JPH0516139A - Fiber composite sheet and its manufacture - Google Patents

Abstract

PURPOSE:To manufacture a fiber composite sheet of high strength and little unevenness of physical properties. CONSTITUTION:Fiber reinforced resin layers comprising reinforcing fibers f5 of 5-10mm length disposed at random in the length direction on thermoplastic resin B are laminated integrally into the sandwich shape on both faces of a fiber reinforced resin layer in which continuous reinforcing fibers 3 are disposed in the state of being arranged in one direction on thermoplastic resin A.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a tough plate material,
For stamping sheet, which is a press forming material for obtaining various products, is used for stamping forming molded parts that require mechanical strength in one direction, such as reinforcing materials for automobile bumpers and doors. And a method for producing the same.

[0002]

2. Description of the Related Art As a fiber composite sheet, there is known a conventional composite sheet (a) obtained by impregnating a laminate of reinforced long fibers aligned in one direction and a long fiber mat with a thermoplastic resin. No. 62-240514).

Further, as a method for producing a fiber composite sheet,
(B) Mixing reinforced short fibers and powdered thermoplastic resin in a jet stream of compressed air and dropping them on a net to accumulate them, and then transferring the aggregates to a moving endless belt, heating and pressurizing and cooling. To form a sheet (JP-A-59-49929)
(See Japanese Patent Publication No. 2), and (c) reinforced short fibers and powdered thermoplastic resin are mixed in a container while keeping them in a fluidized state, taken out of the container, dropped on a moving endless belt, and accumulated, A method is known in which a sheet is fed into a gap between moving upper and lower endless belts which are opposed to each other at a predetermined interval, heated and pressed, and then cooled to form a sheet (JP-A-62-2).
08914 publication).

[0004]

In the fiber composite sheet of the above (a), the resin is not sufficiently impregnated between the filaments of the reinforced long fibers, so that the strength is poor.

Further, in the above-mentioned method (2) for producing a fiber composite sheet, reinforced short fibers having different specific gravities and a powdery thermoplastic resin are mixed under an air stream and fall-assembled. There is a problem that the distribution becomes non-uniform and the physical properties of the obtained sheet vary greatly. Further, in the method for producing a fiber composite sheet according to the above (c), since the reinforced short fibers and the powdery thermoplastic resin are mixed in a container, the sheet cannot be continuously obtained, resulting in poor productivity. There is a problem.

An object of the present invention is to provide a fiber composite sheet which has high strength, particularly strength in one direction, and has little variation in physical properties,
It is to provide a method capable of producing this sheet with high productivity.

[0007]

According to a first aspect of the present invention, there is provided a fiber composite sheet, which comprises a thermoplastic resin (A) and continuous fiber reinforcements arranged in one direction. A) and thermoplastic resin (B) with a length of 5 to 100 m
The fiber-reinforced resin layer (i) in which reinforcing fibers of m, preferably 5 to 50 mm are arranged in a random state in the longitudinal direction are laminated and integrated.

A second aspect of the present invention is the method for producing the fiber composite sheet according to the first aspect, in which a reinforcing fiber bundle composed of a large number of continuous monofilaments is arranged in upper, middle, and lower powdery thermoplastics. The step of passing the resin fluidized bed through each of the filaments of the fiber bundle and adhering the powdery thermoplastic resin to the respective filaments of the fiber bundle, and the intermediate continuous resin-attached fiber bundle of the upper and lower endless belts which are opposed at a predetermined interval. The step of continuously feeding into the gap and cutting the upper and lower resin-attached fibers to 5 to 100 mm, preferably 5 to 50 mm, and dropping the upper cut resin-attached fibers onto the middle continuous resin-attached fiber bundle In addition, the lower cut resin-attached fibers are collected by dropping onto the feeding part of the upper and lower endless belts into the gap, and both aggregates are moved up and down endlessly as the middle continuous resin-attached fiber bundle moves. The process of continuously feeding into the gap of the belt, and passing through the heating region and the cooling region while sandwiching with both endless belts that move the upper and lower cut resin-attached fiber aggregates through the medium-sized continuous resin-attached fiber bundle And a step of forming into a sheet shape.

The method for producing the fiber composite sheet according to claim 1 is not limited to the method according to claim 2.

That is, the respective sheets for forming the fiber-reinforced resin layer (a) and the fiber-reinforced resin layer (ii) according to claim 1 are separately prepared, and the both sheets are superposed. In this state, it may be fed to a heating furnace or the like, heated and melted, and then pressed to laminate and integrate it, or each sheet may be heated and then laminated and integrated under pressure.

A three-layer structure in which the fiber-reinforced resin layer (a) is present on both sides of the fiber-reinforced resin layer (a) is preferable, but the number of layers is not limited (in most cases, 2 to 5 layers are used). is there).

Further, in some cases, in the manufacturing method of claim 2, the powdery thermoplastic resin fluidized bed of either one of the upper and lower layers is not provided, and the other steps are the same, and the fiber having a two-layer structure is subjected. It is also possible to obtain a composite sheet.

As the reinforcing fibers, fibers that are thermally stable at the melting temperature of the thermoplastic resin used are used. Specific examples thereof include glass fibers, carbon fibers, silicon / titanium / carbon fibers, boron fibers, fine metal fibers, aramid fibers, liquid crystal polymer fibers, polyester fibers, and polyamide fibers.

The diameter of the monofilament is preferably 1 to 50 μm. When using a large number of continuous filaments as a reinforcing fiber bundle, a sizing agent may or may not be used. However, when the sizing agent is used, if the amount of the sizing agent attached exceeds 1% by weight,
It becomes difficult to separate the fiber bundles into monofilament units in the fluidized bed, and the impregnating ability of the thermoplastic resin between the monofilaments decreases.

The reinforcing fiber bundle is in the form of a strand or a roving in which hundreds to thousands of continuous monofilaments are formed. And this reinforcing fiber bundle, considering the width, thickness, production speed, etc. of the fiber composite sheet to be produced,
Usually used in parallel.

The reinforcing fibers in the fiber-reinforced resin layer (a) and the reinforcing fibers in the fiber-reinforced resin layer (ii) may be of the same kind or of different kinds, and the content ratios thereof may be different from those of the mechanical strength and the sheet. Is appropriately determined according to the shape of the molded product to be molded.

As the thermoplastic resins (A) and (B), all resins which are melted and softened by heating can be used. For example,
Polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyamide, polyethylene terephthalate,
Polybutylene terephthalate, polycarbonate, polyvinylidene fluoride, polyphenylene sulfide, polyphenylene oxide, polyether sulfone, polyether ether ketone and the like are used. Further, copolymers or graft resins or blend resins containing the above thermoplastic resin as a main component, for example, ethylene-vinyl chloride copolymer, vinyl acetate-ethylene copolymer, vinyl acetate-vinyl chloride copolymer, urethane-vinyl chloride. Copolymers, acrylonitrile-butadiene-styrene copolymers, acrylic acid-modified polypropylene, maleic acid-modified polyethylene and the like can also be used. And the thermoplastic resin, stabilizer, lubricant,
Additives such as processing aids, plasticizers and colorants may be incorporated. Further, both a thermoplastic resin obtained in powder form at the time of polymerization and a thermoplastic resin made into powder form by a pulverizer can be used. The average particle size is preferably less than 2 mm. When the average particle size exceeds 2 mm, it becomes difficult to uniformly impregnate the monofilaments of the reinforcing fiber bundle in the fluidized bed. The thermoplastic resin (A) and the thermoplastic resin (B) may be the same or different.

The proportion of the thermoplastic resin and the reinforcing fiber is appropriately determined according to the required physical properties of the fiber composite sheet, but the reinforcing fiber in the sheet is preferably 5 to 70% by weight. If the reinforcing fiber content is less than 5% by weight, the mechanical strength of the sheet will not be sufficient, and if it exceeds 70% by weight, it will be difficult to obtain a sheet uniformly impregnated with a thermoplastic resin.

[0019]

In the fiber composite sheet according to the invention of claim 1, the fiber-reinforced resin layer (a) in which the continuous reinforcing fibers are aligned in one direction in the thermoplastic resin (A) and the thermoplastic resin ( Since the fiber-reinforced resin layer (i) in which reinforcing fibers having a length of 5 to 100 mm are randomly arranged in the longitudinal direction are laminated on B), this fiber composite sheet is The presence of the fiber reinforced resin layer (a) is suitable for molding a molded part which requires mechanical strength in one direction, and the presence of the fiber reinforced resin layer (i) improves the strength of the entire sheet. Moreover, the length of the reinforcing fiber is 5 to 100.
Since it is mm, the fibers do not rise on the side surface of the fiber reinforced resin layer. When the length of the reinforcing fiber is less than 5 mm, the reinforcing effect of the fiber is not obtained, and when it exceeds 100 mm, the fiber is raised.

According to a second aspect of the present invention, there is provided a method for producing a fiber composite sheet according to the first aspect, in which a reinforcing fiber bundle composed of a large number of continuous monofilaments is arranged in upper, middle, and lower powdery thermoplastic resin flows. Passing through the layer and adhering the powdery thermoplastic resin to each filament of the fiber bundle, and the intermediate continuous resin-adhered fiber bundle to the gap between the upper and lower endless belts facing each other at a predetermined interval. The step of continuously feeding and cutting the upper and lower resin-attached fiber bundles into 5 to 100 mm, respectively, and dropping the upper cut resin-attached fiber bundles onto the intermediate continuous resin-attached fiber bundles and accumulating them, The cut resin-adhered fibers are dropped onto the feeding part into the gap between the upper and lower endless belts and accumulated, and both aggregates are continuously transferred to the gap between the upper and lower endless belts as the middle continuous resin-adhered fiber bundle moves. A step of feeding and a step of passing the upper and lower cut resin-adhered fiber aggregates through a medium-sized continuous resin-adhered fiber bundle with both endless belts and passing them through a heating area and a cooling area to form a sheet. Therefore, the fiber composite sheet according to claim 1 can be continuously obtained.

[0021] First, a reinforcing fiber bundle composed of a large number of continuous monofilaments is passed through a powdery thermoplastic resin fluidized bed arranged in upper, middle and lower layers, and each filament of the fiber bundle is powdered. Since the thermoplastic resin is adhered, the resin is sufficiently impregnated between the monofilaments of the reinforcing fibers in combination with the heating in the subsequent step.

Further, the upper and lower resin-attached fiber bundles are each cut into 5 to 100 mm, and the upper cut resin-attached fiber bundles are dropped and accumulated on the intermediate continuous resin-attached fiber bundle, and the lower cut resin-attached resin bundle is attached. Since the fibers are dropped and accumulated on the feeding part into the gap between the upper and lower endless belts, the reinforcing fibers are well dispersed in the fiber-reinforced resin layer (i) in units of monofilaments. And the resin-attached fiber bundle is 5 to 100 mm
Since it is cut into pieces, the reinforcing fibers in the fiber-reinforced resin layer (i) are within the length range and have good fluidity, and when the obtained sheet is press-molded, the reinforcing fibers are extended to the end of the molded product. Go across. If the resin-attached fiber bundle is cut to less than 5 mm, the length of the fiber inevitably becomes less than 5 mm, and there is no reinforcing effect of the fiber as described above, and if cut over 100 mm, it becomes a lump that falls and accumulates. Not evenly dispersed in the fiber reinforced resin layer.

[0023]

EXAMPLES First, an apparatus used for producing the fiber composite sheet of the present invention will be described with reference to FIG. In the following description, the term “front” means the right direction in FIG. 1.

The fiber composite sheet manufacturing apparatus shown in FIG.
Three upper, middle and lower fluidized bed units (1), a rewinding roll (2) placed behind each fluidized bed unit (1) and a front of each fluidized bed unit (1). A pair of upper and lower scrapers (3), a take-up drive roll (4) disposed diagonally below the upper scraper (3) and in front of the lower scraper (3), and a pair of take-up drive rolls (4). The pinch rolls (5) are arranged above the rotary cutters (6) facing each take-up drive roll (4) at predetermined intervals. The upper and lower endless belts (7) and (8), and the heating means (9) and cooling means (10) sequentially arranged from the rear side with respect to the opposed transfer parts (7a) and (8a) of the both endless belts (7) and (8) ) And, the lower endless belt
(8) The rear part of the upper endless belt (7) is made to project rearward, and the rearward extension of the transfer part (8a) is positioned below the upper and middle rotary cutters (6). It serves as a feeding portion (8b) into the gap between the belts (7) and (8). Instead of extending the transfer part (8a) to form the feeding part (8b), another endless belt may be arranged at the same place to provide the feeding part.

The tank bottom of the fluidized bed apparatus (1) is formed by a perforated plate (11), and gas (G) such as air or nitrogen sent from the gas supply passage is below the perforated plate (11). It is ejected upwards through a large number of holes. As a result, the powdery thermoplastic resin filled in the tank of the fluidized bed apparatus (1) is fluidized by the jetted gas (G) and is in the middle fluidized bed apparatus (1).
The fluidized bed (a) of the thermoplastic resin (A) is in the upper and lower fluidized bed units (1) of the thermoplastic resin (B) in the lower fluidized bed device (1).
Are formed respectively. Reinforcing fiber bundle (F1) is on the middle rewinding roll (2), and upper and lower rewinding rolls (2)
A reinforcing fiber bundle (f1) is wound around each. In addition,
Although only one reinforcing fiber bundle (F1) (f1) is shown for the sake of convenience, many reinforcing fiber bundles (F1) (f1) are actually used in parallel. A guide roll (12) for guiding the fiber bundles (F1) (f1) is provided inside the tank of each fluidized bed apparatus (1) and at the upper ends of the front and rear walls thereof. The medium-strength fiber bundle (F1) is passed through the fluidized bed (a) to become a resin-attached fiber bundle (F2), which is continuously formed between the upper and lower endless belts (7) (8). Guide roll (1
3) is provided in front of the scraper (3), and a guide roll (14) is provided above the feeding section (8b). The upper and lower reinforcing fiber bundles (f1) are also passed through the fluidized bed (b) to become resin-attached fiber bundles (f2), but both resin-attached fiber bundles (f2) are rotary cutters (6). Guide rolls (15) for guiding to the front are provided in front of the scraper (3).

In this apparatus, a pair of upper and lower scrapers (3) are arranged to adjust the gap between the reinforcing fiber bundles (F1) and (f1) in order to adjust the adhesion amount of the powdery thermoplastic resin. However, vibration is applied to the reinforcing fiber bundle (F1) (f1),
Excessively adhered powdery thermoplastic resin may be removed.
In this case, the adhesion amount of the powdery thermoplastic resin can be adjusted depending on the strength of vibration applied.

Both endless belts (7) and (8) are continuously driven in the same direction by driving one of upper and lower pulleys (16) and (17) respectively by a motor (not shown). It is designed to move at the same speed. The rear portion of the transfer portion (7a) of the upper endless belt (7) is inclined rearward and upward, and the gap between the vertical transfer portions (7a) and (8a) is widened rearward. The upper and lower endless belts (7) and (8) are formed of high strength and heat resistant materials such as steel, stainless steel, and glass cloth reinforced Teflon.

As the heating means (9), an electric heating type or hot air circulating type heating furnace is used, and the upper and lower endless belts (7) and (8) may be passed through them, or the upper and lower endless belts may be passed.
(7) A plurality of pairs of heating rolls may be used that press the transfer portions (7a) and (8a) of (7) and (8) from above and below and directly heat them. Heating means
Inside the (9) there are multiple pairs of upper and lower guide rolls (18), and at the corresponding positions of the upper and lower cooling means (10) there are multiple pairs of upper and lower guide rolls.
Rolls (19) are provided, and upper and lower guides
The gaps between the rolls (18) and (19) are adjustable. As the cooling means (10), there is used a blower for blowing air to cool the transfer parts (7a), (8a) of the upper and lower endless belts (7), (8). The guide roll (19) itself may be cooled.

Next, a method for producing a fiber composite sheet using the above apparatus will be described. Each rewind roll
Reinforcing the reinforced fiber bundle (F1) (f1) consisting of a large number of continuous monofilaments from (2) with the take-up drive roll (4) and the pinch roll (5) without twisting, and powdery thermoplastic The resins (A) and (B) are passed through the fluidized beds (a) and (b). Reinforced fiber bundle (F1) (f1) in fluidized bed (a) (b)
Is separated into monofilament units and opened by the jetting of gas and the static electricity generated in the fluidized beds (a) and (b) and the rubbing effect, and the powdery thermoplastic resin invades between the monofilaments. Attach to monofilament.

The resin-adhesion-reinforced fiber bundle (F2) (f2) is passed between a pair of upper and lower scrapers (3), and the scraper (3) removes excess powdery thermoplastic resin to obtain powdery thermoplastic resin. Adjust the ratio of resin and reinforcing fiber.

Then, a medium continuous resin-attached fiber bundle (F2)
Is continuously fed into the gap between the upper and lower endless belts (7) and (8),
On the other hand, the upper and lower resin-attached fiber bundles (f2) are each cut into 5 to 100 mm by a rotary cutter (6),
The upper cut resin-adhered fiber (f3) is dropped onto the middle continuous resin-adhered fiber bundle (F2) and accumulated, and the lower cut resin-adhered fiber (f3) is attached to the upper and lower endless belts (7) (8). The endless belts (7) and (8) are dropped and accumulated on the feeding part (8b) into the gap, and both are moved along with the middle continuous resin-attached fiber bundle (F2).
Continuously feed into the gap. Medium continuous resin-attached fiber bundle
Upper and lower cut resin-attached fiber aggregates (f
4) While moving through the two endless belts (7) and (8), set the minimum gap between the two endless belts (7) and (8) to the upper and lower guide rolls (18).
Then, the three are pressurized in the thickness direction and passed through a heating furnace (9) as a heating means in which hot air circulates to be integrated. The temperature at this time is equal to or higher than the melting temperature of the thermoplastic resin (B).

Subsequently, the mixture of the resin and the reinforcing fiber in the molten state is adjusted by the upper and lower guide rolls (19) with a minimum gap between the upper and lower endless belts (7) and (8) to be pressurized, and as a cooling means. The fiber composite sheet (S) was obtained by cooling with a cooling blower (10).

The fiber composite sheet (S) obtained is, as shown in FIG. 2, arranged with the thermoplastic resin (A) and the continuous reinforcing fibers (F3) aligned in one direction. The length of the thermoplastic resin (B) is 5 through the fiber reinforced resin layer (a).
Two fiber reinforced resin layers (i) in which reinforcing fibers (f5) of -100 mm are randomly arranged in the longitudinal direction are laminated and integrated in a sandwich form.

Example 1 The powdery thermoplastic resins (A) and (B) had a polymerization degree of 80.
A mixture of 100 parts by weight of a vinyl chloride resin of 0 (average particle size 150 μm) with 3 parts by weight of butyltin maleate and 5 parts by weight of a glycidyl methacrylate copolymer was used.

As the reinforcing fiber bundles (F1) and (f1), roving glass fiber bundles (monofilament diameter 14 μm, 1
100 g / km) was used.

The upper and lower endless belts (7) and (8) have a width of 600 mm,
A glass fiber reinforced Teflon belt having a thickness of 1 mm was used.

The medium-strength fiber bundle (F1) is continuously passed through the fluidized bed (a) of the powdery thermoplastic resin (A), and the powdery thermoplastic resin (A) is placed between the monofilaments. Was impregnated and attached to each monofilament, the excess was removed by a scraper (3), and the weight ratio of the resin and the reinforcing fiber was adjusted to 1: 1. At this time, the reinforcing fiber bundle (F2) after adjusting the resin adhesion amount is 1970 g
/ M ² . The continuous resin-attached fiber bundle (F2) is guided by guide rolls (13) (14) to the upper and lower endless belts (7) (8).
Continuously feed into the gap.

The upper and lower reinforcing fiber bundles (f1) are continuously passed through the fluidized bed (b) of the powdery thermoplastic resin (B),
After the powdery thermoplastic resin (B) is impregnated between the monofilaments and attached to each monofilament, the excess is removed by the scraper (3), and the weight ratio of the resin and the reinforcing fiber becomes 8: 2. Was adjusted.
The reinforced fiber bundle (f2) after adjusting the resin adhesion amount is cut into 25 mm each by the rotary cutter (6), and the upper cut resin adhesion fiber (f3) is dropped onto the middle continuous resin adhesion fiber bundle (F2). And collect them, and the lower cut resin-attached fibers (f
3) is dropped and accumulated on the feeding portion (8b) into the gap between the upper and lower endless belts (7) and (8). Medium continuous resin-attached fiber bundle (F2)
The width of the feeding part (8b) was 600 mm, and the upper and lower cut resin-adhered fiber bundles (f3) were dropped and accumulated on the entire width so that they were 1740 g / m ² . At this time, the apparent thickness of the both cut resin-adhered fiber assembly (f4) was about 15 mm.

The accumulated product (f4) of both is continuously fed into the gap between the upper and lower endless belts (7) and (8) together with the movement of the medium-position continuous resin-attached fiber bundle (F2), and the intermediate-position continuous resin-attached fiber bundle is Through the (F2), the upper and lower cut resin-adhered fiber aggregates (f4)
While sandwiching between the two endless belts (7) (8) that move at 0 mm / min,
It was passed through a 1500 mm long hot air heating furnace (9) in which hot air of about 200 ° C. was circulated. This guide roll (1
Adjust the gap between the upper and lower endless belts (7) and (8) to 3.1 mm with 8) and pressurize, and then use the guide roll (19) to reduce the gap between the upper and lower endless belts (7) and (8) to 3 mm. It is cooled by a cooling blower (10) while being adjusted to and pressurized.

In this way, the continuous reinforcing fibers (F3) as shown in FIG. 2 are arranged in one direction.
1 mm each with 25 mm long reinforcing fibers (f5) arranged in random directions on both sides of a mm-thick fiber reinforced resin layer (a)
A sheet (S) in which a thick fiber-reinforced resin layer (i) is laminated, a width of 600 mm, a thickness of 3 mm, a resin is well impregnated between the filaments, and the filaments are uniformly dispersed in the fiber-reinforced resin layer (i) Obtained. 500mm x 500mm of this sheet
A test piece of 30 mm × 30 mm was cut out from 5 random places within the range, and treated at 700 ° C. for 5 hours to burn off the resin component, and the glass fiber content was measured. Width 20mm
× Cut a test piece with a length of 150 mm and set the distance between fulcrums to 120
Bending elastic modulus was measured by performing a 3-point bending test in mm. The results are shown in Table 1.

[0041]

[Table 1]

Example 2 Nylon 66 (average particle size 80 μm) was used as the powdery thermoplastic resin (A), and nylon 12 (average particle size 100 μm) was used as the powdery thermoplastic resin (B). Using.

The reinforcing fiber bundle (F1) has a diameter of 7 μm.
The roving-like polyacrylonitrile-based carbon fiber bundle obtained by bundling 6000 monofilaments was used, and the reinforcing fiber bundle (f1) was a roving-like glass fiber bundle (monofilament diameter 14 μm, 1100 g / km).

The same upper and lower endless belts (7) and (8) as in Example 1 were used.

The medium-strength fiber bundle (F1) is continuously passed through the fluidized bed (a) of the powdery thermoplastic resin (A), and the powdery thermoplastic resin (A) is placed between the monofilaments. Was impregnated and attached to each monofilament, and the excess was removed by a scraper (3), and the weight ratio of the resin and the reinforcing fiber was adjusted to 6: 4. At this time, the reinforcing fiber bundle (F2) after adjusting the resin adhesion amount is 1530 g.
/ M ² . This continuous resin-attached fiber bundle (F2) is guided by guide rollers (13) (14) to the upper and lower endless belts (7) (8).
Continuously feed into the gap.

The upper and lower reinforcing fiber bundles (f1) are continuously passed through the fluidized bed (b) of the powdery thermoplastic resin (B), and the powdery thermoplastic resin (B ) And was attached to each monofilament, the excess was removed by a scraper (3), and the weight ratio of the resin and the reinforcing fiber was adjusted to 3: 1. The reinforced fiber bundle (f2) after adjusting the resin adhesion amount is cut into 50 mm each by the rotary cutter (6), and the upper cut resin adhesion fiber (f3) is cut to the middle continuous resin adhesion fiber bundle (F
2) Drop and accumulate the lower cut resin-attached fibers (f3) on the feeding part (8b) into the gap between the upper and lower endless belts (7) and (8). The width of the middle continuous resin-attached fiber bundle (F2) and the feeding part (8b) is 600 mm, and the upper and lower cut resin-attached fibers (f3) are 1400 g / m ² respectively over the entire width. Accumulated by falling.
The apparent thickness of both cut resin-adhered fiber aggregates (f4) at this time was about 10 mm.

Then, in the same manner as in Example 1, a sheet (S) similar to that in Example 1 was obtained except that the length of the reinforcing fiber (f5) of the fiber-reinforced resin layer (i) was 50 mm.

The glass fiber content and flexural modulus of this sheet were measured in the same manner as in Example 1, and the results are shown in Table 2.
Shown in.

[0049]

[Table 2]

Example 3 As the powdery thermoplastic resin (A) and (B), polypropylene pulverized powder (average particle size 130 μm) was used.

As the reinforcing fiber bundles (F1) and (f1), roving glass fiber bundles (monofilament diameter 23 μm) are used.
m, 4400 g / km) was used.

The medium-strength fiber bundle (F1) is continuously passed through the fluidized bed (a) of the powdery thermoplastic resin (A), and the powdery thermoplastic resin (A) is placed between the monofilaments. Was impregnated and attached to each monofilament, and the excess was removed by a scraper (3), and the weight ratio of the resin and the reinforcing fiber was adjusted to 6: 4. At this time, the reinforcing fiber bundle (F2) after adjusting the resin adhesion amount is 1880 g.
/ M ² . This continuous resin-attached fiber bundle (F2) is guided by guide rollers (13) (14) to the upper and lower endless belts (7) (8).
Continuously feed into the gap.

The upper and lower reinforcing fiber bundles (f1) are continuously passed through the fluidized bed (b) of the powdery thermoplastic resin (B), and the powdery thermoplastic resin (B ) And adhering to each monofilament, the excess was removed by a scraper (3), and the weight ratio of the resin and the reinforcing fiber was adjusted to 7: 3. Cut the reinforcing fiber bundle (f2) after adjusting the resin adhesion amount to 12.5 mm with the rotary cutter (6),
The upper cut resin-adhered fiber (f3) is dropped onto the middle continuous resin-adhered fiber bundle (F2) and accumulated, and the lower cut resin-adhered fiber (f3) is attached to the upper and lower endless belts (7) (8). It drops and collects on the sending part (8b) to the gap. The width of the middle continuous resin-attached fiber bundle (F2) and the feeding part (8b) is 600 mm, and the upper and lower cut resin-attached fibers are in the entire width of these bundles.
(f3) was dropped and accumulated so that each was 2090 g / m ² . The apparent thickness of the both cut resin-adhered fiber assembly (f4) at this time was about 11 mm.

Both of them are continuously fed into the gap between the upper and lower endless belts (7) and (8) along with the movement of the medium continuous resin-adhered fiber bundle (F2), and the intermediate continuous resin-attached fiber bundle (F2) is passed through. A 1500 mm long hot air in which hot air of about 200 ° C circulates while sandwiching the upper and middle cut resin-adhered fiber aggregates (f4) with both endless belts (7) (8) moving at 580 mm / min. It was passed through a heating furnace (9). This guide roll (18) adjusts the gap between the upper and lower endless belts (7) and (8) to 4.2 mm and pressurizes it, and then the upper and lower endless belts (7) (7) by the guide roll (19). While adjusting the gap of 8) to 4 mm and applying pressure, it is cooled by the cooling blower (10).

In this way, each fiber reinforced resin layer (i)
The thickness is 1.5mm and the length of the reinforcing fiber (f5) is 12.5m.
A sheet (S) similar to that of Example 1 was obtained except that the total thickness was m and the total thickness was 4 mm.

The glass fiber content and flexural modulus of this sheet were measured in the same manner as in Example 1, and the results are shown in Table 3.
Shown in.

[0057]

[Table 3]

[0058]

According to the fiber composite sheet of the first aspect of the present invention, the presence of the fiber reinforced resin layer (a) is suitable for forming a molded part that requires mechanical strength in one direction, and the fiber The presence of the reinforced resin layer (ii) improves the strength of the entire sheet, and is therefore excellent as a sheet for press molding.

According to the method for producing a fiber composite sheet of the invention of claim 2, since the fiber composite sheet of claim 1 can be continuously obtained, the productivity is good.

The resin is sufficiently impregnated between the monofilaments of the reinforcing fibers, and the reinforcing fibers are well dispersed in the fiber-reinforced resin layer (i) in units of monofilaments, so that the reinforcing effect of the reinforcing fibers is great. The obtained sheet shows excellent physical properties.

Moreover, since the distribution of the reinforcing fiber and the resin becomes uniform, a fiber composite sheet having uniform physical properties can be obtained.

[Brief description of drawings]

FIG. 1 is a side view showing a state in which the same sheet is manufactured by a fiber composite sheet manufacturing apparatus.

FIG. 2 is a partial plan view of a fiber composite sheet in which an upper fiber reinforced resin layer (i), an intermediate fiber reinforced resin layer (a) and a lower fiber reinforced resin layer (i) are sequentially cut out.

[Explanation of symbols]

(A) (B) Thermoplastic resin (A) (I) Fiber reinforced resin layer (F3) Continuous reinforcing fiber (f5) Reinforcing fiber (F1) (f1) Reinforced fiber bundle (a) (b) Fluidized bed (F2) Continuous resin-attached fiber bundle (f2) Resin-attached fiber bundle (f3) Cut resin-attached fiber (f4) Cut resin-attached fiber aggregate (7) Upper endless belt (8) Lower endless belt

Claims (2)

[Claims] 1. A fiber-reinforced resin layer (a) in which continuous reinforcing fibers are arranged in one direction in a thermoplastic resin (A), and a thermoplastic resin (B) having a length of 5 to 100 mm. A fiber composite sheet in which reinforcing fibers are laminated and integrated with a fiber reinforced resin layer (i) in which the reinforcing fibers are randomly arranged in the longitudinal direction. 2. A) a reinforcing fiber bundle composed of a large number of continuous monofilaments is passed through a powdery thermoplastic resin fluidized bed arranged in upper, middle and lower layers, and each filament of the fiber bundle is powdered. A step of adhering the thermoplastic resin in the form of b), b) a step of continuously feeding a medium-sized continuous resin-adhered fiber bundle into the gaps of the upper and lower endless belts facing each other at a predetermined interval, and c) the upper and lower layers. Resin-attached fiber bundles 5-1
Cut it to 00 mm and drop the upper cut resin-attached fibers on the middle continuous resin-attached fiber bundle to accumulate them, and drop the lower cut resin-attached fibers on the feeding part into the gap between the upper and lower endless belts. Stacking and continuously feeding both aggregates into the gap between the upper and lower endless belts along with the movement of the medium continuous resin-attached fiber bundle, and d) cutting the upper and lower layers through the medium continuous resin-attached fiber bundle. A method for producing a fiber composite sheet, comprising a step of passing a resin-attached fiber assembly through both moving endless belts and passing it through a heating region and a cooling region to form a sheet.