JPH0716936A - Production of fiber reinforced thermoplastic resin sheet - Google Patents

Abstract

PURPOSE:To obtain a fiber reinforced thermoplastic resin sheet good in resin impregnation properties, excellent in thermal dimensional stability and suitable as a material for a multilayered printed wiring board by impregnating a fiber base material with a thermoplastic resin under heating and pressure and cooling and solidifying the impregnated base material before peeling a release sheet material. CONSTITUTION:A laminate consisting of thermoplastic resin films 6a, 6b, 6c each having a thickness of 5-100mum and fiber base materials 7a, 7b, 7c each having a basis wt. of 20-100g/m<2> is supplied to the space between the release sheet materials 8a, 8b each having a thickness of 50mum or more and tensile elastic modulus of 200kg/mm<2> or more interposed between a pair of endless steel belts 1a, 1b. The thermoplastic resin films are softened in a preheating zone to be closely bonded to the fiber base materials and melted in a heating zone under pressure to infiltrate a thermoplastic resin into the fiber base materials. Next, the whole is cooled under pressure in a cooling zone to solidify the thermoplastic resin and the release sheet materials 8a, 8b are peeled.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a fiber-reinforced thermoplastic resin sheet. More specifically, it relates to a continuous production method of a fiber-reinforced thermoplastic resin sheet suitable as a material for a printed circuit board, which is excellent in thermal dimensional stability, surface smoothness and wall thickness accuracy.

[0002]

2. Description of the Related Art Conventionally, as a continuous production method of a fiber-reinforced thermoplastic resin sheet, a thermoplastic resin sheet and a fiber base material are continuously fed between opposed surfaces of a pair of heated endless steel belts, A so-called double belt press method is known, in which press molding is performed while sandwiching the belt between the belts and moving the belt.

[0003]

In recent years, the demand for printed circuit boards has increased with the spread of general-purpose electronic devices such as personal computers, word processors, and video cameras. However, these general-purpose electronic devices have been made smaller, have higher performance, and have lower costs. With the demand for higher performance, there is a strong demand for higher performance and lower cost of the printed circuit board itself.

Conventionally, as a printed circuit board, a so-called copper-clad laminate is generally used in which a thermosetting resin such as epoxy resin or phenol resin is reinforced with glass fiber or paper and copper foil is adhered to the laminate. there were. These conventional printed circuit boards use an organic solvent such as methyl ethyl ketone in the prepreg forming step of impregnating a resin into the reinforcing material, and therefore a desolvation apparatus is required in the drying step, which complicates the manufacturing process and results in There is a problem that the manufacturing cost becomes high. In addition, since a special adhesive is required when the printed circuit board is multi-layered, there is a problem that the cost becomes high in that respect as well.

Recently, in place of these conventional printed boards, there has been an attempt to use a sheet in which a thermoplastic resin having excellent electric characteristics and heat resistance is reinforced with glass fiber as a material for a plastic multilayer wiring board.

As the characteristics of the fiber-reinforced thermoplastic resin sheet used for these plastic multilayer wiring boards, in addition to electrical characteristics, thermal dimensional stability, surface smoothness, wall thickness accuracy, etc. are required. The most demanding for.

The thermal dimensional stability of a fiber-reinforced thermoplastic resin sheet largely depends on the content of the reinforcing fiber in the sheet and the impregnation state of the resin into the fiber base material. When the fiber content is constant, the resin is stable. It depends on the impregnation state of. If the fiber base material is not sufficiently impregnated with the resin, the reinforcing effect of the fiber will not be sufficiently exhibited, resulting in a sheet having poor thermal dimensional stability.

That is, in a fiber-reinforced thermoplastic resin sheet as a material for a plastic multilayer wiring board, it is essential that the resin impregnation is good, the thermal dimensional stability is excellent, and the manufacturing cost is low.

Conventionally, a double belt press is generally used as a method for producing a fiber reinforced thermoplastic resin sheet.

However, there has been a limit in terms of productivity in order to inexpensively produce a fiber-reinforced thermoplastic resin sheet having good resin impregnation and excellent thermal dimensional stability by using the conventional double belt press. In other words, if the running speed of the belt is increased to improve productivity, the residence time in the heating and melting zone becomes shorter, and it becomes impossible to completely impregnate the resin into the inside of the fiber base material. The dimensional stability is poor. Therefore, in order to satisfy the thermal dimensional stability, the belt speed cannot be made higher than a certain limit value, and as a result, there has been a limit in reducing the manufacturing cost. As one means of increasing the running speed of the belt to improve the impregnation property of the resin, it is conceivable to lengthen the heating zone of the double belt press, but in this case,
There is a problem that the cost required for remodeling the equipment becomes enormous, and the power consumption increases due to the extension of the heating zone, resulting in an increase in the manufacturing cost of the sheet.

The present invention has been made in order to improve the above-mentioned drawbacks of the conventional double belt press, and has good resin impregnation and excellent thermal dimensional stability and is suitable as a material for a plastic multilayer wiring board. It is an object of the present invention to provide a method for efficiently and inexpensively producing a resin sheet.

[0012]

The above object of the present invention is to provide a thickness of 5 to 100 between a pair of endless steel belts.
μm thermoplastic resin film and basis weight 20 to 100 g / m
^The laminate comprising the fibrous base material of No. 2 is supplied in a state in which at least two sets are stacked in multiple layers with a release sheet material having a thickness of 50 μm or more and a tensile elastic modulus of 200 kg / mm ² or more interposed, and in a preheating zone. The thermoplastic resin film is softened and brought into close contact with the fiber base material, and the thermoplastic resin film is melted and pressed in the heating zone to impregnate the inside of the fiber base material with the thermoplastic resin, and then the cooling zone. Can be achieved by a method for producing a fiber-reinforced thermoplastic resin sheet, which comprises pressure-cooling to solidify the thermoplastic resin, and then peeling off the release sheet material.

The thermoplastic resin used in the present invention includes polyolefin resins such as polyethylene and polypropylene, polyamide resins such as nylon 6, nylon 66 and nylon 12, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, and polytetrafluoroethylene. Fluorine resin, polycarbonate resin, polysulfone resin, polyether sulfone resin, polyetherimide resin, polyphenylene sulfide resin, polyether ether ketone resin and the like. For plastic multilayer wiring boards, fluororesin, polycarbonate resin, polysulfone resin, polyethersulfone resin, polyetherimide resin, polyphenylene sulfide resin, polyetheretherketone resin are preferable in terms of electrical characteristics, chemical characteristics, heat resistance, etc. Among them, polyphenylene sulfide resin is excellent in dielectric property, high frequency property, and heat resistance.
More preferably used.

These thermoplastic resins are easily processed into a sheet or film by the usual T-die melt extrusion method, calender roll method and the like. For a plastic multilayer wiring board, it is more preferable that the thickness of one layer of the substrate is thin in order to increase the density, and therefore, the thickness of the thermoplastic resin film is preferably in the range of 5 to 100 μm, and more preferably 10 to 50 μm. A range is more preferable.

On the other hand, the fiber base material used in the present invention includes glass fiber, carbon fiber, graphite fiber, silicon carbide fiber, alumina fiber, boron fiber, steel fiber,
Aromatic polyamide fibers, polyester fibers, polyamide fibers, cellulose fibers and the like can be mentioned, but for a plastic multilayer wiring board, glass fibers and aromatic polyamide fibers are preferably used in terms of electrical insulation, and glass fibers are particularly preferable. It is preferably used. These fiber substrates can be used in the form of filaments, mats, non-woven fabrics, woven fabrics, knitted fabrics, or a combination thereof.
Nonwoven fabrics and woven fabrics are preferably used, and woven fabrics are more preferably used. The weave structure is preferably plain weave, satin weave, twill weave or the like, but plain weave is particularly preferably used from the viewpoint of the balance of thermal dimensional stability when used as a substrate. Since the basis weight of the woven fabric is preferably as thin as possible,
The range of ^{20 to} 100 g / m ² is preferable.

The composition ratio of the thermoplastic resin and the fiber base material can be appropriately set according to the application, but from the viewpoint of strength, the volume content of the fiber is preferably in the range of 10% to 80%. Used, but 15 from the viewpoint of thermal dimensional stability
The range of% -65% is more preferably used.

The thickness of the fiber-reinforced thermoplastic resin sheet to be produced can be appropriately set according to the application, but as a sheet for a plastic multilayer wiring board, 1 mm or less is preferably used, and 100 μm or less in terms of high density. Particularly preferably used.

The release sheet material used in the present invention must have a melting point higher than that of the thermoplastic resin used in the present invention, and is composed of a polyimide resin or an aromatic polyamide resin having substantially no melting point. A sheet material is preferably used. Alternatively, a metal foil such as an aluminum alloy, copper, zinc, or stainless steel can be used. Among them, stainless steel is more preferably used because it is excellent in strength, rigidity, surface hardness, thermal conductivity and the like.

The thickness of these release sheet materials is preferably 50 μm or more. More preferably, it is 100 μm or more. When the thickness is less than 50 μm, strength and rigidity are somewhat insufficient, so that sufficient tension cannot be applied to the release sheet material. As a result, when the thermoplastic resin film and the fiber base material are stacked and pressed in multiple stages, a slight slack is generated in the release sheet material, and wrinkles are generated on the surface of the fiber-reinforced thermoplastic resin sheet obtained. There is a risk.
The release sheet material has a tensile modulus of 200 kg / m.
It is indispensable to be m ² or more. If the elastic modulus is lower than this range, the release sheet material cannot be given the necessary tension. Further, in order to improve the releasability after cooling and solidification, the release sheet material is subjected to an appropriate release treatment on the surface according to the thermoplastic resin used. As the release agent, a fluorine-based release agent or a silicon-based release agent having high heat resistance is preferably used.

The manufacturing method of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows an embodiment of a double belt pressing apparatus according to the manufacturing method of the present invention. The double belt press device is composed of a base material unwinding unit 12, a double belt pressing unit 13, and a product winding unit 14.

In the double belt press section 13, 1
Reference characters a and 1b are endless steel belts, which are rotated in the arrow directions by drums 2a, 2a ', 2b and 2b' driven by a motor. 3a and 3b are pressure roll groups of the preheating unit, 4a and 4b are pressure roll groups of the heating unit, 5
Reference numerals a and 5b are pressure roll groups of the cooling unit, and a plurality of pressure rolls are provided in a pair in the upper and lower sides. The pressure roll group is rotating in the traveling direction while being in contact with the endless steel belts 1a and 1b. Among these pressure roll groups, the upper pressure roll groups 3a, 4a, 5a can independently apply pressure to each roll by a disc spring type pressure mechanism. The endless steel belts 1a and 1b and the pressure roll groups 3a, 3b, 4a, 4b, 5a and 5b are far infrared heaters 9a, 9b, 10a, 10b, 11a and 11 respectively.
It is heated by b and is set and controlled at a predetermined temperature. The bearing portion of the pressure roll group is cooled by cooling water to prevent seizure.

In the base material unwinding section 12, 6a, 6b,
6c is a thermoplastic resin film, and 7a, 7b, 7c
Is a fiber base material, and 8a and 8b are release sheet materials, and tension is applied by a unwinding device. The fiber base materials 7a, 7b and 7c are thermoplastic resin films 6 from both sides.
It is sandwiched between a, 6b and 6c to form a laminated body. Of course, the structure of the laminated body is not limited to this combination. A plurality of sets (three sets in the example of FIG. 1, but more layers may be used) are superposed in multiple stages by guide rolls through the release sheet materials 8a and 8b, and the endless steel belt 1a. 1b. The laminated body introduced between the endless steel belts 1a and 1b is preheated in the preheating zone, the thermoplastic resin films 6a, 6b and 6c are softened, and the pressure roll group 3
It is pressed by a and 3b and comes into close contact with the fiber base materials 7a, 7b and 7c.

Next, in the heating zone, the laminated body is higher than the melting points of the thermoplastic resin films 6a, 6b, 6c,
The thermoplastic resin film 6a, 6b, 6c is melted by being heated at a temperature lower than the melting point of the fiber base materials 7a, 7b, 7c,
The fiber base material 7a is pressed by the pressure roll groups 4a and 4b.
The inside of the fiber bundles 7b and 7c is impregnated. At this time, since the release sheet materials 8a and 8b have no melting point and the thermal decomposition point is higher than the melting points of the thermoplastic resin films 6a, 6b and 6c, they do not melt or decompose.

Next, the laminated body which has moved to the cooling zone is pressure-cooled by the pressure rolls 5a and 5b, shaped into a desired thickness and solidified.

The fiber-reinforced thermoplastic resin sheets 15a, 15b, 15c that have been cooled and solidified are peeled off from the release sheet materials 8a, 8b in the product winding section 14 and wound up. At this time, since the release sheet material is subjected to the release treatment, it can be easily peeled from the fiber-reinforced thermoplastic resin sheet. Also, the release sheet materials 8a, 8
b can be reused in the base material unwinding section 12.

Furthermore, the fiber-reinforced thermoplastic resin sheets 15a and 15b, which are obtained by peeling off the release sheet material and wound up,
It is particularly preferable from the viewpoint of thermal dimensional stability that 15c is annealed to increase the crystallinity of the resin.

The temperature of the preheating zone in the present invention is preferably set in a temperature range higher than the second-order transition point of the thermoplastic resin film and lower than the melting point. Further, the temperature of the heating zone is preferably set to a temperature equal to or higher than the melting point of the thermoplastic resin film and within a temperature range in which the thermoplastic resin film is not thermally decomposed. The temperature of the cooling zone is set appropriately according to the resin, since the crystalline state of the resin changes depending on the cooling rate in the case of a crystalline resin, and the thermal properties and mechanical properties of the resulting sheet change. It is preferable to adjust the temperature.

For a resin which is difficult to impregnate with a resin, the impregnation zone can be lengthened by setting the temperature of the preheating zone to the melting point or higher as in the heating zone.

The pressure applied by the pressure roll affects the resin impregnation property, wall thickness accuracy, surface smoothness, etc., so it must be appropriately determined according to the resin, but the roll linear pressure is 5 k.
It is preferably g / cm 2 or more. Linear pressure is 5kg / cm
If it is lower, the resin is not sufficiently impregnated into the inside of the fiber base material, resulting in a sheet having low strength and poor thermal dimensional stability. Especially, it is important to set the roll linear pressure in the cooling zone.

The belt speed is preferably as high as possible from the viewpoint of productivity, but it may be appropriately determined depending on the resin to be used in consideration of the balance with the impregnation property into the fiber base material.

The conditions for annealing the fiber reinforced thermoplastic resin sheet depend on the type of resin,
It is preferable to perform heat treatment for at least 1 minute or more at a temperature equal to or higher than the crystallization temperature. As one method, it is effective in the process to carry out the treatment while continuously running in a heating oven. A heating oven may be installed in front of the winding portion of the double belt press, and after the annealing treatment, the release sheet material may be peeled off and wound up.

[0032]

EXAMPLES Next, more specific examples and comparative examples will be described.

Example 1 Using the apparatus shown in FIG. 1, the temperature of the preheating zone was set to 250.
C., the heating zone temperature was set at 330.degree. C., and the cooling zone temperature was set at 150.degree. The temperature was the surface temperature of the endless steel belt. The running speed of the endless steel belt was set to 0.4 m / min, and the linear pressure of the pressure roll group was set to 15 kg / cm. A silicone release agent (SH7020 dispersion, manufactured by Toray Silicone Co., Ltd.) was applied to the surface of the endless steel belt.

The thickness of the thermoplastic resin film is 25 μm.
m polyphenylene sulfide resin film was prepared.

A plain weave glass cloth (WEA-06-105BY54, manufactured by Nitto Boseki Co., Ltd.) having a basis weight of 48 g / m ² was prepared as a fiber base material.

A 100 μm thick stainless steel foil was prepared as a release sheet material. A mold release treatment was applied to the surface of the stainless steel foil. Silicon release agent (SE620
Using PG and Toray Silicone Co., Ltd., baking treatment was performed at 250 ° C. for 6 hours.

Polyphenylene sulfide resin film /
One set of glass cloth / polyphenylene sulfide resin film was set, and three sets of these base materials were overlapped with a stainless steel foil interposed, and they were supplied to a double belt press.

At the exit of the double belt press, the stainless steel foil was peeled off, and the thickness was 74 μm, the width was 300 mm, and the length was 3 mm.
Three rolls of 0 m glass fiber reinforced polyphenylene sulfide resin sheet were made. The releasability between the sheet and the stainless steel foil was good.

Example 2 A 25 μm thick polyphenylene sulfide resin film was prepared as a thermoplastic resin film.

A plain weave glass cloth (WEA-06-105BY54, manufactured by Nitto Boseki Co., Ltd.) having a basis weight of 48 g / m ² was prepared as a fiber base material.

As a release sheet material, a thickness of 50 μm, 10
0 μm and 125 μm polyimide films (“Kapton” 200V, 400V, 500V, manufactured by Toray DuPont Co., Ltd.) were prepared. A silicone release agent (SH7020 dispersion, manufactured by Toray Silicone Co., Ltd.) was applied to the surface of the polyimide film.

As in Example 1, using the apparatus shown in FIG. 1, the temperature of the preheating zone was set to 250 ° C., the temperature of the heating zone was set to 330 ° C., and the temperature of the cooling zone was set to 150 ° C.
A silicone release agent (SH7020 dispersion, manufactured by Toray Silicone Co., Ltd.) was applied to the surface of the endless steel belt. The running speed of the endless steel belt is 0.4 m / min, and the linear pressure of the pressure roll group is 15
It was set to kg / cm.

Polyphenylene sulfide resin film /
One set of glass cloth / polyphenylene sulfide resin film was set, and three sets of these substrates were stacked with a polyimide film having a thickness of 50 μm interposed therebetween and supplied to a double belt press.

At the exit of the double belt press, the polyimide film was peeled off to give a thickness of 75 μm and a width of 500 mm.
Three rolls of 30 m long glass fiber reinforced polyphenylene sulfide resin sheet were prepared. The releasability between the sheet and the polyimide film was good.

Similarly, thicknesses of 100 μm and 125 μm
Using the above polyimide film as a release sheet material, three glass fiber reinforced polyphenylene sulfide resin sheets each having a thickness of 75 μm, a width of 500 mm and a length of 30 m were prepared in three rolls.

Example 3 The glass fiber reinforced polyphenylene sulfide resin sheet produced by using a 100 μm thick polyimide film as the release sheet material in Example 2 was introduced into a tunnel type heating oven set at a temperature of 200 ° C., After annealing for 5 minutes, it was wound.

Comparative Example 1 A 25 μm thick polyphenylene sulfide resin film was prepared as a thermoplastic resin film.

A plain weave glass cloth (WEA-06-105BY54, manufactured by Nitto Boseki Co., Ltd.) having a basis weight of 48 g / m ² was prepared as a fiber base material.

A 25 μm thick polyimide film (“Kapton” 100H, manufactured by Toray DuPont Co., Ltd.) was prepared as a release sheet material. A silicone release agent (SH7020 dispersion, manufactured by Toray Silicone Co., Ltd.) was applied to the surface of the polyimide film.

Under the same production conditions as in Examples 1 and 2, one set of polyphenylene sulfide resin film / glass cloth / polyphenylene sulfide resin film was laminated, and three sets of these substrates were superposed with a polyimide film interposed therebetween, and a double belt press was performed. Supplied. The polyimide film was peeled off at the exit of the double belt press to prepare three rolls of glass fiber reinforced polyphenylene sulfide resin sheet having a thickness of 75 μm, a width of 500 mm and a length of 30 m. The release property between the sheet and the polyimide film was good, but wrinkles and voids were generated on the sheet.

With respect to the glass fiber reinforced polyphenylene sulfide resin sheets obtained in the above Examples and Comparative Examples, sheet formability (whether there are wrinkles or air bubbles), resin impregnation property, thermal dimensional stability, surface roughness, thickness unevenness It was measured. The measurement results are shown in Table 1.

[0052]

[Characteristic evaluation method] The measurement method for each item is as follows.

(1) Formability of Sheet The surface of the produced sheet was visually observed to determine the presence or absence of wrinkles and bubbles. A sample with no wrinkles or bubbles was evaluated as ○, a sample with a slight amount of occurrence was evaluated as Δ, and a sample with a significant amount was evaluated as ×.

(2) Resin Impregnation Property The prepared sheet was cut with a single-edged razor, and the degree of ink penetration when the cross section was traced with a new magic ink was visually observed and judged. Those that are not soaked at all are ○, those that are slightly soaked are △, and those that are soaked are ×
And

(3) Thermal Dimensional Stability A 10 cm × 10 cm sample was cut out from the produced sheet, marked at a position of 75 mm, and sandwiched in a dedicated glass plate on which dimensional changes before and after heat treatment were engraved.
The sheet was read with a 200 × optical microscope to determine the heat shrinkage rates in the longitudinal direction (MD) and the transverse direction (TD) of the sheet. The heat treatment conditions were two levels of 200 ° C. × 30 minutes and 230 ° C. × 30 minutes. The heat shrinkage ratio (S) was calculated from the dimension before heat treatment (L0) and the dimension after heat treatment (La) by the following equation.

S = [(L0-La) / L0] × 100 (%)

(4) Surface roughness Using a Kosaka type surface roughness meter (model: SE-3E), the center line average roughness (Ra) and the maximum roughness in the MD and TD directions of the sheet at a magnification of 20000 times. (Rt) was measured.

(5) Thickness unevenness The thickness variation of the sheet in the MD direction and the TD direction was measured using a thickness gauge manufactured by Anritsu Electric Co., Ltd. The thickness variation (r) is the maximum thickness (Tmax), the minimum thickness (Tmin),
It was calculated from the average thickness (Tave.) By the following formula.

R = [(Tmax-Tmin) / Tave.] × 100 (%)

[Table 1] As shown in Table 1, the release sheet material has a thickness of 25 μm.
In Comparative Example 1 using the polyimide film of No. 3, wrinkles were generated in the obtained sheet, and bubbles were generated in the peripheral portion of the wrinkles. Moreover, the impregnation property of the resin was not perfect.
On the other hand, Example 1 using a 100 μm-thick stainless foil as the release sheet material and the thickness of 50 μm, 1
In the sheet of Example 2 using the polyimide film of 00 μm and 125 μm, wrinkles and bubbles were not generated, and the resin impregnating property was excellent.

Further, in Examples 1 and 2, sheets which were superior to Comparative Example 1 in terms of thermal dimensional stability, surface roughness and thickness unevenness could be manufactured. Furthermore, in Example 3 in which the sheet of Example 2 was annealed, the thermal dimensional stability was improved as compared with Example 2.

[0061]

EFFECTS OF THE INVENTION Since the present invention has the above-mentioned constitution, it is suitable as a sheet for a plastic multilayer wiring board having good resin impregnation property, excellent thermal dimensional stability, surface smoothness and thickness accuracy. A reinforced thermoplastic resin sheet can be efficiently manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of a method for producing a fiber-reinforced thermoplastic resin sheet of the present invention.

[Explanation of symbols]

 1a: endless steel belt 1b: endless steel belt 2a: drum 2b: drum 2a ': drum 2b': drum 3a: pressure roll group 3b: pressure roll group 4a: pressure roll group 4b: pressure roll group 5a: Pressure roll group 5b: Pressure roll group 6a: Thermoplastic resin film 6b: Thermoplastic resin film 6c: Thermoplastic resin film 7a: Fiber base material 7b: Fiber base material 7c: Fiber base material 8a: Release sheet material 8b : Release sheet material 9a: Far infrared heater 9b: Far infrared heater 10a: Far infrared heater 10b: Far infrared heater 11a: Far infrared heater 11b: Far infrared heater 12: Base material unwinding section 13: Double belt pressing section 14: Product winding portion 15a: Fiber reinforced thermoplastic resin sheet 15b: Fiber reinforced thermoplastic resin sheet 15c: Fiber Reinforced thermoplastic resin sheet

Claims (3)

[Claims] 1. A laminate comprising a thermoplastic resin film having a thickness of 5 to 100 μm and a fiber base material having a basis weight of 20 to 100 g / m ² between a pair of endless steel belts and having a thickness of 50 μm or more and a tensile elastic modulus. A release sheet material of 200 kg / mm ² or more is interposed, and at least two sets are supplied in a multi-tiered state, and the thermoplastic resin film is softened in the preheating zone to be in close contact with the fiber base material, and in the heating zone. The thermoplastic resin film is melted and pressed to impregnate the inside of the fibrous base material with the thermoplastic resin, and then pressure-cooled in a cooling zone to solidify the thermoplastic resin, and then the release sheet. A method for producing a fiber-reinforced thermoplastic resin sheet, which comprises peeling a material. 2. The method for producing a fiber-reinforced thermoplastic resin sheet according to claim 1, wherein the release sheet material is a metal and the surface thereof is subjected to a release treatment. 3. The fiber-reinforced thermoplastic resin sheet according to claim 1, wherein after the release sheet material is peeled off, an annealing treatment is performed at a temperature not lower than the crystallization temperature of the thermoplastic resin and not higher than the melting point. Method.