JPH0725142B2 - Self-curling fiber-reinforced thermoplastic resin sheet, resin tube made of the same, and method for manufacturing resin tube - Google Patents

Description

TECHNICAL FIELD The present invention relates to a self-curling fiber-reinforced thermoplastic resin sheet, a resin tube made of the same, and a method for producing the resin tube.

(Prior Art and Problems Thereof) As a method for producing a fiber-reinforced resin pipe, a sheet winding method, a filament winding method, a tape winding method and the like are known. However, such a method is mainly applied to a thermosetting resin prepreg having high flexibility, and is difficult to apply to a thermoplastic resin prepreg. For example, in the case of producing a fiber-reinforced resin pipe by a sheet winding method, in a thermoplastic resin, a resin sheet formed by impregnating a sheet-shaped fiber with a resin is elastic and difficult to bend, and There are problems such as cracks in the resin sheet during bending, and it is very difficult to manufacture a good quality thermoplastic resin tube. In the case of filament winding method or tape winding method, unlike the case of thermosetting resin, in the case of thermoplastic resin, it is necessary to heat this to a high temperature There is a problem that the device becomes complicated.
For these reasons, fiber-reinforced thermoplastic resin pipes have been hardly manufactured by the winding method as described above.

(Problem of the invention) An object of the present invention is to provide a molded sheet for producing a fiber-reinforced resin pipe, a resin pipe using the same as a raw material, and a method for producing the same.

(Means for Solving the Problems) The present inventors have completed the present invention as a result of intensive studies to solve the above problems.

That is, according to the present invention, a molding sheet for obtaining a thermoplastic resin tube reinforced with reinforcing fibers, wherein the molding sheet has a difference in internal shrinkage stress between an upper surface portion and a lower surface portion of the sheet. Consisting of a reinforced fiber reinforced thermoplastic resin sheet with self-curl (In the formula, X means the radius of curvature of the target resin pipe, and R
Represents a self-curling curvature, which means the curvature of a curled material when the sheet self-curls).

Further, according to the present invention, there is provided a thermoplastic resin pipe reinforced with reinforcing fibers obtained by using the molding sheet.

Further, according to the present invention, the molding sheet is wound around a mandrel having a radius of curvature X by utilizing its self-curling property,
Provided is a method for producing a reinforcing fiber reinforced thermoplastic resin tube, which comprises thermoforming into a unitary tubular body and then removing from the mandrel.

Furthermore, according to the present invention, a molding sheet is wound around a cured resin pipe or a metal pipe by utilizing its self-curling property,
Provided is a method for producing a thermoplastic fiber tube reinforced with reinforcing fibers, which comprises thermoforming into an integral tubular body.

In the present invention, a sheet having self-curl property made of a thermoplastic resin reinforced with reinforcing fibers as a sheet for molding a thermoplastic resin tube reinforced with reinforcing fibers (hereinafter, also simply referred to as a resin tube) (hereinafter, simply (Also called a self-curling sheet). In this case, the self-curl sheet is
It means a sheet having a property of forming a curled material due to a difference in internal contraction stress between the upper surface portion and the lower surface portion of the sheet itself. Such a sheet naturally curls by holding the flat sheet without applying any external force to maintain the curled state, and once the external force is applied to curl in a specific direction, the external force is removed. However, the curled state is maintained. What is a self-curl sheet?
It means a sheet curled by the self-curling property.

In the self-curling sheet of the present invention, the strength (size) of the self-curling property is represented by the self-curling curvature of the curled product when self-curling, and satisfies the following formula. .

In the above formula, R means the self-curling curvature of the molding sheet, and X means the radius of curvature of the resin tube to be manufactured.
The self-curl curvature R means the curvature of the inner diameter of the curled material (tubular body) obtained by self-curling the sheet.

Since the self-curling curvature R of the molding sheet is the reciprocal of the radius of curvature of the self-curling material, the above equation can be expressed by the radius of curvature Y (Y = 1 / R) of the self-curling material. It becomes like a formula.

In the molding sheet of the present invention, the preferable self-curl curvature R is Is. If the self-curl curvature R is smaller than 1 / (5X) (that is, the radius of curvature Y of the self-curl is larger than 5X), the radius of curvature Y of the curl when the molding sheet self-curls. However, since the radius of curvature X of the resin pipe to be manufactured is too large, the molding sheet is
In order to obtain a resin tube having a radius of curvature X, a large tensile force is required when attempting to wind it around a tubular body such as a mandrel having a radius of curvature X, and in some cases, when pulling it This causes cracks in the molding sheet, which is not preferable. The upper limit of the self-curl curvature R is not particularly limited, but it should be 2 times or less, preferably 1.5 times or less, of the curvature (1 / X) of the resin tube to be manufactured, whereby a mandrel having a radius of curvature X, etc. It becomes easy to form a tight winding.

As the reinforcing fiber, conventionally known ones, for example, glass fiber, inorganic fiber such as alumina fiber, stainless steel fiber, metal fiber such as copper fiber, carbon fiber, hardly meltable or non-melting natural or synthetic organic fiber Fiber etc. are mentioned.

As the thermoplastic resin, various conventionally known ones, for example, polyolefin, polyamide, polyester, polycarbonate, polyetheretherketone, polyetherketone, polyetherimide, polyethersulfone, polyacetal, polyacrylic resin, PPS, ABS Etc.

The fiber-reinforced thermoplastic resin sheet having self-curling property is
It can be obtained by making a difference between the contraction stress of the front surface part and the contraction stress of the back surface part, and the manufacturing method thereof includes various methods as described below.

(1) Fiber-reinforced resin sheet (or resin-containing reinforcing fiber)
, So that the orientation directions of the reinforcing fibers intersect,
Method of thermocompression bonding.

The lamination raw material sheet used in this method may be two or more sheets, and when laminating three or more sheets, the orientation direction of the reinforcing fibers of the sheet forming the uppermost layer,
The sheets are laminated so that the orientation of the reinforcing fibers of the sheet forming the lowermost layer intersects. Such a sheet can be self-curled so that the orientation direction of the reinforcing fibers of the sheet forming the inner surface coincides with the axial direction of the curled material.

FIG. 1 shows a cross-sectional structural view of the sheet obtained by this method. In this figure, 1 indicates the entire sheet, 2 indicates the resin layer, and 3 and 4 indicate reinforcing fibers arranged in the resin layer.
The reinforcing fibers 3 and 4 are arranged so that the fiber orientation directions thereof intersect each other at a right angle. In the sheet 1, the shrinkage stress of the second reinforcing fiber layer portion 6 is significantly larger than that of the first reinforcing fiber layer portion 5 in the direction of the arrow (a). That is, with respect to the direction of the arrow (a), the first reinforcing fiber layer portion 5 has continuous fibers oriented in that direction, so that the shrinkage stress thereof is remarkably relaxed, while the second reinforcing fiber layer 5 is relieved. The fiber orientation of the layer portion 6 is orthogonal to the direction of the arrow (a), and since there are no continuous fibers in the direction of the arrow a, the shrinkage stress is large. A force in the direction of the arrow (b) acts on this sheet 1,
It can be self-curled in the direction of arrow (b). FIG. 2 shows an explanatory sectional view of the sheet 1 in the self-curling state. In FIG. 2, the fiber orientation direction of the upper surface first reinforcing fiber layer portion 5 is the arrow (c) direction (circumferential direction), and the fiber orientation direction of the second reinforcing fiber layer portion 6 is the same as the axial direction.

Further, as is clear from the above description, the sheet 1 has the first direction on the contrary to the orientation direction of the fibers 4 orthogonal to the fibers 3.
The contraction stress of the second reinforcing fiber layer portion 6 is significantly larger than that of the reinforcing fiber layer portion 5. Therefore, in the sheet 1, the second reinforcing fiber layer portion 6 is the outer surface, the orientation direction of the fiber 4 is aligned with the circumferential direction, and the first reinforcing fiber layer 5 is the inner surface, and the orientation direction of the fiber 3 is It is also possible to self-curl so as to match the axial direction of the curled material.

The strength of the self-curling property (self-curl degree) of the sheet 1 described above is adjusted by adjusting the fiber density of the first reinforcing fiber layer portion 5 and the second reinforcing fiber layer portion 6 and the crossing angle of the fibers 3 and 4. And so on. For example, the self-curl property of the sheet 1 can be increased by increasing the crossing angle between the fiber 3 and the fiber 4, and the crossing angle 90
The strength of the self-curling property becomes maximum at a certain degree. in this case,
Even with the same crossing angle, the larger the difference between the coefficient of thermal expansion of the reinforcing fiber and the resin and the higher the elastic modulus of the resin, the stronger the self-curling property. Further, by increasing the fiber density of the first reinforcing fiber layer portion 5 and decreasing the fiber density of the second reinforcing fiber layer portion 6, the self-curling property in the direction of the arrow (b) can be strengthened.

As the fiber-reinforced resin sheet or resin-containing reinforcing fiber sheet used in this method, for example, the following ones can be used.

(I) A resin sheet reinforced with fibers (UD fibers) aligned in parallel.

(Ii) A resin-containing reinforcing fiber sheet made of a woven fabric in which thermoplastic resin fibers and reinforcing fibers are mixed and woven.

(2) Another UD fiber layer is laminated on the UD fiber layer so that their fiber orientation directions intersect, and a thermoplastic resin film, powder, pellets, fibers, etc. are laminated on it, and hot pressing, etc. Method of heating and pressing with.

(3) A method of changing the driving density of the warp and weft when a fiber reinforced resin sheet is manufactured using a woven fabric containing reinforcing fibers as warp and weft.

In the sheet obtained by this method, since the shrinkage stress in the orientation direction of the high-density reinforcing fiber is relaxed more than the shrinkage stress in the orientation direction of the low-density reinforcing fiber, the orientation direction of the high-density reinforcing fiber is the circumferential direction. You can curl yourself to become. The self-curl property of the sheet can be enhanced by increasing the difference in the driving density between the warp yarn and the weft yarn.

As a method for producing a resin sheet reinforced with a woven fabric of reinforcing fibers, a conventionally known method can be used. For example, a method of laminating a thermoplastic resin film, powder, pellets, fibers and the like on a woven fabric of reinforcing fibers and heating and pressurizing with a hot press, a woven fabric composed of mixed fibers of reinforcing fibers and thermoplastic resin fibers. Examples include a method of heating and pressing the cloth.

(4) A method for obtaining a fiber-reinforced resin sheet using a reinforcing fiber woven fabric in which two kinds of reinforcing fibers having different coefficients of thermal expansion are warp yarns and weft yarns, respectively.

The sheet obtained by this method has a large shrinkage stress in the orientation direction of the reinforcing fiber with a larger coefficient of thermal expansion, and a smaller shrinkage stress in the orientation direction of the reinforcing fiber with a smaller coefficient of thermal expansion,
It is possible to self-curl so that the orientation direction of the reinforcing fiber having a large coefficient of thermal expansion is the axial direction of the curled material.

Also, in general, when producing a self-curling sheet,
By changing the cooling rate of the upper surface and the lower surface of the sheet, it is possible to increase the strength of the self-curling property.

The fiber-reinforced resin sheet having a self-curling property used in the present invention can be produced by appropriately combining the above-mentioned methods. Further, by using the self-curling property imparting principle described above, a self-curling fiber-reinforced resin sheet containing reinforcing fibers of various layer constitutions, for example, a resin sheet reinforced with fibers composed of UD fibers and woven fabric, etc. Can be obtained.

The preferred self-curling fiber-reinforced resin sheet used in the present invention has a self-curling curvature R of 2 or more of the desired curvature of the resin or the like.
It is not more than twice, preferably not more than 1.5 times. That is, R
≦ 2 / X, preferably R ≦ 1.5 / X, and Y ≧ 1/2 · X, preferably Y ≧ 1 / 1.5 · X.

The resin pipe of the present invention can be manufactured according to a conventionally known sheet winding method used for obtaining a resin pipe using a thermosetting resin prepreg sheet. That is, a desired resin tube can be obtained by winding the above-mentioned self-curling fiber reinforced resin sheet as a raw material sheet on a mandrel, thermoforming it into an integral tubular body, and then removing the mandrel. The raw material sheet wound around the mandrel may be wound once or plural times, and is determined according to the desired wall thickness of the tube. The raw material sheet wound on the mandrel is appropriately fixed by taping or the like. The thermoforming temperature is the temperature at which the resin softens or melts. A mold can also be used for fixing the rolled material and thermoforming.

Further, the self-curling curvature of the raw material sheet can be adjusted by applying an external force to the raw material sheet so as to curl the raw material sheet so as to obtain a desired self-curling curvature, and performing heat treatment in this state. For example, a self-curl sheet having a larger self-curl curvature can be obtained by winding and fixing the self-curl sheet on a mandrel having a curvature larger than the self-curl curvature, and then heat-treating the resin at the softening temperature of the resin. Obtainable. The sheet having such a large self-curl curvature can be wound on a mandrel having a larger curvature than that. In this way, by gradually increasing the self-curling curvature, it is possible to obtain a self-curling sheet suitable for manufacturing an extremely fine resin tube.

In the present invention, in order to obtain a thick resin tube, the length of the wound sheet is increased to increase the number of windings on the mandrel, or a large number of short sheets are wound on the mandrel many times one after another. You can do it.

Further, on the outer surface of the thermoplastic resin tube obtained as described above,
It is also possible to form a cured resin layer reinforced with reinforcing fibers to form a composite resin tube made of a thermoplastic resin and a cured resin. In this case, the cured resin layer reinforced with reinforcing fibers, on the surface of the resin tube, to form a fiber reinforced thermosetting resin layer,
It is formed by heating this. As this heating condition, it is preferable to use a condition in which the thermoplastic resin does not melt, and a temperature below the melting point of the thermoplastic resin forming the resin pipe is usually used. As a method of forming the fiber-reinforced thermosetting resin layer on the resin tube, a conventionally known prepreg sheet winding method, a filament winding method, or the like is used.

Furthermore, in the present invention, a cured resin layer or a metal layer reinforced with reinforcing fibers can be formed on the inner surface of the fiber-reinforced thermosetting resin pipe. A resin tube having a cured resin layer reinforced with reinforcing fibers on its inner surface is a self-reinforced resin tube reinforced with reinforcing fibers on a fiber-reinforced cured resin tube formed according to a conventionally known method such as a prepreg sheet winding method or a filament winding method. It is manufactured by winding a curling thermoplastic resin sheet by utilizing its self-curling property and thermoforming it into an integral tubular body. In addition, a resin tube having a metal layer on the inner surface is formed by winding a self-curling thermoplastic resin sheet reinforced with reinforcing fibers on the metal tube by utilizing its self-curling property to form a single tubular body. It can be manufactured by molding.

As the thermosetting resin that gives the cured resin layer, an epoxy resin, an unsaturated polyester resin, a phenol resin,
Examples thereof include bismaleimide-triazine resin.

In the production of the resin pipe according to the present invention, since the molding sheet is self-curling, there is no need to heat and soften the molding sheet, and without causing inconvenience such as cracks, on the mandrel. It can be easily wound. A molding sheet having no self-curling property is difficult to wind on a mandrel unless it is softened by heating, and cracks occur when it is forcibly applied to wind, but in the case of the present invention, No inconvenience occurs.

In the case of producing a resin pipe according to the present invention, when the desired radius of curvature of the resin pipe is X, the self-curling radius of curvature Y of the forming sheet has a relationship of Y ≦ 5X, preferably Y ≦ 4X. Use is preferred. The self-curling sheet having such a relationship can be easily wound around a mandrel having a desired radius X.

(Effect of the invention) According to the present invention, since the fiber-reinforced thermoplastic resin sheet having self-curl property is used as the molding sheet,
The mandrel can be easily wound, and the fiber-reinforced thermoplastic resin tube can be easily manufactured according to the conventional sheet winding technique. In the present invention,
A resin pipe having an inner diameter of 2 mm or more can be economically manufactured without causing cracks. Further, depending on the shape of the mandrel, it is possible to easily obtain a tubular body such as a conical shape as well as a cylindrical shape.

According to the present invention, a heat-resistant thermoplastic resin such as polyether imide or polyether ether ketone is used, and a high-strength, high-elasticity carbon fiber or the like is used as the reinforcing fiber to improve heat resistance. It is possible to easily obtain a fiber-reinforced thermoplastic resin tube having excellent high strength and high elasticity.

(Example) Next, the present invention will be described in more detail with reference to examples.

Reference Example From various fiber reinforced thermoplastic resin prepreg sheets shown in Table-1, the fiber orientation direction with respect to the reference side is 0, 45, 9
Using vertical and horizontal 100 mm prepreg sheets cut to 0 and -45 (degrees), the two sheets were laminated with their reference sides aligned and thermocompression-bonded under the press conditions shown in Table-2. The sheet was manufactured. The curvature (self-curl curvature) and the radius of curvature (self-curl radius of curvature) of the thus obtained self-curl sheet curl-like object are shown in Table-
2 shows.

In addition, "0/90" in the section of the laminated constitution of Table-2 shows a laminated sheet obtained by laminating and thermocompressing sheets having fiber orientation directions of 0 degree and 90 degrees, and "45 / -45" means the fiber orientation direction. Is 45 degrees and −4
"0/45" indicates a laminated thermo-compressed sheet of 5 degrees
Indicates a sheet obtained by laminating and thermocompressing sheets having fiber orientation directions of 0 degree and 45 degrees.

Next, the shape of the curled material is shown in FIGS. 3 and 4. FIG. 3 shows a self-curling state diagram of a laminated sheet (0/90, 0/45) which is self-curled with a sheet having a fiber orientation direction of 0 degree as an inner layer. Fig. 4 shows a self-curling laminated sheet (0/45, 45 / -4) with a sheet whose fiber orientation is 45 degrees as the inner layer.
5) Shows the self-curl state. In FIGS. 3 and 4, the orientation directions of the fibers of the inner surface sheet of the self-curled product are the same as the axial direction of the curled product.

Example 1 Fiber volume content rate: 60%, sheet thickness: 0.125 mm, width: 520 mm
Two unidirectionally aligned carbon fiber reinforced sheets with a matrix of polyetherketone of 520 mm × 520 mm, laminated so that each fiber direction is orthogonal, temperature: 380 ℃, pressure: 20 kg / cm with a hot press molding machine After holding it at ² for 20 minutes, it was cooled to room temperature to obtain a laminated sheet which was self-curled into a tubular body (self-curling curvature R = 1/30 mm ⁻¹ ) having a thickness of 0.25 mm and an inner diameter of about 60 mm. As shown in FIG. 2, in this self-curled material, the fiber orientation direction of the outer surface portion coincided with the circumferential direction, and the fiber orientation direction of the inner surface portion thereof coincided with the axial direction. This curled laminated plate has a diameter of 40 mm due to its self-curling property.
Wrap around a mandrel of (curvature radius X = 20 mm) so that the fiber orientation direction of the outer surface is orthogonal to the axial direction of the mandrel, and then a polyimide film (width: 25 mm, thickness:
It was fixed by taping with 25 μm). A glass cloth (basis weight: 395 g / m ² , plain weave) was wound around this as a bleeder, wrapped with bagging film, and the inside was evacuated to create a vacuum. This was placed in a heating furnace, kept at a temperature of 380 ° C. for 30 minutes, and then cooled to room temperature. Next, the external bagging film, bleeder, and polyimide film were sequentially removed, and then removed from the mandrel to have an inner diameter of 40 mm and an outer diameter of 42.
A fiber reinforced resin pipe (curvature radius X = 20 mm) having a good surface property of mm and a length of 520 mm was obtained.

Example 2 Glass fiber volume content: 60% polyetherimide fiber was used for weft, glass fiber was used for warp Thickness: 0.07 mm, width:
Two pieces of 520 mm x 520 mm mixed woven fabric are laminated so that the glass fiber directions are orthogonal to each other, and the temperature is 260 using a hot press molding machine.
After holding it at 20 ° C for 20 minutes at a pressure of 20 kg / cm ^2, it was cooled to room temperature to obtain a laminated sheet (R = 1/40 mm ^-1 ) which was self-curled into a tubular body having a thickness of 0.14 mm and an inner diameter of about 80 mm. . As shown in FIG. 2, in this self-curling material, the fiber orientation of the outer surface portion coincided with the circumferential direction, and the fiber orientation of the inner surface portion thereof coincided with the axial direction. Using this self-curling property, this curled laminated plate is wound around a mandrel (X = 20 mm) with a diameter of 40 mm so that the fiber orientation direction of the outer surface is orthogonal to the axial direction of the mandrel. Width: 25mm,
It was fixed by taping with a thickness of 25 μm). A glass cloth (basis weight: 395 g / m ² , plain weave) was wound around this as a bleeder, wrapped with bagging film, and the inside was evacuated to create a vacuum. Put this in the heating furnace, temperature: 260 ℃
After holding for 30 minutes at room temperature, it was cooled to room temperature. Then, the backing film, the glass cloth, the polyimide film is sequentially removed and detached from the mandrel, inner diameter: 40 mm, outer diameter: 41 mm,
Length: 520 mm fiber reinforced resin pipe with good surface property (X =
20mm) was obtained.

Example 3 An experiment was performed in the same manner as in Example 1 except that the backing film was not used. Also in this case, inner diameter: 40 m
A fiber-reinforced resin pipe (X = 20 mm) having a good surface property of m, outer diameter: 42 mm, length: 520 mm was obtained.

Example 4 Two unidirectionally aligned and aligned carbon fiber reinforced sheets with a matrix of polyether ether ketone having a fiber volume content of 60% and a sheet thickness of 0.125 mm, laminated so that the fiber directions are 35 ° and 0 °. Then, with a hot press molding machine, temperature: 380
After holding for 20 minutes under the conditions of ℃, pressure: 20 kg / cm ² , cool it to room temperature and put a self-curling laminated plate (R = 1/50 mm ^-1 ) on a tubular body with a thickness of 0.25 mm and an inner diameter of about 100 mm. Obtained. In this self-curling material, the fiber orientation direction of the surface part is 55
It was an angle of degree. This curled laminated board,
Wound on a mandrel (X = 12.5 mm) with a diameter of 25 mm so that the fiber direction of the outer surface is 35 degrees to the axial direction of the mandrel, and a polyimide film (width: 25 mm, thickness: 25 μm)
It was fixed by taping with. This was placed in a heating furnace, kept at a temperature of 380 ° C. for 30 minutes, and then cooled to room temperature. The outer polyimide film was removed and removed from the mandrel to obtain a spiral laminated pipe (X = 12.5 mm) having an inner diameter of 25 mm and an outer diameter of 26 mm and good surface properties.

Example 5 Fiber volume content: 60%, sheet thickness: 0.125 mm, width: 500 m
m, sheet length (length in the carbon fiber direction): unidirectionally aligned carbon fiber reinforced sheet with 520 mm polyether ether ketone matrix, fiber content rate: 62%, basis weight: 295 g / m ² carbon Woven fabric consisting of mixed fibers of fibers and polyetheretherketone fibers: width: 500 mm, length: 520 mm (the lengthwise and transverse mixed fibers of the woven fabric are oriented in the width direction and the length direction) After being laminated for 20 minutes at a temperature of 380 ° C. and a pressure of 20 kg / cm ² with a hot press molding machine, it was cooled to room temperature and self-curled into a tubular body having a thickness of 0.25 mm and an inner diameter of about 100 mm. A laminated plate (R = 1/50 mm ⁻¹ ) was obtained. This curled laminated plate was wound around a mandrel (X = 12.5 mm) with a diameter of 25 mm so that the fiber orientation direction of the outer surface was perpendicular to the axial direction of the mandrel, and a polyimide film (width: 25 mm, thickness: It was fixed by taping with 25 μm). This was placed in a heating furnace, kept at a temperature of 380 ° C. for 30 minutes, and then cooled to room temperature. Then, remove the outer polyimide film, remove from the mandrel, inner diameter: 25 mm,
Outer diameter: 28 mm, length: 520 mm pipe with good surface property (X = 1
2.5 mm) was obtained.

Example 6 Fiber volume content: 60%, sheet thickness: 0.125 mm, width: 500 m
m, sheet length (length in carbon fiber direction): unidirectionally aligned carbon fiber reinforced sheet with 500 mm polyether ether ketone matrix, fiber content: 62%, basis weight: 300 g / m ² , width : 500mm, length: 500mm carbon fiber weft, polyetheretherketone fiber is used as a warp yarn and a mixed-spun woven fabric are laminated so that the carbon fiber directions are orthogonal to each other, and the temperature is adjusted with a hot press molding machine. : Hold at 380 ℃, Pressure: 20kg / cm ² for 20 minutes, then cool to room temperature and thickness:
A laminated plate (R = 1/50 mm ⁻¹ ) self-curling into a tubular body having a diameter of 0.25 mm and an inner diameter of about 100 mm was obtained. This curled laminated plate was wound around a mandrel (X = 12.5 mm) with a diameter of 25 mm so that the fiber direction of the outer surface was perpendicular to the axial direction of the mandrel, and a polyimide film (width: 25 mm, thickness: 25 μm) ) Taped and fixed. Put this in the heating furnace, temperature: 3
It was kept at 80 ° C for 30 minutes and then cooled to room temperature. Then, remove the outer polyimide film, inner diameter: 25 mm, outer diameter:
28mm, 500mm long pipe with good surface property (X = 12.5m
m) got.

Example 7 A fabric having a basis weight of 214 g / m ² and made of carbon fiber having a satin weave, and a polyetheretherketone sheet were laminated, and the temperature was 380 ° C. and the pressure was 20 kg / cm ² by a hot press molding machine. In 2
After holding it for 0 minutes, it was cooled to room temperature and self-curled into a tubular body with a thickness of 0.25 mm and an inner diameter of 100 mm (R = 1/50 mm
^-1 ) got. This curled laminated plate is wrapped around a mandrel (X = 12.5 mm) with a diameter of 25 mm so that the fiber direction with a low carbon fiber implantation density is orthogonal to the axial direction of the mandrel, and a polyimide film (width: 25 mm, thickness Length: 25μ
m) was taped and fixed. Put this in a heating furnace,
Temperature: kept at 380 ° C. for 30 minutes and then cooled to room temperature. Then, remove the outer polyimide film, the inner diameter: 25m
A pipe (X = 12.5 mm) having a good surface property with m and an outer diameter of 28 mm was obtained.

Example 8 A unidirectionally aligned and aligned carbon fiber reinforced sheet using a polyether ether ketone matrix having a fiber volume content ratio of 60% and a sheet thickness of 0.125 mm was cut into a size of width 150 mm × length 476 mm, and the fibers were arranged in the longitudinal direction. And a sheet in which the fiber direction was arranged in the lateral direction. These two sheets were laminated with the fiber directions orthogonal to each other, hot-press molded under the conditions of Example 1, and self-curled into a cylindrical shape having an inner diameter of about 40 mm, a length of 150 mm and a winding number of about 2.5 (R = 1/20 mm ^-1 ) was obtained.

This was wound on a mandrel (X = 30 mm) having a diameter of 60 mm, fixed by taping with a polyimide film, held at 4 kg / cm ² for 30 minutes in an autoclave, cooled, taken out from the autoclave, and the polyimide film was removed. With this attached to a mandrel, the outer surface is centerless-polished to measure the outer diameter, and the cylindrical self-curled sheet is further wound on it, and taping and autoclave operations are performed in the same manner as above. As a result, the wall thickness was increased. Repeating this operation, PEEK /
I got a CF pipe. Wrap a thermosetting epoxy resin prepreg sheet reinforced with carbon fiber on this pipe,
The tape was taped with an OPP film, cured at 130 ° C. for 60 minutes in a heating furnace, and after cooling, the tape was removed and removed from the mandrel. In this way, a pipe (X = 30 mm) having an inner diameter of 60 mm and a wall thickness of 13 mm formed of a thermoplastic resin on the inside and a cured resin on the outside was obtained.

Example 9 Fiber volume content: 60%, basis weight: 81 g / m ² , width: 580 mm,
Length: 400 mm of carbon fiber is used as a weft yarn, nylon 12 fiber is used as a warp yarn, two pieces of a mixed woven fabric are laminated so that the carbon fiber directions are orthogonal to each other, and the temperature is 260 ° C with a hot press molding machine. After holding for 20 minutes at a pressure of 20 kg / cm ^2, it was cooled to room temperature to obtain a laminated plate (R = 1/40 mm ⁻¹ ) which was self-curled into a tubular body having a thickness of 0.1 mm and an inner diameter of about 80 mm. . Five of these curled laminated plates were wrapped around a carbon fiber reinforced heat-resistant epoxy resin pipe (inner diameter 40 mm, outer diameter 44 mm, length 400 mm fixed to mandrel) (X = 22 mm) and taped and fixed with a polyimide film. . Put this in the autoclave,
After maintaining it in a nitrogen atmosphere at a temperature of 260 ° C and a pressure of 3 kg / cm ² for 20 minutes, cool it to room temperature, remove it from the autoclave to remove the polyimide film, and then set the inner diameter to 40 mm and outer diameter to 48 m
A pipe (X = 22 mm) having an inner layer of m and a length of 400 mm and having an inner layer made of a cured resin and an outer layer made of a thermoplastic resin was obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional structural view of a self-curling resin sheet, and FIG. 2 is an explanatory sectional view of the curled product. 3 and 4
The figure shows the curl state diagram of the self-curling sheet obtained in the reference example. 1 ... Self-curling sheet, 2 ... Thermoplastic resin, 3,4 ... Reinforcing fiber, 5 ... First reinforcing fiber layer, 6 ... Second
Reinforcing fiber layer.

Claims (9)

[Claims] 1. A molding sheet for obtaining a thermoplastic resin tube reinforced with reinforcing fibers, wherein the molding sheet is self-curling due to a difference in internal shrinkage stress between an upper surface portion and a lower surface portion of the sheet. Made of reinforced fiber reinforced thermoplastic resin sheet with (In the formula, X means the radius of curvature of the target resin pipe, and R
Shows a self-curling curvature, which means a curvature of a curled material when the sheet is self-curled). 2. The molding sheet according to claim 1, which is reinforced by reinforcing fibers arranged in parallel and reinforcing fibers arranged in parallel so as to intersect the orientation direction of the reinforcing fibers. 3. A laminate comprising at least two reinforcing fiber reinforced thermoplastic resin sheets, wherein the orientation direction of the reinforcing fibers of the sheet forming the uppermost layer and the orientation direction of the reinforcing fibers of the sheet forming the lowermost layer are The molding sheet according to claim 1, which intersects. 4. The molding sheet according to claim 3, wherein the crossing angle between the orientation direction of the reinforcing fibers of the sheet forming the uppermost layer and the orientation direction of the reinforcing fibers of the sheet forming the lowermost layer is 90 degrees. 5. The molding sheet according to claim 1, which is reinforced by a reinforcing fiber woven fabric having different warp yarn and weft yarn driving densities. 6. A laminate formed by laminating at least two reinforcing fiber reinforced thermoplastic resin sheets, thermocompressing them, and then cooling the laminated thermocompression bonded bodies by changing the cooling rate of the upper surface and the lower surface. Molding sheet. 7. A thermoplastic resin tube reinforced with reinforcing fibers, which is obtained by using the molding sheet according to claim 1. 8. A sheet for molding according to any one of claims 1 to 6 is wound around a mandrel having a radius of curvature X by utilizing its self-curling property, thermoformed into an integral tubular body, and then removed from the mandrel. A method for producing a thermoplastic resin tube reinforced with a reinforcing fiber, comprising: 9. The molding sheet according to claim 1 is wound around a cured resin pipe or a metal pipe by utilizing its self-curling property, and thermoformed into an integral tubular body. For producing a thermoplastic resin tube reinforced with reinforcing fibers for controlling.