of the present invention include glass fiber, carbon fiber, copper fiber, brass fiber, steel fiber, stainless fiber, aluminum fiber, aluminum alloy fiber, titanium alloy fiber, boron fiber, Examples thereof include inorganic fibers such as silicon carbide fiber, alumina fiber, silicon nitride fiber, and zirconia fiber; and organic fibers such as aramid fiber, polyamideimide fiber, polyester fiber, polyamide fiber, polyarylate fiber, and ultrahigh molecular weight polyethylene fiber. Of these, continuous fibers such as glass fiber, carbon fiber, and metal fiber are preferable, and glass fiber is particularly preferably used. These fibers are
If necessary, a plurality can be used.

When the fiber is glass fiber, the diameter is in the range of 3 to 30 μm, preferably 6 to 25 μm from the viewpoints of handleability, mechanical properties of the obtained fiber reinforced resin and impregnation of the thermoplastic resin. It is desirable to have.

In the present invention, the fibers may be treated in advance with a surface treating agent in order to improve the wettability and adhesiveness with the resin. Examples of the surface treating agent include silane-based, titanate-based, aluminum-based, chromium-based, zirconium-based, and borane-based coupling agents. Among these, silane-based coupling agents and titanate-based coupling agents are exemplified. Preferred are silane coupling agents.

As the silane coupling agent, for example, triethoxysilane, vinyl tris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, β- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, N-β- (aminoethyl) -γ
-Aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxy Silane, γ-chloropropyltrimethoxysilane and the like. Among them, γ-aminopropyltriethoxysilane, N-β-
Aminosilanes such as (aminoethyl) -γ-aminopropyltrimethoxysilane are preferred.

The method for treating the fiber with the above-mentioned surface treatment agent is not particularly limited.
For example, any method such as an aqueous solution method, an organic solvent method, and a spray method can be used.

In the method for producing a fiber-reinforced resin according to the present invention, the fiber bundle has various properties such as resin impregnation, wettability and adhesion with the resin, mechanical properties of the obtained composite material, cost and handling. For this reason, those made of 200 to 2,000 glass fibers having a fiber diameter of 3 to 30 μm, preferably 6 to 20 μm are preferable, and those that have been surface-treated with an aminosilane-based coupling agent are particularly preferable.

In the method for producing a fiber-reinforced resin according to the present invention, the fiber bundle is treated with a high-boiling-point liquid treating agent before contact with the thermoplastic resin in order to improve the familiarity at the time of contact between the fiber bundle and the thermoplastic resin. Can be pre-processed. The liquid material to be used has a boiling point higher than the molten resin temperature of the thermoplastic resin in the die, and the thermoplastic resin to be used may be any one that does not adversely affect the thermoplastic resin. Things can be used.

Such a liquid material is preferably a liquid at room temperature, for example, liquid resin additives such as liquid paraffin, process oil, petroleum oil such as high boiling aromatic oil, various plasticizers, and the like. Examples thereof include α-olefin oligomers such as liquid polybutene, liquid resins such as liquid polybutadiene, and high-boiling solvents and heating media. After these liquids are processed, a part of them remains and enters the die. Therefore, it is preferable to use those liquid materials which do not adversely affect the physical properties even when mixed into the molten resin impregnated in the die and are compatible. Of these, petroleum oils such as liquid paraffin are preferred. These liquid materials may be used alone or in combination of two or more.

As described above, this liquid material needs to have a boiling point higher than the temperature of the molten resin in the die. When the boiling point is lower than the temperature of the molten resin in the die, the liquid material is contact-treated with the liquid material. When the fiber bundle is brought into contact with the molten thermoplastic resin in the die, the liquid material evaporates, and the impregnation of the fiber bundle with the resin is reduced.

In this pretreatment method, before the fiber bundle is guided into a die and brought into contact with the molten thermoplastic resin, the fiber bundle is subjected to a contact treatment with the liquid material in advance to wet the fiber bundle and to prevent the fiber bundle from being wetted. It is believed that the air is expelled, thereby improving the impregnation of the thermoplastic resin.

Specifically, the fiber bundle is passed through the liquid material, or the liquid material is applied to the fiber bundle by a roll coater, and if necessary, the fiber bundle is passed through a compression roll or a tension bar. A method of promoting the impregnation of the fiber bundle with the liquid material and expelling air in the fiber bundle is preferably used. Unnecessary liquids can be removed and the amount can be kept constant by the treatment with the compression rolls or the like. By this operation, the impregnating property of the resin in the die is remarkably improved, and impregnation with a high molecular weight resin is possible. When a roll coater is used, the rotation speed is adjusted in accordance with the take-up speed of the fiber bundle, thereby adjusting the amount of the liquid material that is scraped up and wetted by the fiber bundle.

An embodiment of the method for producing a fiber-reinforced resin according to the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic process diagram illustrating a method for producing a fiber-reinforced pellet, which is an example of the method for producing a fiber-reinforced resin of the present invention. In FIG. 1, 1 is a bobbin, 2 is a fiber bundle (roving), 3 is an aligner, 4 is a guide roll, 5 is a pretreatment tank, 6 is a first extruder, 7 is a first die, 8 is a compression roll, 9 is a second extruder, 10 is a second die, 11 is a cooler, 12 is a take-off machine, 13 is a cutting machine, 14 is a pellet,
1, 22, 23, and 24 indicate changes in the state of the fiber bundle. FIG. 2 is an explanatory view of the inside of a first extruder die used in the method for producing a fiber-reinforced resin of the present invention.

A method for producing glass fiber reinforced polypropylene resin pellets using a production apparatus according to the schematic process diagrams of FIGS. 1 and 2 will be specifically described. First, the fiber bundle 2 drawn out from the bobbin 1 is horizontally aligned by the aligner 3. The aligned fiber bundle is processed by the pretreatment tank 5 as needed, and the first die 7 of the first extruder 6 is used.
By guiding to the compression roll 8, the second die 10 of the second extruder 9, the cooling tank 11, the take-off machine 12, and the cutting machine 13,
A stream of fiber bundles is created.

At this time, it is preferable that the fiber bundle 2 is separated by the aligner 3 and the guide roller 4 so that the fiber bundles come into contact with each other and have no adverse effect, for the high-speed running of the fiber bundle. After this, the fiber bundle is
A die in which the exit to the die is divided so as to have a number corresponding to the number of fiber bundles corresponding to the glass fiber content in the strand when the strand is shaped from the die is used. Here, it may be preferable to divide even at the entrance.

The fiber bundles 2 aligned by the aligner 3 are treated in a pretreatment tank 5 by a liquid paraffin having a boiling point higher than the melting temperature of the polypropylene resin in the die.
This treatment reduces air entrapment and improves the impregnation of the polypropylene resin in the contact between the fiber bundle 2 and the molten polypropylene resin. The pretreated fiber bundle is introduced into the first die 7 in a divided state, and comes into contact with the polypropylene resin melt-kneaded in the first extruder 6, and the molten polypropylene resin is partially added to the glass fiber bundle. Impregnated.

In the first die 7, the glass fiber bundle and the polypropylene resin do not sufficiently contact each other at an early stage, and therefore, a structure in which excessive resistance is not applied to the running of the fiber bundle in the die [FIG. It is important to prioritize high-speed running of the fiber bundle over impregnation with the polypropylene resin. In the technology of the conventional proposal, the impregnation at this stage is to be improved, and as a result, it is not possible to achieve both impregnation and high-speed running,
Emphasis was placed on impregnation.

The contact bundle 22 of the fiber bundle and the polypropylene resin coming out of the first die 7 is formed by a pair of compression rolls 8A,
The vehicle is driven at a constant speed and high speed while being compressed by 8B.
Due to this compression, the impregnated impregnation of the molten polypropylene resin becomes a sufficient impregnated substance 23. However, in this state, it cannot be used as a fiber reinforced resin, that is, not only cannot be formed into an arbitrary shape, but also cannot be a uniform fiber reinforced resin. In other words, the strand for pellet production cannot be shaped by a compression roll, and the method of compressing it into a sheet and cutting it into a square pellet only stops in the form of a sheet and reduces the degree of compression. Because there is a limit.

The compression roll here is not necessarily specified depending on the scale of the manufacturing apparatus, but usually has a roll diameter of 100 to 1,000 mm, preferably 3 to 1000 mm.
A metal roll of stainless steel or the like of 00 to 800 mm can be employed. In addition, a metal roll whose surface is coated with a fluororesin or the like as necessary can be used. Also,
If necessary, the metal roll can be heated at about 60 to 300 ° C.

The fiber reinforced material 23 compressed by the compression roll 8
Is introduced into the second die 10, heated, separated into the number of fiber bundles corresponding to the strand formation at the start of molding, pulled out from the second die, and shaped into the strand 24. Then, it is water-cooled in the cooling tank 11, taken off by the take-off machine 12, cut by the cutting machine 13 into a predetermined length of 3 to 100 mm, and fiber-reinforced pellets are obtained.

A feature of the method for producing a fiber-reinforced resin of the present invention is that, after the glass fiber bundle is integrated with the molten resin by the first die, the degree of impregnation of the molten resin by the compression roll is improved, and The second die is used for uniform reheating and shaping. The first extruder and the second extruder have different functions. Therefore, depending on the content of fibers such as glass in the fiber reinforced resin, the first extruder,
The amount of the extruded resin of the second extruder is adjusted. That is, when the glass fiber content ratio is high, the supply of the resin from the second extruder may be stopped, and only the heating and shaping may be performed. However, in the case where the glass fiber content is low as described above, the final ratio is set in the second die under the condition that the fiber content is high in the first die. Here, if the glass fiber content is reduced in the first die, the compression force for impregnation of the resin with the compression roll may not be able to be increased.

The content ratio of the fiber and the resin component in the fiber reinforced resin obtained in this manner is as follows.
It is preferable that the resin component is in the range of 85 to 20% by mass in terms of mass%. When the content of the fiber is less than 15% by mass, the amount of the fiber is insufficient, and it may be difficult to quantitatively extract the fiber. When the content exceeds 80% by mass, the impregnation with the resin may be difficult. From the viewpoints of resin impregnating and drawing properties, it is particularly preferable that the fiber content is 25 to 70% by mass and the resin component is 75 to 30% by mass.

The fiber reinforced resin thus obtained is
It may be an extruded product of the final molded product. But,
As described above, as a fiber-reinforced pellet as a raw material for secondary melt molding in the form of pellets, it may be molded as it is, or may be molded by blending with a resin that does not contain the same or similar fibers, or with another resin. You may.

In the present invention, if necessary, the thermoplastic resin may contain other resins, fillers and additives for improving various physical properties. For example, as impact modifiers, ethylene-propylene copolymer rubber,
Rubbers such as polybutadiene rubber, styrene-butadiene-styrene block copolymer rubber (SBS), and hydrogenated SBS-styrene-ethylene-butylene-styrene block copolymer rubber (SEBS) can also be added.

In consideration of the required characteristics of molded articles, metal powder, carbon black, graphite, talc, mica, clay, calcium carbonate, silica, aluminum hydroxide, magnesium hydroxide, calcium sulfate, glass fiber, titanium Inorganic fillers such as calcium whisker and fibrous magnesium oxysulfate, organic fillers such as cross-linked resin powder, crystallization accelerator, antioxidants (phosphorous, phenolic, sulfuric, etc.), neutralizing agents, foaming Agents, lubricants, dispersants, peroxides, heat stabilizers, ultraviolet absorbers, light stabilizers, antistatic agents, flame retardants, flame retardant aids, plasticizers, epoxy compounds, metal deactivators, zinc sulfide, Additives such as pigments and dyes such as titanium oxide can also be added. These other resins, fillers, and additives can be added to the resin at the time of producing the fiber-reinforced resin. However, except for some additives, they are blended when mixed with the fiber-reinforced pellets.

In the method for producing a fiber-reinforced resin according to the present invention, one extruder may be used in addition to the two dies. As the contact between the fiber bundle and the thermoplastic resin, a method of heating after the contact with the powder resin, the contact with the resin solution, or the like may be used in addition to the melting contact. However, melting contact can be preferably employed from the viewpoint of efficiency, operability, and process.

The fiber-reinforced resin molded product obtained by the production method of the present invention can be directly molded. However, as a fiber-reinforced pellet, for example, an instrument panel core, a bumper beam, a door step, It is suitably used for various automobile parts such as roof racks, rear quarter panels and air cleaner cases, as well as concrete panels and cable troughs.

[0050]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Example 1 A glass fiber reinforced resin pellet was manufactured using a fiber reinforced resin pellet manufacturing apparatus shown in FIG. 1 (however, there is no pretreatment and the inside of a die is a molten resin overflow method shown in FIG. 2A). A fiber bundle (glass roving) composed of 600 glass fibers having a diameter of 10 μm was drawn out from a bobbin, aligned by an aligner, and the glass fiber content of one strand was adjusted by changing the number of rovings and the diameter of the nozzle.

As the thermoplastic resin, MI (JIS K
3% by weight of a maleic anhydride-modified polypropylene resin modified according to 7210, 230 ° C., 2.16 kg load)
The contained polypropylene resin was used. It is divided so as to correspond to the strand and introduced into the die of the first extruder. The strand coming out of the die is similarly introduced into the die of the second extruder, and the polypropylene resin is melted from the first and second extruders. It was kneaded and supplied to a die.

The glass fiber content in the pellets was controlled by the extruding amounts of the first extruder and the second extruder and the take-up speed so as to be as shown in Table 1. The strand containing the resin exiting the first die is compressed into a sheet by a pair of rolls (diameter: 500 mm, roll temperature: 180 ° C.), so that the inside of the fiber bundle (roving) of the glass fibers is removed.
The resin was impregnated. Next, the strand is again divided into strands and introduced into a die of a second extruder to form a strand having a predetermined glass fiber content.
A 0 mm glass fiber reinforced pellet was obtained. Table 1 shows the results obtained by changing the take-up speed and other conditions.

The obtained glass fiber reinforced pellets and MI
However, polypropylene pellets of 60 g / 10 min were dry-blended so that the glass fiber content became 20% by mass, and a flat plate of 140 × 140 × 2 mm was formed by an injection molding machine. Opening status of glass fiber in molded product
The 0 sheets were visually inspected to determine the number (n) of lumps (bundles) of unopened fibers. Table 1 shows the evaluation results based on the following criteria.

：: n / 10 = 0.3 or less Δ: n / 10 = 0.3 to 3.0 ×: n / 10 = 3.0 or more Further, 25 kg of glass fiber reinforced pellets were placed in a 50-liter tumbler. The glass balls were charged and rotated for 5 minutes, and the state of hair ball generation due to the detachment of glass fibers, which was generated by cracking of the pellets, was visually observed. Table 1 shows the evaluation results based on the following criteria.

Good: Almost no hair bulb was observed. Δ: Some hair bulb is observed. X: A large amount of hair bulb is observed.

Comparative Example 1 Glass fiber-reinforced polypropylene pellets were obtained in the same manner as in Example 1 except that a conventional general production apparatus was used without using a compression roll and a second die.
Table 1 shows the evaluation results.

Comparative Example 2 Glass fiber-reinforced polypropylene pellets were obtained in the same manner as in Comparative Example 1, except that the inside of the dice was of a tension applying type shown in FIG. 2B. Table 1 shows the evaluation results.

Comparative Example 3 The procedure of Example 1 was repeated, except that the compression rolls of the first and second dies were not used, and the inside of the die was of a tension applying type shown in FIG. 2B. Glass fiber reinforced polypropylene pellets were obtained according to Table 1 shows the evaluation results.

Comparative Example 4 In Example 1, except that the second die was not used.
A glass fiber reinforced polypropylene pellet was obtained according to Example 1. Table 1 shows the evaluation results.

Example 2 In Example 1, before introducing the fiber bundle into the first die, liquid paraffin (boiling point of 3) was introduced into the pretreatment tank shown in FIG.
58 ° C, manufactured by Idemitsu Kosan Co., Ltd., trade name: Daphne Oil C
After passing through a tank containing P50S), glass fiber reinforced polypropylene pellets were obtained in the same manner as in Example 1 except that the fiber bundle was impregnated with liquid paraffin by passing between compression rolls. Table 1 shows the evaluation results.

Example 3 In Example 1, the supply of the resin to the second die was stopped, and only the shaping of the strand was carried out to obtain a glass fiber-reinforced polypropylene pellet having a good appearance (glass fiber was 40% by mass). Content). Table 1 shows the evaluation results.

Example 4 In Example 1, a glass fiber reinforced sheet-like molded product having good appearance (glass fiber was used) was used according to Example 1, except that the second die was replaced with a strand and a sheet shaping die instead of a strand. 50% by mass). Table 1 shows the evaluation results.

[0063]

[Table 1]

[0064]

According to the present invention, the impregnating property of the fiber bundle with the resin and the suppression of fiber cutting are achieved, and as a result, the high-speed pultrudability and the productivity are remarkably improved. In addition, since the resin almost completely covers the glass single fiber, in the molding using the obtained glass fiber reinforced pellet, the moldability is improved, the cutting of the glass fiber is suppressed, and as a result, the storage of the pellet is performed. In addition to improving the operability of transportation and mixing, the length of the glass fiber in the final molded product can be ensured long, and the dispersibility of the glass fiber is improved, so that a molded product excellent in appearance can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a process for producing fiber-reinforced pellets, which is an example of the method for producing a fiber-reinforced resin of the present invention.

FIG. 2 is an explanatory diagram of the inside of a first extruder die, which is an example of the production method of the present invention.

[Explanation of symbols]

 1: bobbin 2: fiber bundle (roving) 3: aligner 4, 5: guide roll 6: first extruder 7: first die 8: compression roll 9: second extruder 10: second die 11: cooling tank 12: take-off machine 13: cutting machine 14: pellet

Continued on the front page F term (reference) 4F205 AA11 AA24 AA28 AA29 AD02 AD04 AD16 AD33 AR08 HA05 HA27 HA34 HA37 HA47 HB02 HC02 HC16 HC17 HC18 HE06 HE21 HK03 HK04 HK19 HK25 HM06 HM16 HW02 HW21

Claims (7)

[Claims] In producing a fiber reinforced resin from a fiber bundle and a molten thermoplastic resin, the fiber bundle is brought into contact with the thermoplastic resin, then roll-compressed in a molten state of the thermoplastic resin, and then introduced into a shaping die. A method for producing a fiber reinforced resin, comprising: 2. The method according to claim 1, wherein the contact between the fiber bundle and the molten thermoplastic resin is first.
Performed with a die, roll compressed the partially impregnated intermediate material,
The method for producing a fiber-reinforced resin according to claim 1, wherein the fiber-reinforced resin is introduced into a second die for shaping and picked up. 3. The method for producing a fiber reinforced resin according to claim 2, wherein the outlets of the first die and the second die are divided into a plurality. 4. The method for producing a fiber reinforced resin according to claim 2, wherein the molten resin is supplied to the first die and the second die. 5. The method for producing a fiber reinforced resin according to claim 1, wherein the fiber bundle is treated with a liquid having a boiling point higher than the melting temperature of the thermoplastic resin. 6. A take-up speed of 20 to 1 after being introduced into a shaping die.
Stranded at 00m / min, 3-100mm
The method for producing a fiber-reinforced resin according to any one of claims 1 to 5, wherein the fiber-reinforced resin is cut into a length and pelletized. 7. A thermoplastic resin comprising an acid-modified resin such as a polypropylene resin, a styrene resin, a polyamide resin,
The resin is any one of a polycarbonate resin and a polyester resin, and the fiber is any one of a glass fiber, a carbon fiber, and a metal fiber, and the fiber-reinforced resin contains 15 to 80% by mass of the fiber. 7. The method for producing a fiber-reinforced resin according to any one of 6.