JPH0347713A - Composite sheet for fiber-reinforced material - Google Patents

Abstract

PURPOSE:To obtain a composite sheet for a fiber-reinforced material, which is superior in moldability and processability, by a method wherein a quantity of a reinforcing long-sized fiber bundle is of a specific capacity % based on the composite sheet, thermoplastic polymeric fibers are entered into spaces among long-sized fibers constituting a web and entwined each other for unification. CONSTITUTION:A quantity of a reinforcing long-sized fiber bundle within a composite sheet is 5-80vol.%, preferably 30-80vol.%, far preferably 45-70vol.% based on a composite sheet. In the case where the quantity of the reinforcing long-sized fiber bundle is less than 5vol.%, the composite sheet is inferior in strength or the other physical properties and in the case where the quantity of the same exceeds 80vol.%, a void rate becomes high and the same is inferior in the strength and the other physical properties. Then the composite sheet, which is easy in mixing and entwined each other at far larger number of places as compared with fabric or knitting, is obtained by mixing a thermoplastic polymer fiber with the composite sheet under a single fibrous state whose degree of freedom is high. This composite sheet, which does not fall into pieces even if the same is cut into fine pieces, has extremely high shape retension properties and is superior in workability.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a composite sheet for fiber-reinforced materials, and more specifically, the present invention relates to a composite sheet for fiber-reinforced materials, and more specifically, it is composed of a web containing reinforcing long fiber bundles and thermoplastic polymer fibers, and is made of a composite sheet for fiber-reinforced materials. This invention relates to a composite sheet that has a suitable entangled mixture state and has excellent moldability and processability.

(Prior Art) In recent years, fiber-reinforced materials made by bonding reinforcing fibers with various matrix resins have been known to have excellent properties such as high strength, high rigidity, low specific gravity, and high fatigue resistance. Because of this, it is expected to have a wide range of uses and is attracting attention as an industrially important material.

Generally, when obtaining a fiber-reinforced material in which these reinforcing fibers are combined with a matrix resin, the resin is easily dispersed uniformly in the fibers, and is flexible and has excellent shapeability.
Thermosetting resins that have excellent fluidity in an uncured state are generally used.

However, in the curing reaction of these thermosetting resins, -
Boat fishing requires high-temperature and pressurized conditions for a long period of time (usually more than an hour), which poses problems in productivity and limits the general spread of fiber-reinforced materials.

Attempts have been made to use thermoplastic polymers instead of thermosetting resins (for example, JP-A-58-29651). The thermoplastic polymers used for these fiber-reinforced materials have high rigidity at room temperature, and for this reason, it is necessary to simply impregnate the fibers with a polymer solution and then add a solvent to the fibers, or to heat-melt a sheet-like film and insert it into the fibers. A method of press-fitting and dispersing is adopted.

However, the prepreg obtained by the above method is rigid at room temperature, has poor shapeability, and the fibers break when bent forcibly, so its use is limited.

Therefore, in recent years, the development of prepreg reinforcing fiber bundles using thermoplastic polymers with excellent formability as a matrix has been actively conducted.
Mixing with reinforcing fibers is disclosed in JP-A-60-56545 and JP-A-60-209033.

In JP-A No. 60-56545, thermoplastic polymer fibers (hereinafter abbreviated as "FTP fibers") and reinforcing long fibers are simply fiber bundles spliced together, and both fibers are uniformly mixed. Not thin. Although this mixture has fewer single fiber breaks in the reinforcing long fibers and is easy to handle in subsequent processes, it has the disadvantage that it is difficult to uniformly impregnate the reinforcing long fibers with the polymer during hot melt molding. be.

In JP-A-60-209033, an attempt is made to mix single fibers with each other in order to facilitate impregnation with a molten thermoplastic polymer. However, products made by mixing long fiber bundles (continuous filament bundles) at the level of single fibers are in the form of yarn, and in order to make a molded product for practical use,
It is necessary to form this into a sheet, cut it into desired fiber orientation angles and sizes, laminate a plurality of sheets, and then melt, cool, and solidify. In particular, in order to make it into a sheet so that it can be handled for lamination work, a method is adopted in which it is made into a woven or knitted fabric. However, in the weaving process, many yarns are lined up in a narrow space and undergo mechanical reciprocating motion many times, so fuzz is likely to occur. The force that holds it in a woven form is the frictional force between the reinforcing long fiber bundle and the reinforcing long fiber bundle that intersects at right angles to the reinforcing long fiber bundle, and this frictional force does not work on the end surface after cutting, and the yarn spills. Since reinforcing long fiber bundles that cause yarn spillage are generally untwisted to increase their strength, there is no force to hold them together, and they separate into single fibers with a slight force and float. There were many problems in the process, such as the needle sticking to the human body.

Furthermore, as will be described later, reinforcing long fiber bundles are generally produced as thicker bundles than clothing fibers, and when made into a composite, strength and rigidity are required.
It is woven without twisting and with a weaving density of 15 threads/cm or less, preferably 8 threads/cm or less, to reduce bending of the threads. Therefore, when it is cut into a simple polygon close to a circle, it can be handled relatively easily as a sheet, but when it is cut into a complicated shape, such as an oval shape, it falls apart and becomes extremely difficult to handle as a sheet.

A method in which reinforcing long fibers and thermoplastic polymer long fibers are combined and aligned to form a warp, and only the thermoplastic polymer long fibers are used as a weft to form a plain weave sheet (Japanese Patent Application Laid-Open No. 60-28543).
, and a method for producing a knitted fabric in which reinforcing long fiber bundles are wound around thermoplastic polymer fibers (Japanese Unexamined Patent Publication No. 60-45362) has been proposed. However, in these plain woven sheets and knitted fabrics, the thermoplastic polymer fibers and the reinforcing long fibers are not uniformly mixed, and the resulting composite has poor mechanical strength, especially in the direction perpendicular to the reinforcing long fiber bundles. Poor tensile strength.

Furthermore, a sheet-shaped product made by mixing reinforcing short fibers and thermoplastic polymer short fibers has also been proposed (Japanese Patent Publication No. 1986-
Publication No. 1969). This is because the reinforcing fibers are short fibers, and the direction of the fibers is randomly arranged, and compared to a sheet made of long reinforcing fibers, the reinforcing fibers intersect with each other at a much higher rate. requires a large amount of space, which limits the amount of reinforcing fibers that can be filled;
As a matter of course, short fibers have the problem of poor reinforcing effect, which severely limits their use in applications requiring high performance.

Furthermore, in the above-mentioned sheet-like products, the fibers are mixed, but not intertwined and integrated, so the reinforcing fibers are very easy to separate, especially when dried, and can stick to and sting workers during handling. Also, even if you try to bond with heat fusion or adhesive, it is difficult to control the flexibility.
There was a drawback that if too much adhesive was applied, flexibility would be lost.

In addition, the above-mentioned sheet-like products have a very low bulk density after drying, so when inserting them into a press mold, a long stroke is required, and when performing autoclave molding,
There are also drawbacks such as the bagging film wrinkles and remains on the surface of the molded product, so it has not been widely used.

[Problem to be solved by the invention]

Based on the above circumstances, regarding the reinforcing long fiber and TP woven fiber mixed sheet, a material in which the side fibers are well mixed and intertwined has not been found so far, and the development of this material has been strongly desired. .

It is an object of the present invention to provide a composite sheet for fiber-reinforced materials that satisfies such demands and has excellent moldability and processability, in which fibers are uniformly mixed and intertwined and integrated.

[Means to solve the problem]

The present invention provides a composite sheet comprising a web containing reinforcing long fiber bundles and monofilament thermoplastic polymer fibers, wherein the amount of the reinforcing long fiber bundles is 5 to 80% based on the composite sheet.
% by volume, and the thermoplastic polymer fibers are entangled and integrated among the long fibers constituting the web, to provide a composite sheet for a fiber reinforced material.

The above-mentioned composite sheet for fiber-reinforced materials is produced by depositing or containing thermoplastic polymer fibers in the form of single fibers in a web containing reinforcing long-fiber bundles, and applying a fluid jet to the long-fiber fibers constituting the web. It can be produced by interlacing and integrating the thermoplastic polymer fibers between the fibers.

In the present invention, a reinforcing long fiber bundle is used. Generally, reinforcing fibers have high strength per unit cross-sectional area, but are highly rigid and have an elongation of 15% or less, so they are very weak in the form of thin single fibers, so they are produced in bundles. and,
A plurality of these bundles are arranged in parallel, woven, or knitted to form a sheet and used.The present invention is applied to such a sheet-like reinforcing long fiber web.

In the present invention, the term "web" refers to a flat aggregate of fibers with or without shape retention, and the term "sheet" refers to a flat fiber assembly with shape retention. Specifically, in the present invention, a sheet refers to an aggregate of fibers, and refers to a sheet having a width-to-thickness ratio of 2 or more, preferably 6 or more.

In the present invention, as the web, a web in which reinforcing long fiber bundles are aligned in one direction, a woven sheet such as a plain weave or a satin weave, and a knitted sheet are used. especially,
Weaving density is 15/(1 or less, more preferably 8/
Fabric sheets of cm or less in size and webs in which reinforcing long fiber bundles are aligned in one direction (hereinafter abbreviated as "rUD web") are more preferable. This is because these can effectively provide the molded product with strength and rigidity in the necessary directions.

Among them, UD Web is the best. In the reinforcing long fiber bundle constituting the UD web, it is preferable that the individual long fibers are aligned in one direction and the reinforcing long fibers are not intertwined with each other. The presence or absence of entanglement can be easily observed by extracting and removing only the thermoplastic polymer fibers from the composite sheet using a solvent.

The reason why the UD web is superior to the fiber sheet is considered to be as follows. In textiles, the threads bend at the intersection of the warp and weft,
Since the reinforcing long fiber bundles are bundled by this bending, when a composite is made, the reinforcing long fibers are not uniformly dispersed in the composite, stress concentration occurs, and the mechanical properties are poor. In addition, because the boundaries between the warp or weft are clear, when made into a composite, a thermoplastic polymer-rich part is created that extends in the direction of the reinforcing long fibers, and the direction perpendicular to the reinforcing long fibers of the composite. This results in poor strength.

The term "reinforcing long fibers" as used in the present invention refers to substantially continuous fibers used in fiber-reinforced materials, such as carbon fibers, glass fibers, aramid fibers, silicon carbide fibers, boron fibers, metal fibers, Examples include polybenzothiazole fiber, polybenzoxazole fiber, and alumina fiber.

In addition to multifilaments, the reinforcing long fibers include those such as spun yarn, which are not continuous as single fibers but can be treated as substantially continuous fibers. Among these, untwisted continuous filaments are preferably used because they have high strength and elastic modulus when made into a composite material.

In the present invention, thermoplastic polymer long fibers can also be used as reinforcing long fibers as long as they do not substantially melt in the step of heating and melting the thermoplastic polymer fibers and exhibit a reinforcing function after cooling and solidifying. Examples include liquid crystalline thermoplastic polymer long fibers, ultra-high molecular weight polyethylene fibers, polyvinyl alcohol fibers, and rayon and other cellulose-based 1a fibers. Among long reinforcing fibers, elastic modulus is 3000kg/mff12 or more, especially 50
00kg/round 2 or more, and tensile strength is 100kg/
Fibers with a diameter of 2 mm or more are preferred. Examples of such reinforcing long fibers include carbon fibers and aramid fibers.

These reinforcing long fibers must be coated with a thermoplastic polymer on the surface of the single fibers so as not to lose flexibility, in order to facilitate impregnation with the thermoplastic polymer fiber melt during heating and melting during composite formation. is preferred.

The web comprising a reinforcing long fiber bundle as used in the present invention includes a web comprising only a reinforcing long fiber bundle, and a web comprising a reinforcing long fiber bundle and thermoplastic polymer fibers and/or thermoplastic polymer particles. The operation of incorporating thermoplastic polymer fibers or particles into the zero-reinforced long fiber bundle containing the web may be performed at any step before or after forming a composite sheet, but in the case of thermoplastic polymer fibers, This is done before forming into a sheet, and in the case of thermoplastic polymer particles, after forming into a composite sheet. By mixing these thermoplastic polymer fibers and particles, it becomes easier to impregnate the reinforcing long fibers with the thermoplastic polymer. The fibrous or particulate thermoplastic polymer that may be contained in this web and the monofilament thermoplastic polymer do not have to be the same, as long as there is no adverse effect on the physical properties of the material after melt impregnation and cooling. are preferably the same.

The amount of reinforcing long fiber bundles in the composite sheet is 5 to 80% by volume, preferably 30 to 80% by volume, more preferably 45 to 70% by volume, based on the composite sheet. If the amount of reinforcing long fiber bundles is less than 5% by volume, strength and other physical properties will be poor;
If the amount of the reinforcing long fiber bundle exceeds 80% by volume, the void ratio will be high and the strength and other physical properties will be inferior.

In the present invention, "thermoplastic polymer fiber J (TP woven fiber) refers to a material obtained by applying heat or a solvent to a thermoplastic polymer and spinning it into fibers by known means, and the form of the fiber is particularly limited. It does not include fibers in the narrow sense, but also includes fibers.

"Thermoplastic polymer" refers to a polymer that flows at temperatures below the decomposition temperature of the polymer. Examples of thermoplastic polymers include polyolefins, thermoplastic polyesters, thermoplastic polyamides, acrylic resins, polyoxymethylene, polycarbonate, polyphenylene ether, polystyrenes, polyphenylene sulfide, polyether, ether ketone, and polyether ketone. , polyetherimide, polyetherketone, thermoplastic polyamideimide, fluororesins, or copolymers thereof. These may be alloyed in the fibers, or two or more types of thermoplastic polymer fibers may be used as long as the physical properties of the composite sheet are not impaired.

In the present invention, "monofilament" does not mean that the fibers are woven or knitted to form a cloth (e.g., short fibers are arranged randomly or in one direction or in multiple directions to form a monofilament). It is made into a non-woven fabric with a degree of freedom,
It is made into a non-woven fabric by arranging long fibers in a swirl shape to give it flexibility.

In the present invention, by mixing thermoplastic polymer fibers in the form of single fibers with a large degree of freedom, a composite sheet can be obtained that is easy to mix and is entangled at a far greater number of points than woven or knitted materials. . This composite sheet does not fall apart even when shredded, has extremely high shape retention performance, and is excellent in workability.

The blending amount of the monofilament thermoplastic polymer fiber is not particularly limited, and is determined based on colorability, adhesiveness, oxidation resistance, smoothness,
For the purpose of improving easy impregnability, when a TP film and a thermosetting resin are used together, or when the surface of reinforcing fibers is coated with a resin, it can be varied within a wide range. However, the amount incorporated is generally at least 0.1% by volume, preferably at least 1% by volume, based on the composite sheet.

If the amount is less than 0.1% by volume, the resulting composite sheet will lack shape retention. In particular, in order to obtain a fiber-reinforced material with high strength and high elastic modulus with a void ratio of 5% or less, 20 to 95 volume % is preferable. is preferably 30 to 70% by volume, particularly 30 to 55% by volume.

The cross-sectional diameter of the TP woven fibers may be not extremely thick compared to the cross-sectional diameter of the reinforcing fibers, but may be a thickness that is flexible and can be freely bent. Preferably, the cross-sectional diameter of the reinforcing fiber is 1
It is 0 times or less, more preferably 5 times or less. Two or more types of TP woven fibers with different thicknesses may be used to adjust mixability and shape retention.

In this specification, the term "freedom of the rTP long fibers" refers to the degree of freedom of the rTP long fibers that allows the fibers to sneak into the reinforcing long fibers without being cut when the TP long fibers are subjected to mechanical action. Focus on one point (referred to as point A) of a single continuous filament that has a shape. The two points where this continuous single fiber crosses a circle with a radius of 5C1 centered on point A are designated as point B. The length of the continuous single fiber from one point B to the other point B is measured with the fiber stretched in a straight line, and the length is 1
The value when divided by 0 cm is defined as the degree of freedom.

The degree of freedom of the TP long fibers used in the present invention is preferably 1.2 or more, more preferably 1.5 or more, and even more preferably 3.0 or more, from the viewpoint of ease of mixing.

The short thermoplastic polymer fibers used in the present invention have a length of 100 mm.
cm or less and L/D (the value obtained by dividing the length of the fiber by the diameter of the fiber) is 100,000 or less. Preferably, the length is 10 cm or less and the L/D is 1,000,000 or less. be.

Particularly preferably, fibers with a length of 30 mm or less have a high degree of freedom and are easy to mix and entangle.
Fibers with lengths longer than the above can also be suitably used by providing a large degree of freedom in terms of morphology (for example, by crimping or depositing them in a swirl shape). In addition, the lower limit of the fiber length is 5 as L/D.
The number is preferably 50 or more, and more preferably 100 or more for ease of entanglement and shape retention. Further, the absolute length is 10 times or more the diameter of the reinforcing fiber, preferably 50 times or more for ease of shape retention.

"Entanglement" as used in the present invention refers to a state in which the TP woven fibers 9 enter into a bundle of reinforcing long fibers and are mixed three-dimensionally. Most of the single fibers in each book are intertwined in an interstitial manner. Moreover, "integrated" refers to a state in which the TP woven fiber single fibers are entwined with each other and the reinforcing long fibers and are in a bundled state in which they do not come off under their own weight. For integration, it is preferable that at least the TP woven fibers are arranged in a direction different from that of the reinforcing long fiber bundles.More specifically,
When handling the entire sheet, use an inner diameter of 10 cm from the sheet.
, a donut-shaped sample with an outer diameter of 11 CII was cut out, and its -
One of the key features of the product is that it retains its donut shape when held between two fingers and lifted.

In particular, in the case of unidirectional reinforcing long fiber bundles, integration means that when handling the entire sheet, it is possible to grasp a part of the sheet and handle it as a whole.
Furthermore, specifically, unidirectional reinforcement long fiber bundle sea) (
In the case of UD receipt, the tensile strength in the direction perpendicular to the reinforcing fiber direction is 8 g/c or more, preferably 50 g/c
Above, more preferably 200 g/cd or above.

If this integration is achieved, even when cut into fine and complex shapes, they will not fall apart, making it easier to stack them, set them into molds, etc.

Furthermore, as an unexpected effect, it is estimated that the TP polymers are not aligned in the direction of the reinforcing fibers and are three-dimensionally random when melted, cooled, and solidified. High strength in the direction perpendicular to the fiber direction,
In particular, when using liquid crystalline thermoplastic polymer fibers, such as thermoplastic aromatic polyester resins, which exhibit liquid crystallinity in the molten state and exhibit significant anisotropy depending on the orientation direction of the liquid crystal upon cooling and solidification, the strength in the perpendicular direction increases. A significantly higher reinforcement material is obtained.

Furthermore, by closely arranging the rigid reinforcing long fibers, the bulk density increases, making it easier to insert into a drawing die, making it easier to fill a press mold, and improving the volume before and after processing during autoclave molding. Since the change is small, wrinkles due to shrinkage of the bagging film are reduced.The bulk density of the composite sheet is preferably 0.1 gZC- or more, particularly preferably 0.3 g.
/cd or more.

In the composite sheet of the present invention, inorganic or organic filler whiskers, pigments,
One or more types of plasticizers etc. may be included as necessary.
In particular, in order to improve the strength and elastic modulus in the direction orthogonal to the reinforcing long fiber bundle, whiskers such as vapor-grown short carbon fibers, potassium titanate whiskers, and silicon carbide whiskers are added to the composite sheet at a capacity of 0.1 to 20%. % is useful.

Next, the method for producing the composite sheet of the present invention will be explained. The method for obtaining the composite sheet of the present invention is not particularly limited, but preferably, the web containing reinforcing long fiber bundles is coated with thermoplastic resin. A method is adopted in which short or long polymer fibers are deposited or contained in the form of single fibers, and a fluid jet is applied to intertwine the thermoplastic polymer fibers between the long fibers constituting the web to intertwine and integrate them. It will be done.

The thermoplastic polymer may be made into fibers by any of wet spinning, dry spinning, and melt spinning, and is selected depending on each resin. In a preferred embodiment using short fibers of a thermoplastic polymer, the spun fibers of the thermoplastic polymer are cut or pulled into short fibers, the short fibers are dispersed in a liquid, and the dispersion is made into paper. T where the fibers are randomly oriented
A P short fiber web is obtained. On the other hand, a web in which many reinforcing long fiber bundles are aligned in one direction is prepared, and this web and TP
A short fiber web is laminated. Further, in a preferred specific example using long fibers of a thermoplastic polymer, the thermoplastic polymer is heated and melted, and a large number of reinforcing long fiber bundles are aligned in one direction. It is injected into a spindle that is forcibly oscillated in the right angle direction to form fibers, and
A gas stream is applied to the spinning holes, and while the yarn is stretched, it is shaken off onto the web of reinforcing long fiber bundles to form a sheet, which is then laminated.

Next, a mechanical force is applied by a fluid jet to the laminate of the sheet of TP short fibers or long fibers and the web of reinforcing long fiber bundles. That is, this TP fiber sheet and a web of reinforcing long fiber bundles are laminated in two, three, or four or more layers (there are also cases in which the reinforcing fibers are laminated by changing the direction or type of the reinforcing fibers). Then, the force of the fluid jet is applied so as to penetrate from the direction perpendicular to the surface of this sheet, and the T
The P-woven fibers are embedded in a web of reinforcing long fiber bundles and intertwined with individual reinforcing fibers to obtain an integrated composite sheet. The method of entangling the reinforcing fibers by applying a fluid jet is preferable because the reinforcing long fibers are difficult to break and the mixed sheet obtained without mixing the rigid reinforcing long fibers has a high bulk density.

The fluid jet used here is obtained by discharging high-pressure fluid to atmospheric pressure through a nozzle having a bow or slit-like orifice.

The pressure of the fluid and the size of the orifice of the nozzle vary depending on the position and direction of the nozzle, but in general, a pressure of 3 kg/C to 400 kg/C is preferably used, and the pore diameter of the nozzle Those with a diameter of 0.05 to 2 mm are preferably used.

The fluids used are not particularly limited, and include liquids,
It may be a gas, a liquid/gas mixture, a solid/liquid mixture, a solid/gas mixture, etc., but it is preferable to use one with a high density because it is necessary to impart a large mechanical mixing effect to the fibers. Specifically, the density is preferably 0.1 g/cff1 or more. Water is used for boat fishing because of availability and safety. When processing with a fluid jet, it is preferable to quickly remove the fluid that has lost kinetic energy by means such as vacuum suction.

Of course, the object of the present invention can also be achieved by using a woven sheet or a knitted sheet instead of a web of reinforcing long fiber bundles aligned in one direction.

In addition, a preferred alternative method using short thermoplastic polymer fibers is to pre-incorporate TP short fibers into the reinforcing long fiber bundles and apply a fluid jet to this web in the same manner as described above.
It is also possible to intertwine and integrate TP short fibers.

After impregnating the above composite sheet with a thermoplastic polymer emulsion, it is dried at a temperature below the minimum film-forming temperature or sprayed with polymer particles to improve mixability without sacrificing the flexibility of the composite sheet. can be improved. In addition, after mixing by the mechanical action of a fluid jet, T
The TP woven fibers are heated at a temperature above the temperature that causes thermal deformation of the P woven fibers but below a temperature at which they do not fuse, and the TP woven fibers are deformed, and the reinforcing long fibers are pressed to the extent that they do not break to increase the bulk density. , an integrated sheet may be obtained.

Hereinafter, the present invention will be explained in more detail with reference to Examples. However, the present invention is not limited to these Examples in any way.

Example 1 A 770 denier/770 filament long fiber bundle was obtained by melt spinning a nylon 66 polymer (Leona Polymer, manufactured by Asahi Kasei Kogyo). This long fiber bundle was wound up so as not to be twisted so as to be easily opened, and water-soluble PVA (polyvinyl alcohol) was added as a sizing agent. Collect a large number of these long fiber bundles and use a guillotine cutter to cut them into 5 m long fibers.
The fibers were cut into lengths of m to obtain TP short fibers.

When observed under a microscope, this TP short fiber was a cylinder with a diameter of 11 mm and an L/D of 455.

Next, the short fibers were put into water and polyacrylamide was added to make a slurry liquid having a viscosity of 100 cp.
A rectangle with a width of 50C111 and a length of 100cm, with 2
The slurry liquid was uniformly injected into the bottom of a water tank covered with a wire mesh of 0.00 mesh to obtain a paper-made sheet having a basis weight of 64 g/1yf.

When observing the direction of the short thermoplastic polymer fibers in the paper sheet, it was found that the direction was completely random.

Next, PAN-based carbon fiber (manufactured by Shin-Asahi Kasei Carbon Fiber, Hi-Carboron 6Kf yarn, 6000 single fibers, 3
600 denier, tensile strength 400kg/W1m".

375 reinforcing long fiber bundles with a tensile modulus of elasticity of 23 ton/am" and a diameter of 7 Jna) were arranged to have a fabric weight of 300 g.
/ nf, sheets arranged in a width of 5010 without gaps were placed on the above-mentioned TP short fiber paper sheet. Next, a sheet of TP short fibers having a basis weight of 64 g/nf was created on top of this sheet by the same method as for the TP short fiber paper sheet, and formed into a sandwich shape. Next, this sand inch sheet was placed on a 200-mesh wire mesh and was placed in a straight line at equal intervals of l mn+.
．． Using 500 2 m nozzles, the distance between the nozzle and the sheet was 30 mm, and the entire surface of the sheet was free of corners.
Water at a pressure of d was applied perpendicularly from above the sheet surface several times on the front and back sides. Furthermore, water at a pressure of 40) cg/cd was applied three times to the front and back sides, and the composite sheet was dried to obtain a composite sheet. This composite sheet was embedded between the individual long fibers of the TP woven fiber reinforcing long fiber bundle, and had a structure in which the TP fibers and the TP woven fiber reinforcing long fibers were intertwined and integrated. Even when the edge of the sheet was pinched between the index finger and thumb and lifted, the 50 cm x 100 cm sheet remained intertwined without falling apart, and was highly flexible.

From this composite sheet, the outer diameter is 11CTII, the inner diameter is 10cm,
When I cut out a donut with a width of 5 mm, it turned out that 1 of the donut was
It was found that the sheet did not fall apart even when picked up with fingers, and the threads did not come undone from the ends, making it a sheet with excellent workability that could be handled like a sheet of paper.

A tape with a width of 2.5C11 and a length of 15 cm was cut out from the composite sheet in the direction perpendicular to the reinforcing long fibers, and its tensile strength was measured to be 3310 g/aa.

Next, the above composite sheet was cut into 10 cm square pieces, placed on a flat surface, a 3 aa thick iron plate was placed on top, the thickness was measured, and the weight of the sheet was measured to determine the bulk density, which was 0.36. g/cd.

I tried to treat the above composite sheet with concentrated sulfuric acid to gently dissolve and extract only the nylon polymer, make a sheet made of only carbon fibers, and measure the strength in the direction perpendicular to the carbon fibers, but I tried to measure the strength in the direction perpendicular to the carbon fibers. When I tried to lift it up, it fell apart.

The tensile strength was below Ig/aa.

A 10C11 square sheet was cut out from the above composite sheet, one layer in the 0 degree direction, two layers in the 90 degree direction, and one layer in the 0 degree direction, wrapped around a semi-cylindrical cylinder with a diameter of 7C1 m, and covered with a Teflon film. was sealed with Teflon rubber, and while creating a vacuum inside the film, it was placed in an autoclave and treated at 300°C x 20kg/cdx for 30 minutes, and after cooling and solidifying, it was taken out and the film was removed.
Molded into a semi-cylindrical shape. When I cut out a part of this and measured the density, it was the same as the theoretical density, and the void ratio was 0.1
% or less.

Further, when the cross section was observed with an optical microscope at a magnification of 200 times, no voids were observed.

Example 2 The nylon 66 long fiber bundle obtained in Example 1 was inserted into one opening at the top of a Y-shaped pipe, and water was poured through the other opening so that the filament was drawn into the water flow and flowed downward. The filament was discharged from the bottom. The pipe was moved by vibrating 30 times per minute so that the amplitude was 2 cm, and the pipe was made into a rectangle with a width of 50 cm and a length of 100 cm, and was placed evenly on the bottom of a water tank with a 200 mesh wire mesh on the bottom. After shaking off the long fiber bundle, the basis weight is 64 kg/r.
I created an rf sheet.

One single fiber was carefully selected from the prepared sheet so as not to break, and the degree of freedom of this single fiber was measured and found to be 4.7.

Next, the PAN-based carbon fiber sheet obtained in Example 1 was placed on top of this sheet. Next, a nylon 66 long fiber east sheet was prepared on top of this sheet in the same manner to form a sandwich. This sandwich sheet was then treated and dried in the same manner as in Example 1 to obtain a composite sheet.

This composite sheet had a structure in which the TP fibers and the TP woven fiber-reinforcing long fibers were intertwined and integrated by entering between the individual long fibers of the TP woven fiber-reinforcing long fiber bundle. Even when the edge of the sheet was pinched between the index finger and thumb and lifted, the 50 cm x 100 cm sheet did not fall apart, maintained its integrity, and was highly flexible.

The tensile strength of the composite sheet was measured in the same manner as in Example 1, and was found to be 1930 g/c+fl. moreover,
Cut this composite sheet into 10cm squares and place it on a flat surface.
The bulk density was determined by placing a 3m thick iron plate on top and measuring the thickness, and also by measuring the weight of the sheet, and found that it was 0.
．． It was 38 g/ctA.

Comparative Example 1 In Example 2, the pipe was vibrated 30 times per minute, but instead of being vibrated at all, the pipe was lengthened while adjusting the shaking direction so that it was approximately 90 degrees to the direction of the reinforcing long fibers. The fiber bundle was shaken off in the direction of the lungs to obtain a sheet.

The degree of freedom of the single fibers in this sheet was measured in the same manner as in Example 2 and found to be 1.1.

A composite sheet was obtained from the above sheet in the same manner as in Example 1. However, in this composite sheet, the long thermoplastic polymer fibers were not intertwined, and when the edges of the sheet were pinched and lifted, it fell apart, resulting in extremely poor handling properties.

Example 3 In Example 1, the basis weight of the TP short fibers was changed to 42.5 g/bo, and the unidirectional carbon fiber sheet was made of Hicarboron 3Kf yarn (number of single fibers: 3000), and the weaving density was changed to warp. Hand-woven sheet with 5 pieces/cm in both weft and weft (weighing 198g/
A composite sheet was obtained in exactly the same manner except that the material was changed to (rrr). This composite sheet has an outer diameter of 11 marks and an inner diameter of 10 marks.
cm, width 51T [II+] When I cut a donut-shaped sample, it did not fall apart even if I pinched one part of the donut with my fingers and lifted it, and the thread did not come undone from the end, making it look like a sheet of paper. It was found that the sheet has excellent workability and can be handled easily. As a result of measuring the bulk density, it was 0.33g/
It was a CD.

For comparison, when a donut-shaped sample was cut from the carbon fiber plain weave sheet used in this example in the same manner as above, the threads came undone from the end surface, making it very difficult to handle (the sheet was difficult to pick up with fingers). When I picked it up, it fell apart and I had to be very careful to handle it.

Example 4 Instead of the nylon 66 fiber used in Example 1, 780
Two types of short fibers with a length of 10 mm and a length of 5 strands were obtained in the same manner as in Example 1 from continuous fibers of polyether ether ketone polymer (manufactured by Imperial Chemical Industries, trade name: Pictrex) of denier/390 filament. Ta. Next, these short fibers of different lengths were placed in separate containers to form a slurry. The carbon fibers used in Example 1 were continuously introduced into a slurry of 5 mm long short fibers while being opened, and a clothing cloth with needles implanted at 4 mm intervals was stabbed into the carbon fiber bundle and released. The process was repeated to fully open the fibers in the liquid, and the fibers were gently pulled up to obtain a short fiber mixed reinforced long fiber bundle in which 36 g of short fibers were dispersed in the carbon fiber bundle per 100 g of carbon fibers.

This fiber bundle was aligned in the same manner as in Example 1, and the fabric weight was 40.
It was made into a sheet of 8 g/rrf. This sheet did not have short fibers entangled with it, and would fall apart when lifted by hand.

Carefully place the above sheet on piano wire stretched parallel to each other at 4 mm intervals and carry it. Separately, use 10 mm long short fibers to make two sheets with a fabric weight of Log/n.
The above sheets were laminated with the sheets sandwiched between them. This lamination operation was performed through the piano wire, and after lamination, the piano wire was gently pulled out one by one. Next, treatment with a high-pressure water stream was carried out in exactly the same manner as in Example 1, and an intertwined and integrated composite sort was obtained that did not fall apart even if the edges were held by hand. When this cross section was cut and observed, it was found that the reinforcing long fibers and short fibers were more uniformly mixed than in Example 1. The tensile strength of this composite sheet in the direction perpendicular to the reinforcing long fibers is 3510 g/cd, and the bulk density is 0.
．． It was 38g/d.

Example 5 A sheet in which the short fiber mixed reinforcing long fiber bundles used in Example 4 were aligned in one direction was prepared so that the short fibers were aligned with the reinforcing long fibers,
In order to line up in the right angle direction, the diameter of the sharp tip is 1
A skewer with ms+ needles implanted at 511II1 intervals is pierced perpendicularly to the sheet so as to be perpendicular to the direction of the reinforcing long fiber bundle, and in the pierced state is moved 3111aI parallel to the direction of the reinforcing long fiber bundle, I pulled it out. In this way, the operation of arranging only the short fibers in the right angle direction was performed over the entire surface of the sheet without corners. This sheet was subjected to high-pressure water jet treatment and dried in the same manner as in Example 1. When I took this sheet out after drying, I found that the short fibers were evenly mixed and intertwined into a single piece, and it did not fall apart even when I lifted it with both hands, making it easy to work with. The strength in the direction perpendicular to the reinforcing long fibers is 1850 g/cdl, and the bulk density is 0.34 g
/ It was cla.

Comparative Example 2 The 811I11-cut short fibers of nylon 66 used in Example 1 and the 8[1I11-cut carbon fibers cut in the same way were mixed in a weight ratio of 7 parts carbon fiber and 3 parts nylon 66 fiber to form a paper. Got a sheet. This sheet was dried and the bulk density was measured in the same manner as in Example 1 and was found to be 0.037.
It was extremely bulky at g/c+J. What's more, when you held it in your hands after drying it, it immediately fell apart, and the carbon fibers stuck to your hands, making them extremely difficult to handle.

Example 6 In Example 1, the amount of TP short fibers added was adjusted to adjust the basis weight of the short fiber paper sheets, and composite sheets with different blending ratios of carbon fibers as shown in Table 1 were created. Cut each composite sheet into a 30cm x 30cm square, and using a matte die of the same size, heat at 300℃ x 30 minutes x 20 minutes.
A sample plate was prepared under the condition of kg/cd, and the bending strength was measured.

For comparison, a plate was prepared under exactly the same conditions as in Comparative Example 2 by adjusting the amount of TP short fibers, making the length of carbon fiber 25 m, and adjusting the blending ratio of carbon fiber, and measuring the bending strength. The results are shown in Table 1. Note that the composite sheet of the comparative example with a low bulk density has a thickness of 1Qc in order to obtain a thickness of 3am.
Since it exceeded m and could not fit into the mold, it was divided into two or more parts to obtain a plate.

As can be seen from Table 1, when the blending ratio of reinforcing fibers is less than 5 volume pairs, there is no big difference compared to the conventional one of Comparative Example 2, but when it is 5% or more, there is a large difference in physical properties. In particular, when the blending ratio of reinforcing fibers exceeds 30% by volume, the void ratio of the comparison example increases and strength and other physical properties deteriorate, so that the difference between the two becomes even larger. However, it can be seen that when the blending ratio of reinforcing fibers exceeds 80% by volume, the void ratio increases and the strength and other physical properties deteriorate.

Example 7 Instead of the Chinlon 66 fiber of Example 1, 900 denier/300 filament polyetheretherketone (hereinafter abbreviated as rPEEK J) long fibers were used,
Short fibers having a length of 15 strands and 2.5 mm were obtained in the same manner as in Example 1. Two types of short fibers were added to water at a weight ratio of 1:1,
Polyacrylamide was added to form a slurry liquid having a viscosity of 100 cp, and then paper was made using an inclined paper making machine having a width of 50 cm and a wire mesh of 80 meshes to obtain a PERK staple fiber sheet with a basis weight of 73 g/I.

Next, a sheet of the same long-fiber carbon fiber as in Example 1 was made into a sheet with a width of 50 cm and a length of 60 cm in order to prevent the sheet from widening.
It was fixed in the frame of I11 and kept under tension. On top of that, the above PE
EK staple fiber sheets were layered. Then, this laminated sheet was placed on an 80-mesh wire mesh, and using 100 nozzles with diameters of 0 and 2111111 arranged in a straight line at 5-mesh intervals, the entire surface of the sheet was continuously sprayed without corners at a pressure of 20 kg/afl. A high-pressure water stream is ejected vertically from above the seat surface.
one application, then four applications at a pressure of 50 kg/cTa. Furthermore, the sheet is turned over and fixed to a frame to give tension to the carbon fibers, and the PEEK short fiber sheets are stacked and treated with high-pressure water jet in the same manner as above. A composite sheet in which the fiber sheets were entangled and integrated was obtained.

The tensile strength of the composite sheet in the direction perpendicular to the reinforcing long fibers is 3120 g/cn, and the bulk density is 0.34 g/c
111, and even if cut finely as in Example 1,
It was a sheet with excellent workability that could be handled like paper.

Using the mold used in Example 6, stack seven of the above composite sheets with the reinforcing fibers aligned in the same direction, and heat at 360°CXl0kg/c.
The mixture was melted, impregnated, cooled, and solidified under the conditions of nl×5 minutes to obtain a plate-like composite (CI). The content of carbon fiber in the machine was measured using concentrated sulfuric acid and found to be 60% by volume. This board was a uniform black composite. When the cross section of the plate was observed under a microscope, the carbon fibers were found to be uniformly dispersed (see Figure 1). The strength of the plate in the 0 degree direction is 168
．． 5kg/kaku2 The elastic modulus is 10.7 ton/mm", and the 90 degree directions are 8.2 kg/m, respectively.
a", 0.9 ton/nm".

In order to manufacture another composite, 11 of the above composite sheets were stacked with the reinforcing fibers aligned in the same direction, using the mold used in Example 6, and heated at 420°C to prevent air from entering.
The mixture was melted, impregnated, cooled and solidified under the conditions of x 100 kg/cd x 10 minutes to obtain a plate-like composite (C2). The carbon fiber content in the machine is 6ov! The amount was %. This plate is a uniform black composite, and when the cross section of the plate is observed under a microscope, the carbon fibers are uniformly dispersed, and it appears to be the composite (CI) described above (shown in Figure 1). Kakegami was the same.

The strength of the board in the 0 degree direction is 192 kg/IIIlt, the elastic modulus is 11.2 ton 7 mm", and those in the 90 degree direction are 12.1 kg/mm" and 0.9
ton/an”.

Comparative Example 3 Carbon fiber bundle used in Example 1 and PI used in Example 7
The EEK fiber bundles were combined into a yarn with a total weight of 4500 denier. This doubling yarn is used as the warp yarn, with a weaving density of 4 threads/cm, and only PEEK fiber bundles are used as the weft thread, with a weaving density of 3.8 threads/cm.
A plain weave sheet was prepared with a weave density of cm.

In the above-mentioned sheet, the reinforcing long fibers are aligned in one direction to form a sheet. However, this sheet was difficult to handle because the threads came undone from the end surface and changed shape unless handled with care. When I cut out a donut-shaped sample with an outer diameter of 11 cm and an inner diameter of 10 cm, and tried to pick it up with my fingers, it fell apart, making it very difficult to handle it by cutting it into pieces.

Layer 13 of the above sheets with the reinforcing fibers aligned in the same direction and use the mold used in Example 6 to form a 360"cxlOkg/dX
A plate was obtained by melting, impregnating, cooling and solidifying under conditions of 5 minutes. When the content of carbon fiber in the machine was measured using concentrated sulfuric acid, it was found to be 60% by volume, the same as in Example 7, but the appearance was clearly different, and the plate of Example 7 (C1) was a uniform black composite, whereas the plate of this comparative example had a non-uniform polymer, and white striped patterns were observed here and there. When we looked at the cross section of the plate under a microscope, we found that the carbon fibers were solidified (see Figure 2).
The strength of the board in the 0 degree direction is 102 kg/a++a", the elastic modulus is 8.7 ton/ffl1", and those in the 90 degree direction are 4.1 kg/mm" and 0.4, respectively.
ton/l11m'', and the physical properties were very poor.

Comparative Example 4 Carbon fiber bundle used in Example 1 (3600 denier/60
00) and 150 of the PEEK polymer used in Example 7.
A continuous fiber bundle of 0 denier 1500 filaments was immersed in water at the same speed, stirred using opposing nozzles, mixed the fibers, pulled up and dried to form a mixed fiber yarn. I tried to pull this yarn together to make a sheet in the - direction, but when I picked it up by hand, it fell apart and I couldn't handle it using normal methods.

So, a thin Pt with a date of 20g/rrr! Sandwiched with cloth woven from EK fiber, Pt! I sewed it with EK thread and made it into a sheet. However, when I cut it into donuts and lifted it, it fell apart.

Using the mold used in Example 6, stack 16 of the above composite sheets with the reinforcing fibers aligned in the same direction, and melt, impregnate, cool and solidify under the conditions of 420°C x and 100kg/cXaxlO, using the mold used in Example 6. A plate-like composite was obtained. The content of carbon fiber in the machine was 60% by volume. This plate is a uniform black composite, and when the cross section of the plate was observed under a microscope, the carbon fibers were uniformly dispersed, and the appearance was similar to that of the composite of Example 7 (C1, C2). It was the same.

The strength of the plate in the 0 degree direction was 193 kg/m+++", and the elastic modulus was 11.7 ton/am", which was not much different from the composite (C2) of Example 7, but the strength in the 90 degree direction was 9. .2 kg/cm”, elastic modulus is 0.8
ton/w'', and the physical properties in the 90 degree direction were poor.

Example 8 PI of Example 7! II! High-pressure water jet treatment was carried out in exactly the same manner except that polyphenylene sulfide polymer long fibers of 200 denier/72 filaments were used instead of the fibers, and PPS short fiber sheets were entangled and integrated on both sides of the long fibrous carbon fiber sheet. A composite sheet that is easy to handle was obtained. Tensile strength in the direction perpendicular to carbon fiber is 3350 g
/ctA, and the bulk density was 0.34 g/cJ.

Example 9 P-acetoxybenzoic acid and 6-acetoxy-2-naphthoic acid (molar ratio 75:25) were optically fused in a hot molten state by deacetic acid melt polymerization according to the example of JP-A-54-77691. A high polymer exhibiting anisotropy was obtained.

This polymer was extruded at 320° C. through a spinneret equipped with 56 holes of 0.1 mm, air-cooled, and then wound to obtain a single filament 3-denier long fiber bundle. This long fiber bundle was cut into short fibers in the same manner as in Example 1 to lengths of 20 m+ and 5 In[I+, and after dispersing and mixing them in water at a weight ratio of 1:1, a paper sheet was prepared. Obtained. Next, it was stacked with a carbon long fiber bundle aligned in one direction and subjected to high-pressure water jet treatment to obtain an easy-to-handle composite sheet. The tensile strength in the direction perpendicular to the carbon fibers was 3250 g/d, and the bulk density was 0.34 g/cJ.

Example 10 50 g (0.23 mol) of 4,4-difluorobenzophenone, 69 g (0.5 mol) of finely ground potassium carbonate, and 50 g of benzophenone as a solvent were placed in a glass flask with an internal volume of 500 d, and the inside of the flask was replaced with nitrogen. After that, the temperature was raised to 300°C over 1 hour while stirring.
This state was maintained and the reaction was allowed to proceed for 12 hours.

The resulting reaction product was ground and washed with warm acetone and hot water to give 43 g of white powder, η3P/CC concentrated sulfuric acid, o
, i% by weight, measured at 25°C) is 0.56d1/
g of polyetherketone was obtained.

Using the polyetherketone obtained in this way,
The spinning head temperature was 420°C, and the spinning hole diameter was 0.3 mm.
It was extruded through a spinning hole with φ and 8 holes to obtain a single 3.0 denier polyetherketone fiber.

The fibers were collected and cut into a length of 10 mm using a guillotine cutter in the same manner as in Example 1 to obtain TP short fibers.

The above-mentioned polyetherketone short fibers were formed into a short fiber sheet with a basis weight of 64 g/bar in exactly the same manner as in Example 1, and then stacked with a carbon long fiber bundle aligned in one direction,
An easy-to-handle composite sheet was obtained by high-pressure water treatment. The tensile strength in the direction perpendicular to the carbon fiber is 344
0 g/crl, and the bulk density was 0.36 g/cn.

This composite sheet was punched into a circular shape of 96sφ, and the inner diameter was 1
In a mold of 00 mmφ, stack carbon fibers in 6 layers so that the long fiber direction is the same, and heat at 440°C x 10 minutes x 100k.
The molding was carried out under heating and pressure under the conditions of g/cd. The circular molded plate taken out after cooling and solidification was an extremely strong molded plate in which polyetherketone short fibers were melted and impregnated and solidified.

Example 11 43.9 g (0,20
1 mol) of 4,4-difluorobenzophenone, 64.
9 g (0,201 mol) of 4,4-difluoroterephthalophenone, 72.5 g (0,684 mol) of sodium carbonate, 20 g of silica (Aerosil 300, manufactured by Nippon Aerosil Co., Ltd.) and 40 g of diphenyl sulfone were taken. , After replacing with nitrogen, the mixture was heated for 30 minutes with stirring.
The temperature was raised to 80″C and the reaction was carried out for 1.5 hours at this temperature.
Next, the temperature was raised to 325℃ over 30 minutes, and then further heated to 4.5℃.
A time reaction was performed. The obtained polymer had η3. /C is 0.85 dl/g (concentrated sulfuric acid, 0.1% by weight, 25°C
) polyetherketone m=n.

TP short fibers were obtained under the same method conditions as in Example 10, except that the polyetherketone in Example 10 was replaced with the polyetherketone described above, and a composite sheet consisting of carbon fibers was obtained. This sheet was a sheet in which the TP short fibers did not fall apart, were well mixed and integrated, and had extremely high formability.

The tensile strength in the direction perpendicular to the carbon fiber is 3050 g/
cIa, and the bulk density was 0.34 gZc-.

Example 12 Instead of the carbon fiber used in Example 1, aramid fiber (
DuPont Kepler 49 T-965, tensile strength 37
0Icg/llll112, tensile modulus 13ton/m
A composite sheet was made using the same method except that the blending ratio of aramid fibers was 60% by volume.This composite sheet was flexible.
Furthermore, it does not fall apart even when lifted by hand, and its tensile strength in the direction perpendicular to the aramid fibers is 3110 g/CTa.
Met. When a plate was made using this sheet in the same manner as in Example 6, a plate having a bending strength of 62.8 kg/2 and a bending modulus of elasticity of 7.6 tons/ml11'' was obtained.

Example 13 Instead of the carbon fiber used in Example 1, glass fiber (tensile strength 300 kg/mm'', tensile modulus ?, 4
A composite sheet was made in the same manner except that the blending ratio of glass fiber was 60% by volume using ton/ff [Ill 2, diameter; 13=+]. This composite sheet is flexible, does not fall apart when lifted by hand, and has a tensile strength of 3 in the direction perpendicular to the glass fibers.
It was 410g/cd. When a plate was made using this sheet in the same manner as in Example 6, the bending strength was 81 k.
g/rrts”, flexural modulus 4.1 ton/
am'' plate was obtained.

Example 14 A web made of Chinlon 66 polymer fibers with a fiber length of 32 mm was made into a web by an air-laying method, the carbon fiber content was adjusted to 60% by volume, and a composite sheet was obtained by high-pressure water jet treatment. The tensile strength in the direction perpendicular to the carbon fiber is 2550 g/
C11l, and the bulk density was 0.38 g/cj.

When the bending strength and elastic modulus were measured in the same manner as in Example 6, they were 151 kg/kaku8 and 12.8 ton, respectively.
/ 閤3 value is shown.

Example 15 In Example 2, the PPS polymer used in Example 1O (manufactured by Philips Petroleum Co., Ltd., Rydon Polymer) was used instead of the Chinlon 66 polymer, and steam superheated to 350°C was blown into the spinneret. The continuous fibers were spun using a melt blow method, and the spun continuous fibers were overfed and deposited on a 200-mesh wire mesh to create a sheet.

The PPS fibers in this sheet were very thin and had two diameters when observed under a microscope. I tried to measure the degree of freedom, but it was difficult to select a specific single fiber from a 10cm diameter circle because it was so thin, so I took a microscopic photo of a specific fiber inside a 1mm diameter circle and bent it. The degree of freedom was found to be 2.5 by measuring the length.

Using the above PPS fiber sheet, a composite sheet with carbon fiber was obtained in the same manner as in Example 2. The tensile strength of this composite sheet in the direction perpendicular to the carbon fibers is 1850 g/cd, the bulk density is 0.39 g/cd, and the outer diameter is 11C.
II. Even when cut into donut shapes with an inner diameter of 10 CI, they did not fall apart when picked up with fingers and had excellent workability.

Example 16 A mixed yarn was obtained in exactly the same manner as in Comparative Example 4, except that the PEEK fiber was changed to a 1740 denier 1580 filament. This mixed fiber yarn was drawn in the same manner as in Example 1 to create a unidirectional sheet. The degree of freedom of the PEEK fibers in the sheet was 1.05. Fibers were added to this PEF in the same manner as in Example 1.
It was made into short fibers of 0ffi1 and a thin slurry was prepared. Using this slurry, so that the basis weight is 0.4 g/I,
A paper sheet was created on top of the above sheet. Next, high-pressure water jet treatment was carried out in the same manner as in Example 1, and this sheet was further turned over and a 0.4 g/nl paper sheet was placed on top of it (the total of the front and back paper sheets is the entire composite sheet). 0.2% by volume) and subjected to high-pressure water treatment in the same manner. The resulting composite sheet was highly flexible, did not fall apart even when lifted by hand, and did not cross at right angles to the reinforcing fibers. The tensile strength in this direction was 21 g/d, and the bulk density was 0.45 g/d.

Example 17 Instead of the thermoplastic polymer used in Example 9, polyetherimide (Ultem 1000, manufactured by General Electric) was used to obtain a single 5-denier multifilament. A sheet was obtained in exactly the same manner as in Example 16, except that the basis weight of the paper sheet was 1.2 g/rd, and the same carbon fiber as in Example 1 was used as the mixed fiber yarn.

Using the same polyetherimide, JP-A-1-09227
A polyetherimide emulsion was obtained according to Example 1 of Publication No. 1. When this emulsion was poured onto the sheet obtained above to impregnate the sheet and dried at room temperature, the carbon fiber content was 60% by volume, the polyetherimide fiber content was 1% by volume, and the emulsion solid content was 3
A composite sheet with a composition of 9% by volume was obtained. In this sheet, the emulsion particles were almost uniformly dispersed between the reinforcing fibers. Although this composite sheet is slightly harder than the composite sheets of other examples, it is flexible enough that the reinforcing fibers will not be cut even when rolled into a cylinder with a diameter of 1 cIIl, and will not fall apart even when lifted by hand. The tensile strength in the direction perpendicular to was 74 g/d, and the bulk density was 0.51 g/C-d.

For comparison, I made a sheet in exactly the same way as above, except that I did not use a paper-made sheet, but when I bent it a little parallel to the reinforcing fibers, it immediately cracked, so I tried to avoid deforming it by using tape. When the tensile strength in the direction perpendicular to the reinforcing fibers was measured, it was 4 g/c4.

When a plate was made using the composite sheet of the present invention in the same manner as in Example 7, a void-free plate with a bending strength of 171 kg/mm and a bending modulus of 11.1 ton/mm was obtained.

〔Effect of the invention〕

The composite sheet of the present invention has excellent workability when processed into molded products compared to conventional sheets of the same type, and moreover, high-strength molded products can be obtained under the same molding conditions.

In other words, a high-strength plate can be obtained under a wider range of molding conditions and can be made into a molded product, and this molded product can be used in a wide range of applications. Typical applications include the bodies and parts of aircraft and artificial satellites, ports, surfboards, etc. as composites.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a composite obtained from the composite sheet of the present invention, and FIG. 2 is a sectional view of a composite obtained from a conventional composite sheet.

Claims (1)

[Scope of Claims] 1. A composite sheet comprising a web containing reinforcing long fiber bundles and monofilamentous thermoplastic polymer fibers, wherein the amount of the reinforcing long fiber bundles is based on the composite sheet. 5-80% by volume
A composite sheet for a fiber-reinforced material, characterized in that the thermoplastic polymer fibers are intertwined and integrated between the long fibers constituting the web. 2. 2. The composite sheet according to claim 1, wherein the web comprising reinforcing long fiber bundles consists essentially of only reinforcing long fiber bundles. 3. The composite sheet according to claim 1 or 2, wherein the web is a web made of reinforcing long fiber bundles aligned in one direction. 4. The composite sheet according to claim 1 or 2, wherein the web is a woven fabric of reinforcing long fiber bundles. 5. Claim 1, wherein the thermoplastic polymer fibers are short fibers.
The composite sheet according to any one of Items 1 to 4. 6. The composite sheet according to any one of claims 1 to 4, wherein the thermoplastic polymer fibers are long fibers with a degree of freedom of 1.2 or more. 7. Thermoplastic polymer fibers are deposited in the form of single fibers on a web containing a reinforcing long fiber bundle, and a fluid jet is applied to distribute the thermoplastic polymer fibers between the long fibers constituting the web. A method for producing a composite sheet for fiber-reinforced material, characterized by interlacing and interlacing and integrating. 8. A web containing a reinforcing long fiber bundle is made to contain thermoplastic polymer short fibers in the form of single fibers, and a fluid jet is applied to the resulting web to create heat between the long fibers constituting the web. A method for producing a composite sheet for fiber-reinforced material, characterized by incorporating short plastic polymer fibers and intertwining and integrating them. 9. The method for producing a composite sheet according to claim 7 or 8, wherein the web containing the reinforcing long fiber bundles is a web consisting essentially only of the reinforcing long fiber bundles. 10. Manufacture of a composite sheet according to any one of claims 7 to 9, using a web in which the reinforcing long fiber bundles are aligned in one direction as the web containing the reinforcing long fiber bundles. Method. 11. The method for producing a composite sheet according to any one of claims 7 to 9, in which a woven fabric of reinforcing long fiber bundles is used as the web containing the reinforcing long fiber bundles. 12. The method for producing a composite sheet according to claim 7, wherein the thermoplastic polymer fibers are short fibers. 13. The method for producing a composite sheet according to claim 7, wherein the thermoplastic polymer fibers are long fibers with a degree of freedom of 1.2 or more. 14. The method for producing a composite sheet according to claim 12 or 13, in which the web containing the reinforcing long fiber bundle is a web consisting essentially only of reinforcing long fibers.